more dangerous water types we have no where ever single weld has to be xrayed and inspected because the coolant is at such a high pressure and because the loss of pressure is so dangerous
The loss of pressure (and more importantly, the loss of coolant) being dangerous are the important issues. Leaks of light water are generally physically, if not politically, harmless. (CANDU was notorious for significant heavy water leaks).
The loss of pressure is mainly dangerous in PWRs in which large steam explosions are a risk. PWRs have a large negative void coefficient, and a pressure loss will reduce the output power of the reactor pile.
CANDU with its small pressure tubes, for example, is at essentially zero risk of a serious steam explosion, however CANDU also has a small positive void coefficient of reactivity -- voids are steam pockets resulting from pressure loss, and the overmoderated nature of the CANDU calandria system results in a (very) small positive feedback loop in the reaction in their presence. This particular type of positive feedback loop can be very dangerous because the increase in heat can produce more and more voids quickly boiling away essentially all the coolant. A large enough positive coefficient (as in RBMK) can lead to a meltdown.
The loss of coolant is dangerous in reactors with positive void coefficients, and even more dangerous in reactors with positive temperature coefficients. It is possible to design a system which has a negative temperature coefficient at high temperatures -- doppler broadening, phase changes and mechanical deformations of the pile can check a thermal excursion.
Even more dangerous are chemical reactions during a loss of coolant accident. Sodium coolant and graphite moderator both tend to ignite when exposed to air.
Radioactive contaminants released during a coolant leak are also a problem -- sodium coolant is highly likely to contain 24Na and 137Cs, for example, and the nuclear fuel can also melt leading to a difficult to clean up mess.
Passive safety mechanisms are great because they do not require operator intervention. However, most passive safety elements still have dangerous side-effects, so systems which are low touch, easily-monitored, and resilient to early or unnecessary full or partial shutdowns -- that is, systems with good active safety mechanisms that operators will not hesitate to use -- are also important.
The other two points call for designs in which online rearrangements of the reactor pile are safe and easy. The ability to transmute (or burn as fuel) what is now considered nuclear waste is directly related to the (static) geometry of the reactor pile. Maintaining reasonable efficiency of power production at the same time is related to how dynamic the geometry of the reactor pile can be. CANFLEX and other online (mechanical) refuelling mechanisms (pebble conveyors, for example) are huge improvements over designs which cannot access fuel components without a reactor shutdown. There are practical limits to the dynamism, and mechanical systems are prone to failure (jams, collisions...). They are also hard to introduce into systems not engineered with them in mind mainly because of high pressures, high temperature inertia, chemical or radiation hazards found in most conventional designs. Liquid (molten/dissolved) cores are extremely dynamic and avoid machinery troubles, but have separation-and-recovery challenges, and in some cases convective stirring can produce suboptimal mean geometries.
However, I think you've correctly identified three of the four key goals for new reactor designs compared to existing models: operationally safer, much more fuel-efficient, and less polluting (both in terms of waste production and in terms of fuel manufacture). The fourth is lower construction and maintenance costs.
IFR had serious safety flaws. Most notably, the chemical reactivity of the liquid sodium coolant makes it very dangerous, and has been at the centre of several serious nuclear accidents in fast reactors making use of it -- most seriously involving the partial meltdowns at the SSFL in Simi Valley and the Enrico Fermi LMBFR in Lagoona Beach, a sodium fire at the Tsuruga facility, and some safety problems with the BN600. Moreover, the nuclear reactivity of sodium (24Na production) proved to be an issue in the BN600 and the EBR II, and the coolant also readily (and nearly irreversibly) dissolves intensely radioactive decay products.
The design changes to protect against these known flaws were expensive and possibly insufficient -- the tendency of the coolant to become intensely radioactive (24Na, half-life 15h, emitting a 2.7MeV gamma ray and undergoing beta decay; sodium-dissolved 137Cs and so forth), and the risk of particle-scattering chemical explosion -- suggests that an accident of TBq scale is a significant risk of the design, even if the risk of smaller scale accidents is relatively low compared to PWRs. High-becquerel accidents are even liklier in the context of a full fuel cycle because of the ongoing production and handling of intermediate wastes with relatively short half-lives.
Note that even the mere generation of fully-contained 24Na requires a biological shield around the entire primary coolant system, and prevents any human access within the shielded area for any reason whatsoever for perhaps several days after shutdown.
One of the lessons learned over the past several decades is that civilian nuclear accidents most commonly involve deviations from or errors in maintenance and testing procedures, and the IFR on an efficient fuel cycle was considered fairly "high-touch" and fragile.
passively stable
The EBR-II SCRAM demonstration and the mechanisms in IFR terminate the chain reaction automatically in the event of a large reactivity excursion -- this is a passive safety mechanism, but is not passive stability. Dangerous excursions are still possible. Likewise, the arrangement of the mechanical parts of the primary cooling system by their nature only constrain a runaway reaction in the event of mechanical failure.
The major stability mechanism is in the high degree of convection in the sodium coolant when it's hot, which could cope with the high temperatures at which the fuel assemblies expanded due to overheating -- this expansion puts a check on the chain reaction.
The major safety problem here is that a partial loss of the coolant, or a coolant explosion, or other (not then predicted) breakdowns in convective cooling could lead to localized temperature runaways, and thus partial core meltdowns. This was seen in earlier sodium-cooled reactors, and mitigates against claims of passive stability.
Moreover, passive stability comes at the cost of the effective destruction of both the fuel assemblies and the liquid sodium -- that or a SCRAM essentially ends the life of the reactor involved. Approaches to avoiding SCRAM or assembly destruction in the event of a reduction or loss of coolant flow or heat sink capacity wound up being tremendously expensive, and certainly was a factor in the termination of the IFR project.
little waste problems
The IFR calls for extraction and reprocessing on site. This is not online, this is not automatic, and this is definitely a waste problem -- it trades long-term storage of long-half-life extracted during occasional refuellings isotopes for regular short-term handling of short-half-life isotopes.
The nature of the cast fuel assemblies leads to the irretrievable contamination of the sodium coolant, which makes that a nuclear waste that is also extremely dangerous chemically. This presents an enormous problem (and cost) when it comes to decommissioning an IFR style reactor.
Telecom companies are not constantly producing faster last-mile solutions.
Yes they are. Some Telecom companies are even deploying them on regular upgrade cycles.
These companies are almost all in the EU/EEA/EFTA area and Canada where regulators have been encouraging the development of competitive markets by restraining the dominant players (former monopolies) and requiring them market unbundled services.
RADSL, G.SHDSL, VDSL and VDSL2 are all readily available in urban markets in the western half of Europe. Slovenia and Hungary will see urban VDSL2 (ITU-T G.993.2) in 2007.
VDSL2 offerings are typically 24Mbps to 50Mbps downstream, although it is common to see this coupled with a ludicrously low 512kbps return bandwidth on lower-price tariffs.
Etherloop is available in the most competitive markets (Stockholm, notably, and others like Copenhagen), with several flats (very low tens) sharing 100Mbps (both directions) of Internet connectivity.
People in less urban areas, or in the eastern half of Europe (or BC or the Maritimes in Canada), are a bit less lucky.
Incumbent monopolists have little interest in rolling out these new technologies, and there is a tight correlation between a prescriptive rules-based regulatory regime for telecommunications companies versus a principles-based market-forming regulatory regime and broadband users per 100 people.
So with respect to the USA I completely agree with your comment:
especially when regulators keep giving them sweetheart deals
but the USA is not the only rich country in the world, and not all countries have the same social and economic priorities as the current U.S. administration.
average Joe started to use the net as a replacement for TV, then the ISP's would no longer be able to deliver on the bandwidth they have sold
There are two aspects to this: contract timeframes and immediacy of data.
Broadband contracts are not vastly longer than engineering or upgrade cycles, and marketing timeframes are even shorter. If overselling becomes an actual market problem (affecting all providers to some degree) then there is ample scope for adjustment by the market as a whole. We have seen this with the coming and going of all you can eat versus metered-at-peak tariffs in a wide range of related industries.
Some teenagers downloading movies is not a problem
... because it hasn't been just "some" people since about 2002.
File sharing is pervasive and tends to run around the clock, although the peak load can be shifted around contractually. A common example: peak hour usage caps or threshold charging but all-you-can-eat offpeak. With large caps or thresholds, people are encouraged to throttle back or turn off file sharing systems during peak hours, so that they can watch youtube videos or the like during the day.
There has been a close correlation between bandwidth usage and business (and school) hours for more than ten years, and ISPs have been used to threshold charging in contracts with their own international providers for more than five years. That correlation has made it easier to estimate future bandwidth needs, and contracts have been framed to defend that predictability.
From a purely technical perspective, video via TCP bulk transfers is virtuous because of the congestion avoiding behaviour of TCPs (RFC 2001). These bulk transfers typically quickly find and maintain equilibrium with other traffic. These bulk transfers, in other words, are on average fair sharers of bottleneck bandwidth.
There is the occasional objection to bulk transfers because large receive window sizes often run into oversized FIFO queues on the last WAN hop between the sender and the ultimate receiver. Even more often are oversized FIFO queues in the opposite direction. In both cases, there is a many-millisecond pileup between a residential user and the Internet when the user is doing large bulk transfers in either direction (or in both in the case of file sharing).
Although there are known fixes for this behaviour -- rightsized queues, non-FIFO scheduling, or early congestion notification (via explicit congestion notification or by drop, which is just implicit congestion notification) or any combination of these. Sadly, these are not widely used, and neither ISPs nor users demand these features from their last mile equipment or software vendors.
Experimental TCPs also have workarounds for this behaviour, but new TCP features are slow to deploy for a variety of reasons, largely because the overall stability of the Internet is hinged on the dynamics explained in RFC 2001. (Essentially in the event of failure of network infrastructure, transmitters will back off and slowly re-explore the new bottlenecks. Widespread deployment of a slower backoff or much more aggressive exploration can lead to massive congestion and packet loss when there are topology changes (router crashes, line cuts) and this can in turn lead to secondary failures).
At the moment the industry's general non-solution answer is: "if file sharing makes your web browsing slow, stop file sharing".
Or, paraphrasing you: "the industry cannot cope with widespread video transfers".
This may actually be true -- that is the industry might not cope -- but that is mostly because of a depressingly poor understanding of open loop congestion avoidance dynamics across the industry, even in engineering groups which should at least understand the terminology.
There is a final problem associated with video over the Internet, which generalizes into the single sen
That's sorta funny, but it's not very robust code, and you must not like newlines. What do you get with:
(whack 0.1)
or
(whack -1)
or, for fun
(whack #c(4.0 4.0))
?
Hint: it's not
> Error: value FROBOZZ is not of the expected type NUMBER. > While executing: = > Type:POP to abort.
You are also trusting a CommonLisp implementation to be safe for space with respect to tail recursion. This trust is misplaced.
A variety of values of "sleep" (including surprisingly small positive integers) will certainly crash several free and expensive implementations. Others, given the same value for "sleep", may output your string until stopped by an outside force (power outage, user intervention,...).
Finally, the output of your program cannot refer to the program itself, as it has a condition wherein whacking will not continue.
Compare with:
(define (whack sleep)
(if (not (real? sleep))
(error "argument is not a real number and has no ordered relation to 0" sleep)
(let loop ((i sleep))
(if (< i 1)
#f
(begin
(display "Something in here says not to whack you, Al.")
(newline)
(loop (- i 1)))))))
When you consider how the metre (and the second) evolved as international standards, the choice of the current definition of metre makes a great deal of sense, and the definition of a second is a close approximation of a unit of solar time with hundreds (and possibly thousands) of years of legacy use.
The second is the SI base unit of frequency. We have become very good at generating second-based frequencies with high accuracy (1 part in 1e-14 or less frequency uncertainty is achievable in labs, and 1e-09 is readily available with commercial frequency generators).
The second is an old unit of time based on the Earth's rotation, and formalized in the 1600s through the development of mean time (rather than sundial time), not very long after the development of pendulum-based clocks (which were developed no later than 1657 based on late 15th century work by Galileo and later work by several others). In 1660 the Royal Society of London proposed replacing the yard with a metre defined as the length of a pendulum with a half-period of one second (which is a close approximation of the current metre).
SI's initial proposed definition of the metre was exactly that, but was reject in favour of the very similar figure expected from a meridional survey, which expected to determine the length of 1e-07 the distance between the north pole and the equator of a meridian running through Paris. The latter standard was not so much nationalism (there were many non-French scientists involved directly and indirectly in the process, including Thomas Jefferson and several other famous Americans) as a question of repeatability in environments more adverse to pendulum clocks than to meridional measurements, like ships on the high seas, and the different expected measurements at different latitudes (993.83mm in Paris, 993.53mm at 45 North, 990.65mm at the Equator).
However, as with the kilogram, the metre ended up evolving into a carefully maintained and carefully duplicated prototype instead of a length derived from readily repeatable observation or experimentation.
The second, meanwhile, continued to be based on celestial observations, and almanacs became very good at enabling the prediction of ephemeris second frequencies.
Optical interferometry as a way of recoupling the second and the metre developed from the 1890s onward, and by 1925 interferometry was in wide use as a means of easing the work of duplicating of the prototype metre. In the 1950s, interferometry using a specific wavelength as an outright replacement for the prototype metre became an agreed goal, and in 1960 the metre was redefined as 1 650 763.73 wavelengths of the orange-red emission line of 86Kr in vacuum. This still had uncertainty properties mainly associated with materials (the Krypton laser, for example, was considered "awkward"), but was easier than occasional direct comparison of national laboratory copies of the prototype metre, but nonetheless reestablished an association between frequency and length.
The second's present definition arose from the discovery of and subsequent improvements in our understanding of the relationship between the ephemeris second (defined astronomically, and arrived at via astronomical observations of near and distant celestial objects) and the transition frequency of a 133Cs between the two hyperfine levels of the ground state when at 0 K and at rest with respect to the observer.
(Such an ideally still atom would emit radiation at 9 192 631 770 Hz).
133Cs clocks comprise tunable resonance cavity which feed microwaves at as close as practical to this frequency into 133Cs gas in a single initial electronic state. The tuning of the frequency is steered to maximize the detected state changes of 133Cs atoms leaked out of the cavity. This steering needs to take into account the various inputs which move the 133Cs atoms away from the at rest / 0K ideal, and ensemble effects. A series of PLLs and a high performance quartz oscillator are used to emit a signal at a desired
However, the relevant country is really "Norway" (somewhat to the east) and the appropriate adjective is "Norwegian".
As in DVD Jon is a Norwegian citizen.
As the link you provided says
It didn't say that then, it doesn't say that now. In fact, it uses the words "Norway" and "Norwegian" in the first sentence of the article, so your reading comprehension fell apart early, or your memory is worse than you suspect.
Congratulations! You score top/. points for accuracy!
Hypothesis is prior to observation, as in any scientific discipline.
The relevant hypotheses don't erupt by magic, they're well-grounded in more than a decade of ever-closer observation of temperature fluctuations in the CMBR. The operating theory is that these small fluctuations are the images of local energy variations in the early universe, and that since the time of those local variations, gravity (within the framework of GR) has acted to shape the large scale structure of the Universe (galaxies etc.).
This particular hypothesis makes several specific predictions about the CMBR. If it is wrong in any of these predictions, it will have to be abandoned as non-physical.
DNA was also understood (and misunderstood) in steps starting with Miescher and Altmann's isolation of it. It took some work to arrive at the hypothesis that DNA is a phosphate-sugar-base polymer (Caspersson and Hammersten) and that was well before the use of X-rays to study the molecule, first by denaturation then through X-ray diffraction analysis (Astbury). It wasn't until the 1950s that strong hypotheses about the structure of DNA arose (Cambridge, Caltech and KCL). Each group ended up with a number of hypotheses unsupported by their own (and the others') data, and each group developed new hypotheses taking into account other research work into the chemical properties of DNA (especially Chargaff's observations of the constantly equal proportions of A+T and C+G).
The Cambridge team had already been operating within a framework which would become their Central Dogma by the time they had sufficient evidence (early 1953) to announce their double helix model. That is, they had already developed a theory that the transfer of information (in the residue sense) from DNA to protein was a one-way process, and that no information was tranferred from protein to protein.
The Central Dogma theoretical framework was developed "prior to observation", but it made specific predictions about what would be observed in future experiments on DNA, just as the cosmological theory you seem unhappy with makes specific predictions about what the WMAP experiment's observations will include. In the "Central Dogma" case the theory held up well in the general case, however it is now known to be incomplete, particularly with respect to non nuclear heritable conformation-changing proteins (McClintock) and new work on chaperonins and stress proteins (particularly Lundquist).
Returning to cosmology, this particular hypothesis has arisen out of decades of work on big bang theory and Cosmic Inflation, both of which arose as theories in advance of sufficiently detailed examination of the CMBR (indeed, the CMBR had not been discovered before BBT, however it was one of BBT's predictions -- another one of those "theory before observation" things that you object to). It was consistent with known observations, is plausible, and is readily falsifiable. (In fact, it is pretty likely to be falsified now that the new WMAP data have arrived, that will narrow the error bars on omega, and are likely to narrow them away from the high limit below which this hypothesis can be physical.)
if we did in fact see multiple similar observations of galaxies and other objects which were at 36 degrees offset from each other
The hypothesis has a reasonable explanation for redshift versus the "reflections", but no hypothesis would be safe resting only upon the possibility of identifying duplication at galactic or "Great Wall" scales, because we will not have instruments able to search for those for many years to come. HUDF-style observations examine only tiny slivers of the sky and require considerable time. Although a direct search using ultra-deep-field observations is plausible, it's not very practical because of the time requirements and the non-resilience to small aiming errors. More importantly, its originators carefully developed observational tests which could be performed by known-to-be-s
I seem to have missed your Networking 101. Maybe that's good, because it seems your Networking 101 has garbled your understanding of layers and abstraction within a protocol stack.
As CTCP is a protocol carried in IP, there should be no impact within the network, as practically nothing does deep introspection of packets other than firewalls (for policy) and end systems (for multiplexing and demultiplexing). Intermediate systems (i.e., IP routers) simply won't care or necessarily even notice that the IP datagrams they're forwarding have something other than TCP or UDP or GRE or UTI or, well, there are a hundred other "layer 4" (transport layer) possibilities counting only those with assigned numbers from IANA. Internet routers examine and forward "layer 3" (network layer) packets.
Your ethernet switches and other varieties of LAN equipment will see frames carrying only one network layer protocol for any of these: IP. These switches examine and forward "layer 2" packets.
AppleTalk, IPX, XNS and so forth are separate network layer protocols ("layer 3") from IP, and it is extremely unlikely that CTCP ("layer 4") will be defined for any of these other than IPv6, and it's unlikely that any of them (possibly including IPv6) will be carried natively (i.e., not tunnelled) across more than the tiniest fraction of wide area networking infrastructure.
Using a single network layer ("layer 3") protocol is operationally easier than using multiple network layer protocols, and operator skill has not scaled nearly as well as either bandwidth or forwarding performance since multiprotocol WANs were common (late 1980s, early 1990s). This is especially true for very large scale networks, like international backbones and national network operators, and even larger regional and metro operators.
The trade-off favouring reduced operator knowledge ("we just move IP very very quickly") at the expense of encapsulation overhead (computation in the end systems, bandwidth everywhere else) has been an economic one, not a technical one. Indeed, many technical people, particularly IPv6 and MPLS proponents, really like the idea of a multiprotocol big-I Internet in order to experiment with possible future network-based services like finer-grained addressability or explicit routing. I am not one of these people, but my objections are almost entirely economic (well, I do think both MPLS and IPv6 are weak and overly conservative hacks at operational problems which unsurprisingly have evolved faster and further than these two protocol suites can reasonably be expected to cope with).
RFC 2001 describes the congestion-avoiding system at the heart of TCP, which is the Internet's dominant bulk transfer protocol. Any other bulk transfer protocol with a similar system to RFC 2001's slow start and congestion avoidance could reasonably say that it is designed for "TCP fairness" in that -- on average -- the occupancy of a pure tail-drop FIFO queue in front of a chronic bottleneck will be inversely proportional to the number of congestion-avoiding flows traversing that bottleneck at the same time.
This sort of fairness is easy to demonstrate both in simulation and live across a WAN or the Internet, and is done regularly, since improving TCP specifically or bulk transfer performance in general is an active area of networking research.
With respect to intermediate systems, their operators generally won't care about well-behaved (in the fairness sense) flows, since they should be nondisruptive and should not require special handling of the IP packets they're carried in.
Badly behaved flows are generally counterproductive. Most "greedy" and "impatient" bulk transfer protocols do not perform well in comparison with TCP, and usually end up generating more traffic and take more time to do the same work. Unfortunately, such flows can also slow down TCP bulk transfers by causing and increasing actual network congestion.
commercial television in this country would rapidly descend to the depths that American and European broadcast television has
Uh, you're speaking from ignorance if you think most other European broadcast television markets are especially different from the UK one. Several European countries have exactly the tv-licencing.com model, complete with an authority that sends out "detector vans" and threatening letters to people without licences who are able to receive signals from the public broadcaster. Some of these broadcasters, like the BBC, are fully funded by licence. Others have other funding as well.
In the EFTA (the current 25 EU countries plus Iceland, Norway and Switzerland) the breakdown for member-state public broadcast funding is:
Commercial funding only, no licence: LU
In Western Europe only Luxembourg, Monaco and Liechtenstein have never had a licence scheme or funded broadcaster. These are tiny states surrounded by much bigger ones speaking essentially the same language.
Government grants and limited commercial advertising, no licence: LT, LV, HU, NL, BE(* Dutch-language), ES, PT, CY (* Turkish-language)
In 2000 the Netherlands and in 2001 the Flemish region of Belgium abolished the licence and began funding the local public broadcaster entirely out of general taxation. In both cases the primary reason was excessive collection costs, and in both cases there was a proportionate rise in income tax.
Levy added to general personal taxes, no licence: EE
Countries with public broadcasting fully funded only by licence, no commercial advertising: FI, NO, SE, UK.
Countries with mandatory licence plus some commercial advertising: IS, DK, IE, DE, PL, CZ, AT, SI, GR, CY (* Greek-language), MT, IT, CH, FR, BE (* French-language * German-language)
Mixed funding (mandatory licence, government grant, and commercial advertising): SK
Most of these markets support several commercial broadcasters as well, in some cases in spite of being a small-population country with a local language -- or set of languages -- not widely spoken elsewhere. Many of these markets have significant numbers of people who can follow English-language programming (with optional subtitles). German-language programming has cross-border markets. French-language and English-language programming likewise, and there are markets globally for programming in both of those languages.
UK and IE (in English) and FR, BE and CH (in French) are markets which can easily import programming from elsewhere in the world -- the USA, Canada and Australia principally in the case of the first two, while in France there is TV5 which makes an art of showing "the best" of programming from around the French-speaking world (the big three in Europe, Canada, North/West/Central Africa, Southeast Asia, and elsewhere). TV5 Monde is the fourth largest global television network (after the BBC, CNN and MTV), and operates much like BBC Worldwide's television operations.
Although people often grumble about their public broadcasters, the populations in the EFTA countries in general believe they are good value for money. Even in countries with funding coming fully or primarily from mandatory levies or licences, where the costs are made explicit (in some cases several hundred euros per year), they are considered good value for money, reasonably neutral with respect to politics, and innovative organizations exploring HD and Internet delivery mechanisms at no extra cost for licence holders, much like the BBC is doing.
Moreover, those public broadcasters which are permitted or required to sell commercial avertising tend to do so unobtrusively -- during particular hours, or on either side of an uninterrupted full program or movie, for example.
Finally, most people in EFTA have the ability to tune in local commercial broadcasters or readily receive cross-border transmissions in their own primary or common second or third language (often English
Burning of Washington, DC: 1814. Canadian "Independance": 1867.
How can Canada burn down DC when Canada wasn't invented yet?
Well, in fact, it had been invented some years earlier...
Sure, Confederation happened in 1867. That was simply the consolidation of several colonies into the federal political system that has remained essentially intact since then.
Confederation united the Province of Canada, which had been established by the Act of Union (1840) with two other colonies, namely Nova Scotia and New Brunswick.
Prior to the 1867 Act, the Province of Canada had itself been administered as two federated subunits, Canada East (now in modern Quebec) and Canada West (now in modern Ontario).
Earlier still, until the 1840 Act, Canada East was called Lower Canada (because it was closer to sea level, and farther down the St. Lawrence River from Lake Ontario) and Canada West was called Upper Canada.
Upper and Lower Canada formally acquired their names in 1791 and Canadians were styled as such from 26 December 1791 per the Constitutional Act passed a year earlier by the Parliament of the United Kingdom. Informal use of the term, particularly in French, dates even earlier.
So, legally speaking, the people in what is now central Canada were calling themselves Canadians for a generation. Most of the militia and many of the troops involved on the non-USA side of the war of 1812 were born in what was actually called Canada even before the time of their births.
The Articles of Confederation and Perpetual Union (USA, Second Continental Congress 1777, ratified 1781), in article XI says "Canada acceding to this confederation, and adjoining in the measures of the United States, shall be admitted into, and entitled to all the advantages of this Union; but no other colony shall be admitted into the same, unless such admission be agreed to by nine States." Note the "C" word.
More generally, the term Canadian was in widespread general use by both English and French speakers in the then Province of Quebec from the 1760s, and maps described the area around the St Lawrence River as "Canada" from as early as the mid-1550s.
Theories that allow these "constants" to vary and postulating that gravity is NOT the dominant force, especially in the beginning, will make for a lot simpler, more elegant explanations of current observations.
But the point is not to explain what we see in the sky now. The point is to be able to make testable predictions about what we will see in the sky when we have the means to look in new ways with new telescope technology and deployments at some time in the future.
The problem with many alternative theories which more simply explain what we see so far is that they make different predictions than the standard one, and these predictions have been tested (through closer examination of the sky and through higher energy physics on Earth) and have failed.
Practically everyone in astronomy and cosmology would dearly like simpler maths and simpler explanations that make the same predictions (or more accurate predictions!) than what we have now.
There is no conspiracy to "lock out" the more simple or more elegant. Indeed, those tend to be the most heavily tested alternatives, mostly because they are so simple or elegant. Thus they tend to be proven incompatible with observations faster than weirder and more complicated options than the standard models.
In particular, it is much easier to write up an analysis of a simple theory than a complicated one, and such a write up counts as a publication for many scientists working in this area. That puts bread on the table.
A young, quickly formed universe flies in the face of current scientific dogma and beliefs just as much as Galileo and Kepler's assertions irked the religious establishments of their day.
If you come up with a theory of a young and quickly formed universe that not only describes what we have already observed to date, but also makes better predictions than the current model for things we will see (this includes devising your own particular observational techniques and methods if you somehow think that the current set that are being developed are insufficient tests for your alternative theory), then you will probably win a Nobel Prize and be very popular indeed for making the jobs of even the most embarrassed cosmologists both easier and more interesting.
Yes, deuterated water tastes the same as ordinary water (which will also have some heavy and semiheavy water in it naturally at a ratio of 1:3200 (for HDO) and 1:4.1e06 (for D2O)).
The reason is simple: they are chemically identical substances, despite the nuclear differences (extra neutrons).
The only readily testable physical difference between heavy and light water is that the former is denser. Ice made of it will sink in light water.
Light water in itself does not really have a taste. Thoroughly distilled water is an interesting thing to drink.
On the other hand, ritiated water, while also chemically identical to light water, emits ionizing radiation. This will affect its taste (and is not healthy to imbibe in tasteable quantities).
The mass difference in heavy hydrogen compounds can cause slight deformations of complex structures relying on hydrogen bonds, since heavy hydrogen will form stronger bonds than light hydrogen. This happens naturally (deuterium : hydrogen in a 1:6400 ratio is normal in water) so organisms can cope with small quantities of heavy water just fine. A "diet" with a large proportion of heavy water, however, tends to disrupt certain enzymatic activity especially with respect to cell division in eukaryotes, seed germination in plants, fertilization in animal species with eggs, and so on. A diet where almost all water is heavy will usually kill the organism in a matter of time (several days usually, for most eukaryotes, while some succumb much more quickly). The critical factor is reaching 25-50% deuteration.
Prokaryotes, on the other hand, usually thrive in heavy water and most can be fully deuterated (that is, 100% of their hydrogen atoms are deuterium).
Tritiated water even in minuscule quantities rapidly damages or kills most organisms. In higher ratios, it will even kill ionizing-radiation-resistant prokaryotic species. It also makes great roach spray.
Back around 1990, when the commercial world was first discovering that new interweb thing
Er, the first web site in the world wasn't even up until late summer 1991. Well into 1992, practically every web site or home page in existence was documented and linked to by Berners-Lee on his. There weren't many. NCSA Mosaic wasn't released until 1993.
lots of local ISPs (and a few big ones) were forming rapidly in North America and Europe
You're right in part about Europe, in that EUNET was using Internet protocols internally (as an "island" not connected to the Internet per se) even in the late 1980s. However, the very first commercial ISPs (PSI and UUNET) started offering commercial organizations Internet connectivity in 1990, and both refused to provide services to smaller ISPs until 1992. The market-maker and market dominator there was Sprint, who had no qualms at all about selling to local ISPs, since to an extent that is how their Internet services originated (connecting overseas networks to the NSFNet backbone).
Rapid commercialization really didn't get underway until 1994. The important factors there were: the implementation of the NSF93-52 program which created NAPs and encouraged NSF-funded regional networks to shop among competing backbones and more importantly led to the undoing of the NSFNET Acceptable Use Policy; the establishment and clear victory of the Commercial Internet eXchange versus ANS CO+RE; the release of Mosaic 2.0 with 1.0 releases for Windows and the Mac in December 1993 and the establishment of Mosaic Communications Corporation (pre-IPO Netscape) in April 1994.
The Commercial Internet didn't really arrive until 1995 exemplified by Netscape's IPO, the release of Internet Explorer (which if nothing else made it easy for most users to get online), UUNET's IPO, and so forth.
And then of course there's the development of the intardweb in 1997 with the arrival both of slashdot and flat-fee dialup Internet connectivity offered by AOL. </me too>
While there was aggressive competition (and occasionally ugly tactics) starting with the UUNET-PSI-ANS rivalries in the early 1990s, the Internet had until that point had two important features: firstly, it was dominated by the U.S. government, most notably through the National Science Foundation, the Department of Defense, the Department of Energy, and NASA. Secondly, these backbone operators and underwriters imposed Acceptable Use Policies. The "mission" fednets were mostly used by staff and contractors, but NSF's community of interest that directly or indirectly received NSF funding was much broader and did not like being told to self-censor or be censured for violating the AUP.
UUNET in particular contrasted itself with these AUP-ridden networks in two ways: firstly, its "AlterNet" service had nearly no restrictions on what UUNET's network could be used for (pay your bill and don't launch denials-of-service and similar attacks on others, essentially) and secondly, it strove to be able to offer useful service to organizations who refused to abide by the NSFNET AUP and who therefore would not be able to use the NSFNET backbone service to reach most of the universities. PSI and ANS CO+RE followed suit in somewhat creative (and slightly rule-stretching) ways, and UUNET, PSI and Sprint established CIX essentially to build an "AUP-free" Internet.
CIX (the Commercial Internet eXchange) was involved in early censorship-type fights. For instance, it offered help to an ISP raided by federal marshalls on behalf of the Church of Scientology, which wanted to keep its trade secrets off the Internet.
The U.S. government also, interestingly, took issue with a European ISP's connection to Iran in the early mid 1990s, and there were threats of censorship against that and other European ISPs as a result, by the NSF and by other agencies and departments. At the same time it was busily encouraging foreign governme
Incidentally, the indie media labels in the UK would love to see media levies introduced, or even levies on Internet use.
Some might see it that way, but others will react like this: "Oh hell, no!". The key problem is in the distribution of centrally collected funds. The usual experience of this elsewhere has been a stultified bureaucracy which develops its own system of judging "merit" for the purposes of answering two questions:
1) Who qualifies for payouts? and 2) How much should a particular qualified person or organization receive?
These are never answered satisfactorily, and often descend into the hands of the big labels who have strong (and sometimes unlawful) influence over such commonly used metrics as radio play count.
In other words, fully socializing music risks getting you lots more well-paid boybands. (I hope) there aren't many indie labels who don't see that.
Moreover, smaller labels already have enough paperwork to do in running their businesses without engaging with another large bureaucracy affecting their incomes.
The majors also don't like uncertainty about payout rules, even though they probably correctly believe they can arrange for unfairly favourable treatment under them. At least as importantly, the majors don't like the idea of missing out on upsell opportunities through their established sales channels, and that endangers their scattershot investment and cross subsidy model.
As for parliamentary sovereignty, that was effectively removed when the UK joined the EU
A small nit: the UK acceded to the ECHR in 1953. The Convention originated in, and is a body of, the Council of Europe, not the European Union. However, all EU member-states are obliged to be members in good standing of the Council of Europe and to subject themselves to the ECHR.
The EEC (as it then was) was not established as such until 1958, with the UK not fully participating in the EC (as it then had become) until 1973.
Parliamentary sovereignty is frequently overstated anyway; it has always been constrained by non-statutory instruments (like treaties), common law principles, its own rules, and agreements (or infighting) among the three bodies (Commons, Lords, Crown) that form Parliament.
ironically enough is *far* more protective of the "common man" than the government of the day
The modern House of Lords is well populated with people who used to be the "common man", although most have some form of talent in politics. Not having to face an electorate every few years nor having much hope of advancement politically (it's hard to be promoted once you've hit the House of Lords) and instead being allowed to have a day job outside politics gives members of the House of Lords considerable protection from both the government of the day and from short-term political and popularity considerations.
it certainly would be a lot easier if everything was collected in one place
I guess you don't follow U.S. news very closely?
I'd like a constitution that placed limits on the UK government
You'd like a UK government that places limits on itself and its successors. Great. Me too! The instruments used to do that need not be gathered together in a document called "The Constitution". In fact, trying to write a consolidated Constitution is more likely to delay any self-imposition of restraints while it is being hammered out, and is a process that is easier to derail.
I claim the general silliness of the proposed Treaty Establishing a Constitution for Europe in terms of its heft and in terms of public reaction to it in some of the most pro-EU member-states as evidence... compared with the current UK government's early moves to give up its control over interest rates. Bizarrely, some of the same people (lawyers and politicians) were deeply involved with creating both of these bits of evidence.
Without a judiciary that has veto power over parliamentary acts
It exists, though.
The judicial body with blocking power over Constitutional amendments was the Judicial Committee of the Privy Council prior to the Constutional Reform Act (2005). This function is now mainly in the Supreme Court of the United Kingdom.
The JCPC is independent of the government of the day, and its membership includes current and previous Lords Chancellors, the current members of the Supreme Court, previous Law Lords, other rebadged Lords of Appeal (Senior Court justices), any Privy Councillor who has been a senior judge, and a variety of others with partial membership in order to deal with canon law and law as it relates to other countries who still use JCPC in their appeals system.
If the JCPC -- or now the Supreme Court -- declares that a statutory instrument is incompatible with the Constitution, or a Constitutional change has been made improperly, then Parliament is bound by that decision. These declarations are published and publicized and considered by more junior judges and lawyers.
Typically the Cabinet will meet with its legal advisors before any major legislation is introduced, precisely to consider the possibility of a reference to and an unfavourable ruling from JCPC or the Supreme Court with respect to constitutionality in terms of conflicts with other documents or the use of the appropriate amending mechanism (which is not guaranteed to be a simple majority in the Commons and maybe the Lords).
For all practical intents and purposes, a determined House of Commons could still take away any rights you hold dear
No, not against the wishes of the executive, since the Prime Minister has the absolute prerogatives of prorogation, dissolution, and refusal of royal assent. The Prime Minister also effectively controls the military and police through his Cabinet ministers and the Queen in her role of Commander-in-Chief.
It is more likely that a determined executive would ignore both houses of parliament (and the courts).
The major practical check on this is that the Cabinet system appears to encourage bitter infighting and backstabbing among the senior members of the executive such that they more often frustrate each other's power grabs rather than maintaining a common front in organizing a joint one.
1. Royal Assent (not "ascent"). Covered earlier. This is now fully "automated", and no monarch has been personally involved in the giving (or denying) of Royal Assent since Victoria. It is not a "rubber-stamp", it is the prerogative of the Prime Minister, and the current Prime Minister has advised the withholding of Royal Assent on mulitple occasions (the most recent in 1999 against a Private Member's Bill).
2. Written Bill of Rights. Covered earlier. UK Human Rights Act (1998) and the accession to the European Convention on Human Rights (which, incidentally, was largely drafted by UK lawyers) in 1953. The UK was in fact one of the first signatories of the Convention.
3. The House of Lords. Parliament consists of the House of Commons, the House of Lords, and the Monarch. The initial theory was that all three parties would be largely co-equal in the legislative process, and this remains mainly the case in some Westminster-type countries such as Canada. The House of Lords has been substantially weakened in its legislative role because the current theory is that the government of the day need only be responsible to the House of Commons (i.e., only the confidence of the Commons is required), and that only the Commons may originate Bills of Supply. Secondarily, the prerogative of elevating commoners to the House of Lords was seized by the Prime Ministers of the 1800s and this was used as a weapon in eliminating the outright veto of the Lords in 1911 by threatening to elevate vast numbers of commoners friendly to David Lloyd George's ministry into the House of Lords in order to support even more drastic changes to the balance of power between the House of Parliament.
Lately there has been a tendency to blunt this prerogative (as is done with the Irish Senate) with a committee who would choose who is elevated into the House of Lords based on some (not necessarily political) merit, as well as real reductions in the hereditary membership of that House. This is likely to change the dynamics between the two Houses yet again, should the new type of member of the House of Lords be able to claim some sort of political legitimacy. Even now, the Lords is far from merely symbolic, as it regularly insists upon amendments to legislation introduced in the House of Commons, and has used its suspensive veto on numerous occasions in the last two Parliaments.
4. There is an actual Supreme Court as of the proclamation of the Constitutional Reform Act (2005). Before this there was still a "supreme court" although it was constituted as a special committee of the House of Lords, and would meet in a committee room of the House of Lords and comprised particular members of the House of Lords (the Law Lords). The establishment of the Supreme Court of the United Kingdom is more an organizational clean-up post Human Rights Act (1998) than a significant Constitutional development on its own.
5. "anything a new House passed was part of the constitution". This is not correct. The Constitution is not consolidated, but it is largely written down. It consists of several well known Acts of Parliament and treaties such as the Act of Settlement (1701) and Magna Carta.
Westminster-type countries with consolidated Constitutions (such as Canada) also have several statuory and treaty instruments which are given "constitutional weight" even though they are not directly part of the document labelled "The Constitution", so this is not unusual. These countries typically have an official amending formula for their Constitution that also applies to these other documents.
Westminster itself does not have a consolidated Constitution, nor a document labelled "The Constitution", nor a uniform amending formula for the other documents of "constitutional weight", however some such documents have their own amending formulas which go beyond a simple majority in the House of Commons (and maybe House of Lords). Others probably cannot be altered without running the risk of such alterations violating other st
It is not a Bill of Rights of the people, in the US sense, that lays out the individual rights of citizens and establishes their permanent protections from all forms of government. What the British lack is a Bill of Rights that sets boundaries on the supremacy of Parliament and holds individual liberties above any future acts of parliament.
The Human Rights Act (1998) came into force on 2000-10-02.
Since then, not only is there a direct equivlaent of the "Bill of Rights" in UK law, but the various UK courts are required to adjudicate upon conflicts between various UK laws and the European Convention on Human Rights.
The courts are entitled to declare actions and Acts of government and Parliament as incompatible with the ECHR. It is unlawful for any public body to act in a manner incompatible with the ECHR under the HRA (1998), and the Act sets out both remedies and penalties for such incompatible actions.
The HRA has real teeth. Donate to Liberty if you want to help make them sharper against the authoritarians still in powerful positions.
Both the HRA and the ECHR are protected from repeal by Parliament by other legislation and the Treaty of Amsterdam, which obliges all signing parties (all EU member states must be signing parties) to hold to the Convention and subject itself to the Court established by it.
The HRA entrenched ECHR in UK jurisprudence. Prior to it, the ECHR acted as a "Bill of Rights" but required pursuit of remedies in Strasbourg as a parallel court system, which was expensive and awkward for all parties.
Undoing the past six years would result in the undoing of now well-established local case law and several new common principles. It would also require the full exit of the UK from both the European Union and the Council of Europe. These are unlikely events, despite the rhetoric from the UKIP and a variety of Tories.
That Parliament could do something in principle does not mean that it can afford to face the consequences of doing so, and legislative voltes face undoing the work of previous governments -- especially when that work was done after developing a broad consensus -- are exceptionally rare.
There is a strict formula by which the UK monarch invites a person (who need not be an M.P.!) to form a government and seek the confidence of the House of Commons. There is very little room for personal initiative on the part of the monarch her- or himself any more.
The rule is straightforward:
1. The present Prime Minister (if alive) is offered the opportunity. If there is no Prime Minister at the time, the offer goes to a living Privy Councillor by strict precedence, starting with the relatively new office of Deputy Prime Minister, and then the Second Lord of the Treasury.
2. If the Prime Minister (or Acting Prime Minister with respect to (1)) refuses the opportunity, the Prime Minister is entitled to recommend a successor, on his or her personal initiative.
This two points are a key prerogatives of the Prime Minister -- even faced with a newly elected House of Commons that is openly hostile to him or her, the Prime Minister is entitled to face the House of Commons and seek its confidence. Moreover, until the Prime Minister dies or his or her resignation takes effect, the Prime Minister has the exclusive right to advise the monarch with respect to the Ministry. The monarch does not have the right to refuse such advice, on any grounds.
3. If no recommendation can be made, or if recommended persons all refuse, then the offer is made to the leaders of the largest groupings of MPs in the incoming House of Commons, then to Privy Councillors by precedence, then to M.P.s who are not Privy Councillors, by length of service.
If and only if these hundreds of candidates are unavailable or unwilling to try to secure the confidence of the House of Commons, AND if the Privy Council cannot make a recommendation, then the monarch may make a personal selection on his or her own initiative.
A Prime Minister who fails to retain the confidence of the House of Commons is entitled to "give it another go" with a different Ministry. Undoubtedly there would be some candid discussion between the monarch and such a Prime Minister, however the monarch is not entitled to refuse the P.M. the opportunity if he insists upon it.
There is little wiggle room even under the Lascelles principles for a monarch to make a personal decision with respect to the dissolution of a newly elected Parliament when recommended by a Prime Minister who fails to retain the confidence of the House of Commons; the request should be granted despite Lascelles's pseudonymous legal argument that theoretically the dissolution could be refused. The reason is simple: a UK version of the (Canadian) King-Byng Affair would destroy the office of the monarch, as it would no longer be able to hide behind the mask of being effectively a state machine (pardon the pun).
Royal Assent with respect to the United Kingdom has been given by a royal commission since 1854, when then-queen Victoria became the final UK monarch to give royal assent in person. Moreover, since 1967 the commissioners do not even do so in person except in a ceremony once at the end of each parliamentary session (where the date is known sufficiently in advance of dissolution or prorogation).
Typically a clerk in the royal household or in parliament acts as commissioner under the Royal Assent Act (1967) and issues letters patent formally indicating the granting of royal assent. Neither the monarch nor any royal commissioner is even required to have seen the Bill as passed by both houses of Parliament, and the monarch and commissioners are not entitled to interfere in this process unless advised to do so by the Privy Council (which in practice means solely the Prime Minister or a Privy Councillor and Cabinet Minister deputized by him).
The refusal to grant Royal Assent is solely the prerogative of the Prime Minister now, and it has been used in modern times. Moreover, it is likely to be used again should there be a hung parliament that passes Bills against the wishes of the (minority) government.
Although the monarch may have some theoretical residual powers, the withholding or granting of Royal Assent against the advice of the Prime Minister is not one of them.
It's still easy to have memory 'leaks' in a language with a GC.
Only if you redfine 'leak' to be something other than data which is no longer reachable.
A precise collector will always correctly identify the liveness of data, because it knows what is a pointer into the GCed heap. (That is the definition of a precise collector).
A conservative collector is used when an object may or may not be a pointer into the GC heap (e.g., it may be a pointer into memory that is not to be managed by the collector, sometimes it may be another type of object entirely). Conservative collectors must err on the side of retaining possibly (but not provably) unreachable objects, and so can leak. However, for a number of years now, modern approaches such as barriers and generational scavenging asymptotically eliminate such retained dead objects from the managed heap, unless they are deliberately created. Such deliberation usually requires some effort, can be prevented by the compiler, is readily detected at runtime, and is easy to debug.
Bad programming practices can result in the growth of lots of live data. Typically this involves using global variables. Sometimes this is accidental, such as when the top-level retains a history of results returned to it for debugging purposes or other convenience. However, these are not leaks per se -- the data is live in that it is reachable. Making the data in question unreachable (reset the global variable or previous-results list) will allow either type of collector to reclaim the space.
In general it is much more common that memory is consumed by abandoned data that was created in heaps not managed by the collector, and these heaps are almost always used by code written in another non-GCed language. This includes the runtime, libraries, and foreign functions. Usually this is fixed via careful wrapping of the non-GC-language code with finalizers (exceptions, dynamic winding/unwinding, and other techniques), and in most GCed languages which expect to interact with things like the POSIX API this is usually done through libraries written in the GCed language.
Finally, some GC implementations, particularly conservative ones, are simply buggy or are not using modern techniques. In this case it's the implementation's collector leaking, not the language.
Even if the metre itself was originally based on a dodgy survey of Paris
No, the metre itself was initially based on the length of a pendulum with a half-period of one second. Thus the name, metre. Like in music, or poetry.
There was a second defintion (one ten millionth of the length of a meridian along a quadrant of the Earth (i.e., the distance between pole and equator)) which was easier to standardize because the metre as "beat" could vary based on local differences in the force of gravity.
One problem was mainly that there were several terrestrial and astronomical ways of arriving at the meridional distance, some more easily reproduced than others. The land survey of the meridian running through Dunquerque, Paris and Barcelona was an attempt to find out which of these was most practical for navigation and to consider ways to improve clock synchronization and reliability. It was "dodgy" only because there was a great deal of experimental work involved in the absence of things like radio or satellite synchronization of clocks, the unavailability of horizons (mountains in the way), and so forth. However, it was never intended to produce a definitive measurement of the meridional distance, as that was already well understood and readily measurable with decent reliability under good conditions. (Even the Ancient Greeks managed this!)
The main problem was in producing a prototype metre. The first had a small error in it caused by a series of calculation problems (one involving oblation, another involving marking), causing the metre to be such that the meridional distance was off by about 10 metres from 40000 precisely.
The modern metre has returned to time as the underlying standard.
There have been too few generations of widespread obesity to be accounted for by natural selection.
Sexual selection is more plausible over the period of time in which the obesity "crisis" has developed, but even less likely, since the cultures in which obesity is most prevalent also most value the looks of people who are thin.
The evolutionary biology analysis is that the human body is well adapted for periodic food shortages, and thus is able to store surplus energy as fat very quickly (with the insulin response) and release it relatively slowly (through lipolysis and conversion into glycogen). Moreover, a chronic food energy deficit triggers a chain of metabolic slowdowns so as to require less release of stored energy when drawing upon fat stores rather than glycogen stores.
An abundance of food therefore makes for a fat human; it takes a long term period of virtual starvation to eliminate a large amount of fat.
Modern agricultural processes are not even a half century old (Borlaug's work in the 1960s). It was modern agriculture that provided such a surplus of grain and other crops that raising food animals in large numbers became practical, especially since concurrent economic growth made the real cost (as in adjusted for inflation) of purchasing animal protein (meat) plummet in the West.
In an economy with an abundant and stable food supply, an efficient food->fat anabolism requires a limiting process that moderates hunger downwards, or the feeling of being stuffed upwards. Another way of putting it is that when there is a lot of food around, you are at a disadvantage if you (a) are driven by a strong food-searching instinct and (b) have a highly efficient metabolism.
The thrifty gene hypothesis suggests that there are gene-linked variations in hunger/fullness signals, and that natural selection (and sexual selection) will weed out those who are well adapted to survive no-longer-existing famines but are ill adapted to an abundance of cheap and readily available food energy.
Such selection is usually only visible retrospectively after several generations. There simply have not yet been enough new generations in order to make a rigorous test of the thrifty gene hypothesis in humans. Mammals which have shorter reproduction intervals are being studied in labs, but even mice and rats are fairly slow breeders for studying natural selection in controlled experiments. However, there is sufficient evidence that the related Barker hypothesis (which deals in phenotypes) is widely accepted.
In exactly the same fashion, evolutionary changes to mental capacity (at a given age) also take multiple generations, and can only be examined retrospectively.
A strong correlation with a reduction in mental capacity could suggest that the brain is involved in a comorbid process in obese individuals. There are a number of possibilities involving the circulatory system and the respiratory system; known comorbidities include circulatory problems and breathing difficulties in obese people, either of which could chronically impair the flow of oxygen to the brain.
There is evidence in this study that as the studied individuals became fatter, their mental impairment worsened relative to that experienced by an average person as a result of the aging process.
Therefore, it's more likely that onset mental impairment is a symptom rather than a cause of obesity.
Slashdot Mirror
However:
The loss of pressure (and more importantly, the loss of coolant) being dangerous are the important issues. Leaks of light water are generally physically, if not politically, harmless. (CANDU was notorious for significant heavy water leaks).
The loss of pressure is mainly dangerous in PWRs in which large steam explosions are a risk. PWRs have a large negative void coefficient, and a pressure loss will reduce the output power of the reactor pile.
CANDU with its small pressure tubes, for example, is at essentially zero risk of a serious steam explosion, however CANDU also has a small positive void coefficient of reactivity -- voids are steam pockets resulting from pressure loss, and the overmoderated nature of the CANDU calandria system results in a (very) small positive feedback loop in the reaction in their presence. This particular type of positive feedback loop can be very dangerous because the increase in heat can produce more and more voids quickly boiling away essentially all the coolant. A large enough positive coefficient (as in RBMK) can lead to a meltdown.
The loss of coolant is dangerous in reactors with positive void coefficients, and even more dangerous in reactors with positive temperature coefficients. It is possible to design a system which has a negative temperature coefficient at high temperatures -- doppler broadening, phase changes and mechanical deformations of the pile can check a thermal excursion.
Even more dangerous are chemical reactions during a loss of coolant accident. Sodium coolant and graphite moderator both tend to ignite when exposed to air.
Radioactive contaminants released during a coolant leak are also a problem -- sodium coolant is highly likely to contain 24Na and 137Cs, for example, and the nuclear fuel can also melt leading to a difficult to clean up mess.
Passive safety mechanisms are great because they do not require operator intervention. However, most passive safety elements still have dangerous side-effects, so systems which are low touch, easily-monitored, and resilient to early or unnecessary full or partial shutdowns -- that is, systems with good active safety mechanisms that operators will not hesitate to use -- are also important.
The other two points call for designs in which online rearrangements of the reactor pile are safe and easy. The ability to transmute (or burn as fuel) what is now considered nuclear waste is directly related to the (static) geometry of the reactor pile. Maintaining reasonable efficiency of power production at the same time is related to how dynamic the geometry of the reactor pile can be. CANFLEX and other online (mechanical) refuelling mechanisms (pebble conveyors, for example) are huge improvements over designs which cannot access fuel components without a reactor shutdown. There are practical limits to the dynamism, and mechanical systems are prone to failure (jams, collisions...). They are also hard to introduce into systems not engineered with them in mind mainly because of high pressures, high temperature inertia, chemical or radiation hazards found in most conventional designs. Liquid (molten/dissolved) cores are extremely dynamic and avoid machinery troubles, but have separation-and-recovery challenges, and in some cases convective stirring can produce suboptimal mean geometries.
However, I think you've correctly identified three of the four key goals for new reactor designs compared to existing models: operationally safer, much more fuel-efficient, and less polluting (both in terms of waste production and in terms of fuel manufacture). The fourth is lower construction and maintenance costs.
The design changes to protect against these known flaws were expensive and possibly insufficient -- the tendency of the coolant to become intensely radioactive (24Na, half-life 15h, emitting a 2.7MeV gamma ray and undergoing beta decay; sodium-dissolved 137Cs and so forth), and the risk of particle-scattering chemical explosion -- suggests that an accident of TBq scale is a significant risk of the design, even if the risk of smaller scale accidents is relatively low compared to PWRs. High-becquerel accidents are even liklier in the context of a full fuel cycle because of the ongoing production and handling of intermediate wastes with relatively short half-lives.
Note that even the mere generation of fully-contained 24Na requires a biological shield around the entire primary coolant system, and prevents any human access within the shielded area for any reason whatsoever for perhaps several days after shutdown.
One of the lessons learned over the past several decades is that civilian nuclear accidents most commonly involve deviations from or errors in maintenance and testing procedures, and the IFR on an efficient fuel cycle was considered fairly "high-touch" and fragile.
The EBR-II SCRAM demonstration and the mechanisms in IFR terminate the chain reaction automatically in the event of a large reactivity excursion -- this is a passive safety mechanism, but is not passive stability. Dangerous excursions are still possible. Likewise, the arrangement of the mechanical parts of the primary cooling system by their nature only constrain a runaway reaction in the event of mechanical failure.
The major stability mechanism is in the high degree of convection in the sodium coolant when it's hot, which could cope with the high temperatures at which the fuel assemblies expanded due to overheating -- this expansion puts a check on the chain reaction.
The major safety problem here is that a partial loss of the coolant, or a coolant explosion, or other (not then predicted) breakdowns in convective cooling could lead to localized temperature runaways, and thus partial core meltdowns. This was seen in earlier sodium-cooled reactors, and mitigates against claims of passive stability.
Moreover, passive stability comes at the cost of the effective destruction of both the fuel assemblies and the liquid sodium -- that or a SCRAM essentially ends the life of the reactor involved. Approaches to avoiding SCRAM or assembly destruction in the event of a reduction or loss of coolant flow or heat sink capacity wound up being tremendously expensive, and certainly was a factor in the termination of the IFR project.
The IFR calls for extraction and reprocessing on site. This is not online, this is not automatic, and this is definitely a waste problem -- it trades long-term storage of long-half-life extracted during occasional refuellings isotopes for regular short-term handling of short-half-life isotopes.
The nature of the cast fuel assemblies leads to the irretrievable contamination of the sodium coolant, which makes that a nuclear waste that is also extremely dangerous chemically. This presents an enormous problem (and cost) when it comes to decommissioning an IFR style reactor.
EBR-II's defuelling and shut
These companies are almost all in the EU/EEA/EFTA area and Canada where regulators have been encouraging the development of competitive markets by restraining the dominant players (former monopolies) and requiring them market unbundled services.
RADSL, G.SHDSL, VDSL and VDSL2 are all readily available in urban markets in the western half of Europe. Slovenia and Hungary will see urban VDSL2 (ITU-T G.993.2) in 2007.
VDSL2 offerings are typically 24Mbps to 50Mbps downstream, although it is common to see this coupled with a ludicrously low 512kbps return bandwidth on lower-price tariffs.
Etherloop is available in the most competitive markets (Stockholm, notably, and others like Copenhagen), with several flats (very low tens) sharing 100Mbps (both directions) of Internet connectivity.
People in less urban areas, or in the eastern half of Europe (or BC or the Maritimes in Canada), are a bit less lucky.
Incumbent monopolists have little interest in rolling out these new technologies, and there is a tight correlation between a prescriptive rules-based regulatory regime for telecommunications companies versus a principles-based market-forming regulatory regime and broadband users per 100 people.
(There are studies available in places like OECD's broadband statistics).
So with respect to the USA I completely agree with your comment: but the USA is not the only rich country in the world, and not all countries have the same social and economic priorities as the current U.S. administration.
There are two aspects to this: contract timeframes and immediacy of data.
Broadband contracts are not vastly longer than engineering or upgrade cycles, and marketing timeframes are even shorter. If overselling becomes an actual market problem (affecting all providers to some degree) then there is ample scope for adjustment by the market as a whole. We have seen this with the coming and going of all you can eat versus metered-at-peak tariffs in a wide range of related industries.
File sharing is pervasive and tends to run around the clock, although the peak load can be shifted around contractually. A common example: peak hour usage caps or threshold charging but all-you-can-eat offpeak. With large caps or thresholds, people are encouraged to throttle back or turn off file sharing systems during peak hours, so that they can watch youtube videos or the like during the day.
There has been a close correlation between bandwidth usage and business (and school) hours for more than ten years, and ISPs have been used to threshold charging in contracts with their own international providers for more than five years. That correlation has made it easier to estimate future bandwidth needs, and contracts have been framed to defend that predictability.
From a purely technical perspective, video via TCP bulk transfers is virtuous because of the congestion avoiding behaviour of TCPs (RFC 2001). These bulk transfers typically quickly find and maintain equilibrium with other traffic. These bulk transfers, in other words, are on average fair sharers of bottleneck bandwidth.
There is the occasional objection to bulk transfers because large receive window sizes often run into oversized FIFO queues on the last WAN hop between the sender and the ultimate receiver. Even more often are oversized FIFO queues in the opposite direction. In both cases, there is a many-millisecond pileup between a residential user and the Internet when the user is doing large bulk transfers in either direction (or in both in the case of file sharing).
Although there are known fixes for this behaviour -- rightsized queues, non-FIFO scheduling, or early congestion notification (via explicit congestion notification or by drop, which is just implicit congestion notification) or any combination of these. Sadly, these are not widely used, and neither ISPs nor users demand these features from their last mile equipment or software vendors.
Experimental TCPs also have workarounds for this behaviour, but new TCP features are slow to deploy for a variety of reasons, largely because the overall stability of the Internet is hinged on the dynamics explained in RFC 2001. (Essentially in the event of failure of network infrastructure, transmitters will back off and slowly re-explore the new bottlenecks. Widespread deployment of a slower backoff or much more aggressive exploration can lead to massive congestion and packet loss when there are topology changes (router crashes, line cuts) and this can in turn lead to secondary failures).
At the moment the industry's general non-solution answer is: "if file sharing makes your web browsing slow, stop file sharing".
Or, paraphrasing you: "the industry cannot cope with widespread video transfers".
This may actually be true -- that is the industry might not cope -- but that is mostly because of a depressingly poor understanding of open loop congestion avoidance dynamics across the industry, even in engineering groups which should at least understand the terminology.
There is a final problem associated with video over the Internet, which generalizes into the single sen
That's sorta funny, but it's not very robust code, and you must not like newlines. What do you get with:
:POP to abort.
...).
(whack 0.1)
or
(whack -1)
or, for fun
(whack #c(4.0 4.0))
?
Hint: it's not
> Error: value FROBOZZ is not of the expected type NUMBER.
> While executing: =
> Type
You are also trusting a CommonLisp implementation to be safe for space with respect to tail recursion. This trust is misplaced.
A variety of values of "sleep" (including surprisingly small positive integers) will certainly crash several free and expensive implementations. Others, given the same value for "sleep", may output your string until stopped by an outside force (power outage, user intervention,
Finally, the output of your program cannot refer to the program itself, as it has a condition wherein whacking will not continue.
Compare with:
(define (whack sleep)
(if (not (real? sleep))
(error "argument is not a real number and has no ordered relation to 0" sleep)
(let loop ((i sleep))
(if (< i 1)
#f
(begin
(display "Something in here says not to whack you, Al.")
(newline)
(loop (- i 1)))))))
When you consider how the metre (and the second) evolved as international standards, the choice of the current definition of metre makes a great deal of sense, and the definition of a second is a close approximation of a unit of solar time with hundreds (and possibly thousands) of years of legacy use.
The second is the SI base unit of frequency. We have become very good at generating second-based frequencies with high accuracy (1 part in 1e-14 or less frequency uncertainty is achievable in labs, and 1e-09 is readily available with commercial frequency generators).
The second is an old unit of time based on the Earth's rotation, and formalized in the 1600s through the development of mean time (rather than sundial time), not very long after the development of pendulum-based clocks (which were developed no later than 1657 based on late 15th century work by Galileo and later work by several others). In 1660 the Royal Society of London proposed replacing the yard with a metre defined as the length of a pendulum with a half-period of one second (which is a close approximation of the current metre).
SI's initial proposed definition of the metre was exactly that, but was reject in favour of the very similar figure expected from a meridional survey, which expected to determine the length of 1e-07 the distance between the north pole and the equator of a meridian running through Paris. The latter standard was not so much nationalism (there were many non-French scientists involved directly and indirectly in the process, including Thomas Jefferson and several other famous Americans) as a question of repeatability in environments more adverse to pendulum clocks than to meridional measurements, like ships on the high seas, and the different expected measurements at different latitudes (993.83mm in Paris, 993.53mm at 45 North, 990.65mm at the Equator).
However, as with the kilogram, the metre ended up evolving into a carefully maintained and carefully duplicated prototype instead of a length derived from readily repeatable observation or experimentation.
The second, meanwhile, continued to be based on celestial observations, and almanacs became very good at enabling the prediction of ephemeris second frequencies.
Optical interferometry as a way of recoupling the second and the metre developed from the 1890s onward, and by 1925 interferometry was in wide use as a means of easing the work of duplicating of the prototype metre. In the 1950s, interferometry using a specific wavelength as an outright replacement for the prototype metre became an agreed goal, and in 1960 the metre was redefined as 1 650 763.73 wavelengths of the orange-red emission line of 86Kr in vacuum. This still had uncertainty properties mainly associated with materials (the Krypton laser, for example, was considered "awkward"), but was easier than occasional direct comparison of national laboratory copies of the prototype metre, but nonetheless reestablished an association between frequency and length.
The second's present definition arose from the discovery of and subsequent improvements in our understanding of the relationship between the ephemeris second (defined astronomically, and arrived at via astronomical observations of near and distant celestial objects) and the transition frequency of a 133Cs between the two hyperfine levels of the ground state when at 0 K and at rest with respect to the observer.
(Such an ideally still atom would emit radiation at 9 192 631 770 Hz).
133Cs clocks comprise tunable resonance cavity which feed microwaves at as close as practical to this frequency into 133Cs gas in a single initial electronic state. The tuning of the frequency is steered to maximize the detected state changes of 133Cs atoms leaked out of the cavity. This steering needs to take into account the various inputs which move the 133Cs atoms away from the at rest / 0K ideal, and ensemble effects. A series of PLLs and a high performance quartz oscillator are used to emit a signal at a desired
However, the relevant country is really "Norway" (somewhat to the east) and the appropriate adjective is "Norwegian".
As in DVD Jon is a Norwegian citizen.
It didn't say that then, it doesn't say that now. In fact, it uses the words "Norway" and "Norwegian" in the first sentence of the article, so your reading comprehension fell apart early, or your memory is worse than you suspect.
Congratulations! You score top
The relevant hypotheses don't erupt by magic, they're well-grounded in more than a decade of ever-closer observation of temperature fluctuations in the CMBR. The operating theory is that these small fluctuations are the images of local energy variations in the early universe, and that since the time of those local variations, gravity (within the framework of GR) has acted to shape the large scale structure of the Universe (galaxies etc.).
This particular hypothesis makes several specific predictions about the CMBR. If it is wrong in any of these predictions, it will have to be abandoned as non-physical.
DNA was also understood (and misunderstood) in steps starting with Miescher and Altmann's isolation of it. It took some work to arrive at the hypothesis that DNA is a phosphate-sugar-base polymer (Caspersson and Hammersten) and that was well before the use of X-rays to study the molecule, first by denaturation then through X-ray diffraction analysis (Astbury). It wasn't until the 1950s that strong hypotheses about the structure of DNA arose (Cambridge, Caltech and KCL). Each group ended up with a number of hypotheses unsupported by their own (and the others') data, and each group developed new hypotheses taking into account other research work into the chemical properties of DNA (especially Chargaff's observations of the constantly equal proportions of A+T and C+G).
The Cambridge team had already been operating within a framework which would become their Central Dogma by the time they had sufficient evidence (early 1953) to announce their double helix model. That is, they had already developed a theory that the transfer of information (in the residue sense) from DNA to protein was a one-way process, and that no information was tranferred from protein to protein.
The Central Dogma theoretical framework was developed "prior to observation", but it made specific predictions about what would be observed in future experiments on DNA, just as the cosmological theory you seem unhappy with makes specific predictions about what the WMAP experiment's observations will include. In the "Central Dogma" case the theory held up well in the general case, however it is now known to be incomplete, particularly with respect to non nuclear heritable conformation-changing proteins (McClintock) and new work on chaperonins and stress proteins (particularly Lundquist).
Returning to cosmology, this particular hypothesis has arisen out of decades of work on big bang theory and Cosmic Inflation, both of which arose as theories in advance of sufficiently detailed examination of the CMBR (indeed, the CMBR had not been discovered before BBT, however it was one of BBT's predictions -- another one of those "theory before observation" things that you object to). It was consistent with known observations, is plausible, and is readily falsifiable. (In fact, it is pretty likely to be falsified now that the new WMAP data have arrived, that will narrow the error bars on omega, and are likely to narrow them away from the high limit below which this hypothesis can be physical.)
The hypothesis has a reasonable explanation for redshift versus the "reflections", but no hypothesis would be safe resting only upon the possibility of identifying duplication at galactic or "Great Wall" scales, because we will not have instruments able to search for those for many years to come. HUDF-style observations examine only tiny slivers of the sky and require considerable time. Although a direct search using ultra-deep-field observations is plausible, it's not very practical because of the time requirements and the non-resilience to small aiming errors. More importantly, its originators carefully developed observational tests which could be performed by known-to-be-s
Do they even have to be humanoid?
I, for one, would welcome a Horta captain.
I seem to have missed your Networking 101. Maybe that's good, because it seems your Networking 101 has garbled your understanding of layers and abstraction within a protocol stack.
As CTCP is a protocol carried in IP, there should be no impact within the network, as practically nothing does deep introspection of packets other than firewalls (for policy) and end systems (for multiplexing and demultiplexing). Intermediate systems (i.e., IP routers) simply won't care or necessarily even notice that the IP datagrams they're forwarding have something other than TCP or UDP or GRE or UTI or, well, there are a hundred other "layer 4" (transport layer) possibilities counting only those with assigned numbers from IANA. Internet routers examine and forward "layer 3" (network layer) packets.
Your ethernet switches and other varieties of LAN equipment will see frames carrying only one network layer protocol for any of these: IP. These switches examine and forward "layer 2" packets.
AppleTalk, IPX, XNS and so forth are separate network layer protocols ("layer 3") from IP, and it is extremely unlikely that CTCP ("layer 4") will be defined for any of these other than IPv6, and it's unlikely that any of them (possibly including IPv6) will be carried natively (i.e., not tunnelled) across more than the tiniest fraction of wide area networking infrastructure.
Using a single network layer ("layer 3") protocol is operationally easier than using multiple network layer protocols, and operator skill has not scaled nearly as well as either bandwidth or forwarding performance since multiprotocol WANs were common (late 1980s, early 1990s). This is especially true for very large scale networks, like international backbones and national network operators, and even larger regional and metro operators.
The trade-off favouring reduced operator knowledge ("we just move IP very very quickly") at the expense of encapsulation overhead (computation in the end systems, bandwidth everywhere else) has been an economic one, not a technical one. Indeed, many technical people, particularly IPv6 and MPLS proponents, really like the idea of a multiprotocol big-I Internet in order to experiment with possible future network-based services like finer-grained addressability or explicit routing. I am not one of these people, but my objections are almost entirely economic (well, I do think both MPLS and IPv6 are weak and overly conservative hacks at operational problems which unsurprisingly have evolved faster and further than these two protocol suites can reasonably be expected to cope with).
RFC 2001 describes the congestion-avoiding system at the heart of TCP, which is the Internet's dominant bulk transfer protocol. Any other bulk transfer protocol with a similar system to RFC 2001's slow start and congestion avoidance could reasonably say that it is designed for "TCP fairness" in that -- on average -- the occupancy of a pure tail-drop FIFO queue in front of a chronic bottleneck will be inversely proportional to the number of congestion-avoiding flows traversing that bottleneck at the same time.
This sort of fairness is easy to demonstrate both in simulation and live across a WAN or the Internet, and is done regularly, since improving TCP specifically or bulk transfer performance in general is an active area of networking research.
With respect to intermediate systems, their operators generally won't care about well-behaved (in the fairness sense) flows, since they should be nondisruptive and should not require special handling of the IP packets they're carried in.
Badly behaved flows are generally counterproductive. Most "greedy" and "impatient" bulk transfer protocols do not perform well in comparison with TCP, and usually end up generating more traffic and take more time to do the same work. Unfortunately, such flows can also slow down TCP bulk transfers by causing and increasing actual network congestion.
Queueing discip
Uh, you're speaking from ignorance if you think most other European broadcast television markets are especially different from the UK one. Several European countries have exactly the tv-licencing.com model, complete with an authority that sends out "detector vans" and threatening letters to people without licences who are able to receive signals from the public broadcaster. Some of these broadcasters, like the BBC, are fully funded by licence. Others have other funding as well.
In the EFTA (the current 25 EU countries plus Iceland, Norway and Switzerland) the breakdown for member-state public broadcast funding is:
Commercial funding only, no licence: LU
In Western Europe only Luxembourg, Monaco and Liechtenstein have never had a licence scheme or funded broadcaster. These are tiny states surrounded by much bigger ones speaking essentially the same language.
Government grants and limited commercial advertising, no licence: LT, LV, HU, NL, BE(* Dutch-language), ES, PT, CY (* Turkish-language)
In 2000 the Netherlands and in 2001 the Flemish region of Belgium abolished the licence and began funding the local public broadcaster entirely out of general taxation. In both cases the primary reason was excessive collection costs, and in both cases there was a proportionate rise in income tax.
Levy added to general personal taxes, no licence: EE
Countries with public broadcasting fully funded only by licence, no commercial advertising: FI, NO, SE, UK.
Countries with mandatory licence plus some commercial advertising: IS, DK, IE, DE, PL, CZ, AT, SI, GR, CY (* Greek-language), MT, IT, CH, FR, BE (* French-language * German-language)
Mixed funding (mandatory licence, government grant, and commercial advertising): SK
Most of these markets support several commercial broadcasters as well, in some cases in spite of being a small-population country with a local language -- or set of languages -- not widely spoken elsewhere. Many of these markets have significant numbers of people who can follow English-language programming (with optional subtitles). German-language programming has cross-border markets. French-language and English-language programming likewise, and there are markets globally for programming in both of those languages.
UK and IE (in English) and FR, BE and CH (in French) are markets which can easily import programming from elsewhere in the world -- the USA, Canada and Australia principally in the case of the first two, while in France there is TV5 which makes an art of showing "the best" of programming from around the French-speaking world (the big three in Europe, Canada, North/West/Central Africa, Southeast Asia, and elsewhere). TV5 Monde is the fourth largest global television network (after the BBC, CNN and MTV), and operates much like BBC Worldwide's television operations.
Although people often grumble about their public broadcasters, the populations in the EFTA countries in general believe they are good value for money. Even in countries with funding coming fully or primarily from mandatory levies or licences, where the costs are made explicit (in some cases several hundred euros per year), they are considered good value for money, reasonably neutral with respect to politics, and innovative organizations exploring HD and Internet delivery mechanisms at no extra cost for licence holders, much like the BBC is doing.
Moreover, those public broadcasters which are permitted or required to sell commercial avertising tend to do so unobtrusively -- during particular hours, or on either side of an uninterrupted full program or movie, for example.
Finally, most people in EFTA have the ability to tune in local commercial broadcasters or readily receive cross-border transmissions in their own primary or common second or third language (often English
Well, in fact, it had been invented some years earlier...
Sure, Confederation happened in 1867. That was simply the consolidation of several colonies into the federal political system that has remained essentially intact since then.
Confederation united the Province of Canada, which had been established by the Act of Union (1840) with two other colonies, namely Nova Scotia and New Brunswick.
Prior to the 1867 Act, the Province of Canada had itself been administered as two federated subunits, Canada East (now in modern Quebec) and Canada West (now in modern Ontario).
Earlier still, until the 1840 Act, Canada East was called Lower Canada (because it was closer to sea level, and farther down the St. Lawrence River from Lake Ontario) and Canada West was called Upper Canada.
Upper and Lower Canada formally acquired their names in 1791 and Canadians were styled as such from 26 December 1791 per the Constitutional Act passed a year earlier by the Parliament of the United Kingdom. Informal use of the term, particularly in French, dates even earlier.
So, legally speaking, the people in what is now central Canada were calling themselves Canadians for a generation. Most of the militia and many of the troops involved on the non-USA side of the war of 1812 were born in what was actually called Canada even before the time of their births.
The Articles of Confederation and Perpetual Union (USA, Second Continental Congress 1777, ratified 1781), in article XI says "Canada acceding to this confederation, and adjoining in the measures of the United States, shall be admitted into, and entitled to all the advantages of this Union; but no other colony shall be admitted into the same, unless such admission be agreed to by nine States." Note the "C" word.
More generally, the term Canadian was in widespread general use by both English and French speakers in the then Province of Quebec from the 1760s, and maps described the area around the St Lawrence River as "Canada" from as early as the mid-1550s.
But the point is not to explain what we see in the sky now. The point is to be able to make testable predictions about what we will see in the sky when we have the means to look in new ways with new telescope technology and deployments at some time in the future.
The problem with many alternative theories which more simply explain what we see so far is that they make different predictions than the standard one, and these predictions have been tested (through closer examination of the sky and through higher energy physics on Earth) and have failed.
Practically everyone in astronomy and cosmology would dearly like simpler maths and simpler explanations that make the same predictions (or more accurate predictions!) than what we have now.
There is no conspiracy to "lock out" the more simple or more elegant. Indeed, those tend to be the most heavily tested alternatives, mostly because they are so simple or elegant. Thus they tend to be proven incompatible with observations faster than weirder and more complicated options than the standard models.
In particular, it is much easier to write up an analysis of a simple theory than a complicated one, and such a write up counts as a publication for many scientists working in this area. That puts bread on the table.
If you come up with a theory of a young and quickly formed universe that not only describes what we have already observed to date, but also makes better predictions than the current model for things we will see (this includes devising your own particular observational techniques and methods if you somehow think that the current set that are being developed are insufficient tests for your alternative theory), then you will probably win a Nobel Prize and be very popular indeed for making the jobs of even the most embarrassed cosmologists both easier and more interesting.
Yes, deuterated water tastes the same as ordinary water (which will also have some heavy and semiheavy water in it naturally at a ratio of 1:3200 (for HDO) and 1:4.1e06 (for D2O)).
The reason is simple: they are chemically identical substances, despite the nuclear differences (extra neutrons).
The only readily testable physical difference between heavy and light water is that the former is denser. Ice made of it will sink in light water.
Light water in itself does not really have a taste. Thoroughly distilled water is an interesting thing to drink.
On the other hand, ritiated water, while also chemically identical to light water, emits ionizing radiation. This will affect its taste (and is not healthy to imbibe in tasteable quantities).
The mass difference in heavy hydrogen compounds can cause slight deformations of complex structures relying on hydrogen bonds, since heavy hydrogen will form stronger bonds than light hydrogen. This happens naturally (deuterium : hydrogen in a 1:6400 ratio is normal in water) so organisms can cope with small quantities of heavy water just fine. A "diet" with a large proportion of heavy water, however, tends to disrupt certain enzymatic activity especially with respect to cell division in eukaryotes, seed germination in plants, fertilization in animal species with eggs, and so on. A diet where almost all water is heavy will usually kill the organism in a matter of time (several days usually, for most eukaryotes, while some succumb much more quickly). The critical factor is reaching 25-50% deuteration.
Prokaryotes, on the other hand, usually thrive in heavy water and most can be fully deuterated (that is, 100% of their hydrogen atoms are deuterium).
Tritiated water even in minuscule quantities rapidly damages or kills most organisms. In higher ratios, it will even kill ionizing-radiation-resistant prokaryotic species. It also makes great roach spray.
Er, the first web site in the world wasn't even up until late summer 1991. Well into 1992, practically every web site or home page in existence was documented and linked to by Berners-Lee on his. There weren't many. NCSA Mosaic wasn't released until 1993.
You're right in part about Europe, in that EUNET was using Internet protocols internally (as an "island" not connected to the Internet per se) even in the late 1980s. However, the very first commercial ISPs (PSI and UUNET) started offering commercial organizations Internet connectivity in 1990, and both refused to provide services to smaller ISPs until 1992. The market-maker and market dominator there was Sprint, who had no qualms at all about selling to local ISPs, since to an extent that is how their Internet services originated (connecting overseas networks to the NSFNet backbone).
Rapid commercialization really didn't get underway until 1994. The important factors there were: the implementation of the NSF93-52 program which created NAPs and encouraged NSF-funded regional networks to shop among competing backbones and more importantly led to the undoing of the NSFNET Acceptable Use Policy; the establishment and clear victory of the Commercial Internet eXchange versus ANS CO+RE; the release of Mosaic 2.0 with 1.0 releases for Windows and the Mac in December 1993 and the establishment of Mosaic Communications Corporation (pre-IPO Netscape) in April 1994.
The Commercial Internet didn't really arrive until 1995 exemplified by Netscape's IPO, the release of Internet Explorer (which if nothing else made it easy for most users to get online), UUNET's IPO, and so forth.
And then of course there's the development of the intardweb in 1997 with the arrival both of slashdot and flat-fee dialup Internet connectivity offered by AOL. </me too>
While there was aggressive competition (and occasionally ugly tactics) starting with the UUNET-PSI-ANS rivalries in the early 1990s, the Internet had until that point had two important features: firstly, it was dominated by the U.S. government, most notably through the National Science Foundation, the Department of Defense, the Department of Energy, and NASA. Secondly, these backbone operators and underwriters imposed Acceptable Use Policies. The "mission" fednets were mostly used by staff and contractors, but NSF's community of interest that directly or indirectly received NSF funding was much broader and did not like being told to self-censor or be censured for violating the AUP.
UUNET in particular contrasted itself with these AUP-ridden networks in two ways: firstly, its "AlterNet" service had nearly no restrictions on what UUNET's network could be used for (pay your bill and don't launch denials-of-service and similar attacks on others, essentially) and secondly, it strove to be able to offer useful service to organizations who refused to abide by the NSFNET AUP and who therefore would not be able to use the NSFNET backbone service to reach most of the universities. PSI and ANS CO+RE followed suit in somewhat creative (and slightly rule-stretching) ways, and UUNET, PSI and Sprint established CIX essentially to build an "AUP-free" Internet.
CIX (the Commercial Internet eXchange) was involved in early censorship-type fights. For instance, it offered help to an ISP raided by federal marshalls on behalf of the Church of Scientology, which wanted to keep its trade secrets off the Internet.
The U.S. government also, interestingly, took issue with a European ISP's connection to Iran in the early mid 1990s, and there were threats of censorship against that and other European ISPs as a result, by the NSF and by other agencies and departments. At the same time it was busily encouraging foreign governme
Some might see it that way, but others will react like this: "Oh hell, no!". The key problem is in the distribution of centrally collected funds. The usual experience of this elsewhere has been a stultified bureaucracy which develops its own system of judging "merit" for the purposes of answering two questions:
1) Who qualifies for payouts?
and
2) How much should a particular qualified person or organization receive?
These are never answered satisfactorily, and often descend into the hands of the big labels who have strong (and sometimes unlawful) influence over such commonly used metrics as radio play count.
In other words, fully socializing music risks getting you lots more well-paid boybands. (I hope) there aren't many indie labels who don't see that.
Moreover, smaller labels already have enough paperwork to do in running their businesses without engaging with another large bureaucracy affecting their incomes.
The majors also don't like uncertainty about payout rules, even though they probably correctly believe they can arrange for unfairly favourable treatment under them. At least as importantly, the majors don't like the idea of missing out on upsell opportunities through their established sales channels, and that endangers their scattershot investment and cross subsidy model.
A small nit: the UK acceded to the ECHR in 1953. The Convention originated in, and is a body of, the Council of Europe, not the European Union. However, all EU member-states are obliged to be members in good standing of the Council of Europe and to subject themselves to the ECHR.
The EEC (as it then was) was not established as such until 1958, with the UK not fully participating in the EC (as it then had become) until 1973.
Parliamentary sovereignty is frequently overstated anyway; it has always been constrained by non-statutory instruments (like treaties), common law principles, its own rules, and agreements (or infighting) among the three bodies (Commons, Lords, Crown) that form Parliament.
The modern House of Lords is well populated with people who used to be the "common man", although most have some form of talent in politics. Not having to face an electorate every few years nor having much hope of advancement politically (it's hard to be promoted once you've hit the House of Lords) and instead being allowed to have a day job outside politics gives members of the House of Lords considerable protection from both the government of the day and from short-term political and popularity considerations.
I guess you don't follow U.S. news very closely?
You'd like a UK government that places limits on itself and its successors. Great. Me too! The instruments used to do that need not be gathered together in a document called "The Constitution". In fact, trying to write a consolidated Constitution is more likely to delay any self-imposition of restraints while it is being hammered out, and is a process that is easier to derail.
I claim the general silliness of the proposed Treaty Establishing a Constitution for Europe in terms of its heft and in terms of public reaction to it in some of the most pro-EU member-states as evidence... compared with the current UK government's early moves to give up its control over interest rates. Bizarrely, some of the same people (lawyers and politicians) were deeply involved with creating both of these bits of evidence.
PS: Join Liberty. They do good work.
It exists, though.
The judicial body with blocking power over Constitutional amendments was the Judicial Committee of the Privy Council prior to the Constutional Reform Act (2005). This function is now mainly in the Supreme Court of the United Kingdom.
The JCPC is independent of the government of the day, and its membership includes current and previous Lords Chancellors, the current members of the Supreme Court, previous Law Lords, other rebadged Lords of Appeal (Senior Court justices), any Privy Councillor who has been a senior judge, and a variety of others with partial membership in order to deal with canon law and law as it relates to other countries who still use JCPC in their appeals system.
If the JCPC -- or now the Supreme Court -- declares that a statutory instrument is incompatible with the Constitution, or a Constitutional change has been made improperly, then Parliament is bound by that decision. These declarations are published and publicized and considered by more junior judges and lawyers.
Typically the Cabinet will meet with its legal advisors before any major legislation is introduced, precisely to consider the possibility of a reference to and an unfavourable ruling from JCPC or the Supreme Court with respect to constitutionality in terms of conflicts with other documents or the use of the appropriate amending mechanism (which is not guaranteed to be a simple majority in the Commons and maybe the Lords).
No, not against the wishes of the executive, since the Prime Minister has the absolute prerogatives of prorogation, dissolution, and refusal of royal assent. The Prime Minister also effectively controls the military and police through his Cabinet ministers and the Queen in her role of Commander-in-Chief.
It is more likely that a determined executive would ignore both houses of parliament (and the courts).
The major practical check on this is that the Cabinet system appears to encourage bitter infighting and backstabbing among the senior members of the executive such that they more often frustrate each other's power grabs rather than maintaining a common front in organizing a joint one.
1. Royal Assent (not "ascent"). Covered earlier. This is now fully "automated", and no monarch has been personally involved in the giving (or denying) of Royal Assent since Victoria. It is not a "rubber-stamp", it is the prerogative of the Prime Minister, and the current Prime Minister has advised the withholding of Royal Assent on mulitple occasions (the most recent in 1999 against a Private Member's Bill).
2. Written Bill of Rights. Covered earlier. UK Human Rights Act (1998) and the accession to the European Convention on Human Rights (which, incidentally, was largely drafted by UK lawyers) in 1953. The UK was in fact one of the first signatories of the Convention.
3. The House of Lords. Parliament consists of the House of Commons, the House of Lords, and the Monarch. The initial theory was that all three parties would be largely co-equal in the legislative process, and this remains mainly the case in some Westminster-type countries such as Canada. The House of Lords has been substantially weakened in its legislative role because the current theory is that the government of the day need only be responsible to the House of Commons (i.e., only the confidence of the Commons is required), and that only the Commons may originate Bills of Supply. Secondarily, the prerogative of elevating commoners to the House of Lords was seized by the Prime Ministers of the 1800s and this was used as a weapon in eliminating the outright veto of the Lords in 1911 by threatening to elevate vast numbers of commoners friendly to David Lloyd George's ministry into the House of Lords in order to support even more drastic changes to the balance of power between the House of Parliament.
Lately there has been a tendency to blunt this prerogative (as is done with the Irish Senate) with a committee who would choose who is elevated into the House of Lords based on some (not necessarily political) merit, as well as real reductions in the hereditary membership of that House. This is likely to change the dynamics between the two Houses yet again, should the new type of member of the House of Lords be able to claim some sort of political legitimacy. Even now, the Lords is far from merely symbolic, as it regularly insists upon amendments to legislation introduced in the House of Commons, and has used its suspensive veto on numerous occasions in the last two Parliaments.
4. There is an actual Supreme Court as of the proclamation of the Constitutional Reform Act (2005). Before this there was still a "supreme court" although it was constituted as a special committee of the House of Lords, and would meet in a committee room of the House of Lords and comprised particular members of the House of Lords (the Law Lords). The establishment of the Supreme Court of the United Kingdom is more an organizational clean-up post Human Rights Act (1998) than a significant Constitutional development on its own.
5. "anything a new House passed was part of the constitution". This is not correct. The Constitution is not consolidated, but it is largely written down. It consists of several well known Acts of Parliament and treaties such as the Act of Settlement (1701) and Magna Carta.
Westminster-type countries with consolidated Constitutions (such as Canada) also have several statuory and treaty instruments which are given "constitutional weight" even though they are not directly part of the document labelled "The Constitution", so this is not unusual. These countries typically have an official amending formula for their Constitution that also applies to these other documents.
Westminster itself does not have a consolidated Constitution, nor a document labelled "The Constitution", nor a uniform amending formula for the other documents of "constitutional weight", however some such documents have their own amending formulas which go beyond a simple majority in the House of Commons (and maybe House of Lords). Others probably cannot be altered without running the risk of such alterations violating other st
The Human Rights Act (1998) came into force on 2000-10-02.
Since then, not only is there a direct equivlaent of the "Bill of Rights" in UK law, but the various UK courts are required to adjudicate upon conflicts between various UK laws and the European Convention on Human Rights.
The courts are entitled to declare actions and Acts of government and Parliament as incompatible with the ECHR. It is unlawful for any public body to act in a manner incompatible with the ECHR under the HRA (1998), and the Act sets out both remedies and penalties for such incompatible actions.
The HRA has real teeth. Donate to Liberty if you want to help make them sharper against the authoritarians still in powerful positions.
Both the HRA and the ECHR are protected from repeal by Parliament by other legislation and the Treaty of Amsterdam, which obliges all signing parties (all EU member states must be signing parties) to hold to the Convention and subject itself to the Court established by it.
The HRA entrenched ECHR in UK jurisprudence. Prior to it, the ECHR acted as a "Bill of Rights" but required pursuit of remedies in Strasbourg as a parallel court system, which was expensive and awkward for all parties.
Undoing the past six years would result in the undoing of now well-established local case law and several new common principles. It would also require the full exit of the UK from both the European Union and the Council of Europe. These are unlikely events, despite the rhetoric from the UKIP and a variety of Tories.
That Parliament could do something in principle does not mean that it can afford to face the consequences of doing so, and legislative voltes face undoing the work of previous governments -- especially when that work was done after developing a broad consensus -- are exceptionally rare.
There is a strict formula by which the UK monarch invites a person (who need not be an M.P.!) to form a government and seek the confidence of the House of Commons. There is very little room for personal initiative on the part of the monarch her- or himself any more.
The rule is straightforward:
1. The present Prime Minister (if alive) is offered the opportunity. If there is no Prime Minister at the time, the offer goes to a living Privy Councillor by strict precedence, starting with the relatively new office of Deputy Prime Minister, and then the Second Lord of the Treasury.
2. If the Prime Minister (or Acting Prime Minister with respect to (1)) refuses the opportunity, the Prime Minister is entitled to recommend a successor, on his or her personal initiative.
This two points are a key prerogatives of the Prime Minister -- even faced with a newly elected House of Commons that is openly hostile to him or her, the Prime Minister is entitled to face the House of Commons and seek its confidence. Moreover, until the Prime Minister dies or his or her resignation takes effect, the Prime Minister has the exclusive right to advise the monarch with respect to the Ministry. The monarch does not have the right to refuse such advice, on any grounds.
3. If no recommendation can be made, or if recommended persons all refuse, then the offer is made to the leaders of the largest groupings of MPs in the incoming House of Commons, then to Privy Councillors by precedence, then to M.P.s who are not Privy Councillors, by length of service.
If and only if these hundreds of candidates are unavailable or unwilling to try to secure the confidence of the House of Commons, AND if the Privy Council cannot make a recommendation, then the monarch may make a personal selection on his or her own initiative.
A Prime Minister who fails to retain the confidence of the House of Commons is entitled to "give it another go" with a different Ministry. Undoubtedly there would be some candid discussion between the monarch and such a Prime Minister, however the monarch is not entitled to refuse the P.M. the opportunity if he insists upon it.
There is little wiggle room even under the Lascelles principles for a monarch to make a personal decision with respect to the dissolution of a newly elected Parliament when recommended by a Prime Minister who fails to retain the confidence of the House of Commons; the request should be granted despite Lascelles's pseudonymous legal argument that theoretically the dissolution could be refused. The reason is simple: a UK version of the (Canadian) King-Byng Affair would destroy the office of the monarch, as it would no longer be able to hide behind the mask of being effectively a state machine (pardon the pun).
Royal Assent with respect to the United Kingdom has been given by a royal commission since 1854, when then-queen Victoria became the final UK monarch to give royal assent in person. Moreover, since 1967 the commissioners do not even do so in person except in a ceremony once at the end of each parliamentary session (where the date is known sufficiently in advance of dissolution or prorogation).
Typically a clerk in the royal household or in parliament acts as commissioner under the Royal Assent Act (1967) and issues letters patent formally indicating the granting of royal assent. Neither the monarch nor any royal commissioner is even required to have seen the Bill as passed by both houses of Parliament, and the monarch and commissioners are not entitled to interfere in this process unless advised to do so by the Privy Council (which in practice means solely the Prime Minister or a Privy Councillor and Cabinet Minister deputized by him).
The refusal to grant Royal Assent is solely the prerogative of the Prime Minister now, and it has been used in modern times. Moreover, it is likely to be used again should there be a hung parliament that passes Bills against the wishes of the (minority) government.
Although the monarch may have some theoretical residual powers, the withholding or granting of Royal Assent against the advice of the Prime Minister is not one of them.
Only if you redfine 'leak' to be something other than data which is no longer reachable.
A precise collector will always correctly identify the liveness of data, because it knows what is a pointer into the GCed heap. (That is the definition of a precise collector).
A conservative collector is used when an object may or may not be a pointer into the GC heap (e.g., it may be a pointer into memory that is not to be managed by the collector, sometimes it may be another type of object entirely). Conservative collectors must err on the side of retaining possibly (but not provably) unreachable objects, and so can leak. However, for a number of years now, modern approaches such as barriers and generational scavenging asymptotically eliminate such retained dead objects from the managed heap, unless they are deliberately created. Such deliberation usually requires some effort, can be prevented by the compiler, is readily detected at runtime, and is easy to debug.
Bad programming practices can result in the growth of lots of live data. Typically this involves using global variables. Sometimes this is accidental, such as when the top-level retains a history of results returned to it for debugging purposes or other convenience. However, these are not leaks per se -- the data is live in that it is reachable. Making the data in question unreachable (reset the global variable or previous-results list) will allow either type of collector to reclaim the space.
In general it is much more common that memory is consumed by abandoned data that was created in heaps not managed by the collector, and these heaps are almost always used by code written in another non-GCed language. This includes the runtime, libraries, and foreign functions. Usually this is fixed via careful wrapping of the non-GC-language code with finalizers (exceptions, dynamic winding/unwinding, and other techniques), and in most GCed languages which expect to interact with things like the POSIX API this is usually done through libraries written in the GCed language.
Finally, some GC implementations, particularly conservative ones, are simply buggy or are not using modern techniques. In this case it's the implementation's collector leaking, not the language.
No, the metre itself was initially based on the length of a pendulum with a half-period of one second. Thus the name, metre. Like in music, or poetry.
There was a second defintion (one ten millionth of the length of a meridian along a quadrant of the Earth (i.e., the distance between pole and equator)) which was easier to standardize because the metre as "beat" could vary based on local differences in the force of gravity.
One problem was mainly that there were several terrestrial and astronomical ways of arriving at the meridional distance, some more easily reproduced than others. The land survey of the meridian running
through Dunquerque, Paris and Barcelona was an attempt to find out which of these was most practical for navigation and to consider ways to improve clock synchronization and reliability. It was "dodgy" only because there was a great deal of experimental work involved in the absence of things like radio or satellite synchronization of clocks, the unavailability of horizons (mountains in the way), and so forth. However, it was never intended to produce a definitive measurement of the meridional distance, as that was already well understood and readily measurable with decent reliability under good conditions. (Even the Ancient Greeks managed this!)
The main problem was in producing a prototype metre. The first had a small error in it caused by a series of calculation problems (one involving oblation, another involving marking), causing the metre to be such that the meridional distance was off by about 10 metres from 40000 precisely.
The modern metre has returned to time as the underlying standard.
There have been too few generations of widespread obesity to be accounted for by natural selection.
Sexual selection is more plausible over the period of time in which the obesity "crisis" has developed, but even less likely, since the cultures in which obesity is most prevalent also most value the looks of people who are thin.
The evolutionary biology analysis is that the human body is well adapted for periodic food shortages, and thus is able to store surplus energy as fat very quickly (with the insulin response) and release it relatively slowly (through lipolysis and conversion into glycogen). Moreover, a chronic food energy deficit triggers a chain of metabolic slowdowns so as to require less release of stored energy when drawing upon fat stores rather than glycogen stores.
An abundance of food therefore makes for a fat human; it takes a long term period of virtual starvation to eliminate a large amount of fat.
Modern agricultural processes are not even a half century old (Borlaug's work in the 1960s). It was modern agriculture that provided such a surplus of grain and other crops that raising food animals in large numbers became practical, especially since concurrent economic growth made the real cost (as in adjusted for inflation) of purchasing animal protein (meat) plummet in the West.
In an economy with an abundant and stable food supply, an efficient food->fat anabolism requires a limiting process that moderates hunger downwards, or the feeling of being stuffed upwards. Another way of putting it is that when there is a lot of food around, you are at a disadvantage if you (a) are driven by a strong food-searching instinct and (b) have a highly efficient metabolism.
The thrifty gene hypothesis suggests that there are gene-linked variations in hunger/fullness signals, and that natural selection (and sexual selection) will weed out those who are well adapted to survive no-longer-existing famines but are ill adapted to an abundance of cheap and readily available food energy.
Such selection is usually only visible retrospectively after several generations. There simply have not yet been enough new generations in order to make a rigorous test of the thrifty gene hypothesis in humans. Mammals which have shorter reproduction intervals are being studied in labs, but even mice and rats are fairly slow breeders for studying natural selection in controlled experiments. However, there is sufficient evidence that the related Barker hypothesis (which deals in phenotypes) is widely accepted.
In exactly the same fashion, evolutionary changes to mental capacity (at a given age) also take multiple generations, and can only be examined retrospectively.
A strong correlation with a reduction in mental capacity could suggest that the brain is involved in a comorbid process in obese individuals. There are a number of possibilities involving the circulatory system and the respiratory system; known comorbidities include circulatory problems and breathing difficulties in obese people, either of which could chronically impair the flow of oxygen to the brain.
There is evidence in this study that as the studied individuals became fatter, their mental impairment worsened relative to that experienced by an average person as a result of the aging process.
Therefore, it's more likely that onset mental impairment is a symptom rather than a cause of obesity.