Reinforced = more massive = harder to launch (and a lot more expensive).
The closest Cassini will have gotten to the A and B rings is almost certainly during orbital insertion when it flew over the A ring. That was still too far away to see individual particles, though.
To be fair, the group had another press release (saying much the same thing, but with some new results) that triggered the Slashdot story. So it's not *exactly* a dupe.
he only problem I have with that at a larger scale (planetary/galactic) is that the planets don't collide with each other to maintain a flat orbit.
No, they don't. But they did form that way. Why? Because gas clouds collide even better than dense stars and planets. The stars or planets that form out of those clouds will then be in disks.
Proof that your theory doesn't work can be found all around the universe: there are non-disk galaxies everywhere. Clearly, their stars aren't be forced into coplanar orbits.
As I stated before, the known data in medieval times was that the world was flat.
That's not true in the first place. Even the Greeks knew that the Earth was round and Europeans never forgot it. The Greeks early on looked at the data and quickly saw that it pointed to a round planet. They even measured the radius.
Yes, there are times when thinking "outside the box" is great, but more often than not, it doesn't pan out. Just because people tell you you're wrong (just like Wegner, Darwin, and others), it doesn't mean you're *right*. Usually, it means you're wrong.
This will cause them to adjust their orbits to match. Well duh, right?
Actually, no. That isn't what happens, in spite of your intuition. The moon's response to the rings is largely to have a more rapid vertical motion than it would around just the planet. (This can be worked out for an embedded moon/planet in a disk using a Gaussian pillbox argument. It's a classic galactic dynamics question for undergrads, in fact.) There are more effects possible, depending on the relative masses and locations. For example, the moon can launch bending waves in the ring of material, which can then tug back on the moon. This can either pump up or damp down the moon's inclination. (Which isn't obvious and depends on a variety of parameters in the system.) The moon can also cause warps in the ring, but those tend to wind up pretty fast.
On the other hand, people *have* simulated rings. (Including myself, I might add.) You find that gravitational encounters between particles in the rings actually pump *up* the ring thickness. It's only with dissipative collisions that you get the ring to collapse down.
Your objections to the Cosmic Microwave Background are probably fodder for a different discussion, but it's difficult to see how that data shows evidence of a galactic collision, given the low energy involved (and the precise match to the predictions of the Big Bang). You should probably be worried that you're letting your desires for how the universe *should* be make you closed to what the data say it probably *is*. It's a very human response, but one that works contrary to good science.
There are two lines of evidence suggesting young rings. Against that, you're saying that the first reaction should be "we screwed up"? That's pure arrogance. You're elevating your opinions above the value of the data and that's the opposite of science.
The universe is full of surprising things that humans find counter-intuitive. If we always assumed that we screwed up when we found them, we'd still be believing that the Sun goes around the Earth and that God created us in six days.
(Also, as it is, no one has showed the the rings are old yet. All that's been shown here is that one of the two lines of evidence for young rings *could* be misleading.)
Gravity has little to do with the disk shape. Collisions drive the flatness. Collisions tend to average out speeds, so that eventually everyone moves in the same direction at almost the same speed. (In Saturn's rights, where speeds are tens of kilometers per second, relative collision speeds are at about a millimeter per second.)
"No effect" is a reasonable way of avoiding clutter when the effect is many orders of magnitude less important than the dominant players. I figured the people who knew the difference would be able to connect the dots.
No, they weren't. Previous theories were based on the spectra of the particles (stuff left in space gets 'weathered' with time due to meteoritic dust and high-energy particle/photon alterations) and to dynamical arguments. What this study has suggested is that the spectra are misleading because the material that's exposed now may not have always been on the surfaces.
Not likely, the ring particles have been bouncing off of each other for a long time. Saturn's rings are dynamically-speaking one of the oldest systems known (meaning each particle has made lots of orbits) and collisions occur on the scale of at *least* a few per orbit per particle in the B ring. (If clumping is occurring, it's even higher.) So the particles will probably have evolved from that alone. Plus, we don't know where the ring material came from. There's reason to think it was from an earlier moon which broke up, in which case a lot of the material may have been reprocessed in the moon's interior.
Over scales of tens or hundreds of meters, none of that mattes. The nearest known moons are in the outer edge of the A ring (Pan and Daphnis) and don't affect the B ring much (moons are too small). Jupiter has no effect at all being at least 4 AU away, generally more. The larger moons can muck things up, but the effects tend to be at resonances and are pretty localized.
What Larry Esposito and others are talking about is localized clumping, more like what's known in the A ring. Over a scale of a few hundred meters, you wouldn't necessarily expect suck clumping to occur.
Right, in many ways this is just want police do themselves (look for people acting "oddly" and then pay rather more attention to them).
But you have to get your false-positive rate *way* down to make it useful for that. If you have a 80% success rate and only one person in a hundred is planning to commit a crime, only about 5% of your flags will pay off. The problems you get into then is a) Cost of the system (obvious) b) Distraction (if you're directing the cops to the wrong people a lot, you might actually reduce their ability to spot real threats) c) Possible harassment of innocent people
The idea behind the technology isn't bad, but it needs a lot of work before I expect it can match even a reasonably adept person.
No, GP means "proton decay". Neutrons *do* decay, it's been observed. They don't do it in nuclei, though. Protons are *hypothesized* to decay, but no one has ever seen it. (And the timescale estimates keep getting revised upwards in response to the non-detections. Makes ya wonder, doesn't it?)
The density of water (or anything else) in the plumes is awfully low and Enceladus is pretty deep in Saturn's gravity. You'd probably be better off mining water ice on a comet nucleus in the outer solar system or at least on a distant moon of one of the giant planets. (Which are basically captured comets.)
If you're thinking of the upcoming flyby in October, I don't expect that much imaging will occur. That flyby is optimized for the fields and particles instruments. The next imaging flyby is on Halloween and is at 200 km altitude.
Images are definitely data. Analysis of these has already begun and it's already getting interesting. That said, the raws on the JPL site and the versions CICLOPS releases are never the full-quality, science-grade data. That's released to the Planetary Data System a nine-months to a year later, though.
Cassini is an international mission as well. Except that in this case, our international partners aren't backing out of their obligations and making us foot the bill.
I'm going to reply assuming that you're not flame-baiting me, in spite of the troll accusation.
I didn't suggest that "floodgates" implied a flat Earth. I really don't see how you got that impression from my post. However, the usage was *not* taken to be metaphorical in ancient times, since (I've been taught that) the ancient Hebrews had a literal view of the sky that had floodgates in it. Not so hard to believe if you also believe that the sky is a solid sphere, as was indeed the going belief until the Copernican revolution.
As for implications for a flat Earth, there are several places in the Old and New Testaments where objects which are tall enough to be seen on the entire Earth are mentioned. You can't do that on a spherical surface, so a literalist could easily take that as Biblical support for a flat Earth model. Google will show you the verses with a pretty simple and obvious search as well as others that are cited to support the claim.
As the BBC article points out, the Flat Earth movement began about 150 years ago in response to perceived loss of traction by religion due to growing power of science. So we might deduce (however tentatively) that they're at least partly pointing to the Bible for their support. As I recall, the Bible really does make statements that suggest a flat Earth (and floodgates in the sky and other patently incorrect things that even most Creationists ignore).
I actually meant the intrinsic PSF for the camera, which is somewhat complicated as it turns out. We've actually considered de-blurring before, but I don't think we had a lot of luck with it and it didn't seem worth it. I can recall trying to deconvolve Enceladus's bright limb with the PSF before and having that turn out awfully. For these, considering the speed, I think that de-blurring would be neigh impossible.
(It's also worth noting that we're aiming for science-class images here and not so just public releases. The standards for the former are higher than the latter, even small errors due to deconvolution are often unacceptable.)
Slashdot Mirror
Reinforced = more massive = harder to launch (and a lot more expensive).
The closest Cassini will have gotten to the A and B rings is almost certainly during orbital insertion when it flew over the A ring. That was still too far away to see individual particles, though.
To be fair, the group had another press release (saying much the same thing, but with some new results) that triggered the Slashdot story. So it's not *exactly* a dupe.
he only problem I have with that at a larger scale (planetary/galactic) is that the planets don't collide with each other to maintain a flat orbit.
No, they don't. But they did form that way. Why? Because gas clouds collide even better than dense stars and planets. The stars or planets that form out of those clouds will then be in disks.
Proof that your theory doesn't work can be found all around the universe: there are non-disk galaxies everywhere. Clearly, their stars aren't be forced into coplanar orbits.
As I stated before, the known data in medieval times was that the world was flat.
That's not true in the first place. Even the Greeks knew that the Earth was round and Europeans never forgot it. The Greeks early on looked at the data and quickly saw that it pointed to a round planet. They even measured the radius.
Yes, there are times when thinking "outside the box" is great, but more often than not, it doesn't pan out. Just because people tell you you're wrong (just like Wegner, Darwin, and others), it doesn't mean you're *right*. Usually, it means you're wrong.
This will cause them to adjust their orbits to match. Well duh, right?
Actually, no. That isn't what happens, in spite of your intuition. The moon's response to the rings is largely to have a more rapid vertical motion than it would around just the planet. (This can be worked out for an embedded moon/planet in a disk using a Gaussian pillbox argument. It's a classic galactic dynamics question for undergrads, in fact.) There are more effects possible, depending on the relative masses and locations. For example, the moon can launch bending waves in the ring of material, which can then tug back on the moon. This can either pump up or damp down the moon's inclination. (Which isn't obvious and depends on a variety of parameters in the system.) The moon can also cause warps in the ring, but those tend to wind up pretty fast.
On the other hand, people *have* simulated rings. (Including myself, I might add.) You find that gravitational encounters between particles in the rings actually pump *up* the ring thickness. It's only with dissipative collisions that you get the ring to collapse down.
Your objections to the Cosmic Microwave Background are probably fodder for a different discussion, but it's difficult to see how that data shows evidence of a galactic collision, given the low energy involved (and the precise match to the predictions of the Big Bang). You should probably be worried that you're letting your desires for how the universe *should* be make you closed to what the data say it probably *is*. It's a very human response, but one that works contrary to good science.
There are two lines of evidence suggesting young rings. Against that, you're saying that the first reaction should be "we screwed up"? That's pure arrogance. You're elevating your opinions above the value of the data and that's the opposite of science.
The universe is full of surprising things that humans find counter-intuitive. If we always assumed that we screwed up when we found them, we'd still be believing that the Sun goes around the Earth and that God created us in six days.
(Also, as it is, no one has showed the the rings are old yet. All that's been shown here is that one of the two lines of evidence for young rings *could* be misleading.)
Gravity has little to do with the disk shape. Collisions drive the flatness. Collisions tend to average out speeds, so that eventually everyone moves in the same direction at almost the same speed. (In Saturn's rights, where speeds are tens of kilometers per second, relative collision speeds are at about a millimeter per second.)
"No effect" is a reasonable way of avoiding clutter when the effect is many orders of magnitude less important than the dominant players. I figured the people who knew the difference would be able to connect the dots.
No, they weren't. Previous theories were based on the spectra of the particles (stuff left in space gets 'weathered' with time due to meteoritic dust and high-energy particle/photon alterations) and to dynamical arguments. What this study has suggested is that the spectra are misleading because the material that's exposed now may not have always been on the surfaces.
Or another way to look at it: the article is being honest and presenting evidence to the contrary. There are ways around Jeff's concerns, though.
Not likely, the ring particles have been bouncing off of each other for a long time. Saturn's rings are dynamically-speaking one of the oldest systems known (meaning each particle has made lots of orbits) and collisions occur on the scale of at *least* a few per orbit per particle in the B ring. (If clumping is occurring, it's even higher.) So the particles will probably have evolved from that alone. Plus, we don't know where the ring material came from. There's reason to think it was from an earlier moon which broke up, in which case a lot of the material may have been reprocessed in the moon's interior.
Over scales of tens or hundreds of meters, none of that mattes. The nearest known moons are in the outer edge of the A ring (Pan and Daphnis) and don't affect the B ring much (moons are too small). Jupiter has no effect at all being at least 4 AU away, generally more. The larger moons can muck things up, but the effects tend to be at resonances and are pretty localized.
What Larry Esposito and others are talking about is localized clumping, more like what's known in the A ring. Over a scale of a few hundred meters, you wouldn't necessarily expect suck clumping to occur.
Right, in many ways this is just want police do themselves (look for people acting "oddly" and then pay rather more attention to them).
But you have to get your false-positive rate *way* down to make it useful for that. If you have a 80% success rate and only one person in a hundred is planning to commit a crime, only about 5% of your flags will pay off. The problems you get into then is
a) Cost of the system (obvious)
b) Distraction (if you're directing the cops to the wrong people a lot, you might actually reduce their ability to spot real threats)
c) Possible harassment of innocent people
The idea behind the technology isn't bad, but it needs a lot of work before I expect it can match even a reasonably adept person.
No, GP means "proton decay". Neutrons *do* decay, it's been observed. They don't do it in nuclei, though. Protons are *hypothesized* to decay, but no one has ever seen it. (And the timescale estimates keep getting revised upwards in response to the non-detections. Makes ya wonder, doesn't it?)
The density of water (or anything else) in the plumes is awfully low and Enceladus is pretty deep in Saturn's gravity. You'd probably be better off mining water ice on a comet nucleus in the outer solar system or at least on a distant moon of one of the giant planets. (Which are basically captured comets.)
With apologies for pimping the hard work of my co-workers over NASA's copies of the release, the website that originally carried this is http://ciclops.org/view_event/89/Targeting_the_Jet_Sources.
With a spacecraft the size of a bus, that's very fast. Especially considering that it takes tens of minutes to turn between targets, typically.
Just because you know things that can spin in less than 10 seconds doesn't mean that that's a reasonable rotation rate for every object.
If you're thinking of the upcoming flyby in October, I don't expect that much imaging will occur. That flyby is optimized for the fields and particles instruments. The next imaging flyby is on Halloween and is at 200 km altitude.
http://xkcd.com/307/
(Which is itself practically becoming a meme, now.)
Images are definitely data. Analysis of these has already begun and it's already getting interesting. That said, the raws on the JPL site and the versions CICLOPS releases are never the full-quality, science-grade data. That's released to the Planetary Data System a nine-months to a year later, though.
There are none (or few, anyway) in the South Polar region of Enceladus. That's what makes it interesting, the terrain appears to be quite young.
Cassini is an international mission as well. Except that in this case, our international partners aren't backing out of their obligations and making us foot the bill.
That'll actually take a little while, but we're working on it. The shadows should help interpret the topography, but it's a non-trivial analysis.
I'm going to reply assuming that you're not flame-baiting me, in spite of the troll accusation.
I didn't suggest that "floodgates" implied a flat Earth. I really don't see how you got that impression from my post. However, the usage was *not* taken to be metaphorical in ancient times, since (I've been taught that) the ancient Hebrews had a literal view of the sky that had floodgates in it. Not so hard to believe if you also believe that the sky is a solid sphere, as was indeed the going belief until the Copernican revolution.
As for implications for a flat Earth, there are several places in the Old and New Testaments where objects which are tall enough to be seen on the entire Earth are mentioned. You can't do that on a spherical surface, so a literalist could easily take that as Biblical support for a flat Earth model. Google will show you the verses with a pretty simple and obvious search as well as others that are cited to support the claim.
As the BBC article points out, the Flat Earth movement began about 150 years ago in response to perceived loss of traction by religion due to growing power of science. So we might deduce (however tentatively) that they're at least partly pointing to the Bible for their support. As I recall, the Bible really does make statements that suggest a flat Earth (and floodgates in the sky and other patently incorrect things that even most Creationists ignore).
I actually meant the intrinsic PSF for the camera, which is somewhat complicated as it turns out. We've actually considered de-blurring before, but I don't think we had a lot of luck with it and it didn't seem worth it. I can recall trying to deconvolve Enceladus's bright limb with the PSF before and having that turn out awfully. For these, considering the speed, I think that de-blurring would be neigh impossible.
(It's also worth noting that we're aiming for science-class images here and not so just public releases. The standards for the former are higher than the latter, even small errors due to deconvolution are often unacceptable.)