Astronomers use a hodge-podge of units in different systems. Cgs units are common, but for the really fun things we tend to use units like solar masses, parsecs, magnitudes, and foes (although that one never really caught on).
Yes, crooks will steal identities, and personal information, just like they do today. The reality is that the internet is a public place just like a street, or a town square, or a public park. Whatever you do there is potentially visible to (and recordable by) anyone. There are ways to make this hard to do, but they are not going to stop someone who has a bit of determination and a bit of technical knowledge.
That is not correct. Radiation fields have temperature. The cosmic background radiation has a blackbody temperature of about 2.7 kelvin. This is the effective temperature of the vacuum of space.
A vacuum has the temperature of the cosmic background radiation, which is about 2.7 kelvin, unless if you insulate your chamber by putting it in a Faraday cage.
The various refurbishment missions have done a lot more than just correct for the flaw in the primary mirror. Most of the instruments have been replaced with newer instruments over Hubble's lifespan. In many ways Hubble is almost a completely different observatory from what was launched.
The big difference between ground-based telescopes using active optics or adaptive optics to obtain diffraction-limited images, and the Hubble taking advantage of the lack of an atmosphere to obtain diffraction-limited images is that Hubble can do this over a large field of view whereas ground-based telescopes can only do this for extremely small fields. This is because the coherence length of the turbulence cells in the atmosphere that are responsible for atmospheric blurring (called seeing) are very small, and the active optics (or adaptive optics) can only correct over areas that are about the same size as the coherence length. So, ground-based telescopes are not going to be replacing space-based telescopes for research that requires fields of view larger than about 10 arcsecond square.
Nonsense. Single author papers are common in science. The number of authors has absolutely nothing to do with the quality of the paper. Ditto for publishing on arXiv. ArXiv has become the de facto standard venue for publishing preprints. The Gupta result may be rubbish, but the fact that he published without co-authors, and put the preprint on arXiv has nothing to do with the quality of the paper.
The story is very sensationalist. All that happened is that the X-ray photons reached the detector faster than they could be recorded. Once the rate of photons slowed down the detector was fine again. This is a fairly normal occurrence for X-ray detectors. Roughly half of all of the gamma-ray bursts that Swift detects have X-ray emission higher than the XRT's coincidence limit.
It is not unusual for gamma-ray bursts to have X-ray afterglows, but no optical afterglows. About 95% of gamma-ray bursts have X-ray afterglows, but only about 60% have optical or infrared afterglows. The reason is that if there is a clump of dust between us and the gamma-ray burst the X-rays will go through, but the optical light will be scattered and never reach us.
Requiring real names is a great idea. There is a reason that newspapers have generally confirmed the identities of people who write letters to the editor before publishing those letters. The same should be done for on-line comments. The 99 cent fee, however, seems silly.
No. Glaciation epsiodes have been happening fairly regularly for the past two million years or so. Before that the planet appears to have been free of ice ages for a few hundred million years.
The preprint has been peer reviewed and has been accepted for publication in Monthly Notices of the Royal Astronomical Society, one of the most prestigious astrophysics journals on this planet.
Slashdot Mirror
Astronomers use a hodge-podge of units in different systems. Cgs units are common, but for the really fun things we tend to use units like solar masses, parsecs, magnitudes, and foes (although that one never really caught on).
Oops. Posted to remove a bad moderation.
I suspect that this proof may just be some misdirection from The Laundry.
I , for one, welcome our new robotic vuvuzela-playing overlords.
Yes, crooks will steal identities, and personal information, just like they do today. The reality is that the internet is a public place just like a street, or a town square, or a public park. Whatever you do there is potentially visible to (and recordable by) anyone. There are ways to make this hard to do, but they are not going to stop someone who has a bit of determination and a bit of technical knowledge.
He is right. I do not like it, but he is right.
That may not be a good idea. Read The Mechanical Sky by Donald Moffitt.
Kinetic energy is not the only way to define temperature. Temperature is one of the defining quantities of a radiation field.
That is not correct. Radiation fields have temperature. The cosmic background radiation has a blackbody temperature of about 2.7 kelvin. This is the effective temperature of the vacuum of space.
A vacuum has the temperature of the cosmic background radiation, which is about 2.7 kelvin, unless if you insulate your chamber by putting it in a Faraday cage.
The various refurbishment missions have done a lot more than just correct for the flaw in the primary mirror. Most of the instruments have been replaced with newer instruments over Hubble's lifespan. In many ways Hubble is almost a completely different observatory from what was launched.
The big difference between ground-based telescopes using active optics or adaptive optics to obtain diffraction-limited images, and the Hubble taking advantage of the lack of an atmosphere to obtain diffraction-limited images is that Hubble can do this over a large field of view whereas ground-based telescopes can only do this for extremely small fields. This is because the coherence length of the turbulence cells in the atmosphere that are responsible for atmospheric blurring (called seeing) are very small, and the active optics (or adaptive optics) can only correct over areas that are about the same size as the coherence length. So, ground-based telescopes are not going to be replacing space-based telescopes for research that requires fields of view larger than about 10 arcsecond square.
You need to quote the entire thing, not just the "information wants to be free" part. "Information wants to be free" does not mean anything by itself.
Nonsense. Single author papers are common in science. The number of authors has absolutely nothing to do with the quality of the paper. Ditto for publishing on arXiv. ArXiv has become the de facto standard venue for publishing preprints. The Gupta result may be rubbish, but the fact that he published without co-authors, and put the preprint on arXiv has nothing to do with the quality of the paper.
On the other hand, Apollo 13 blew the pants off the previous 12 Apollo movies.
Posting to undo a bad moderation.
> No matter how clever the engineering, there's no cheating the law
> of physics.
The laws of physics to not apply to Apple.
The distribution is not spherical. Gamma-ray burst are thought to be beamed into jets with opening angles of about 1-10 degrees.
The story is very sensationalist. All that happened is that the X-ray photons reached the detector faster than they could be recorded. Once the rate of photons slowed down the detector was fine again. This is a fairly normal occurrence for X-ray detectors. Roughly half of all of the gamma-ray bursts that Swift detects have X-ray emission higher than the XRT's coincidence limit.
It is not unusual for gamma-ray bursts to have X-ray afterglows, but no optical afterglows. About 95% of gamma-ray bursts have X-ray afterglows, but only about 60% have optical or infrared afterglows. The reason is that if there is a clump of dust between us and the gamma-ray burst the X-rays will go through, but the optical light will be scattered and never reach us.
I have been using Mr Squid on line for a long time -- since the mid-90s. Perhaps I should sue Spongebob.
No, but if slashdot ever initiates such a rule I will legally change it.
Requiring real names is a great idea. There is a reason that newspapers have generally confirmed the identities of people who write letters to the editor before publishing those letters. The same should be done for on-line comments. The 99 cent fee, however, seems silly.
No. Glaciation epsiodes have been happening fairly regularly for the past two million years or so. Before that the planet appears to have been free of ice ages for a few hundred million years.
The preprint has been peer reviewed and has been accepted for publication in Monthly Notices of the Royal Astronomical Society, one of the most prestigious astrophysics journals on this planet.