(it seems that gasoline station owners here in Massachusetts got a different memo, though)
Despite the fact that the outcome is similar, there's a legal difference between "surcharge for credit" and "discount for cash". The former is/was illegal, the latter is legal. Presumably gas stations in MA and elsewhere are doing the latter.
Well, in some cases, astronomy is an order of magnitude science. As this collections of objects doesn't seem to have any gravitational lensing associated with it, there is no way to independently determine the mass of the system. A rough guess at the mass can be determined by assuming a mass to light radio since we know how bright it is (and presumably how far). That would lead to the mass estimates.
Although, it's necessary to point out that there's literally only a handful of people who believe redshifts are intrinsic to a source, and not due to expansion.
So the intrinsic redshift argument could very likely end up in the same bin as thinking andromeda was a nebula inside our galaxy.
Quantum Mechanics is the most thoroughly tested and successful theory of the universe. While yes, it doesn't extend to large scales (or mesh with gravity all that well), it is the most successful theory.
While General Relativity is generally considered to be a very accurate theory, there have been papers proposing that higher order terms are necessary to accurately describe the universe we live in. I believe this partially results from a simplifying assumption made in the derivation of the Einstein Field Equations (via one of the methods) where you ignore higher order terms to simplify the derivations. AFAIK, there is not physical basis for ignoring these terms, other than they contribute in smallish ways and make the derivation more complicated.
The Sun is a pretty small star compared to others...
Right, but the 1000 times the mass would be a huge star. The most massive stars known today are on the order of 100 times the mass of our sun. So these might be stars that are ~10x larger than the largest currently observed stars.
Actually, that is possible. I was at the SKA meeting this past Friday and listened to the talk by the SETI people. They would be able to do their thing during normal science operations by the SKA.
Well, I'm not saying it couldn't be overcome, but I doubt it'd be as efficient as with a free-floating telescope. The beauty of a separate telescope is that it can orient itself in any direction. Attached to a space station, it can't point through the station, and I imagine it couldn't point other directions as well. It would generally be limited to a hemisphere, mabye a larger solid angle, but not the full range with a separate instrument.
Well, one thing I can think of is vibrations. Attaching a telescope to ISS would likely hurt the resolution of the telescope. Also, ISS might not be in the preferred orbit for a space telescople. Finally, having the telescope attached to ISS would likely limit the ability to point the telescope in any direction.
I imagine there are other issues with it, but that's all I can think of off the top of my head.
Another reply pointed out that galaxies behind us are moving away as well. This can be looked at another way though. In order for this effect to happen on the largest scales of the universe, all galaxies must be gravitationally interacting. However, the distances involved are often too great to make such interactions significant. On smaller scales, such as clusters of galaxies, these gravitational interactions are significant, so it is concievable that something similar to what's in the article could occur.
Actually, I don't believe you need a massive body at the center of the cluster to cause this to happen. Dynamical friction (due to the gravitational interactions between the stars) could have this effect, with small stars slingshotting off large stars, causing the large stars to loose energy.
If for the cost of a servicing mission you can set up a ground observatory that can meet or exceed the hubble's capabilies and cost less to maintain, it makes no sense to keep the hubble operational.
If that were true... But it's not. Hubble has it's area where it is much better than any ground based telescope. The other reply to your post makes this point as well.
Having the ability to use a telescope that's above the atmosphere is a great advantage. It doesn't matter how big your telescope mirror is if it's cloudy where you are. I've spent time at a telescope facility during the local monsoon season.. 3 nights of wasted time. The ability to take pictures above the atmosphere is a great feature. Not only does it avoid weather issues, but you can also attain higher resolutions because you're not looking though air.
Slashdot Mirror
And to add, this is why people often refer to Ia's as "Standardizable Candles". :)
(it seems that gasoline station owners here in Massachusetts got a different memo, though)
Despite the fact that the outcome is similar, there's a legal difference between "surcharge for credit" and "discount for cash". The former is/was illegal, the latter is legal. Presumably gas stations in MA and elsewhere are doing the latter.
Well, in some cases, astronomy is an order of magnitude science. As this collections of objects doesn't seem to have any gravitational lensing associated with it, there is no way to independently determine the mass of the system. A rough guess at the mass can be determined by assuming a mass to light radio since we know how bright it is (and presumably how far). That would lead to the mass estimates.
solved a 400-year-old mystery
have confused moon-gazers since the time of ancient scientists
I'm not sure I'd consider 400 "ancient".
Although, it's necessary to point out that there's literally only a handful of people who believe redshifts are intrinsic to a source, and not due to expansion.
So the intrinsic redshift argument could very likely end up in the same bin as thinking andromeda was a nebula inside our galaxy.
Does it come with an inflatable Astronaut for entertainment on those long cold nights?
And the diapers and pepper spray to go attack its imaginary lover?
There is a downside however... it's not peer reviewed.
Although you can use the journals for that...
They're more interested in the power to do stuff they can't right now.
They should get the Sudoku books with the easier puzzles!
Quantum Mechanics is the most thoroughly tested and successful theory of the universe. While yes, it doesn't extend to large scales (or mesh with gravity all that well), it is the most successful theory.
While General Relativity is generally considered to be a very accurate theory, there have been papers proposing that higher order terms are necessary to accurately describe the universe we live in. I believe this partially results from a simplifying assumption made in the derivation of the Einstein Field Equations (via one of the methods) where you ignore higher order terms to simplify the derivations. AFAIK, there is not physical basis for ignoring these terms, other than they contribute in smallish ways and make the derivation more complicated.
Why? You only need 1.21 gigawatts.
:p
Wow, slashdot is kinda slow on the uptake. I read about this a few days ago.
Why is this under "science" ?
The Sun is a pretty small star compared to others...
Right, but the 1000 times the mass would be a huge star. The most massive stars known today are on the order of 100 times the mass of our sun. So these might be stars that are ~10x larger than the largest currently observed stars.
Mr President! We must not allow there to be a mineshaft gap!
I prefer squats with my grey matter.
'what happens if I put my lunch in front of a 300 megaelectronvolt beam?'
Nothing you can see, because that's ~ 4e-11 J.
Then we can have a poll of the top five, to let the readers decide which one is the top story of 2006.
Why don't we just pick the top 5, and they can dupe them to get the top "10"?
Actually, that is possible. I was at the SKA meeting this past Friday and listened to the talk by the SETI people. They would be able to do their thing during normal science operations by the SKA.
They must...
kill -9 saddam
Well, I'm not saying it couldn't be overcome, but I doubt it'd be as efficient as with a free-floating telescope. The beauty of a separate telescope is that it can orient itself in any direction. Attached to a space station, it can't point through the station, and I imagine it couldn't point other directions as well. It would generally be limited to a hemisphere, mabye a larger solid angle, but not the full range with a separate instrument.
Well, one thing I can think of is vibrations. Attaching a telescope to ISS would likely hurt the resolution of the telescope. Also, ISS might not be in the preferred orbit for a space telescople. Finally, having the telescope attached to ISS would likely limit the ability to point the telescope in any direction.
I imagine there are other issues with it, but that's all I can think of off the top of my head.
I'm not sure this should come as much of a surprise, given that this has been predicted by dynamical theorey.
It's nice that it's been observed though.
Another reply pointed out that galaxies behind us are moving away as well. This can be looked at another way though. In order for this effect to happen on the largest scales of the universe, all galaxies must be gravitationally interacting. However, the distances involved are often too great to make such interactions significant. On smaller scales, such as clusters of galaxies, these gravitational interactions are significant, so it is concievable that something similar to what's in the article could occur.
Actually, I don't believe you need a massive body at the center of the cluster to cause this to happen. Dynamical friction (due to the gravitational interactions between the stars) could have this effect, with small stars slingshotting off large stars, causing the large stars to loose energy.
If for the cost of a servicing mission you can set up a ground observatory that can meet or exceed the hubble's capabilies and cost less to maintain, it makes no sense to keep the hubble operational.
If that were true... But it's not. Hubble has it's area where it is much better than any ground based telescope. The other reply to your post makes this point as well.
Having the ability to use a telescope that's above the atmosphere is a great advantage. It doesn't matter how big your telescope mirror is if it's cloudy where you are. I've spent time at a telescope facility during the local monsoon season.. 3 nights of wasted time. The ability to take pictures above the atmosphere is a great feature. Not only does it avoid weather issues, but you can also attain higher resolutions because you're not looking though air.