Well, that wouldn't preserve the impact craters on the surface, I don't think. Also, it's difficult to imaging a lot of serious collapsing occurring after formation since formation is essentially a bunch of impacts to begin with.
Except that there's no sensible way to take Hyperion (which is just beyond the orbit of Titan) and swing it into the rings, the latter being much closer to the planet. Orbiting bodies don't just change their orbits. Moving them around takes a lot of torque. To move Hyperion back *out* to its present orbit and then to circularize the orbit would be extremely difficult and very, very unlikely. We can rule your second option out.
Crud, they put The Jetson's in front of Futurama. That cartoon is as much SciFi as The Flinstones is historical fiction. And it certainly NOT a better show (on any grounds: humor, sci-fi, story-telling, art, whatever) than Futurama.
If the computers are going down, why do they need the credit card information on my room key? If they can't read my credit card, how are they reading the key?
I agree that they key cards are for the hotel's convenience, but I'm not following why they need my credit card info on the key.
'It's an easy bet that cosmologists' notions of "dark matter" and "dark energy" adding up to over 99 times as much stuff as the visible universe are fantasies ginned up to rescue failed hypotheses. It's a matter of public record that astrophysicists, as a rule, have only rudimentary training in the dynamics of the plasma that they admit fills all of space, but insist on calling "ionized gas".'\
Sure it's an easy bet. That's because talk is cheap when you don't have to back it up. So here's my challenge: provide data to back up your claim. The cosmologists have provided ample data to support their arguments. (They've even convinced me, and I was dead-set against dark energy for quite a long time. But eventually the data was overwelming.)
As for our training in plasma physics, most astrophysicists have multiple graduate level courses in the topic before we write our theses. Since a lot of us collaborate with plasma physics folks from the physics community, I'd like to think that we would have been called on any nonsense we were spouting.
Incidentally, how are you accessing our student records in a way that you consider it "a matter of public record"? I'd consider that a violation of FERPA, myself.
So what's YOUR plasma physics background that makes you able to causually dismiss what my collegues have spend careers researching?
Actually, dust tends to fall in towards the planet over short timescales due to various forms of drag not felt by the larger particles. (Mostly associated with emission of thermal radiation or the magnetosphere.) Gas would tend to diffuse out the ring plane and probably escape or ionize and become part of the magnetosphere.
To answer the first question, yeah, we know that there isn't a lot of dust in there. Recent measurements from Cassini show that there just isn't a lot of small stuff around.
Most of the ice particles are pretty big, so while ionization of them through collisions could occur, it's not likely to affect them much. (It's like shuffling your feet on the carpet: you can give yourself a good shock, but you aren't going to stick to the walls due to the excess charge.) What you're really after is forming a plasma around the particles. That could happen through particle bombardment in the magnetosphere or through photo-ionization. We suspect the latter for various reasons. (And I'm not up on all of those, to be honest.)
As for who goes faster... it's actually depends on where in the rings you are. The synchronous orbit for Saturn is in the outer B ring, near the Cassini division. Inside of that distance the rings move faster, outside the spokes. (This is because the spokes are tied to the magnetic field, which rotates with the planet.)
Incidentally, surface density is useful for gravity issues in the rings, but for collisions the parameter of interest is the "optical depth". It's a measure of how likely you are to collide with something if you try to run through the rings in that spot. For the B ring, the value is around 0.5-2.5 which is astonishingly high. Collisions occur multiple times per orbit, typically.
There's nothing that we do that would lead to radial features. Especially across multiple images at consistent magnetic longitudes. Also, these have been seen by at least three or four cameras, now. So it's hard to imagine these being artifacts.
(In fact, the images on the space.com site might even be the raw images.)
That doesn't really cover the seasonal nature of the spokes. (Or should I say "the apparent seasonal nature"?) It's likely that sunlight is involved in that case. It probably comes in through photo-ionization, which generates the same sort of plasma.
The spokes do appear to be tied to the seasons on Saturn. (Which has a much longer year, of course.)
The field, however, is not. The field can't go away and come back that quickly and there's nothing that I can think of that would cause it to since it's generated in the interior of the planet where it's hard to come up with a way for a seasonal influence.
In a word, no. The spokes must be tied to the magnetic field of Saturn. This explains why the stay at the same magnetic longitude of the planet and why they don't wind up as the inner parts of the rings orbit the planet faster. So they're not disturbances in the ring particles themselves, since the ring particles are too massive to really feel the magnetic field.
However, if you levitated dust over the rings, that would do the trick. The problem is how to levitate the dust. It turns out that you can develop a negative potential on the rings (I think it's negative... I forget, to be honest) which can repel the dust and cause it to hover. So under the right conditions, if dust were kicked up by a small collision in ther rings (say a meteroid collision), it can float over the rings and spread radially, making a spoke.
The spokes aren't a disturbance in the ring material itself. They can't be: the maintain their radial orientation over time. The parts of the rings that are closer to Saturn orbit more rapidly and so the spokes would shear out if they were part of the rings proper.
In reality, they spokes hover over the rings, probably levitated electrostatically. They hold their orientation because they are tied to the magnetic field of Saturn.
No. Some of the rings are diffuse and dusty. The A and B rings of Saturn, however, are thick and filled with larger (figure meter-sized) particles. A typical photon doesn't make it through these rings without meeting a particle somewhere, so a meteroid would more likely than not hit something solid.
Ah, the like the case with the discovery of Neptune? It appeared that the Contiental and English teams essentially simultaneously discovered the planet... unless a couple of years ago when we learned that the British astronomers were blantantly lying to save face.
More importantly, unless I am mis-recalling the circumstances, Mike wasn't in *control* of the webserver in question. The records were opened up by the people in control of the telescope, not Mike Brown. It wasn't his fault.
Where are you getting the dark matter information? We know the galaxies were rotating too quickly long before COBE. (In fact, as far as I know, COBE didn't measure rotation speeds of galaxies. It surely wasn't the first, anyway.) Galactic rotation curves were plotted in the 70's by Vera Rubin and others. The evidence for dark matter goes back even farther to the 30's when Zwicky noted that glaxies in clusters were moving too quickly to remain bound to the clusters unless there was more mass there than we could see.
Damn straight. They didn't even organize the preferences/settings enough so that I can shut off all of the auto-formatting features and generally find the settings I need.
Even thinking about Word makes my blood pressure rise. Ug.
Wait... is Bill Gates suggesting that Microsoft doesn't want to tell us how to organize our information?
Has he *used* any of his products? Seriously. Every Microsoft product I can think of seems overly interested in constantly organizing my work for me, often without my permission or my desire for it.
The kind of radiation that leaks out of the Sun's interior is light. The UV gives us skin cancer, the visible lets us see. The Earth, being much cooler, emits very little UV so we're in no danger there.
The particle radiation from the Sun comes off due to the high heat at the surface. Again, with a cooler Earth, there is little radiation and little risk. Most of what is emitted deep in the Earth is absorbed and turned into heat long before we ever see it on the surface.
The only one of those that can generate heat (in this case, anyway) is tidal flexing. Friction converts kinetic energy to heat, but you have to supply the kinetic energy. Where do you get it from? From to heat in the Earth's interior trying to escape, causing the mantle to convect and driving plate tectonics.
Pressure does not produce heat. It in now way can supply energy. For gaseous bodies, a high inernal pressure suggests high temperature (to balance gravity with thermal pressure), but for the solid Earth this isn't required.
Finally, tidal flexing is not a very significant player for Earth. The Moon moves too slowly and simply isn't large enough to generate that much heat in the Earth. The Sun's tidal forces are every smaller, although the total power should be higher in that case. (The frequency of the forcing is one day rather than 28 days.)
It really does come down to radioactive isotopes producing heat.
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Well, that wouldn't preserve the impact craters on the surface, I don't think. Also, it's difficult to imaging a lot of serious collapsing occurring after formation since formation is essentially a bunch of impacts to begin with.
Except that there's no sensible way to take Hyperion (which is just beyond the orbit of Titan) and swing it into the rings, the latter being much closer to the planet. Orbiting bodies don't just change their orbits. Moving them around takes a lot of torque. To move Hyperion back *out* to its present orbit and then to circularize the orbit would be extremely difficult and very, very unlikely. We can rule your second option out.
Crud, they put The Jetson's in front of Futurama. That cartoon is as much SciFi as The Flinstones is historical fiction. And it certainly NOT a better show (on any grounds: humor, sci-fi, story-telling, art, whatever) than Futurama.
I usually write someone else's room number on my check, but to each his own...
Perhaps. But usually they just put the charge onto your hotel bill rather than charge the meal separately.
If the computers are going down, why do they need the credit card information on my room key? If they can't read my credit card, how are they reading the key?
I agree that they key cards are for the hotel's convenience, but I'm not following why they need my credit card info on the key.
'It's an easy bet that cosmologists' notions of "dark matter" and "dark energy" adding up to over 99 times as much stuff as the visible universe are fantasies ginned up to rescue failed hypotheses. It's a matter of public record that astrophysicists, as a rule, have only rudimentary training in the dynamics of the plasma that they admit fills all of space, but insist on calling "ionized gas".'\
Sure it's an easy bet. That's because talk is cheap when you don't have to back it up. So here's my challenge: provide data to back up your claim. The cosmologists have provided ample data to support their arguments. (They've even convinced me, and I was dead-set against dark energy for quite a long time. But eventually the data was overwelming.)
As for our training in plasma physics, most astrophysicists have multiple graduate level courses in the topic before we write our theses. Since a lot of us collaborate with plasma physics folks from the physics community, I'd like to think that we would have been called on any nonsense we were spouting.
Incidentally, how are you accessing our student records in a way that you consider it "a matter of public record"? I'd consider that a violation of FERPA, myself.
So what's YOUR plasma physics background that makes you able to causually dismiss what my collegues have spend careers researching?
"So do these spokes appear on both sides of the rings? A second probe would help with comparing angles."
Yes, they appear on both the night and day sides.
Actually, dust tends to fall in towards the planet over short timescales due to various forms of drag not felt by the larger particles. (Mostly associated with emission of thermal radiation or the magnetosphere.) Gas would tend to diffuse out the ring plane and probably escape or ionize and become part of the magnetosphere.
To answer the first question, yeah, we know that there isn't a lot of dust in there. Recent measurements from Cassini show that there just isn't a lot of small stuff around.
Most of the ice particles are pretty big, so while ionization of them through collisions could occur, it's not likely to affect them much. (It's like shuffling your feet on the carpet: you can give yourself a good shock, but you aren't going to stick to the walls due to the excess charge.) What you're really after is forming a plasma around the particles. That could happen through particle bombardment in the magnetosphere or through photo-ionization. We suspect the latter for various reasons. (And I'm not up on all of those, to be honest.)
As for who goes faster... it's actually depends on where in the rings you are. The synchronous orbit for Saturn is in the outer B ring, near the Cassini division. Inside of that distance the rings move faster, outside the spokes. (This is because the spokes are tied to the magnetic field, which rotates with the planet.)
Incidentally, surface density is useful for gravity issues in the rings, but for collisions the parameter of interest is the "optical depth". It's a measure of how likely you are to collide with something if you try to run through the rings in that spot. For the B ring, the value is around 0.5-2.5 which is astonishingly high. Collisions occur multiple times per orbit, typically.
There's nothing that we do that would lead to radial features. Especially across multiple images at consistent magnetic longitudes. Also, these have been seen by at least three or four cameras, now. So it's hard to imagine these being artifacts.
(In fact, the images on the space.com site might even be the raw images.)
That doesn't really cover the seasonal nature of the spokes. (Or should I say "the apparent seasonal nature"?) It's likely that sunlight is involved in that case. It probably comes in through photo-ionization, which generates the same sort of plasma.
Glad to help.
The spokes do appear to be tied to the seasons on Saturn. (Which has a much longer year, of course.)
The field, however, is not. The field can't go away and come back that quickly and there's nothing that I can think of that would cause it to since it's generated in the interior of the planet where it's hard to come up with a way for a seasonal influence.
In a word, no.
The spokes must be tied to the magnetic field of Saturn. This explains why the stay at the same magnetic longitude of the planet and why they don't wind up as the inner parts of the rings orbit the planet faster. So they're not disturbances in the ring particles themselves, since the ring particles are too massive to really feel the magnetic field.
However, if you levitated dust over the rings, that would do the trick. The problem is how to levitate the dust. It turns out that you can develop a negative potential on the rings (I think it's negative... I forget, to be honest) which can repel the dust and cause it to hover. So under the right conditions, if dust were kicked up by a small collision in ther rings (say a meteroid collision), it can float over the rings and spread radially, making a spoke.
Or so we think...
The spokes aren't a disturbance in the ring material itself. They can't be: the maintain their radial orientation over time. The parts of the rings that are closer to Saturn orbit more rapidly and so the spokes would shear out if they were part of the rings proper.
In reality, they spokes hover over the rings, probably levitated electrostatically. They hold their orientation because they are tied to the magnetic field of Saturn.
No.
Some of the rings are diffuse and dusty.
The A and B rings of Saturn, however, are thick and filled with larger (figure meter-sized) particles. A typical photon doesn't make it through these rings without meeting a particle somewhere, so a meteroid would more likely than not hit something solid.
Acutally, small impacts are believed to be involved. But how do you levitate the dust that they kick up over the ring plane?
Ah, the like the case with the discovery of Neptune? It appeared that the Contiental and English teams essentially simultaneously discovered the planet... unless a couple of years ago when we learned that the British astronomers were blantantly lying to save face.
More importantly, unless I am mis-recalling the circumstances, Mike wasn't in *control* of the webserver in question. The records were opened up by the people in control of the telescope, not Mike Brown. It wasn't his fault.
Where are you getting the dark matter information? We know the galaxies were rotating too quickly long before COBE. (In fact, as far as I know, COBE didn't measure rotation speeds of galaxies. It surely wasn't the first, anyway.) Galactic rotation curves were plotted in the 70's by Vera Rubin and others. The evidence for dark matter goes back even farther to the 30's when Zwicky noted that glaxies in clusters were moving too quickly to remain bound to the clusters unless there was more mass there than we could see.
Damn straight. They didn't even organize the preferences/settings enough so that I can shut off all of the auto-formatting features and generally find the settings I need.
Even thinking about Word makes my blood pressure rise. Ug.
Wait... is Bill Gates suggesting that Microsoft doesn't want to tell us how to organize our information?
Has he *used* any of his products? Seriously. Every Microsoft product I can think of seems overly interested in constantly organizing my work for me, often without my permission or my desire for it.
You're confusing kinds of radiation.
The kind of radiation that leaks out of the Sun's interior is light. The UV gives us skin cancer, the visible lets us see. The Earth, being much cooler, emits very little UV so we're in no danger there.
The particle radiation from the Sun comes off due to the high heat at the surface. Again, with a cooler Earth, there is little radiation and little risk. Most of what is emitted deep in the Earth is absorbed and turned into heat long before we ever see it on the surface.
The only one of those that can generate heat (in this case, anyway) is tidal flexing. Friction converts kinetic energy to heat, but you have to supply the kinetic energy. Where do you get it from? From to heat in the Earth's interior trying to escape, causing the mantle to convect and driving plate tectonics.
Pressure does not produce heat. It in now way can supply energy. For gaseous bodies, a high inernal pressure suggests high temperature (to balance gravity with thermal pressure), but for the solid Earth this isn't required.
Finally, tidal flexing is not a very significant player for Earth. The Moon moves too slowly and simply isn't large enough to generate that much heat in the Earth. The Sun's tidal forces are every smaller, although the total power should be higher in that case. (The frequency of the forcing is one day rather than 28 days.)
It really does come down to radioactive isotopes producing heat.