“Imagination is more important than Knowledge.” Albert Einstein.
Have you ever wondered what the General Theory of Relativity is? In this blog, I'm going to put all this prolixity in my own words. Essentially, it is a theory about gravity. For a long time (and thanks to Newton), people thought of gravity as a force. We toss up a ball, it reaches an apex, and then it seems like some force pulls it back down to us. A force made the apple hit Newton on the head. A force keeps us on the ground so we don’t float out into space.
Think of the orbit of the moon around the world, or any moon, or any orbit for that matter. Suppose you tied a 5-foot rope to a ball and then set the ball down beside you: there the ball would sit, with the rope dangling from your hand, and yet (remember) connected to the ball. Suppose further that you pick the ball up using the rope and start to rotate faster and faster. The ball would begin to ‘orbit’ around you. In this analogy, gravity is the rope. Newton would say: the earth’s gravity is greater than the moon’s, and that’s why the moon orbits the earth - in the spirit of Jimmy Stewart in It's a Wonderful Life, the Earth through a lasso around the moon!
Or, do you remember the ride at the Roller-Coaster Theme Park that spun around at a high speed? We would press our backs up against a mat around the perimeter of the ride, and as the the ride would spin faster and faster we would feel more and more pressure up against the wall. Newton would also like this analogy. That’s why everything on Earth stays on the ground: the Earth is spinning very fast. Airplanes actually ride gravity like a surfer catches a wave: they don’t actually defy gravity, but use it, harness it, to become airborne.
Enter Albert Einstein. Einstein changed everything. For instance, up until Newton, everyone thought of Space and Time as two distinct realities. Space was understood using the metaphor of a spatial container (Newton) or particular points on a graph (Leibniz). Time was understood using the metaphor of already existing dominos, and time’s ‘flow‘ was understood using the metaphor of the point during which the domino falls and hits the one in front of it.
But not Einstein. According to him, there aren’t anymore two distinct realities: Space and Time - there is just one: space/time. And space/time should be understood using the metaphor of a fabric, with space and time interwoven together. Think of a trampoline. If you stand in the center, there’s a big hollow there. Now, think of our solar system. The sun is in the center of a huge, space/time fabric that is like the fabric of a trampoline, making a huge hollow. The reason why the planets revolve around the sun is because they’re making revolutions along the space/time fabric ‘because of’ the hollow.
Every single object - ants, trees, you, me, cell phones, Obama, mites, spiders - make tiny hollows or dents in the fabric of space/time! Everything stays on the Earth because the Earth makes the biggest dent in space/time compared to anything else on Earth, and the dent is big enough to do this.
Lets go little further in understanding something else. If the metaphor of a fabric is accurate (and it probably is - it’s had a near perfect history of predictive value), something else is possible: wormholes. If Einstein’s theory is right, there are dents in this fabric everywhere; but what if a part of the fabric at one end ‘folds over’ and meets the ‘underside’ of another part of the same fabric? And what if at that point of mutual contact, we could travel - instantaneously - to another part of space/time literally billions of light years away? There would be paradoxes, and I’ll get into those in more depth later. But quickly: the moment you arrived there - according to the theory - everyone you knew would have been dead for a while. And yet: if you went back through a second later, you would have aged a second, and perhaps everyone else would have aged 50 years. So, what to you took a second, took for them 50 years. But this gets into the Special Theory of Relativity, which is a little harder to understand, but I’ll get to it in the next blog!
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Recent research by physicists at Indiana University are now challenging certain aspects of Einstein’s Theory of Relativity, both special and general .
ReplyDeletePhysicists are actually finding irregularities in an important aspect of Einstein’s theory termed Lorentz’s Covariance that was actually discovered by a scientist named Hendrik Lorentz. Lorentz’s Covariance makes up a key aspect of what is termed “spacetime”, which specifies that space and time are a part of the same continuum. From what I understand, and someone can feel free to correct me if I am wrong, new research is suggesting that space and time do not always flow the same. For example, let’s use the common example of Newton’s apples. If one were to sit under an apple tree, much like Newton is said to have done, one would notice that every apple does not fall the same. This is do to the conditions surrounding the fall. For example, some apples may be shaken from the tree or become to heavy and fall from the tree. Either way, the apples will not fall the same because there are different conditions surrounding their fall. Both apples fell from the tree, but their reason for falling is different.
Much like Newton’s Law of Universal Gravitation was replaced by Einstein’s Theory of Relativity, it now looks as if certain aspects of this theory may be replaced as well. I guess that’s science!
http://news.softpedia.com/news/Einstein-039-s-Space-Time-Continuum-Theory-Challenged-101275.shtml
ReplyDeleteThanks for the news! According to the article, space/time might not be one fabric everywhere. And according to the Lorenz Covariance principle, it is. So, Einstein's General Theory may be in trouble, since it's based on space and time being interwoven everywhere. The article does say, though, that his theory is still on the whole correct; it just doesn't cover the entire map.
ReplyDeleteA little further on in the article it starts to talk about anti-matter, discovered 'after' Einstein published his stuff. So, while Einstein's theory (and so Lorenz's covariance principles) applies to matter pretty hunky dory, they don't apply to antimatter at all.
Antimatter is the rift they're talking about when they say space and time aren't interwoven everywhere. Antimatter is made up of antiparticles, particles that have an opposite sign (an opposite, negative electric charge) from their counterpart: the counterpart is the matter made up of particles with positive charges.
Even with matter, the article does say what you said. Different conditions makes the apple fall differently. But I don't think their talking about the the trajectory of the fall, but the rate of the fall in ideal conditions: say, two applies falling at the same time after a shake of the tree.
But that's not the end of the story. There are discoveries - in that article - that show that objects might fall differently even in the SAME conditions. Very interesting!
Thanks a bunch for that article!