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LOL. If the human body were a simply combustion chamber, like in your car's engine, I would agree with your simplistic view. Storing/burning fat is not as simple as "too many calories, store as fat, too few calories, burn fat.", if it were, we could look at everyone who is fat and morally shame them without worrying about whether or not we are being unfair.

My judgements are based on physical laws, you might as well be arguing with me about gravity here

Funny that you should mention that. :)

Gravity is NOT a fundamental force as you and most people tend to believe. It is the result of acceleration due to time differentials. Go ahead and dismiss this without further thought as I am sure you will; however, you should probably answer this before you do if you want to sleep without any nagging doubts in your mind:

Time flows more slowly the closer to a mass you get. For example, GPS satellites orbiting the Earth need to account for this aspect of Relativity http://www.astronomy.ohio-stat... , about 3/4 of the way down for the relevant information. What would you expect to see happen if time was flowing at different speeds but you were sitting still? For myself, and apparently I may be alone in this, I would expect to feel an acceleration since I can't satisfy both time references by staying still.

All weight gain is certainly not due to being a pig. Pigs actually know when to stop

Again with the judgemental attitude. Relax bro. Life is not that serious. We all leave this place sooner or later. Try to make it more fun since it is all ephemeral. :)

Electric universe is bullshit.

Their assertions are complete bullshit. There is a reason they make those assertions, and that is where things get interesting.

Pretty much everyone agrees that at The Beginning, their was nothing but energy. It is explained as being at a single point, no mass, no space. Assuming that is correct:

Energy, for whatever reason, "knotted" or "condensed" into 'matter'. When energy became 'matter' it forced the creation of the 'compliment' of mass, which is what we call spacetime. Spacetime is a field. A field of electromagnetism. Space is literally electromagnetic. This is how photons move. Photons aka electromagnetic waves, are literally ripples in this electromagnetic field. The photons are always measured at the same speed regardless of the strength of this field because measurements are always taken in relation to the electromagnetic field, aka spacetime.

The spacetime field falls off in proportion to lorentz invariance as applied to speed in relation to the speed of light. http://www2.lbl.gov/MicroWorld.... If you look at the graph in the lower right corner, the center of the galaxy would be at the far top right of that graph. Technically, any "black hole" will do as far as the top right of that graph goes. The field falls off in direct relation towards the outside of the galaxy. This is why galactic rotation curves do not make "sense" to humans. Time is literally moving faster at the edge of the galaxy than the center. Proof: http://www.astronomy.ohio-stat...

Since spacetime is literally an electromagnetic field, I can understand why the Electric Universe folks get so bent out of shape... they perceived part of a Truth and went running with it... rather like I am. ;)

You are naive. That's how you make a really crappy supercomputer.

This machine will have more than 100,000 cores. At that scale there are many things that must be carefully thought out. Even just _launching_ a job at 100k procs presents challenges (enough so that people who do it well put out press releases about it: http://mvapich.cse.ohio-state.... ). Beyond choosing the processor (obvious) here are some of the things that must be thought about / balanced:

1. Power - for machines this large you often have to make special deals with local utility companies to power it efficiently.
2. Cooling - The heat load will be immense, deciding how to cool it is incredibly important
3. Interconnect - There are many options here (although fewer than in the past). Choosing e.g. Infiniband vs Ethernet, etc. comes with different tradeoffs and can depend on what your average application will be doing (many short messages vs large messages, etc.)
4. Switching - How many switches are needed? What topology will you use (fat-tree, hypercube, etc.). It depends somewhat on how much you want to spend on switches and somewhat on what your typical application workload looks like.
5. RAM - RAM is currently incredibly expensive (thanks to cell-phones using so much of it!). How much RAM, what type, how fast can greatly tip the scales in price / performance
6. OS - Most of these machines these days run Linux - but there are many different flavors. Things get optimized all the way down to exactly which Kernel version to use - and everything is hand-tuned
7. Job Scheduler - Several options here from PBS to Slurm and proprietary vendor specific options. How good your job scheduler is can have a HUGE impact in the usability of the machine.
8. Filesystem - Most of these machines have at least two types of filesystems: "home" and "scratch"... where "home" can be something reliable - maybe even using NFS and "scratch" is typically some highspeed filesystem (Lustre, Panasas, etc.). Choosing the balance between the two is critical. Note that 100,000 processes reading/writing simultaneously can take even carefully crafted filesystems to their knees.
9. Local disk - for a long time it was in voguge to run a "diskless" system - but now "disks" are making a come back (in the way of NV-RAM). Depending on what your applications look like this can provide huge speedups.

(I'm sure I missed something - but these are the big ones)

Anyway: It's not simple. Purchasing for these machines typically takes at least a year just in the phase where you're defining the requirements and then another 6 months or so to put out bids and go through the selection process.

In case you're wondering - I do work in the national lab system, I use these machines daily and am part of procurement decisions for them...

What we call gravity arises from spacetime. ... The concept of time moves faster the further away it is from the matter that it is part of (e=mc^2 simplified).

*facepalm*

In summary, galactic rotation curves are flat because time is faster and space is smaller where there is less matter.

Then why doesn't the same thing happen in the solar system? If it did, we wouldn't have had a mystery in the first place.

It does happen in the solar system.
http://www.astronomy.ohio-stat...
Read paragraph 7 in particular. That is all.

> General Relativity is built into the design - the time kept by the spacecraft is deliberately retarded (slowed) from their clock's proper time sufficiently to make the time sent from GPS match the proper time kept here on the Earth's surface.

The effect is apparently quite real, I found a clear explanation at http://www.astronomy.ohio-stat.... And it's fascinating: special relativity says the clocks would be slowed by their orbital velocity, but general relativity says clocks on earth's surface are even _more_) slowed by being deeper in Earth's gravity well.

I will point out that, technically, you don't have to have the science to explain the discrepancy: you can just measure it and admit the results are real You don't actually have to _understand_ the 38 usec/day speedup of the clocks to work with it, though it is apparently important to factor. And a noticeable discrepancy like that would be fascinating to try to explain _without_ General Relaitivity, so you've made a very good point.

You can probably get away with just Special Relativity, rather than needing full blown General Relativity

It's actually closer to the other way around. The effect from general relativity is ~5 times stronger than the effect from special relativity (link below). I wouldn't have guessed that either.

http://www.astronomy.ohio-stat...

Allowing for relativistic effects makes it more accurate, but it would work fairly well without doing this.

No, GPS would be inaccurate to the point of being useless without accounting for relativistic effects. There are many references explaining this out there (see google), but here is one (emphasis added):

The combination of these two relativitic effects means that the clocks on-board each satellite should tick faster than identical clocks on the ground by about 38 microseconds per day (45-7=38)! This sounds small, but the high-precision required of the GPS system requires nanosecond accuracy, and 38 microseconds is 38,000 nanoseconds. If these effects were not properly taken into account, a navigational fix based on the GPS constellation would be false after only 2 minutes, and errors in global positions would continue to accumulate at a rate of about 10 kilometers each day! The whole system would be utterly worthless for navigation in a very short time. This kind of accumulated error is akin to measuring my location while standing on my front porch in Columbus, Ohio one day, and then making the same measurement a week later and having my GPS receiver tell me that my porch and I are currently somewhere in the air kilometers away.

http://www.astronomy.ohio-stat...

Time dilation isn't proven, otherwise we wouldn't have been able to see anything.

What are you babbling about? The GPS system has detailed time dilation compensation built into it. It's not only proven, it has to be accounted for in the engineering of a functioning system in worldwide use.

GPS satellites are moving at 14,000 km/hr relative to Earth's surface, a Special Relativity time dilation of 7 microseconds per day. But Earth-based clocks are deeper in the gravity well of Earth, so they suffer a General Relativity time dilation of 45 microseconds per day. The nanosecond accurate clocks on board the satellites are pre-calibrated before launch to tick more slowly than they should while on Earth, so once in orbit, they tick at a General-Relativity-time-dilation-compensated rate that then matches Earth clocks. The software still has to compensate for any additional, unpredictable drift caused by orbital variances.

Time dilation is quite real, and must be accounted for, or GPS and Galileo wouldn't work at all. Uncompensated clock error amounts to 10km on Earth per day.

The late Ordovician ice age period is known at the Hirnantian. It did a little searching myself and came up with a paper from 2010 that shows significant changes in CO2 levels corresponded with the late Ordovician ice age. In particular I direct you to Figure 9 that shows sea level/ice volume compared with pCO2.

Did changes in atmospheric CO2 coincide with latest Ordovician glacial–interglacial cycles? [PDF]
Seth A. Young, Matthew R. Saltzman, William I. Ausich, André Desrochers, Dimitri Kaljo

Abstract
The Late Ordovician Hirnantian Stage (444 million years ago) was one of three time periods during the past half billion years in which large continental glaciers formed over Earth's polar regions. The effects of this glaciation were far-reaching and coincided with one of the largest marine mass extinction events in Earth history. The cause of this ice age is uncertain, and a paradoxical association with evidence for high atmospheric CO2 levels has been debated. Precise linkages between sea level, ice volume, and carbon isotope (13Ccarb and 13Corg) proxy records of pCO2 have been poorly understood due in part to uncertainties in stratigraphic correlation and the interpretation of globally important sections. Although correlation difficulties remain, recent Hirnantian biostratigraphic studies now allow for improved correlations. Here we show that consistent trends in both 13Ccarb and 13Corg from two well-dated stratigraphic sequences in Estonia and Anticosti Island, Canada coincide with changes in Late Ordovician (Hirnantian) climate as inferred from sea level and the extent of ice sheets. The integrated datasets are consistent with increasing pCO2 levels in response to ice-sheet expansion that reduced silicate weathering. Ultimately, the time period of elevated pCO2 levels is followed by geologic evidence of deglaciation.

And

6. Implications and conclusions
Our data are consistent with the notion that a long-term drop in pCO2 due to increased silicate weathering (Kump et al., 1999; Saltzman and Young, 2005; Young et al., 2009) possibly also combined with reduced poleward ocean heat transport (Herrmann et al., 2004) resulted in the initial stage of glaciation beginning prior to Stage 1 in Fig. 9. As expanding ice sheets reduced the fraction of continental silicates available for weathering, pCO2 began to rise and 13Ccarb continued to increase due to carbonate weathering in low to mid latitudes (Stage 2 in Fig. 9). The elevated pCO2 levels eventually led to deglaciation, as recorded by the rapid transgression above an unconformity in both Estonia and Anticosti Island (start of Stage 3 in Fig. 6). Following deglaciation, renewed silicate weathering (possibly supplemented by enhanced burial of organic matter in the deepening oceans) led to a second draw down in pCO2 levels and a final episode of Hirnantian glacial advance (end of Stage 3). Organic matter burial or enhanced preservation Corg in the deep oceans through much of Hirnantian is supported by recent documentation of a large positive excursion (+10–20) in 34S of pyrites that tracks the positive 13Corg excursion potentially resulting from both isotopically light carbon (12C) and sulfur (32S) being sequestered in deeper anoxic waters during the Hirnantian (Zhang et al., 2009). However, further studies of 34S of carbonate-associated sulfates are needed to determine if the Hirnantian seawater sulfate reservoir became enriched in 34S as a result of anoxic deep waters. The resultant second episode of glaciation was short lived and deglaciation may also have been related to changes in pCO2 levels, but the available data are not at high enough resolution to determine this.

I'm not sure how to translate pCO2 into ppm and I have no doubt that CO2 levels were still higher than today's but it's obvious there was a significant change in CO2 leve

The thing is, we're getting there. These are no longer science fiction: the path to each of these abilities is very clear. And when these abilities converge we'll have matrix style give-me-knowledge-now and complete VR. Not to mention brain augmentation. This future is far, far closer than it seems.

I'd love to think that you're right, but to paraphrase the old Sidney Harris cartoon, I think you need to be more explicit in your last step. Even if we could stitch up the whole brain with safe and robust wires and sensors, knowledge encoding is still largely a blank map.

Of course, broad- and fine-scale read/write hardware interfaces to the brain will give us a big boost toward figuring out the harder stuff. But that's going to be a massive undertaking, and outside of hand-waving "superintelligent machines will take care of it for us" daydreams, it's going to take a very long time.

I'm pretty confident in this prediction, but it does occupy a place of pride in my display of "things I'd really love to be wrong about".

Actually, you can kill yourself with a single 9 V battery -- or the 12 V battery of your car. One man did:

http://darwinawards.com/darwin...

The computation goes as follows. The issue, as several people have pointed out, is that it is current across the heart that causes defibrillation (basically interrupting the heart's natural rhythm so that it pulses chaotically), not a matter of cooking the person (which will also work, BTW, but isn't the most common cause of electrical shock deaths). It isn't even the case that more current is always worse -- there appears to be a range of currents that are more toxic than others. A brief explanation of this is here:

https://www.physics.ohio-state...

The maximally toxic range of currents across the thorax is empirically 0.1 to 0.2 amps. Below that it isn't enough to defibrillate, above that the heart muscle clamps all the way which means that when the current is removed it is actually more likely that it can with help or will on its own restore a normal rhythm.

The internal resistance of the human body once you introduce probes through the comparatively insulating skin is around 100 ohms. A 9V battery across ~100 ohms makes a thoracic current of roughly 0.1 amp, right at the start of the maximally fatal range. The Darwin above was given because an idiot didn't believe this and stuck probes through his skin to "prove" that it wasn't so.

Personally I've experienced shocks from 12 V car batteries when screwing around with them on rainy nights with salt water on my hands. That's another good way of reducing skin resistance. I didn't take the hit across the torso, but it was every bit as painful as a 110V shock through dry skin -- more so, actually -- and caused my muscles to contract like lightning.

None of this is actually news -- it has been known as long as there has been electricity, because people have been killing themselves accidentally with electricity just that long. My scout leader 50 years ago worked for GE (as an inventor, actually -- one of the people who invented the photodiode controlled light). He taught me that long ago to ground one finger and then brush another finger of the same hand against any possible hot wire so that you find out with a jolt across your hand, not through your torso. Hand to foot, hand to hand, not so good. People used to kill themselves all the time touching hot electrical switches while standing in wet feet on bathroom floors before ground fault circuits were invented and mandated by code.

None of which has much to do with TFA, but it is good to know if you work at all with electricity. Physicists need to know it just to be able to teach it to their students so THEY don't kill themselves accidentally one day. It isn't the voltage that kills you, it's the current, and it doesn't take much current to do the job (or much voltage to create a fatal current).

I checked your link. Most of the pages in fact explain that there *aren't* any "out of place fossils". The closest was a page so blindly-stupid as to think an overthrust creates out of place fossils, and about two lpages that bafflingly think that a newly found slightly earlier ancestor, or a later descendant, is somehow "out of place". Not one single example of a rabbit in the Precambrian, or any other remotely out of place fossil. An out of place fossil has to be an evolutionary descendant (like rabbits) appearing before an ancestor (like dinosaurs). You didn't present a single one, your link didn't present a single example.

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Even with built-in battery or UPS, while that reduces the risk of unexpected power loss, in my experience it still happens.

As far as comparing reliability of SSDs to HDDs, an actual study found that SSDs were much more likely to lose lots of data, sometimes bricking the entire drive.

http://www.cse.ohio-state.edu/...

Enterprise HDDs were the most reliable, even the best SSD they tested was not as good (though similar to consumer grade HDD).

Unfortunately, the study does not reveal which drives were tested.

Fukushima is a serious nuclear disaster. It's a very situation that we should all be concerned about. But this should not lead to any pause in our appetite for nuclear energy.

What people often fail to appreciate is that even coal fired powerstations release quite large amounts of radioactive material in to atmosphere. Coal fired powerstations burn about a million times as much material as a nuclear powerstation per joule of energy produced. Some of that material is radioactive. That stuff isn't been sealed in a container in burrried in a mountain, it's being blown up chimney stacks along with the rest of the rather unpleasant stuff.

Don't believe me? Reflect on this passage taken from this (PDF) document:

The EPA found slightly higher average coal concentrations than used by McBride et al. of 1.3 ppm and 3.2 ppm, respectively. Gabbard (A. Gabbard, “Coal combustion: nuclear resource or danger?,” ORNL Review 26, http://www.ornl.gov/ORNLReview... 34/text/colmain.html.) finds that American releases from each typical 1 GWe coal plant in 1982 were 4.7 tonnes of uranium and 11.6 tonnes of thorium, for a total national release of 727 tonnes of uranium and 1788 tonnes of thorium. The total release of radioactivity from coal-fired fossil fuel was 97.3 TBq (9.73 x 1013 Bq) that year. This compares to the total release of 0.63 TBq (6.3 x 1011 Bq) from the notorious TMI accident, 155 times smaller.

So far, there has not been a single confirmed death due to Fukushima accident. In comparison, there were 20 deaths in the US just mining for coal in 2013. This is not to mention all the deaths being caused by cancers and other health problems being caused by breathing polluted air.

If we're ever going to get on top of this climate change challenge, nuclear must be leading the charge. Nuclear is a safe, non-polluting technology. Modern designs are fail-safe in every sense of the word. The newer designs can even cope with a loss of external power (like Fukushima experienced) yet still stay safe.

This is the 21st century. The technology is mature, sensible and safe. Really, we should be looking to retire every coal fired plant as a matter of urgency, if only to reduce the amount of radioactive contamination of the atmosphere!!

A friend of mine was working on sentiment analysis. They studied the content of yahoo answer and it was quite interesting all the correlations that you can make. The study is of course not enough to provide a direct identification, but it shows how many parameters you need to keep in mind when building a "virtual identity".
http://www.cse.ohio-state.edu/...

Samir Mathur, who is prolific in his studies of the black hole information paradox in a string theory context (in particular, he is one of the main proponents of "fuzzball" black hole solutions), has a good explanation in the "Can we make objects of zero mass?" page of the overview. You'll only need high-school-level algebra, although some high-school-level physics will help understanding somewhat.

Essentially, there is an observer-dependent point near a huge mass at which the (Einsteinian) mass-energy of an infalling small mass (of matter, from particles to planets) goes to zero. Closer to that point the mass-energy of the object becomes negative and the mass of the whole system is reduced.

This is because the potential energy of the small mass dominates its whole mass-energy, assuming it is moving sufficiently slowly. When it hits the "surface" of the huge mass, is effectively zero, because it cannot fall further. However the "surface" in question and the potential energy "depends" -- dropping a marble onto the roof of an office tower makes its potential energy with respect to the roof zero, but not with respect to the ground. Consider the potential energy of dropping the marble onto a flat patch of ground at sea level or onto the peak of a tall mountain. The former has less potential energy. However, a marble dropped into the Mariana Trench has less potential still. A marble tossed onto the "surface" at the Swarzchild radius has its potential energy go to zero for any observer who calculates the existence of the Swarzchild "surface". However, that radius may be at some distance from the centre of a black hole, and the marble falling in towards that accumulates *negative* potential energy.

So small, slow-moving things that fall into a black hole reduce the overall mass-energy of the black hole because the small things' overall energies are dominated by their potential energies, which become negative at the event horizon.

However, truly massive things or things moving relativistically, are dominated by energies other than their gravitational potential energy with respect to the black hole, so when they are at the Swarzchild radius, their mass-energy is still positive, and may remain so even as they move further towards the centre.

Small, slow moving things: shrink a black hole's mass-energy (and thus shrink the horizon); big and/or fast moving things: grow a black hole's mass-energy. The latter is the typical case for things swept up in the accretion disk -- they are accelerated to ultrarelativistic speeds as they spiral inwards. However, particles which just appear thermally (via quantum fluctuations or whatever) very near the event horizon actually remove energy from the black hole system.

http://www.physics.ohio-state....

Oh how naive you are...

The combination of these two relativitic effects means that the clocks on-board each satellite should tick faster than identical clocks on the ground by about 38 microseconds per day (45-7=38)! This sounds small, but the high-precision required of the GPS system requires nanosecond accuracy, and 38 microseconds is 38,000 nanoseconds. If these effects were not properly taken into account, a navigational fix based on the GPS constellation would be false after only 2 minutes, and errors in global positions would continue to accumulate at a rate of about 10 kilometers each day! The whole system would be utterly worthless for navigation in a very short time.

Your statements seem to imply that GPS satellites are in geostationary orbit. They are not. The system would not work if they were.

Which is true, but a little quick google searching shows that relativistic effects do indeed need to be taken into account with GPS satellites (such as this link).

It's not an accident that the average Fox News fan is less informed than people that don't watch any news at all, it is on purpose.

According to that linked "study", Fox News viewers are stupid because "91 percent believe the stimulus legislation lost jobs" and "72 percent believe the health reform law will increase the deficit" and so forth. Such a high percentage of Fox News viewers believe in these obvious falsehood is a proof that Fox News makes you stupid! or so that article claims.

91 percent believe the stimulus legislation lost jobs.
Study: stimulus created 450,000 government sector jobs and destroyed 1,000,000 private sector jobs.

72 percent believe the health reform law will increase the deficit.
GAO report: In rosy scenario, where everything goes perfect, it could decrease deficit by $13.25 trillion!!! or it could increase the deficit by $6.2 trillion.

Apparently not buying into White House's propaganda and disagreeing with liberal's worldview make Fox News viewers stupid. At least they weren't accused of being racist.

Predictions of rotation speed of stars towards the edges of galaxies do not agree with Keplerian predictions used to predict the orbital speed of planets around our sun. So either gravity doesn't behave the same in the outer parts of galaxies as it behaves around our sun, or (the hypothesis) there is some other mass that we can't see (dark mass). Right now, what we know is that observations don't match predictions based on the math that works for our solar system's planets.

http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit6/dark.html

Well, consider that relativity tells us that the satellites zooming up above us have slower ticking clocks.

Actually, the GPS satellite clocks run 38 microseconds faster than ground based clocks.
This is because they are not moving fast enough (special relativity: faster means slower clock) to counter the general relativistic effects (stronger gravitational field means slower ground clocks).
Both clocks seem to be slower for an observer in free space.
http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html

You are absolutely right. I appreciate the correction.

Well, consider that relativity tells us that the satellites zooming up above us have slower ticking clocks.

Actually, the GPS satellite clocks run 38 microseconds faster than ground based clocks.
This is because they are not moving fast enough (special relativity: faster means slower clock) to counter the general relativistic effects (stronger gravitational field means slower ground clocks).
Both clocks seem to be slower for an observer in free space.
http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html

It's current that kills you, not voltage, and it doesn't take much. Even a cheap USB cable will transfer more than enough power to kill you if you're unlucky.

If it's thick enough for 500mA(minimum USB standard), it's enough to kill you, as it only takes 100-200mA. Matter of fact, it says that 100-200mA is actually more dangerous than above 200mA if the victim can get prompt attention.

I'm not buying it, how could you possibly screwup a USB charger to the point where it would be lethal? I mean the cables aren't generally thick enough to carry enough 220V current to kill someone before they melt and 5.5V DC certainly isn't going to kill someone.

It only takes 100mA - 200mA of current to kill someone, and every USB cable is designed to carry at least 500mA since the USB spec says that USB hosts can supply up to 500mA of current (and many plug-in chargers exceed that). So it's certainly feasible that a USB cable can carry enough current to kill someone. It's not the voltage the determines the size of the conductor, it's the current.

The USB cable wires may not have sufficient insulation to protect against 220VAC (peak voltage is higher, around 310V if I remember correctly), but that's the point -- 220VAC is not supposed to be supplied to a USB device. But even if it's not certified for the voltage it seems that the individual conductor insulation combined with the plastic outer sleeve of the USB cable would seem to provide at least enough isolation, I think most plastics used for insulation have around 500 - 1000V/mil (1/1000th of an inch) of breakdown voltage.

I'm surprised that a phone doesn't have at least 220VAC of isolation between the USB power and the phone case. Is this typical in phones?

Anyway, to get relativistic effects, we would need much better propulsion than anything we have thought of so far. Science fiction for now.

So so informative seeming. So so wrong. Relativistic effects are clearly visible in the GPS system.

Now, the statement "to get a useful proportional reduction in perceived trip time from relativistic effects we would need much better propulsion.." would be true. The problem is not, however, with the maximum rate of acceleration; we already do many G acceleration and 1G continuous might be a very good way to go. The problem is that we have no reasonable way of fuelling such a rocket

it is fast enough that they can notice the difference in very accurate clocks...thus it is relativistic

for example GPS Satellites loses about 7 microseconds a day due to relativistic effects.

Seoul is halfway between Beijing and Tokyo. War has visited their peninsula many times over the centuries, yet they have managed to retain their identity.

http://people.cohums.ohio-state.edu/bender4/eall131/EAHReadings/module02/m02korean.html

They will fight.

There is no burning. Apparently that is the key innovation.

Coal is oxidized to produce CO2 and heat. That's "burning", regardless of whether you use air or iron oxides as the oxidizer.

Ummm, sorry, I'm gonna have to go with the Ph.D. in Chemistry on this one buddy, and he says it's NOT burning. I would not call your comment, Informative. Uninformed, but not informative. Ooo, that's a t-shirt right there...

GPS would work perfectly fine without relativity calculations. [...]

False and false. Relativity matters when you care about nanosecond timing.

No, no it's not. As the AC above you says, it is amperage that kills and not voltage. See Ohio state Physics for more info.

Go ahead and check for yourself.

GRACE can resolve nearly uncorrelated mascons that are blocks 400km on each side with a noise floor of ~1cm equivalent water height. (This is latitude dependent because GRACE's denser ground tracks near the poles allow for better resolution.) Each mascon has a mass of ~1.6 gigatons, and a fully-loaded coal train is ~10 kilotons, so GRACE falls short by about five orders of magnitude.

The improved laser ranging on the GRACE follow-on will increase sensitivity, and David Wiese analyzes improvements due to lowering the satellites' altitude and/or adding more satellites to the GRACE system.

You're right to suspect that detecting a tiny change in local gravity is limited by uncertainties in models such as atmosphere dynamics. I've discussed how GPS occultation data (among many other data sources) can be used to reduce these uncertainties.

Other anthropogenic effects such as groundwater depletion can already be detected with GRACE. Rodell et al. 2009 (PDF) and Tiwari et al. 2009 (PDF) observed this in northern India, and Famiglietti et al. 2011 (PDF) recently observed similar groundwater depletion in California.

I guess I should toss this in as well: http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html

"I became a skeptic when they tried to erase the Medieval Warm Period and the Little Ice Age."

Which climatologists did this exactly?

This guy did. Here is what he had to say in his conclusion:

Thus, the temperature data give no support for the global Medieval Warm Period and the Little Ice Age.

HERE is an environmental website's take on it.

HERE is another from an environmental website.

HERE is a whole paper on it (PDF warning).

Do you need more? Google it.

Apparently you never have taken statistics. If the Mean average is about 8% and the standard deviation of grades is 1% So the the people who got 8% will get a 2.0 the people who got 9% will get a 3.0 and the one who got 10%+ will get a 4.0 the poor slob who got 6% or lower would have failed.

Right so the 10% guy who clearly does not understand anything about the subject gets a pass. This works in reverse too, the guy who gets 90% but is the lowest in the class fails. Clearly the 90% guy is better than the 10% guy however the grades don't reflect this in any way.

Now this allow the professor to raise the bar up very high, and really see how much the students get out of the class. The students will work harder because low percentages do not feel good, and there is always that kid who will break the average that will make sure you are on your toes. I have never seen a class based on a curve that ever got away with lets all try to fail so we all can pass succeed. Also this helps keep the professors material at the right level too. If the average is 10% for passing then he knows either he is not teaching the material or it is much too difficult. If students are getting high grades of 90% and 100% then he is making the class too easy. If he gets an average grade about 70-75% and a Standard deviation 15% then he is around on mark.

The professor can still run as many statistical tests on the data until the cows come home, but what has that got to do with the grades given out?

Consider that I could take a class twice, score exactly 75% each time (a firm grasp of the subject), however the first time I'm with geniuses and hence get graded as a fail as I'm in the lowest 1%. Next time the opposite and top the class with the same 75% and since I am now in the top 1% get the best marks. How can that be considered even remotely rational?

Have you looked in to how its actually used in practice. First the curve is computed, then it is distorted based on judgment calls and a host of other dodgy practices. Far better to set objectives at the beginning and then grade the students on how they individually performed, and ignore how the person sitting next to them performed, its irrelevant.

There have been a couple of stories about 3000 to 5000 year old corpses recovered from these melting glaciers. One of the is famous, but I've forgotten his name. Igwi or something. Ohhh, here, I'll google for a couple stories:

Ötzi here, in a PDF
http://geog-www.sbs.ohio-state.edu/courses/g820.01/sp06/alpine_iceman.pdf

Incan ice children and others here:
http://www.mummytombs.com/mummylocator/featured/glacier.htm

http://www.physics.ohio-state.edu/~p616/safety/fatal_current.html

It's The Current That Kills

Offhand it would seem that a shock of 10,000 volts would be more deadly than 100 volts. But this is not so! Individuals have been electrocuted by appliances using ordinary house currents of 110 volts and by electrical apparatus in industry using as little as 42 volts direct current. The real measure of shock's intensity lies in the amount of current (amperes) forced though the body, and not the voltage. Any electrical device used on a house wiring circuit can, under certain conditions, transmit a fatal current.

Provided by: New Jersey State Council of Electrical Contractors Associations, Inc.
Bulletin VOL. 2, NO. 13, February, 1987

http://en.wikipedia.org/wiki/Electric_shock

Ventricular fibrillation

A domestic power supply voltage (110 or 230 V), 50 or 60 Hz alternating current (AC) through the chest for a fraction of a second may induce ventricular fibrillation at currents as low as 60 mA. With direct current (DC), 300 to 500 mA is required.[2] If the current has a direct pathway to the heart (e.g., via a cardiac catheter or other kind of electrode), a much lower current of less than 1 mA (AC or DC) can cause fibrillation. If not immediately treated by defibrillation, fibrillations are usually lethal because all the heart muscle cells move independently instead of in the coordinated pulses needed to pump blood to maintain circulation. Above 200 mA, muscle contractions are so strong that the heart muscles cannot move at all.

What he probably means are record overlays (like struct unions in C, but readable): populate a record and then refer to bits and pieces in innumerable ways.

There's also MOVE CORR and INITIALIZE.

What he probably means are record overlays (like struct unions in C, but readable): populate a record and then refer to bits and pieces in innumerable ways.

There's also MOVE CORR and INITIALIZE.

GPS already normally accounts for relativity.... nothing new there. Base on the original paper I think it's highly unlikely they mismeasured the distances. http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html

I hate to say this, because I know it's probably painfully obvious to most people, but I have no idea what you're talking about.

He's talking about GPS. In order for the triangulation to work correctly, relativity must be taken into account.

That said, another poster pointed out that the researchers apparently did account for the effects of gravity when synchronizing their clocks. The paper just wasn't sufficiently clear on that point, and they're rewriting that section.

But I think it boils down to not only can we not exceed C we can't go slower either. Everything moves at C and the axis of that motion we perceive as time. And everything else we call reality is the contortions required to make that so under all circumstances.

Sir –

I wouldn't quite describe it that way, from the perspective of the epiphany Einstein must have had. I don't think it's that complex, and in any case I think it's more beautiful than that. As a matter of interest, perhaps someone will find the following worth reading.

We have space, and it's where we live. This space is physical but can be represented by representations in our brains and on various media, which representations we call physics.

We make rules in physics to reflect what happens in our space, our reality. Some rules we can see, and they are generally intuitive. For example: Two points - places - are distinct when not the same position, and these points are indivisible (identity). Also, two lines added together make a third line, regardless of the order those lines are added in (commutativity). Three lines can be added in any order to equal the same distance (associativity). Two lines never meet (parallelism). This is the Euclidian space, and applying such to our universe is Newtonian physics (aka classical physics).

Suppose though that the physical world in which we live is not Euclidean, contrary to our observations and intuition. Suppose in this world parallel lines in our world meet at infinity. We can call this a Lobachevsky space (also known as a hyperbolic geometry), and its principles formed the essential breakthrough in general relativity.

Once one accepts as axiomatic that we live in a Lobachevskian space, the acceleration of mass becomes governed (for reasons beyond the scope of this note) - otherwise we would violate other rules (e.g. identity). Hence the perception of time slows in lieu of infinite acceleration (imagine two trains travelling at the speed of light towards each other; to each other they would appear to be travelling only at the speed of light - not, as one might expect, twice the speed of light - because time relative to each other slows; contrast a stationary that expects both to pass at the speed of light in opposite directions). This effect is observed and compensated for in our Global Positioning System.

All to say, by changing our perspective from representing our accepted physical world as a Euclidean geometry to something unintuitive, a Lobachevskian geometry, we arrive at the ability to represent and predict what happens in our physical world.

The consequences inherent to the axiomatic perspective of living in Lobachevskian space are commonly and collectively referred to as "general relativity", and they are non-trivial. The underlying premise that commenced that perspective is itself quite simple.

So if they're coding that "whitespace separates words", then any text written in Mandarin will consist of sentences with one single word? Mandarin and many other Asian languages (other Chinese dialects, Korean, Japanese, Thai) do not use whitespace to indicate word boundary.

Look at the proceedings of any major NLP conference in the last five years (e.g. ACL 2011 or EMNLP 2010) and you'll find a number of papers on unsupervised word segmentation.

Thanks for the links; it is interesting to see what NLP conferences are talking about. That said, I didn't see many articles on unsupervised word segmentation...

I won't find language AI interesting until we have true language learning. Sure, this may be better than previous attempts at language AI, but when there are limiting assumptions built into the foundation of the code, I find it hard to believe that it will ever be able to "learn" any language.

Do you mean that? You won't even find AI interesting until we have solved the entire problem of language acquisition? I don't know about you, but problems strike me as much less interesting once we have solved them, and consider progress towards that solution extremely interesting.

I meant that I don't find language AI interesting when it starts learning with coded assumptions about the language. I just don't think it will be useful beyond the specific case they're programming for. I'd be a lot more interested in this /. story if they showed the win percentage increase across multiple languages.

So if they're coding that "whitespace separates words", then any text written in Mandarin will consist of sentences with one single word? Mandarin and many other Asian languages (other Chinese dialects, Korean, Japanese, Thai) do not use whitespace to indicate word boundary.

Look at the proceedings of any major NLP conference in the last five years (e.g. ACL 2011 or EMNLP 2010) and you'll find a number of papers on unsupervised word segmentation.

I won't find language AI interesting until we have true language learning. Sure, this may be better than previous attempts at language AI, but when there are limiting assumptions built into the foundation of the code, I find it hard to believe that it will ever be able to "learn" any language.

Do you mean that? You won't even find AI interesting until we have solved the entire problem of language acquisition? I don't know about you, but problems strike me as much less interesting once we have solved them, and consider progress towards that solution extremely interesting.

No, GPS does takes General Relativity and Special Relativity into account, and confirms both nicely. Due to the motion of the spacecraft in orbit with respect to us on the ground, one would expect the GPS satellites to lose about 7 microseconds a day. However, because the satellites are further out of our gravity well, General Relativity predicts the satellites will gain about 45 microseconds a day. Basically, this means that if GR and SR were not taken into account, the GPS system would be useless after about 2 minutes.

Source: http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html

However, the effect of Frame Dragging is many orders of magnitude smaller, to the point where it will not have a measurable effect on GPS. To even have a hope of measuring it, Gravity Probe B had gyroscopes made from a set of the most perfect spheres ever manufactured. If you were to scale these spheres up to the size of the earth, the tallest mountain would be less than 1 meter tall.

Space/time is a fundamental concept of the global GPS system. Without taking General Relativity into account, the GPS system would have its time run out of sync with Earth.

See this for more information.

Professors here at Ohio State have a variety of ways to deal with secondhand book sales. Some textbooks here are only available in looseleaf form so they cannot be sold back. Many are "OSU Edition" copies, to ensure they cannot be sold online; to book stores in other regions; or at all after 1--2 years once the publisher comes out with the next edition. Barns & Noble, the "official" OSU bookstore has a program called "textbook rental" to curb resale of used textbooks. Then, one of the worst models is in the Physics department; they have an agreement with the publishers and a company called WebAssign, where although you can buy a used copy of a textbook, only the new ones have a "product key" which you need to do your (required) online homework.

Under none of these circumstances do professors pay anything for students, and (for obvious) reasons professors get the materials for free and most don't have a clue what the books cost until a student tells them (which they ignore). I can't say I'm surprised by any of this. Publishers make enormous profits by revising textbooks and requiring newer versions, and because students (who have to buy the books) don't have a choice. All the while, these new techniques are being upheld as "cost saving" and "convenient" for students. Consumer choice and the free market at work I guess.

To the hell with online textbooks!

Maybe, but those rural areas create the food that the cities need to house and feed their populations

And this is relevant how?

The roads needed to truck in supplies, heavily subsidized food programs, and greatly disproportionate distribution of state tax income as well as federal aid.

Well since the majority of the people live there, and the majority of the wealth is both generated and consumed there, then of course cities account for the most of government revenue and expenditures. It's pretty damn hard to say that cities are "greatly disproportionate" when according to the 2000 Census, 79 % of all Americans live in urban areas. If you really want to look at disproportionate spending look at the rural area. Mapping states according to federal contributors and beneficiaries (contributors receive less than $1 of federal spending for each dollar paid in taxes, beneficiaries receive more than $1 for each dollar paid in taxes), you find two curious facts. First. there's the irony of the political leanings of the states; but more importantly for this conversation, the more populous and urban states are net contributors and the less populous and rural states tend to be beneficiaries. We see this again and again by any metric and any population you choose. For instance, poverty rates for instance.

I grew up in the rural area. It sucked. I'm glad I got out, because there's simply no future there.

Oh, you silly eggheads!
Miracles can happen, you know!
You simply don't have enough FAITH!

Oh, you silly eggheads!
Miracles can happen, you know!
You simply don't have enough FAITH!