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Double Pulsar Discovered
jabberjaw writes "Nature is reporting that a set of two pulsars could be emitting gravitational waves. Einstein predicted the existence of gravitational waves in his general theory of relativity, but a gravitational wave has yet to be detected. Find out more about gravitational waves and pulsars at Eric Weisstein's World of Physics."
John Goodman's ass has been emitting gravity waves for years.
- I am made of meat.
Does someone know if these waves travel at the speed of light? Of course, as predicted by the theory.
:)
I suppose so... otherwise we could eventually devise faster-than-light communications, and I don't think the Universe is that nice
I wonder how many times these two neutron stars could bounce if they were to hit the water at an angle of 20 degrees.
I would be very suprised if they could actually "prove" the existance of such waves. Gravity is such a weak force compared to the other three (strong, weak, and electromagnetic) that pulsars light-years upon light-years away would be washed out by the gravitational effects of, well, the rest of the universe! There's been conjecture about this for years, and entire theories to try and resolve this problem of no detection (several string theories have been developed around this problem) We've even built miles long observation "tools" (like this one in Livingston, LA). However, if we can solve the background noise radiation, and the pulsars are close enough to earth, and have a large enough gravity, they just might do it! Einstein's theory of general relativity states that two orbiting stars (two orbiting anythings, but stars have a lot of mass and therefore gravity, so it would be pronounced) will 'shed' some of their momentum through gravity waves. The detection of these waves could revolutionize physics! It would allow us to determine the existance of the graviton, and if we ever did that, the world as we know it would change. Because once we pin it down, we can start converting energy to it, and probably start research on a feasible "anti-graviton" of sorts. Warp Drives, here we come! (well, not likely, but a guy can hope)
Just on an intuitive level, at least. Gravity is a lot like electro-magnetism, in that it produces it's effects invisibly. That, to me at least, implies some method of energy transfer. Waves seem a reasonable enough explanation. I wonder though, if the same wave/particle duality will be observed as we see in photons. Cool stuff.
Gravitational waves have always been notoriously difficult to detect (infact near nigh impossible) because of their weak nature. This looks like a good opportunity to do that.
How fast is gravity?
If the sun went poof, how long would it take for Earth to go off into space? 8 minutes or as soon as it happened?
Article
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I think you might be confused: Moore's Law applies to the speed of computers, not their size.
True story.
Actually, Moore's Law originally refered to the number of transistors that could be packed onto an integrated circuit - it didn't directly refer to speed or size at all.
"Prefiero morir de pie que vivir siempre arrodillado!"
As an aside, with a system this unique, and not to sound too much like a loon, but perhaps we should look for an ET presence. Not as the creators, but there maybe unique physical process than can be exploited in such a system, and doing so may give off a detectable technological signature.
Letter To Iran
I remember one time I was trippin and threw a ball into the air and it never came down... could this have caused the ball to hover over my head for 20 minutes? This probably wouldn't explain how the ball was laughing at me though....
Well, the ball floated because you missed the Earth, basically the same effect as stated in The Hitchhiker's Trilogy. Your drug induced state probably allowed you to throw the ball at specific yet unrepeatable while sober trajectory. As far as the ball laughing at you, it was obviously a Happy Fun Ball.
Deltron 3030 - Virus (music video)
Here's a cool kid's site that has some animations
It's for the LISA (Laser Interferometer Space Antenna). Space.com did a story on it a little while back, and it was in a Scientific American, but I'm not sure which, I have too many lying around. Unfortunantly, it doesn't launch until 2009.
Your ex-wife is John Goodman?
I've always belived that our concept of gravity is wrong. I think the reason our universe is expanding is not because of "dark energy", but because space is trying to displace a minority substance called matter.
Imagine if you will that the earth is a bubble in water. The more dense a planet is (or the higher the air pressure is in a bubble), the more effort it takes for space to want to displace that matter. But, what if we could control the "pressure". In other words, what if we could spoof a matter in the form of energy in front of a space craft? Rather then the ship propelling itself through space, you could instead have space push the craft much like the difference in water pressure wants to push an air bubble to the surface.
Life is not for the lazy.
BUT, assume the Sun winked out while it was night for you.
You wouldn't feel a thing.
No massive, "Oh, MY GOD we're lurching into space!" That's the whole point of space curved by gravity, you can't tell that you're not traveling a straight line. The weather would goto hell in a handbasket fast from no incoming heat after a few minutes or hours, and of course dawn wouldn't come. There might be some tectonic activity, some isolated magnitude seven and eights here and there, but most likely not immediately.
No you wouldn't even notice at first as the night hung on forever, and Earth continued on a straight line into the blackness...
Letter To Iran
No, the graviton can very well have an anti-graviton and a photon an anti-photon. The argument against it would be that both things don't have a charge...well neutrinos don't have charges either, but they have anti-particles. If particle A has a charge of 0, then Anti-A has a charge of 0 as well. However, the graviton is special...it produces 'gravity waves'. Photons and gravitons are more dissimilar though, gravitons cause gravity waves. If an anti-graviton were to exist, and we could convert photons to gravitons/anti-gravitons (though with some energy loss) you could cancel out the effects of gravity..hence warp travel. Gravitons in the back, anti-gravitons in the front, and then you have faster than light travel. That would be a great big leap in technology, don'cha think? NASA thinks it might exist (along with negative energy)
Anybody know why Jocelyn Bell received no credit for actually discovering pulsars, yet her thesis advisor, who actually seemed to do nothing, did?
It seems that Hewish and Ryle got the Nobel for their role in radio astronomy, not pulsars.
If the system is emitting gravity waves then it's losing energy by doing so, and the orbit will gradually decay.
s es//astro201/psr1913.htm and read about 3/4 of the way down.
You can measure the orbit precisely when there's a pulsar in the system, which is a good timing source. Then you can check whether the orbit's decaying at the rate predicted by the math of gravity wave radiation.
That measurement's been done for another binary system. See http://astrosun2.astro.cornell.edu/academics/cour
Observation agrees with Einstein in this case.
Article 1, Article 2.
Some scientists that have inspected the calculations believe the experiment is flawed and that they instead measured the speed of light itself (ie: they probably measured the speed of the light they were using to make their observations with, not the speed of the Jupiter distortion).
Correct answer: The speed of gravity is not (yet) a scientifically proved and universally accepted fact. Saying anything else is bad science.
The Standard Model of particles says there's no graviton, that's who! :)
:] )since we've never actually observed one and there are hints that the Standard Model may break soon (though it must be noted that it is the most sucessful theory at describing our universe ever devised). Then who knows what the superseding theory (supersymmetry? strings?) will say about quanta of gravity.
You said:
"No, the graviton can very well have an anti-graviton and a photon an anti-photon. The argument against it would be that both things don't have a charge...well neutrinos don't have charges either, but they have anti-particles."
You're misunderstanding why Photons Gluons and presumably Gravitons, if they exist, do not have anti-photons, anti-gravitons etc. and are actually THEIR OWN ANTIPARTICLES. It is not because they have no charge, that's irrelevant, it's because they are Bosons which are particles with integer spin. The chargeless Neutrino and anti-Neutrino are Fermions which have non-integer spin. I would suggest a look at CERN's The Particle Adventure site if you want to learn a bit more about subatomic particles, it's a great site.
However, this being said, there is a very tiny chance you may still be partially right about gravitons (though it's not your fault
Disclaimer: IANAP but I do know a thing or two about physics (if there is a physicist here and I've made a mistake in my post please feel free to correct me, though I'm fairly certain the contents are accurate).
- "Hear that?! The percolations are imminent! Cease your ingress!"
The news has been welcomed by gravitational wave hunters, since it boosts their hopes for detecting the gravitational waves [...] General relativity predicts that the two stars will slowly wobble like spinning tops allowing new tests of the theory.
Alternative theories to general relativity usually also predict such effects, including gravitational waves. So, these results, even if confirmed, don't actually tell you a whole lot. What they do tell you is that Newtonian mechanics isn't quite right, but, then, we already knew that.
In the university press release:
The stars will coalesce in only approximately 85 million years, sending a ripple of gravity waves across the Universe
So...wait, 85 million years from when? Now? Or is it 85 million years from what we currently observe, which is probably several million years in the past (neither link provides the distance of the pulsars from earth)?
In other words, will we observe the coalescing in 85 million years, or 85 million + time of transit?
Sheesh, it never occurred to me how dicey verb tense is in astronomy...Talking about the future of distant objects that exist in the past which we are observing presently.. Reminds me of Dr. Streetmentioner's Time Traveler's Handbook of 1001 Tense Formations from Restaurant at the End of the Universe.
Wrong. Hulse and Taylor's discovery was of a pulsar and companion neutron star. The companion was not a pulsar. This is the first known double pulsar system. One of the discoverers is a couple of doors down the corridor from me, so I can confirm this as true.
What is the inverse of the Matrix?
Animations of the evolution and current state of the pulsar system are available.
What is the inverse of the Matrix?
- The first is to photograph the upper atmosphere with an incredibly sensitive camera during night time, the reason is that gravity waves (that have a period of a few hours) cause the upper atmosphere to strech and compress causing the atoms that cause air glow to seporate into layers. this shows up on the image as bands. these gravity waves are emitted from the center of the earth.
- the second is to use an incredibly precise receiver tuned to a reliable transmitter in the HF bands, to a frequency that gets reflected by the ionosphere. since gravity waves will cause the ionosphere to expand and contract the change in velocity will cause the HF signal to be doppler shifted, meaning the gravity wave will be shown up in a slight variation of the incomming frequency.
the second option can be done by ham radio operators (if they really know there stuff), the first option is for universities since only they have the budget to buy the expensive equipment.simon
I've got to thinking about this more tonight. I think this idea holds more water then I thought. Let me further explain. Because matter is the minority substance in space, it will be space that is trying to displace matter. Hence forth, gravity is a push and not a pull. But, what happens when you have two solid objects floating in space? Eventually, they will move toward each other because now the amount of space between the two objects is superseded by the increase in combined proportional mass relative to the two objects (however, the space on other side of both objects is now the majority). So the closer two objects in space are, an exponential increase in attraction (rather, being pushed together) will occur.
But, what if the space between these two objects supersedes the over all proportional mass relative to each other? If this model is correct, they will now be pushed AWAY from each other. Maybe, this is why galaxies are moving farther away from each other. You see, the space between galaxies far supersedes the proportion of displacement of space due to the mass of the galaxies in relation to each other.
I really don't have any better way to word this. I'm sure this is a very confusing to read at first, so you might have to read it a few time.
Life is not for the lazy.
They will never discover Gravity Waves because Gravity is not a force. It is an illusion of geometry caused by mass moving in space. It's kind of like an optical illusion - it looks like gravity exists, but it really doesn't. It's just how objects move through space/time.
Next?
HW
the glass isn't half full or empty - it's just too big.
Shoes for Industry. Shoes for the Dead.
When physicists speak of unifying the fundamental forces of nature, they (we) don't mean that nuclear physics is the same thing as electromagnetism, really, or that gravity waves are the same as light waves. It's more like saying that all of the fundamental forces we know of are facets of one "superforce", or that the various physical laws we've learned all make sense as consequences of a set of simpler, over-arching laws. Physicists would say that at very high energies, the differences between the various forces melt away and the overall "superforce" behavior can be seen. It's a little like the old story about blind men - we've spent our time understanding the seemingly unrelated behaviors of parts (trunks, tails, ears, and feet), and then begin to realize that we should really be studying the behavior of a previously unknown whole (an elephant). This doesn't mean we've explained the trunk in terms of the ears, but both as small facets of the whole.