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'Einstein Probe' Delayed
isorox writes "The BBC is reporting that a NASA satellite designed to test frame dragging, predicted by the theory of relativity, has been delayed for 24 hours because mission control couldn't verify the correct software had been loaded. The probe was proposed 35 years ago, but has never had the funding until now. The question remains is what happens if Frame Dragging isn't observed - will the experiment be wrong (in other words there's no point to it), or will we get faster-than-light ships for Christmas?"
you dumbass .. that's like saying Newton was wasting his time coming up with his theories .. I mean who knew there'd be any practical applications of figuring out the laws of physics?
They had built the pyramids and horse & buggy just fine without Newton.
The question remains is what happens if Frame Dragging isn't observed
You can listen to John Turneaure, co principle investigator for Gravity Probe B. He was interviewed by Ira Flatow on NPR's Science Friday.
When Ira Flatow asked him what would happen if the probe did not find anything and that Einstein might be wrong, he "hemmed and hawwed" a lot and said that wouldn't be the case - that Einstein was right. He also mentioned that the data would go to a physicist and then be released to the public.
It's not that I'm wearing a tin-foil hat (well maybe), but science is based on conducting experiments in the open and openly sharing data with an unbiased view and procedure, even if it means that Einstein might be wrong.
If they really wanted to do this neat, they would stream the data live to a website, rather than can up the data until they are ready to release it.
There are critics of Einstein that are academically serious and not off their rocker like some zero point/tesla fanatics. There have been critics of Einstein ever since he released his theories. You don't hear much about them as they are all heaped into one group and astrocized.
I am not saying that Einstein was wrong (not in the sense that Newton was wrong either), but that true science is keeping an open mind, rather than cower to the politically favorable theory of the moment.
As an aside, frame dragging is like when you take a single electric mixer and use it in a bowl of pudding. Or when you use an electric stirrer in a can of paint. That is frame dragging.
This happens because gravity is a field (according to Einstein). Newton treated gravity like a force.
Physicists reading may improve upon this anology.
Take the cheese to sickbay, the doctor should see it as soon as possible - B'Elanna Torres, "Learning Curve"
Building a ship to go faster than the *speed* of light is (relatively, ha ha) easy. Building a ship to *pass* light is difficult. No matter how fast you chase after that light (even if you cross the universe in seconds!), it will always remain 300,000 km/sec faster than you are! And if you do manage to reach light speed (good luck) you'll be just as frozen in time as photons are. In other words, you'll get to travel the universe, but you'll never know that you did it.
Of couse, the only way we know we're travelling "faster than the speed of light" is that we can measure the time between our point of origin and our point of destination. Time dilation makes sure that we're never able to pass light. If there was nothing else in the universe but your ship and light, you'd have no way of knowing that you were moving! How annoying is that?
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If this test showed that frame dragging did not exist, we would be have to figure out a new way of making those two consistant, and (on the surface at least) one (unlikely) possibility would be that some things can travel faster than light.
Why do you humans always misquote Einstein. General relativity states that nothing can *accelerate* to the speed of light. It says nothing about things already going the speed of light. Experiments in Photon / Quantium Tunneling have indicated that photons can apear to tunnel through barriers faster then light.
Why do you humans always misquote Einstein.
:-)
Because schools nail silly ideas into people heads, and Einsteins book "Relativity: An Explaination That Anyone Can Understand" wasn't so easy to understand?
General relativity states that nothing can *accelerate* to the speed of light.
Err... I thought that was Special Relativity. General Relativity deals with the way that gravity works. i.e. Gravity is acceleration. Therefore, matter and energy must curve space-time to make a "downward" slope.
That being said, you have the "halfway" problem of accelerating to light speed. As you accelerate, time dilation increases. As time dilation increases, your engines are less effective to an external observer. Therefore it becomes a lot like drawing a line halfway to the destination, then drawing another line halfway of the remainder, ad infinitum. You'll never reach the end. And because your mass increases, you could only use a rocket (converts your near infinite mass -> energy) to make the transition. An external force like a particle accelerator doesn't have enough energy (infinite) to push you to light speed.
It says nothing about things already going the speed of light.
Correct. When a collegue of Einstein's suggested that it was impossible for an object with mass to reach light speed, Einstein felt compelled to point out that a photon has mass and it travels at light speed.
Experiments in Photon / Quantium Tunneling have indicated that photons can apear to tunnel through barriers faster then light.
That really has more to do with Quantum Mechanics than relativity. Overall, the photon is incapable of exceeding light speed. However, it can temporarily "steal" a bit of energy from nearby particles to tunnel out of existance and into existance elsewhere. The amount stolen is then payed back, resulting in a zero sum gain in velocity.
There are many things in this universe that appear to defy light speed. Unfortunately, not one of them is capable of transmitting useful information faster than light. Considering that this holds true at all levels of physics, one would almost conclude that the universe is out to "get" us.
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Not really. The main motivation for the general theory was simply that Newtonian gravity (or more specifically, the Newtonian gravitational potential) failed to make predictions which agreed with observation. The most well-known example of this is the precession of perihelion of Mercury. If you're referring to the fact that Newtonian gravity imposes no upper bound on velocities, then you're correct, but this was more an illustration of the fact that Newtonian gravity was largely irreconcilable with special relativity.
Nope. I am afraid that the parent was correct and that you may have misunderstood him.
Einstein's motivation for GR (General Relativity) was that SR (Special Relativity) is inconsistant with NG (Newtonian Gravity). NG does indeed predict faster than light effects. If you wiggle a particle on one side of the galaxy, then a particle on the other side would feel that immediately.
This is a theoretical motivation, and not a physical motivation. Once you have SR, you immediately have to fiddle with gravity. He would have had to do this even if we had no conflicting evidence against NG.
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Gravitons are only theoretical. At this point it looks like they don't exist.
Actually, according to String Theory, they're very real.
ST's use of them is really interesting - there's always been kind of a mystery as to why gravity is so weak compared to the other forces. ST says that the strong/weak forces and electromagnetism have carrier particles whose strings are anchored to our brane in the bulk*. It goes on to say that gravitons' strings are free-floating, so they are not bound to our brane. This would mean that when a source of gravity was present, much of it was leaking out of our brane, leaving behind the relatively weak force we feel instead.
Apparently something that is being looked forward to with the Large Hadron Collider is that they might be able to see evidence of a graviton escaping from our brane.
* For those who aren't familiar with these concepts, ST includes the idea that our 3+1 dimensional universe (3 spatial, plus time) is only one "slice" of an extradimensional body called "the bulk." The "slice" is referred to as a "brane." If String Theory is right, there are other branes millimetres away from us, but in a higher spatial dimension. The only theoretical way to communicate between them is with a graviton-generating device.
Incidentally, Alastair Reynolds makes use of this concept in his latest novel, Absolution Gap. There are some quotes from his books in my journal if anyone is interested.
"...always new atoms but always doing the same dance, remembering what the dance was yesterday." -Richard Feynman