2. Everyone was wrong about Zweistein's theory: it was testable, and Dreistein found the test.
3. Dreistein's theory did add something new (i.e. it contains content not deducible from Zweistein's theory). Wouldn't the test of Dreistein's theory necessarily only test the nonZweistein part?
"...the CSIRO (Commonwealth Scientific and Research Organisation) is financially supported mainly (I believe) by the (Australian) federal government to find/discover/create/invent things that benefit Australia. Does this happen in other countries?"
Canada has NRC, Britain has PPARC and some other things, Germany has the Max Planck Institutes, France has CNRS, and Japan has the Ministry of Sports (and Education. I think they might have rearranged things, but they should still have some food physicists take on the Iron Chefs!).
"It seems the point is to actually catch signals
that are otherwise too faint... rather than 'zoom' in more on things that are too small."
No, the point is to zoom in on small things. Black holes are fairly bright (as long as they're being fed) but tiny. You may be thinking of using gravitational lensing by foreground clusters of galaxies to detect very distant galaxies behind them.
The Brittish 'billion' is what American's consider a 'trillion'.
Correct, but irrelevant unless a trillion is smaller than a billion in quaint Detroit.
The Detroit Free Press, and/., both of whom should have a correction up by now, goofed. The right number is 9.78 x 10^10, which is 97.8 billion in the U.S. or 97800* million anywhere.
*except for the sig. fig. problem. The American number system really is better.
Faulty interpretation of Libet's experiment?
on
AI in Sci-Fi
·
· Score: 1
From the article: In 1985, the neurosurgeon Benjamin Libet performed some experiments with surprising results. He put electrodes on subjects to detect their brain waves and the flexing of their wrists. The subjects watched a revolving spot on a clock face. They could flex their wrists whenever they chose, but had to note the exact position of the spot when they made this decision. Libet was timing the beginning of the action, the precise moment of the decision to act, and the beginning of a particular brain wave pattern known as the readiness potential. When the brain preplans a series of movements, this pattern occurs just before the complex action.
Libet found that the readiness potential starts about one half of a second before the action, but the decision to act occurs about one-fifth of a second before the action. The conscious decision to act is not in fact the starting point. The event is already beginning before the person consciously chooses to start.
Conscious awareness lags behind what happens. You jerk your hand away from a hot surface before you consciously feel the pain. However, we do not realize this because of what Libet called subjective antedating. The brain puts events in order after the event. "I feel that I consciously did such and such," but tests prove otherwise.
Uh...but wouldn't you expect the brain to take some time between making a decision and realizing that it had made a decision and checking the time (looking at the spot)? Just because Libet asked the subjects to note the exact time of their decision doesn't mean they were actually able to do so with no delay. Sheesh.
Also, what if the "readiness potential" formed, but the subject changed their mind and decided not to flex?
Re:I think therefore I am...
on
AI in Sci-Fi
·
· Score: 1
I believe his point was, if Descartes was going to discard everything else as not provably existing, then he'd have to, by logical extension, say the same of himself if he wasn't able to pin down exactly where the "self" lies.
Nowhere in "Cogito ergo sum." is there anything about where the self is. Even the act of perception is a thing that exists, therefore Descartes' statement was valid. Whether or not he had a soul, or free will, or just a bunch of chemicals sloshing around in his skull is a different matter. I see his statement as being based on having experienced something (thinking), and how that something came about, or even what the something was, are irrelevant (but interesting).
Most tangible objects in our world would be considered "provably existant" by the majority of us, assuming we accept certain laws of physics as correct. If we're not even willing to do that much, then I think our own existance is just as questionable.
But we never know of any physical objects without perceiving them through our sensory organs. Therefore our existence is automatically more certain to ourselves than any external "tangible objects".
Re:Universal expansion doesn't mean *we* expand!
on
The Big Rip
·
· Score: 1
Bzzt. Wrong. If the expansion is accelerating, then the solar system is expanding.
Exactly where are you getting this from?
>But the Friedmann equations assume a >homogeneous universe for mathematical >convenience, so not all of their predictions >apply everywhere in the real universe.
Doubtless true; all equations have limits to their applicability. It seems very unlikely that that would be enough though.
?!?! You know how they say space is a vacuum? They're talking about within the solar system, which is of course a collapsed protostellar disk, so it is in fact much denser than the rest of the galaxy. Same goes for galaxies, on a bigger scale - they are much denser than the universe as a whole. So there's a HUGE difference between what goes on inside them and the large scale behavior of the universe, which is what the Friedmann equations are about. Very unlikely? Not enough? Yeah, right. Just admit you don't know what you're talking about.
the U.S. Justice Department is apparently planning to criminalize encryption when used during the commission of a felony under federal law.
So now we'll be able to change the old saw of "only criminals encrypt" to "only criminals don't encrypt".;-)
Seriously, would such a law really stop them from encrypting? Duh...no! The fact that the authorities are fighting encryption so hard is advertizing that it must be a good way of not getting caught.
Since it came out in 2000, have modern browsers fixed the cache cookie problem? (Besides refusing cookies?)
Re:Universal expansion doesn't mean *we* expand!
on
The Big Rip
·
· Score: 1
As the expansion rate increases, the size of the observable universe shrinks i.e. the point of the universe that is moving away faster than the speed of light comes ever closer.
Once the Sun 'falls' over that edge- you are no longer gravitationally bound to the Sun.
You missed the point. The Solar system isn't expanding. Galaxies are like the raisins in a baking loaf of raisin bread. As the bread rises the raisins move farther apart, but the raisins (and their contents) stay more or less the same size.
What you said about shrinking horizons in an accelerating universe is correct - as long as the universe on the horizon scale is well described by the Friedmann equations. But the Friedmann equations assume a homogeneous universe for mathematical convenience, so not all of their predictions apply everywhere in the real universe.
It does in trinary. Irrational numbers cannot be fully expressed as a "decimal" in any base.
More interestingly, I don't think you could make "effective pi" rational. Try drawing circles of different sizes on a grainy medium, like say, pixels on a screen.
Universal expansion doesn't mean *we* expand!
on
The Big Rip
·
· Score: 3, Informative
Any reasonably dense collection of matter (like a planet, our solar system, and our galaxy) is gravitationally bound and stays together. Universal expansion means that the galaxies get farther apart, not that they get bigger.
Shame on New Scientist.
And now the above, with (a little) math. The gravitational force between two objects is basically (leaving out mass)
F = -k / r^2 + L * r
where k is a constant, r is the separation between the 2 objs, and L is either a constant or a function of time (we don't know yet).
The k term is good old Newtonian (or even Einsteinian up until a couple of years ago) gravity. Strong for small r, weak for low r.
The L term represents the new discovery that the universal expansion is accelerating. It is (unnoticeably) weak on small scales, and only important for large r (i.e. size of the visible universe). For the L term to matter on planetary scales, it would have to become much larger in the future. But we just discovered that it even exists - how it behaves with time is the next thing to find. So don't worry (yet;-).
If they do prove that space is grainy and can measure the size of the grain, will we finally be able to truncate Pi at some point and actually point to its last digit?
Sigh. pi is a mathematical constant, so it is what it is independently of physics. It just happens to be useful in physics.
What will be interesting will be to see if he actually does make money off his book. All the fabulous word-of-mouth in the world is no good to him if nobody actually buys it.
Untrue. There are more ways for him to make money off the book than selling books. His day job is at the Electronic Freedom Foundation, an internet lobby group. Ascending to netdemigodhood is job security/promotion potential (possibly somewhere other than the EFF).
Besides, if it becomes the talked about book of the epoch, people will have to buy it so they can display it on their bookshelf without reading it.
My bet is the first to provide fairly solid evidence of gravitational waves gets a Nobel.
You win your bet. Russell Hulse and Joe Taylor won in 19xx for their work on the slowing down of a binary pulsar. The slowdown matches the expected orbital energy loss for dissipation by gravity waves. But you knew that, didn't you?
I believe gravity waves also make their presence known in the large angle fluctuations of the cosmic microwave background.
Some people will argue that those effects could be caused by something else, but such a coincidence seems as least as large as a simultaneous* jiggle in two places. What excites me about gravitational wave telescopes is that they are just that...telescopes that use something other than light. Black holes and supernovae tend to be dense and opaque, so gravity waves should reveal things that light (or even neutrinos) cannot.
* with the appropriate semblance of simultaneity, of course.
If these clotting bandages work, great, but couldn't long term willy-nilly use cause too much clotting in a few people? Maybe that's why these aren't on the market.
could amateur pics capture something astronomers miss?
Until pros get telescopes monitoring all of the sky all of the time at all wavelengths, yes. Most telescope fields of view are so small (depending on wavelength) that we miss a lot of transient phenomena. To some extent that's OK since astronomical timescales are notoriously long, but some things happen on faster timescales.
But this case is a bunch of nonastronomers using images taken by professional astronomers, who better understand the flaws in the images.
I wouldn't even dignify Euroseti as amateurs, since their selling SOHO images for 15 pounds REEKS of a scam. If you had found good evidence of ET, would you be trying to hawk it like that?
Re:All chips are protected on a craft like this!
on
SOHO Strikes Back
·
· Score: 1
You actually don't want to stop them, but let them pass right through, since most radiation damage is caused by the secondary shower of stuff knocked off the target by the original particle.
I used to work in the radiation therapy part of a cancer clinic. One time I put a key down on top of the film beside the calibration wedge, (i.e. I was calibrating, not beaming anyone) and exposed it to gamma rays. Instead of the key making a shadow on the film, the film was mostly unexposed except where it had had metal on top to contribute electrons. So tinfoil hats might not be a good idea! Unless they're thick enough to soak up the secondary shower.
Of course it's hard to be sensitive to optical wavelengths and NOT pick up cosmic rays, so this is a common problem for telescope CCDs. Often the blips are removed by taking several exposures and averaging with 5 or 7 sigma outliers for each pixel rejected. SOHO probably doesn't do that, however, because they look at transient phenomena.
Most of us have a rough idea what the troposphere and stratosphere are, but I missed the border crossing sign at the tropopause last plane trip I took.
What is the definition by which they measure its height? The article doesn't say.
Mostly, yes, but in Consider Phlebas I don't see how Vavatch (a small ringworld/large space station for those who haven't read it) could have had both arctic and tropical regions. Or at least arctic along the rims and tropical along the equator is not as obvious as he seemed to think. Is there heat loss from the rims? Maybe, but I think he just goofed.
Ah, it feels so geekly good to get that off my chest.
Slashdot Mirror
I see three possibilities:
1. You are right.
2. Everyone was wrong about Zweistein's theory: it was testable, and Dreistein found the test.
3. Dreistein's theory did add something new (i.e. it contains content not deducible from Zweistein's theory). Wouldn't the test of Dreistein's theory necessarily only test the nonZweistein part?
Canada has NRC, Britain has PPARC and some other things, Germany has the Max Planck Institutes, France has CNRS, and Japan has the Ministry of Sports (and Education. I think they might have rearranged things, but they should still have some food physicists take on the Iron Chefs!).
They're not. They're refracting, like normal lenses. A good example would be looking at something through the turbulent air over a barbecue.
No, the point is to zoom in on small things. Black holes are fairly bright (as long as they're being fed) but tiny. You may be thinking of using gravitational lensing by foreground clusters of galaxies to detect very distant galaxies behind them.
Correct, but irrelevant unless a trillion is smaller than a billion in quaint Detroit.
The Detroit Free Press, and /., both of whom should have a correction up by now, goofed. The right number is 9.78 x 10^10, which is 97.8 billion in the U.S. or 97800* million anywhere.
*except for the sig. fig. problem. The American number system really is better.
Libet found that the readiness potential starts about one half of a second before the action, but the decision to act occurs about one-fifth of a second before the action. The conscious decision to act is not in fact the starting point. The event is already beginning before the person consciously chooses to start.
Conscious awareness lags behind what happens. You jerk your hand away from a hot surface before you consciously feel the pain. However, we do not realize this because of what Libet called subjective antedating. The brain puts events in order after the event. "I feel that I consciously did such and such," but tests prove otherwise.
Uh...but wouldn't you expect the brain to take some time between making a decision and realizing that it had made a decision and checking the time (looking at the spot)? Just because Libet asked the subjects to note the exact time of their decision doesn't mean they were actually able to do so with no delay. Sheesh.
Also, what if the "readiness potential" formed, but the subject changed their mind and decided not to flex?
Nowhere in "Cogito ergo sum." is there anything about where the self is. Even the act of perception is a thing that exists, therefore Descartes' statement was valid. Whether or not he had a soul, or free will, or just a bunch of chemicals sloshing around in his skull is a different matter. I see his statement as being based on having experienced something (thinking), and how that something came about, or even what the something was, are irrelevant (but interesting).
Most tangible objects in our world would be considered "provably existant" by the majority of us, assuming we accept certain laws of physics as correct. If we're not even willing to do that much, then I think our own existance is just as questionable.
But we never know of any physical objects without perceiving them through our sensory organs. Therefore our existence is automatically more certain to ourselves than any external "tangible objects".
Exactly where are you getting this from?
>But the Friedmann equations assume a
>homogeneous universe for mathematical
>convenience, so not all of their predictions
>apply everywhere in the real universe.
Doubtless true; all equations have limits to their applicability. It seems very unlikely that that would be enough though.
?!?! You know how they say space is a vacuum? They're talking about within the solar system, which is of course a collapsed protostellar disk, so it is in fact much denser than the rest of the galaxy. Same goes for galaxies, on a bigger scale - they are much denser than the universe as a whole. So there's a HUGE difference between what goes on inside them and the large scale behavior of the universe, which is what the Friedmann equations are about. Very unlikely? Not enough? Yeah, right. Just admit you don't know what you're talking about.
So now we'll be able to change the old saw of "only criminals encrypt" to "only criminals don't encrypt". ;-)
Seriously, would such a law really stop them from encrypting? Duh...no! The fact that the authorities are fighting encryption so hard is advertizing that it must be a good way of not getting caught.
Since it came out in 2000, have modern browsers fixed the cache cookie problem? (Besides refusing cookies?)
Once the Sun 'falls' over that edge- you are no longer gravitationally bound to the Sun.
You missed the point. The Solar system isn't expanding. Galaxies are like the raisins in a baking loaf of raisin bread. As the bread rises the raisins move farther apart, but the raisins (and their contents) stay more or less the same size.
What you said about shrinking horizons in an accelerating universe is correct - as long as the universe on the horizon scale is well described by the Friedmann equations. But the Friedmann equations assume a homogeneous universe for mathematical convenience, so not all of their predictions apply everywhere in the real universe.
It does in trinary. Irrational numbers cannot be fully expressed as a "decimal" in any base.
More interestingly, I don't think you could make "effective pi" rational. Try drawing circles of different sizes on a grainy medium, like say, pixels on a screen.
Shame on New Scientist.
And now the above, with (a little) math. The gravitational force between two objects is basically (leaving out mass)
F = -k / r^2 + L * r
where k is a constant, r is the separation between the 2 objs, and L is either a constant or a function of time (we don't know yet).
The k term is good old Newtonian (or even Einsteinian up until a couple of years ago) gravity. Strong for small r, weak for low r.
The L term represents the new discovery that the universal expansion is accelerating. It is (unnoticeably) weak on small scales, and only important for large r (i.e. size of the visible universe). For the L term to matter on planetary scales, it would have to become much larger in the future. But we just discovered that it even exists - how it behaves with time is the next thing to find. So don't worry (yet ;-).
Sigh. pi is a mathematical constant, so it is what it is independently of physics. It just happens to be useful in physics.
Untrue. There are more ways for him to make money off the book than selling books. His day job is at the Electronic Freedom Foundation, an internet lobby group. Ascending to netdemigodhood is job security/promotion potential (possibly somewhere other than the EFF).
Besides, if it becomes the talked about book of the epoch, people will have to buy it so they can display it on their bookshelf without reading it.
Can anyone outline some algorithms that use 3 way entanglement?
But this is one (the only?) place where a dead tree magazine would be better, for piling up on their doorstep purposes.
You win your bet. Russell Hulse and Joe Taylor won in 19xx for their work on the slowing down of a binary pulsar. The slowdown matches the expected orbital energy loss for dissipation by gravity waves. But you knew that, didn't you?
I believe gravity waves also make their presence known in the large angle fluctuations of the cosmic microwave background.
Some people will argue that those effects could be caused by something else, but such a coincidence seems as least as large as a simultaneous* jiggle in two places. What excites me about gravitational wave telescopes is that they are just that...telescopes that use something other than light. Black holes and supernovae tend to be dense and opaque, so gravity waves should reveal things that light (or even neutrinos) cannot.
* with the appropriate semblance of simultaneity, of course.
If these clotting bandages work, great, but couldn't long term willy-nilly use cause too much clotting in a few people? Maybe that's why these aren't on the market.
Until pros get telescopes monitoring all of the sky all of the time at all wavelengths, yes. Most telescope fields of view are so small (depending on wavelength) that we miss a lot of transient phenomena. To some extent that's OK since astronomical timescales are notoriously long, but some things happen on faster timescales.
But this case is a bunch of nonastronomers using images taken by professional astronomers, who better understand the flaws in the images.
I wouldn't even dignify Euroseti as amateurs, since their selling SOHO images for 15 pounds REEKS of a scam. If you had found good evidence of ET, would you be trying to hawk it like that?
You actually don't want to stop them, but let them pass right through, since most radiation damage is caused by the secondary shower of stuff knocked off the target by the original particle.
I used to work in the radiation therapy part of a cancer clinic. One time I put a key down on top of the film beside the calibration wedge, (i.e. I was calibrating, not beaming anyone) and exposed it to gamma rays. Instead of the key making a shadow on the film, the film was mostly unexposed except where it had had metal on top to contribute electrons. So tinfoil hats might not be a good idea! Unless they're thick enough to soak up the secondary shower.
Of course it's hard to be sensitive to optical wavelengths and NOT pick up cosmic rays, so this is a common problem for telescope CCDs. Often the blips are removed by taking several exposures and averaging with 5 or 7 sigma outliers for each pixel rejected. SOHO probably doesn't do that, however, because they look at transient phenomena.
What is the definition by which they measure its height? The article doesn't say.
And you're not going to overload their server if it just sends static images/pages.
Maybe something like Razor? Or Distributed Checksum Clearinghouse?
Mostly, yes, but in Consider Phlebas I don't see how Vavatch (a small ringworld/large space station for those who haven't read it) could have had both arctic and tropical regions. Or at least arctic along the rims and tropical along the equator is not as obvious as he seemed to think. Is there heat loss from the rims? Maybe, but I think he just goofed.
Ah, it feels so geekly good to get that off my chest.