There is something called quantum entanglement, which is the key ingredient behind the work of this year's Nobel winners. By about the year 2000, though, the field had been completely changed by experimental progress. This is because many rather simple facts about quantum mechanics couldn't be proven until the 1980s through experiments. But the research into quantum mechanics is more active now than it was a hundred years ago. Quantum mechanics, in its pristine theoretical framework, has been around for more than a century. So much so that three physicists - John Clauser, Alain Aspect, and Anton Zeilinger - have won this year's Nobel Prize for Physics for seeking to answer it. Yet that question is being asked, answered, re-asked, re-answered even now. This is allowed because it is not a local speed.Once, Albert Einstein famously bemoaned to a friend, "Do you really believe the moon is not there when you are not looking at it?" This is, of course, deeply contrary to our everyday experiences. As another example, there are some distant stars in the universe that are moving away from each other at a speed faster than light. If a different beam of light was sent from earth to the North Star and did go through the worm hole with you, there is no way you could outrun it. This is allowed because you never locally exceeded the speed of light. In other words, you would have reached the North Star first. Compared to a bit of light that traveled from earth to the North Star and did not go through the wormhole, you would have been traveling faster. For instance, if wormholes exist, you could use one to take a shortcut from earth to the North Star. A more accurate statement of the principle would be, "nothing can locally travel faster than light." This means that we can indeed acquire effective speeds faster than light if we use non-local scales. The restriction that nothing can travel faster than light is not as limiting as it seems. However, there is so much evidence now supporting relativity that, if it is wrong, it will have to be wrong in a small way that does not change these basic principles. You might say that maybe Einstein's theories of relativity are wrong. In fact, the phrase "faster than light" is physically meaningless. Because the concept of "speed" requires measuring a certain amount of distance traveled in space during a certain period of time, the concept of speed does not even physically exist beyond the speed of light. Therefore, this tells us that nothing can ever go faster than the speed of light, for the simple reason that space and time do not actually exist beyond this point. A reference frame with zero width and with no progression in time is really a reference frame that does not exist. If you look at the equations which are at the core of Einstein's theories of relativity, you find that as you approach the speed of light, your spatial dimension in the forward direction shrinks down to nothing and your clock slows to a stop. Instead, space and time can warp and bend. In other words, space and time are not a fixed background on which everything takes place in the same way it always does. It is difficult to visualize this if you have never heard about it before, but scientists have found that the faster you go, the more your spatial dimension in the forward direction shrinks and the slower your clock runs when viewed by an external observer. The universal speed limit, which we commonly call the speed of light, is fundamental to the way the universe works.
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