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"Death Dance" Stars Found - May Help Prove Einstein Right

43 points by coderdude 15y ago

andrewcooke 15y ago
oh for goodness sake. journalists - do you have no better ideas than "prove einstein right"? einstein was right. his work was an improvement on what went before. we know this. it has been confirmed by many, many experiments and observations. and reported countless times with the same tedious headline. please, use something a little more original.
- Ronkdar 15y ago
  Einstein has advanced many ideas. Most have been demonstrated/observed, but not all. There is still considerable debate about gravity waves.
  - andrewcooke 15y ago
    you are misunderstanding how physics works. einstein didn't think up a bunch of different random ideas. he had a small number of very deep insights. various things follow from those insights - come out in the maths, if you like. gravity waves are just one way that his description of gravity can be confirmed. it's true that they are difficult to observe and so haven't been confirmed yet, but no-one expects them to not exist. at this point it would be hugely more interesting if they were not found than if they were.
- Almaviva 15y ago
  Yes, Einstein was right even about things he thought he was wrong about, e.g. the cosmological constant.
  - andrewcooke 15y ago
    again, there's a big difference between that, which was a simple constant of integration, and the consequences of a consistent theory. you are being exploited by journalists who are telling you attractive stories about "right" and "wrong" without giving any idea of their relative importance. einstein's work is now considered normal, boring, mainline physics. it's not controversial - in some areas it is being improved on (and i guess then we're going to see "einstein was wrong" which, again, does not reflect how science works),
- coderdude 15y ago
  You're clearly very passionate about this topic and I think that passion has blinded you a little as to just how important an article's title is. The actual article only says this: "But astronomers hope that, before the collision, the spinning stars will help scientists test Einstein's general theory of relativity and even reveal the origins of an entire class of supernovae." The title was undoubtedly written by some editor whose job is to drive traffic. Nothing to get so upset about. Most people are pretty ignorant about these sorts of things (myself included). That doesn't mean that I saw the title and was like "well finally they proved that mad man right."
- Roboprog 15y ago
  Well, of course we expect the gravity waves to be there, given the other effects of relativity that have been confirmed so far. However, scientists still observe, verify, measure. As one other poster mentioned, the equipment to detect gravity waves from afar has not yet been able to do the job (due to opportunity or sensitivity, don't know). If for some reason they do not find the waves (and the instruments are shown to be good), then there will be some more deep thinking to do: were we really looking at objects different than what we thought? Is there some theory more twisted than relativity that needs to be made to explain the previous results as a special case and also explaining the new results???
  - andrewcooke 15y ago
    sure. i have already said the same below. i am not criticising the physicists, or the person who originally posted the article, or denying how interesting it would be if waves were not found, or disparaging the technical difficulties involved. i am just tired of the same hackneyed phrase being used in every article related to general relativity. google has over 12 million hits for the phrase "einstein was right". the national geographic is a quality publication. it should know better.
- Florin_Andrei 15y ago
  Einstein's relativity is undoubtedly correct in its basic tenets. But there are some finer points which were or are still up for debate. Frame dragging is one example. There were several theories offering slightly different predictions in that field (that broke down to perfect identity for real-life situations), Einstein's GR being just one of them. So, in physics it's like this: trust, but verify.
- lotharbot 15y ago
  > einstein was right. his work was an improvement on what went before. Einstein is less wrong; his work has smaller error bars than what went before. It's "sufficiently right to allow advances to be made". See http://hermiene.net/essays-trans/relativity_of_wrong.html http://hermiene.net/essays-trans/relativity_of_wrong.html (by Isaac Asimov)
mrspeaker 15y ago
Android devs have known about this for ages. That's why there's already a field for it in the sensor manager SDK docs... http://developer.android.com/reference/android/hardware/SensorManager.html#GRAVITY_DEATH_STAR_I http://developer.android.com/reference/android/hardware/Sens...
flatline 15y ago
Does anyone know how they would go about observing the gravitational waves? Through lensing effects? Or are they just depending on the orbital decay to demonstrate something?
- jessriedel 15y ago
  I don't have any expertise in astrophysics (just physics), but I am pretty sure that white dwarfs aren't nearly strong enough to produce observable lensing. You need black holes or whole galaxies for that. Further, these stars are separated by less than the earth-moon distance, so they aren't individually resolvable. The fact that it is a binary system has been inferred from periodicities in it's brightness and spectrum. ("Astronomers measured the stars' relative motions by looking at the light signatures, or spectra, coming from the stars as they eclipse each other.") I think your guess is right that all the data about the gravitational waves will be taken from the orbital decay. This is actually a decent amount of data since the rate of decay isn't constant, and because the eclipse maneuver isn't a smooth process.
- CanSpice 15y ago
  They can (in theory) observe them using an observatory named LIGO, or Laser Interferometer Gravitational-Wave Observatory. It's essentially lasers set up to shoot along long corridors such that any changes in the distance between the ends can be measured. Gravitational waves will change this distance, so the laser interferometer should be able to measure gravitational waves. LIGO hasn't yet observed gravitational waves (it's currently being upgraded to "Advanced LIGO") but has set important upper limits on the strengths of gravitational waves. And importantly, it hasn't ruled them out.
jevinskie 15y ago
I'm unclear about how they are spiraling towards each other at 370 mi/s, just 1/3 the Earth-Moon distance apart, yet will take 900,000 years to merge. Can anyone clarify that?
- tmhedberg 15y ago
  They aren't moving directly toward each other at that rate; they are orbiting each other at that rate, and very gradually moving closer.
CanSpice 15y ago
I'm trying to figure out how these are different from the binary pulsar PSR B1913+16 (other than they're white dwarfs and the binary pulsar is two neutron stars). PSR B1913+16 is two neutron stars orbiting each other in a tight spiral, and their orbital decay corresponds with what Einstein's general relativity predicts. In fact, the discoverers of PSR B1913+16 (Hulse and Taylor) received the Nobel Prize in Physics in 1993 for showing that this was the case.

43 points by coderdude 15y ago

oh for goodness sake. journalists - do you have no better ideas than "prove einstein right"? einstein was right. his work was an improvement on what went before. we know this. it has been confirmed by many, many experiments and observations. and reported countless times with the same tedious headline. please, use something a little more original.

Ronkdar 15y ago
Einstein has advanced many ideas. Most have been demonstrated/observed, but not all. There is still considerable debate about gravity waves.
- andrewcooke 15y ago
  you are misunderstanding how physics works. einstein didn't think up a bunch of different random ideas. he had a small number of very deep insights. various things follow from those insights - come out in the maths, if you like. gravity waves are just one way that his description of gravity can be confirmed. it's true that they are difficult to observe and so haven't been confirmed yet, but no-one expects them to not exist. at this point it would be hugely more interesting if they were not found than if they were.
Almaviva 15y ago
Yes, Einstein was right even about things he thought he was wrong about, e.g. the cosmological constant.
- andrewcooke 15y ago
  again, there's a big difference between that, which was a simple constant of integration, and the consequences of a consistent theory. you are being exploited by journalists who are telling you attractive stories about "right" and "wrong" without giving any idea of their relative importance. einstein's work is now considered normal, boring, mainline physics. it's not controversial - in some areas it is being improved on (and i guess then we're going to see "einstein was wrong" which, again, does not reflect how science works),
coderdude 15y ago
You're clearly very passionate about this topic and I think that passion has blinded you a little as to just how important an article's title is. The actual article only says this: "But astronomers hope that, before the collision, the spinning stars will help scientists test Einstein's general theory of relativity and even reveal the origins of an entire class of supernovae." The title was undoubtedly written by some editor whose job is to drive traffic. Nothing to get so upset about. Most people are pretty ignorant about these sorts of things (myself included). That doesn't mean that I saw the title and was like "well finally they proved that mad man right."
Roboprog 15y ago
Well, of course we expect the gravity waves to be there, given the other effects of relativity that have been confirmed so far. However, scientists still observe, verify, measure. As one other poster mentioned, the equipment to detect gravity waves from afar has not yet been able to do the job (due to opportunity or sensitivity, don't know). If for some reason they do not find the waves (and the instruments are shown to be good), then there will be some more deep thinking to do: were we really looking at objects different than what we thought? Is there some theory more twisted than relativity that needs to be made to explain the previous results as a special case and also explaining the new results???
- andrewcooke 15y ago
  sure. i have already said the same below. i am not criticising the physicists, or the person who originally posted the article, or denying how interesting it would be if waves were not found, or disparaging the technical difficulties involved. i am just tired of the same hackneyed phrase being used in every article related to general relativity. google has over 12 million hits for the phrase "einstein was right". the national geographic is a quality publication. it should know better.
Florin_Andrei 15y ago
Einstein's relativity is undoubtedly correct in its basic tenets. But there are some finer points which were or are still up for debate. Frame dragging is one example. There were several theories offering slightly different predictions in that field (that broke down to perfect identity for real-life situations), Einstein's GR being just one of them. So, in physics it's like this: trust, but verify.
lotharbot 15y ago
> einstein was right. his work was an improvement on what went before. Einstein is less wrong; his work has smaller error bars than what went before. It's "sufficiently right to allow advances to be made". See http://hermiene.net/essays-trans/relativity_of_wrong.html http://hermiene.net/essays-trans/relativity_of_wrong.html (by Isaac Asimov)

mrspeaker 15y ago

Android devs have known about this for ages. That's why there's already a field for it in the sensor manager SDK docs... http://developer.android.com/reference/android/hardware/SensorManager.html#GRAVITY_DEATH_STAR_I http://developer.android.com/reference/android/hardware/Sens...

flatline 15y ago

Does anyone know how they would go about observing the gravitational waves? Through lensing effects? Or are they just depending on the orbital decay to demonstrate something?

jessriedel 15y ago
I don't have any expertise in astrophysics (just physics), but I am pretty sure that white dwarfs aren't nearly strong enough to produce observable lensing. You need black holes or whole galaxies for that. Further, these stars are separated by less than the earth-moon distance, so they aren't individually resolvable. The fact that it is a binary system has been inferred from periodicities in it's brightness and spectrum. ("Astronomers measured the stars' relative motions by looking at the light signatures, or spectra, coming from the stars as they eclipse each other.") I think your guess is right that all the data about the gravitational waves will be taken from the orbital decay. This is actually a decent amount of data since the rate of decay isn't constant, and because the eclipse maneuver isn't a smooth process.
CanSpice 15y ago
They can (in theory) observe them using an observatory named LIGO, or Laser Interferometer Gravitational-Wave Observatory. It's essentially lasers set up to shoot along long corridors such that any changes in the distance between the ends can be measured. Gravitational waves will change this distance, so the laser interferometer should be able to measure gravitational waves. LIGO hasn't yet observed gravitational waves (it's currently being upgraded to "Advanced LIGO") but has set important upper limits on the strengths of gravitational waves. And importantly, it hasn't ruled them out.

jevinskie 15y ago

I'm unclear about how they are spiraling towards each other at 370 mi/s, just 1/3 the Earth-Moon distance apart, yet will take 900,000 years to merge. Can anyone clarify that?

tmhedberg 15y ago
They aren't moving directly toward each other at that rate; they are orbiting each other at that rate, and very gradually moving closer.

CanSpice 15y ago

I'm trying to figure out how these are different from the binary pulsar PSR B1913+16 (other than they're white dwarfs and the binary pulsar is two neutron stars). PSR B1913+16 is two neutron stars orbiting each other in a tight spiral, and their orbital decay corresponds with what Einstein's general relativity predicts. In fact, the discoverers of PSR B1913+16 (Hulse and Taylor) received the Nobel Prize in Physics in 1993 for showing that this was the case.