Slashdot Mirror
Stellar Trio Could Put Einstein's Theory of Gravity To the Test
sciencehabit writes "In a cosmic coup, astronomers have found a celestial beacon known as a pulsar in orbit with not one, but two other stars. The first-of-its-kind trio could soon be used to put Einstein's theory of gravity, or general relativity, to an unprecedented test. 'It's a wonderful laboratory that nature has given us,' says Paulo Freire, a radio astronomer at the Max Planck Institute for Radio Astronomy in Bonn, Germany, who was not involved in the work. 'It's almost made to order.'"
Isn't that the point of a Beta release? To obtain feedback and to fix what isn't right with something?
Harrison's Postulate - "For every action there is an equal and opposite criticism"
n-body calculations are hard enough with Newtonian physics. The "Einsteinian physics" calculations must be a bit maddening, but at least they have found a star system to test it out.
Priest: "Universe from nothing, no laws of physics, sped up time"+ huge discrepancies. Creationism? No. Big Bang Theory
The summary is light on any details, so here:
The distinctive new system opens the way for testing a concept behind general relativity known as the equivalence principle, which relates two different conceptions of mass. An object's inertial mass quantifies how it resists pushing or pulling: It's easier to start a stroller rolling than a car because the stroller has less inertial mass. A thing's gravitational mass determines how much a gravitational field pulls on it: A barbell is heavier than a feather because it has more gravitational mass.
The simplest version of the equivalence principle says inertial mass and gravitational mass are equal. It explains why ordinary objects like baseballs and bricks fall to Earth at the same rate regardless of their mass—as legend claims Galileo showed by dropping heavier and lighter balls from the Leaning Tower of Pisa.
The strong equivalence principle takes things an important step further. According to Einstein's famous equation, E = mc2, energy equals mass. So an object or system's mass can be generated by the energy in the gravitational fields within the system itself. The strong equivalence principle states that even if one includes mass generated through such "self-gravitation," gravitational and inertial mass are still equal. ...
By tracking the system's evolution, Ransom and colleagues should be able to tell whether either the inner white dwarf or the pulsar falls faster toward the outer white dwarf and test strong equivalence about 100 times as precisely as before, Damour says.
"Gravitational Field"... space-time curvature "field"? Uhm, "gravitational mass" vs "inertial mass" equivalence... "explains why" o_O? Shh! The astrophysicists are over. Don't mention the Higgs!
In all seriousness, we know damn well Einstein's equations are simply better approximations / explanations than Newton's approximations are -- It's only a matter of time before we prove them "wrong" (but still damn good and useful approximations, like Newton's) -- We just need some elusive experimental evidence to prove it, and this could be it due to the large gravitational coefficients and a steady measurement scale provided in the pulsar. That is, unless Einstein's approximation turns out to be more accurate than our observations of this system. It shouldn't be any more of a "revolution", as TFA states, if the observations prove to be in violation of the equations: We should be trying to find better equations anyway thanks to that whole Standard Model thing, and we are. Physics seems to goes through these periods where a bunch of new theories explain various things to a precision, the precision is surpassed in observations, and then someone like Newton, Einstein, Feynman, Hawking, etc. comes along and presents elegant / unifying equations to explain the disparate pieces better. Looks like we're still in the middle of the very important prove old-theories "wrong" (read: inaccurate, conflicting with some observations) and scratch our head over tests for new hypotheses to fit more accurate measurements stage.
In a cosmic coup, astronomers have found a celestial beacon
Mmm...cosmic soup with bacon!
Some problems shouldn't make it past the design phase, let alone through alpha and into beta.
Not a sentence!
Your heart is true, you're a pal and a cosmonaut.
God dammit I keep seeing this posted here over and over with the same error every time. Every time!
It's "you're a GAL" you dipshits!
True. That should never have made it to the beta stage.
More importantly, a beta should be to get feedback, and aside from writing comments in articles that have nothing to do with it, I see no obvious feedback forum.
Ok, help my layman ass out here. IIRC, according to Einstein, acceleration and gravity aren't just similar phenomena, but are the exact same phenomena, and, since you are always travelling at c through the combined spacetime continuum, which gravity warps, the gravitational pull is you actually accelerating through this warped spacetime.
That seems way too freaking cool to fail at some umpteenth decimal.
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
... since you are always travelling at c ...
Light travels at c in a vacuum and anything with mass does not. Be wary of anyone who tells you otherwise.
(I'm a physicist)
on top left of the main site there's a link to http://www.surveymonkey.com/s/sdredesign
Sneak teach kids Algebra using a game
The only difference between physics and religion though is the fact that the 'temple' built to it is there to test to see if predictions made by the standard model are in fact correct, or if the theory needs revision. You will not see anything along those lines in a religion.
What the heck do exchange address lists have to do with anything?
I'm sorry, I cant tell if your a targeted spambot or serious.
You have 5 Moderator Points!
Which Helpless Linux zealot/MS basher do you want to mod down today?
much more modern looking, it works fine for me. I can reply to stuff, understand the threading and generally it works just great.
Whose to say it wasn't? Maybe some advanced civilisation built it to test just this principal. Maybe we are simply looking over the shoulder of someone else's work. How do they correctly reference that in the eventual paper? :-)
Bob.
The only difference between physics and religion...
There is nothing whatever that physics and religion have in common. Physics is the study of the physical universe, religion is not about the physical universe at all.
Free Martian Whores!
Einstein's French science.
I come here for the love
Since De Pretto and Preston and Poincare and Newton all were ether advocates, isn't it about time we try some ether theories once again?
I come here for the love
Hello Sava,
I completely agree with you about the ether, and in fact I just posted such a comment before I read your comment.
I look forward to reading more about your theory and humbly offer my own for your consideration.
Best,
Floyd
I come here for the love
The article suggests that E=MC^2 does not solely mean antimatter and matter collide and tada you get energy or that a hadron collide can convert energy into matter. They claim that mass that is moving contains energy and thus generates more mass/gravity. I certainly don't remember learning THAT in school. I know if you're heavy and moving fast, more time will occur throughout the mass but they didn't say gravity would increase. Then they refer to "self gravitation" as in the object pulling in on itself as in the expected gravitational field of anything with mass larger than a singularity, which IS inline with normal physics. Can anyone verify that they're actually correct on that other point or is it as nonsensical as it sounds?
"Made to order?" Hmm, so the creationists are right after all. There is a creator and he clearly likes science...
Could have been worse I guess.
Stefan Axelsson
It's the Electric Universe folderal again, I think. Better than arguing with the people who believe in 'morphic fields', but not much.
"Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
He's probably insisting on a more direct form of observation, even though he actually knows this is impossible. (Well, perhaps not, if the new lens design that allows one to see things fractions of a wave length long can be built at the right wave length. I've got my doubts...and even then the wavelength would be too short to see directly.)
OTOH, I'm also not very pleases with the quality of the evidence that we need to deal with, and would like something a lot less indirect. But right now that's the best we can do. So we are only "statistically certain" that certain observations mean what we think they mean. The statistics are conseervative enough that we can place a great deal of reliance on them, but...
Yet again, even direct physical observation of things of the appropriate size and opacity can't really be trusted, as was proved by experiments where a guy was stabbed with a banana, or a guy wandered through a basket ball game wearing a gorilla suit. (The cameras saw him, but very few of the observers did. They were too busy counting baskets.)
So I understand people being dissatisfied by "statistical certainty", but really, it can be better than eye-witness observation...at least unless that "eye-witness observation" is backed up by a camera.
I think we've pushed this "anyone can grow up to be president" thing too far.
Sorry, but though the claim was made General Relativity didn't predict the correct deviation of Mercury's orbit. The key turned out to be the flattening of the sun at the poles. (I think once that was taken into account, General Relativity gave a better answer than Newton, but the Newtonian answer was good enough that it wouldn't have been noticed originally.)
I think we've pushed this "anyone can grow up to be president" thing too far.
IIRC though (this is several decades ago) you only get the simplified form by dropping higher order terms. There was a good reason to do so (IIRC they were *extremely* small in value), but it does mean that it's an approximation. However, since even the deviation of Einsteinian theory from Newtonian is difficult to detect, I expect that the corrected version would differ from the Einsteinian version to such a slight degree that it would still be impossible to detect. And (again, IIRC) there was an infinite series of such terms, each (nearly) infinitesimally small when compared to the prior term. So you couldn't find the exact value no matter what you did. And the length of the calcularions would more than double for each term you added.
I think we've pushed this "anyone can grow up to be president" thing too far.
Thanks. As I said, it's been a LONG time since I did this.
I think we've pushed this "anyone can grow up to be president" thing too far.