Slashdot Mirror
Einstein's Theory Passes Strict New Test
FiReaNGeL writes with an excerpt from a story at e! Science News: "Taking advantage of a unique cosmic configuration, astronomers have measured an effect predicted by Albert Einstein's theory of General Relativity in the extremely strong gravity of a pair of superdense neutron stars. Essentially, the famed physicist's 93-year-old theory passed yet another test. Scientists at McGill University used the National Science Foundation's Robert C. Byrd Green Bank Telescope (GBT) to do a four-year study of a double-star system unlike any other known in the Universe. The system is a pair of neutron stars, both of which are seen as pulsars that emit lighthouse-like beams of radio waves."
in summary:
1. GE says two objects can cause a wobble in each other's axes due to gravity
2. Measurement of this wobble wasn't possible earlier
3. With this star system, since they are massive and pulsate, and that they are aligned in a manner that makes a measurement possible, astronomers took the plunge
4. Prof...proved.
Consider, as examples, Newton's laws of motion, or the laws of thermodynamics. Newton's theory of motion is deduced from his laws; the conventional theory of thermodynamics, likewise.
I say this because there are plenty of non-scientists who deliberately attempt to exploit confusion induced by popular use of the terms "law" and "theory" so as to imply that scientific theories, notably the theory of evolution, are held tentatively.
Wikileaks, no DNS
Some time ago, I took a "History of Science" course. My memory is fuzzy around the dates, but originally, anything in science was granted the term "law". IIRC, "Caloric Theory" which was superseded by the theory of heat and thermodynamics was originally called a "law".
Around the 1700's, it was decided to call all new science a "Theory". In deference to previous conventions, the things still held over previously known as laws retained the name. Hence the apparent difference between the two terms.
Try to hack my 31337 firewall!
You do realize that is what they're doing, right? They're looking out into the Universe for ways to test the theory against real live data.
The world's burning. Moped Jesus spotted on I50. Details at 11.
Heres a couple of others:
Electrochemistry: http://alford.bios.uic.edu/teaching/Nernst.html
Fluid Dynamics: http://mse-092697c.princeton.edu/lecture1001/page3.htm
The word you are searching for is hypothesis.
There are 4 terms that need to be understood in the realm of science - hypothesis, theory, law & fact. They are all separate & distinct, except for the only progression that occurs - hypothesis => theory.
A fact is what has been carefully observed.
A law describes that observation.
A hypothesis is a proposal intended to explain that observation.
A theory seeks to explain that observation & has been confirmed by considerable evidence and has endured all attempts to disprove it.
example:
Fact
Objects fall at the same rate regardless of mass.
Law
http://www.glenbrook.k12.il.us/GBSSCI/PHYS/Class/circles/u6l3c1.gif
Hypothesis => Theory
Mass causes a curvature of spacetime which creates the effect of gravity.
Now THAT is a summary
Actually I recommend reading the article. It's short, understandable, and contains other cool facts about these neutron stars.
Also, as for that last "proved" bit, the article ends with:
"It's not quite right to say that we have now 'proven' General Relativity," Breton said. "However, so far, Einstein's theory has passed all the tests that have been conducted, including ours."
Lecture 1-1 of the Feynman Lectures in Physics that he gave as a two-year undergraduate course in physics at Caltech.
Not sure if you're talking about superluminal travel or subluminal travel.
Theory already allows slower than light travel. You're spaceship would have to be big. VERY big. But if we really wanted to we could probably send mankind to the nearest stars with current technology.
But superluminal travel is a different kettle of fish. There are only two possible universes, one where there's an upper limit in the speed of information and another where there is no upper limit. The two universes have very different characteristics and our universe appears to be the smaller. It's hard to think of a way where you can transmit matter without also allowing information transfer.
Of course, even today faster than light travel is possible by current theory - but only by points A and B separating faster than light, not by allowing points A and B to communicate faster than light. Effectively this means that the speed of light is only constant locally. Maybe it would be possible to reverse the expansion and shrink the universe so that although the speed of light would still be an upper limit, communication between A and B could occur in less time than light could make the journey in a flat universe.
But I'd wager that faster than light travel in the special relativity sense is, and always will be, impossible.
Tim.
God said, "div D = rho, div B = 0, curl E = -@B/@t, curl H = J + @D/@t," and there was light.
Ok, but to clarify for some readers, "particle" does not mean corpuscular like a tennis ball, which is why the term "particle" tends to be a little misleading. In fact, it is why any "it's like a " phrase tends to fail, and why it was such a shock to discover indeterminable states to begin with. Quantum theory rests on the (unsurprising) revelation that at small scales, things are not as we have always visualized in the large, solid man-world. I don't think anyone other than Bohr was comfortable at the time with *any* explanation of some of these phenomena, even with models that were so fucking accurate.
And light does travel in wave form. Pics from a slashdot story very short while ago:
http://technology.newscientist.com/article/dn14172-fastestever-flashgun-captures-image-of-light-wave.html?DCMP=ILC-hmts&nsref=news1_head_dn14172
But it is easier to think of the quantized light in terms of... quanta! New particles, now with many new features and a money back guarantee!
Happy Independence Day!