Further, the fundamental laws of physics governing lights at the quantum level are not fully understood.
This isn't true; if there's a better understood, more accurate theory -- for any physical phenomenon -- than QED is for electrodynamics, I'd like to know what it is.
I'm not sure if/how the existence of anti-matter galaxies would effect the Big Bang theory.
It would be very hard to explain in standard cosmology. The universe was very homogenous--e.g., well mixed -- in its early existance (and we know this pretty confidently because we can take a look at the cosmic microwave background, which is a constant background with fluctuations of only a hundredth of a percent.)
It's hard to reconcile the existance of large chunks of antimatter now with a very well-mixed universe earlier; the antimatter would have annhillated.
I'm not sure that India was the example country that I was looking for about forbidding multiple citizenships; please someone correct me if I'm wrong on that point.
My previous post was overly rude. I oughtn't have nastilly dismissed those paragraphs as nonsense; they're widely held beliefs, they just happen to be incorrect. I'm just in a snarky mood today, and apologize for it.
Actually, if you read that site, you'll find that in MOST cases you can NOT have dual citizenship. In certain individual cases the US Government will allow the recognition of dual-citizenship, but in the majority they do not.
The point of that site is saying as long as you're careful about it, it doesn't really matter. But its generally not a good idea to pass off a Canadian passport upon entry to the US if you're a US citizen, and vice versa. If you had true dual citizenship, you could use either citizenship at any time.
These paragraphs are nonsense.
`Dual Citizenship' is not some special status, nor is it something which countries generally have to `officially recognize'. It is the state of having citizenships in two countries. The US can't disallow you from having a citizenship in another country; all it could do is threaten to take your US citizenship away, and it can almost never do that except in cases of out-and out treason, because of extensive case law, US and international.
Yes, whenever a (for example) Canada-US dual citizen deals with US authorities, they'd have to show US papers, and Canadian papers to Canadians. But that's because all US citizens have to show US papers to US authorities, and all Canadians likewise. Being a `dual citizen' doesn't change that; why should it?
Pretending like one wasn't a citizen when one had responsibilities as a citizen -- i.e., paying duties, or taxes, or registering for selective service, or showing papers -- will always be illegal. Why do you believe it should be different for `true dual citizenship?'
maybe the US will let you keep dual citizenship (but I know a bunch of people who have been forced to choose
If this is true, which I doubt, these people were misinformed by state department blustering, not actual legalities. (The state department hates multiple citizenships as it complicates their life -- but even they've lightened up, see here what you have to do to loose your US citizenship -- and notice that you have to do them with the intention to relinquish U.S. citizenship . So unless you're being nationalized in India, for example, where multiple citizenships are fobidden, being nationalized to another country -- much less accepting the already-existing fact of citizenship by birth -- explicitly does not qualify. Check out the case law section of that page.)
You *don't have to choose*, unless you're dealing with a nation like India which explicitly forbids multiple citizenships.
You (at least in the US) revoke your US citizenship (you can't have dual citizenship in the US past the age of 18)
Completely untrue. If it were true, the U.S. would be one of the only countries in the world to have such a ridiculous policy. For a pragmatic look at US law on dual citizenship, heck out, for instance, this site.
I agree that peer-review is vital to filter out crackpots and commercial propaganda.
Why?
The various LANL preprint servers have been running since 1991 with no such scoring system. Everything that's submitted from somebody associated with a university or research institution is simply accepted.
People are pretty knowledgeable about their own fields; it doesn't take more than skimming the abstract to see if its written by a crackpot, and only a bit more to see if its interesting to them. (And if it is to them, it need not be to someone even working on very similar problems.) People looking for info out of their fields shouldn't be reading the current state-of-the-art; they need to get up to speed first with, eg, review articles.
So I'd tend to just skip the `rating' totally; other than an ego boost/dasher, I think most scientists would skim with, in Slashdot terms, the threshold set to -2 anyway.
If a few people started using a broken web-browser that didn't work with their server, and your ISP didn't keep you on top of the situation, would you sue them for that, too?
People are using a client that won't view your stuff because of your web host. Poor you. Get a new ISP, bitch out the censorware vendor, (who you also can't sue, any more than you could sue the hypothetical broken-browser company), and move on with your life.
t really doesn't matter what design rules you follow and how well you follow them, the only thing that matters is this: does it look good or crappy?
Exactly wrong. Oddly enough, I agree with the rest of the posting, so I wonder if that sentance above is really what you mean.
The aesthetics do not matter except indirectly. A portal-ish-type-page is not a piece of artwork to be framed and hung and for people to have strong emotional feelings about how beautiful/powerful/sensitive it is. The readability and useability matter.
If a page looks so ugly that it distracts from usability, that's fine, but I'd much rather visit an ugly-ish useable site than a gorgeous unuseable site any day. The design rules you reject are expressely for the purpose of enhancing readability and usablility. Even at the cost of beauty.
If you can create two photons with opposite polarization, as soon as you measure the polarization of one, the state of the other is immediately fixed, regardless of the distance.
Arggh!
Repeat after me: You can't send information this way. You can't send information this way. You can't send information this way.
Imagine the following scenario:
You have a bag containing a black marble and a white marble.
Two people pick marbles with their eyes closed and then,
Without looking walk a far distance away and then look at their marble
Instantly, they'll know what color marble they have and the other person has. So what. Not one single bit of information has been transmitted from one person to the other; all that's happened is that equivalent bits of information have been sent from the bag to each person. And since it was a random bit of information to begin with, you're no better off than before.
I'll agree with this and remind people who might be worried that this is an underestimate that 5 Newtons is about 1 lb of force. It's a cool idea, but even when you're clattering along at 60wpm, this is only.06 W while you're typing; and I know that I personally don't spend a lot of time typing a lot at a laptop, I use it more for browsing reports than writing them. All my serious typing is done on a real keyboard, usually attatched to a desktop.
There was a nice article about biometrics posted above, but I'll parot the standard problems:
You can't revoke a biometric.
You can't keep a biometric secret in any serious way.
That is, biometrics don't have the two properties that any sort of key really should have.
Other miscellaneous problems:
It's a bad idea to use the same key/password for many things. How many eyes/thumbs do you have?
Using one key or method of identification for any transaction is a bad idea. Biometric or not. You should have at least two -- eg, card + PIN. (so, if you _must_ use an iris scan, you should use a PIN too.)
For any biometric, there's some non-zero fraction of the demographic that doesn't have one.
and it'll be interesting to see what happens when this issue comes up in other countries.
Current fee structures for local calls, and current use leves of local telco networks, are designed for people making 20 min calls to Aunt Maude. As more and more people use their local service to make 1-2 hour calls to their ISP every night, somewhere, someone's fees are going to have to rise. And it seems to me its potentially reasonable to single out data calls for special fees, not because of the content, but because people tie up phone lines longer (typically) with data connections.
I guess in markets that already charge for local calls, this isn't such a big deal. In markets where that's not the case, though, either people will have to pay for all local calls, which may not be politically feasible, or data calls will have to pay extra fees.
What, we should ban celebrating scientific progress until we have perfect knowledge?
It's completely true that the interpretation of the measurements depends on the model you use to interpret it (and as has been pointed out earlier in the thread, the `Age' can vary quite a bit even within this model; the addition of a cosmological constant, for instance.) This is the case for any result in any field of study, from history and psychology to particle physics.
Nonetheless, this model seems to be working quite nicely, and these measurements fit snugly into it. So, until we know better, using this as the standard model and accepting the ages we get from that is perfectly reasonable.
This is exactly right. We can't see the entire Universe, we can only see our patch (the region within the so-called `Hubble radius', which is defined much the way you've done the calculation above.) Another way of thinking of this is that if, at the birth of the Universe, a protogalaxy (which is now a few Gpc away) shot a photon at us, the current age of the universe hasn't been enough time for the photon to hit us yet; so, we can't see that galaxy yet. This is an extremely important point for understanding why another question, homogeneity, puzzles cosmologists so. The bits of universe that are just barely within our horizon now but in opposite directions are not yet in each others horizon; so they haven't had any chance to interact with each other yet at all, much less come to any sort of equilibrium. However, we can see both bits -- and they look exactly the same. The CMB from both directions is identical. How on earth did THAT happen? Is it just co-incidence that all these completely so-far unconnected bits of universe were at exactly the same temperature?
The measures of the Hubble constant include dark matter; the Hubble constant comes from the total amount of mass in the universe, so anything that interacts gravitationally is included. Dark matter is the stuff that seems to have mass but isn't `glowing' like stars, so can't be seen; it's in there. These measurements don't discriminate between different forms of mass.
The Cosmic Micrwowave Background (CMB) definately does contribute to the mass/energy density of the universe, as you say. However, it's effect is tiny. 3K radiation corresponds to an energy density of ~(kT) ~4x10-23 J/m3, vs. on the order of 10-19 for Omega=1; so the CMB contributes about 10-4. In earlier, hotter times, the CMB contributed more; but in this cold epoch, not so much.
FWIW: This is a NASA announcement, to sort of trumpet the end of their 10-yr `Key Project' using the Hubble Telescope. A lot of good work's been done by the Key Project Team, but the announcement isn't exactly news to working cosmologists; the number has been converging to this for a while.
2. The Virgin Shmi and the "Immaculate Conception" of Anakin
Sorry, but people misusing terms bugs me, and this one has occurred so often recently it really bugs me.
In Christian mythological tradition, `Immaculate Conception' does NOT refer to some supernatural conception of a Christ figure, it refers to the mother being born `without stain of sin'.
I think the basic idea of the article is that if you block things that annoy you, you're going to end up losing out, because there'll inevitably be something of interest in what's filtered out, and by narrowing your exposure to other ideas, you're hurting yourself.
It's hard to disagree with that sentiment in principle. The problem is that in practice, I (for instance) have a finite amount of time to spend reading, and an even more limited amount of time to spend reading on the net.
I already use shutup ``wetware'' by not clicking my way to Microsoft advocacy sites, or by not picking up up Bill Gates' new book, or not reading journal articles in my field by authors who are doing work I don't find interesting. I already filter what I read; it's somewhat disingenious to suggest otherwise.
It's absolutely true that I'm missing out useful insights by doing this. But given how short my time each day is I can spend reading, I have no choice but to try to select things that have the highest signal-of-relevance-to-me to noise ratio I can find. I will always miss some very useful signal that way; and, what's worse, I will systematically be missing the same sort of signal all the time -- stuff that I don't find interesting or that I disagree with. But I don't see that I have a choice.
I'd love to read everything I can get my hands on, regardless of relevence or intelligence; but it would be irresponsible, because ultimately I have to sleep and work and eat and spend time with my loved ones. So I don't read Danielle Steele novels, Republican election materials, Bill Gates books, or flamers on usenet. Life's too short.
How can the same tech that allows directional distance pinpointing of a handheld cellular watch also be undetectable and untraceable in a marine communications device?
`Undetectable' is a poor word for this. What happens is that if the walkie-talkie is putting out 5W of power on a spectrum spread over many hundreds of MHz, and the exact frequencies chosen / timings given are either pre-arranged and unknown to others, or being changed in a seemingly random way, the signal becomes very hard to notice.
It becomes very difficult to `scan' for a spread-spectrum signal the way one could for a single-frequency signal, as you need a great deal of information beforehand.
And a little misleading. (``a walkie-talkie that's not only undetectable but can tell a Marine the location of all the other members of his unit''; they obviously have a very different definition of undetectable than the one I use.)
Spread-spectrum stuff is not particularly new; combining it with digital stuff and extremely precise time measurements (`time domain' refers to measuring signals in `time space', rather than `frequency space') is pretty cool.
The article is pretty confusing about which of those additions gives you what. The spiffy hand-held radar things are a result of the precise time measurements; radar works by examining return times from radio signals, and measuring these times very precisely obviously gives better resolution. Accurate measurements also makes for less signal necessary as well to transmit a given amount of information; a factor of 100 seems optimistic, but I'm not a radio engineer.
Much of the rest of the stuff -- increased bandwidth, the ability for encryption and signal hiding -- is the result of using digital techniques.
None of this changes the fact that a given amount of frequency space has a given bandwidth and possible information content, however. Encoding things digitally can make more efficient use of that bandwidth for many signals, but using `radio pulses' vs `radio waves' (?!) doesn't change this.
I'm sure this has been brought up before, but I do have one worry about the refund thing and basing it on the EULA. (Don't get me wrong; I way agree that paying the Microsoft Tax on machines is something that shouldn't be so hard to avoid, epecially for non-nerd types, in a competitive marketplace).
Doesn't this give legitimacy to the EULA and shrink-wrap licenses? By attempting to enforce one clause of the license, it seems that we're implicitly saying that such things are valid. The `beating them at their own game' aspect of it all is very attractive, but I don't like their game, and I'd be cautious about tacitly accepting their rules.
Slashdot Mirror
It would be very hard to explain in standard cosmology. The universe was very homogenous--e.g., well mixed -- in its early existance (and we know this pretty confidently because we can take a look at the cosmic microwave background, which is a constant background with fluctuations of only a hundredth of a percent.)
It's hard to reconcile the existance of large chunks of antimatter now with a very well-mixed universe earlier; the antimatter would have annhillated.
4.1% in Canada.
These paragraphs are nonsense.
`Dual Citizenship' is not some special status, nor is it something which countries generally have to `officially recognize'. It is the state of having citizenships in two countries. The US can't disallow you from having a citizenship in another country; all it could do is threaten to take your US citizenship away, and it can almost never do that except in cases of out-and out treason, because of extensive case law, US and international.
Yes, whenever a (for example) Canada-US dual citizen deals with US authorities, they'd have to show US papers, and Canadian papers to Canadians. But that's because all US citizens have to show US papers to US authorities, and all Canadians likewise. Being a `dual citizen' doesn't change that; why should it?
Pretending like one wasn't a citizen when one had responsibilities as a citizen -- i.e., paying duties, or taxes, or registering for selective service, or showing papers -- will always be illegal. Why do you believe it should be different for `true dual citizenship?'
If this is true, which I doubt, these people were misinformed by state department blustering, not actual legalities. (The state department hates multiple citizenships as it complicates their life -- but even they've lightened up, see here what you have to do to loose your US citizenship -- and notice that you have to do them with the intention to relinquish U.S. citizenship . So unless you're being nationalized in India, for example, where multiple citizenships are fobidden, being nationalized to another country -- much less accepting the already-existing fact of citizenship by birth -- explicitly does not qualify. Check out the case law section of that page.)You *don't have to choose*, unless you're dealing with a nation like India which explicitly forbids multiple citizenships.
Why?
The various LANL preprint servers have been running since 1991 with no such scoring system. Everything that's submitted from somebody associated with a university or research institution is simply accepted.
People are pretty knowledgeable about their own fields; it doesn't take more than skimming the abstract to see if its written by a crackpot, and only a bit more to see if its interesting to them. (And if it is to them, it need not be to someone even working on very similar problems.) People looking for info out of their fields shouldn't be reading the current state-of-the-art; they need to get up to speed first with, eg, review articles.
So I'd tend to just skip the `rating' totally; other than an ego boost/dasher, I think most scientists would skim with, in Slashdot terms, the threshold set to -2 anyway.
If a few people started using a broken web-browser that didn't work with their server, and your ISP didn't keep you on top of the situation, would you sue them for that, too?
People are using a client that won't view your stuff because of your web host. Poor you. Get a new ISP, bitch out the censorware vendor, (who you also can't sue, any more than you could sue the hypothetical broken-browser company), and move on with your life.
Exactly wrong. Oddly enough, I agree with the rest of the posting, so I wonder if that sentance above is really what you mean.
The aesthetics do not matter except indirectly. A portal-ish-type-page is not a piece of artwork to be framed and hung and for people to have strong emotional feelings about how beautiful/powerful/sensitive it is. The readability and useability matter.
If a page looks so ugly that it distracts from usability, that's fine, but I'd much rather visit an ugly-ish useable site than a gorgeous unuseable site any day. The design rules you reject are expressely for the purpose of enhancing readability and usablility. Even at the cost of beauty.
Arggh!
Repeat after me: You can't send information this way. You can't send information this way. You can't send information this way.
Imagine the following scenario:
- You have a bag containing a black marble and a white marble.
- Two people pick marbles with their eyes closed and then,
- Without looking walk a far distance away and then look at their marble
Instantly, they'll know what color marble they have and the other person has. So what. Not one single bit of information has been transmitted from one person to the other; all that's happened is that equivalent bits of information have been sent from the bag to each person. And since it was a random bit of information to begin with, you're no better off than before.I'll agree with this and remind people who might be worried that this is an underestimate that 5 Newtons is about 1 lb of force. It's a cool idea, but even when you're clattering along at 60wpm, this is only .06 W while you're typing; and I know that I personally don't spend a lot of time typing a lot at a laptop, I use it more for browsing reports than writing them. All my serious typing is done on a real keyboard, usually attatched to a desktop.
- You can't revoke a biometric.
- You can't keep a biometric secret in any serious way.
That is, biometrics don't have the two properties that any sort of key really should have.Other miscellaneous problems:
Current fee structures for local calls, and current use leves of local telco networks, are designed for people making 20 min calls to Aunt Maude. As more and more people use their local service to make 1-2 hour calls to their ISP every night, somewhere, someone's fees are going to have to rise. And it seems to me its potentially reasonable to single out data calls for special fees, not because of the content, but because people tie up phone lines longer (typically) with data connections.
I guess in markets that already charge for local calls, this isn't such a big deal. In markets where that's not the case, though, either people will have to pay for all local calls, which may not be politically feasible, or data calls will have to pay extra fees.
Blue Mountain's up to speed, but of course things are always being tweaked and reconfigured. Blue Pacific, however, has issues.
It's completely true that the interpretation of the measurements depends on the model you use to interpret it (and as has been pointed out earlier in the thread, the `Age' can vary quite a bit even within this model; the addition of a cosmological constant, for instance.) This is the case for any result in any field of study, from history and psychology to particle physics.
Nonetheless, this model seems to be working quite nicely, and these measurements fit snugly into it. So, until we know better, using this as the standard model and accepting the ages we get from that is perfectly reasonable.
This is exactly right. We can't see the entire Universe, we can only see our patch (the region within the so-called `Hubble radius', which is defined much the way you've done the calculation above.) Another way of thinking of this is that if, at the birth of the Universe, a protogalaxy (which is now a few Gpc away) shot a photon at us, the current age of the universe hasn't been enough time for the photon to hit us yet; so, we can't see that galaxy yet. This is an extremely important point for understanding why another question, homogeneity, puzzles cosmologists so. The bits of universe that are just barely within our horizon now but in opposite directions are not yet in each others horizon; so they haven't had any chance to interact with each other yet at all, much less come to any sort of equilibrium. However, we can see both bits -- and they look exactly the same. The CMB from both directions is identical. How on earth did THAT happen? Is it just co-incidence that all these completely so-far unconnected bits of universe were at exactly the same temperature?
Oops. I hoped that those things would turn out as superscripts. 10-23 is 10^(-23), 10-19 is 10^(-19), and 10-4 is 10^(-4). sorry.
The Cosmic Micrwowave Background (CMB) definately does contribute to the mass/energy density of the universe, as you say. However, it's effect is tiny. 3K radiation corresponds to an energy density of ~(kT) ~4x10-23 J/m3, vs. on the order of 10-19 for Omega=1; so the CMB contributes about 10-4. In earlier, hotter times, the CMB contributed more; but in this cold epoch, not so much.
FWIW: This is a NASA announcement, to sort of trumpet the end of their 10-yr `Key Project' using the Hubble Telescope. A lot of good work's been done by the Key Project Team, but the announcement isn't exactly news to working cosmologists; the number has been converging to this for a while.
In Christian mythological tradition, `Immaculate Conception' does NOT refer to some supernatural conception of a Christ figure, it refers to the mother being born `without stain of sin'.
Altavista can give you a bunch of references, the first one that popped up for me was http://totustuus.com/immacula.htm
Use whatever makes you most productive. It's all about choice.
It's hard to disagree with that sentiment in principle. The problem is that in practice, I (for instance) have a finite amount of time to spend reading, and an even more limited amount of time to spend reading on the net.
I already use shutup ``wetware'' by not clicking my way to Microsoft advocacy sites, or by not picking up up Bill Gates' new book, or not reading journal articles in my field by authors who are doing work I don't find interesting. I already filter what I read; it's somewhat disingenious to suggest otherwise.
It's absolutely true that I'm missing out useful insights by doing this. But given how short my time each day is I can spend reading, I have no choice but to try to select things that have the highest signal-of-relevance-to-me to noise ratio I can find. I will always miss some very useful signal that way; and, what's worse, I will systematically be missing the same sort of signal all the time -- stuff that I don't find interesting or that I disagree with. But I don't see that I have a choice.
I'd love to read everything I can get my hands on, regardless of relevence or intelligence; but it would be irresponsible, because ultimately I have to sleep and work and eat and spend time with my loved ones. So I don't read Danielle Steele novels, Republican election materials, Bill Gates books, or flamers on usenet. Life's too short.
`Undetectable' is a poor word for this. What happens is that if the walkie-talkie is putting out 5W of power on a spectrum spread over many hundreds of MHz, and the exact frequencies chosen / timings given are either pre-arranged and unknown to others, or being changed in a seemingly random way, the signal becomes very hard to notice.
It becomes very difficult to `scan' for a spread-spectrum signal the way one could for a single-frequency signal, as you need a great deal of information beforehand.
Spread-spectrum stuff is not particularly new; combining it with digital stuff and extremely precise time measurements (`time domain' refers to measuring signals in `time space', rather than `frequency space') is pretty cool.
The article is pretty confusing about which of those additions gives you what. The spiffy hand-held radar things are a result of the precise time measurements; radar works by examining return times from radio signals, and measuring these times very precisely obviously gives better resolution. Accurate measurements also makes for less signal necessary as well to transmit a given amount of information; a factor of 100 seems optimistic, but I'm not a radio engineer.
Much of the rest of the stuff -- increased bandwidth, the ability for encryption and signal hiding -- is the result of using digital techniques.
None of this changes the fact that a given amount of frequency space has a given bandwidth and possible information content, however. Encoding things digitally can make more efficient use of that bandwidth for many signals, but using `radio pulses' vs `radio waves' (?!) doesn't change this.
I tend to agree. He was saying not to go with
hype and emotions, to carefully, rationally choose what's best. Nothing wrong with that.
Doesn't this give legitimacy to the EULA and shrink-wrap licenses? By attempting to enforce one clause of the license, it seems that we're implicitly saying that such things are valid. The `beating them at their own game' aspect of it all is very attractive, but I don't like their game, and I'd be cautious about tacitly accepting their rules.