Xiaohua: Hello, and welcome to Round Table’s Word of the Week. This week we are going to talk about some science theories that are made known by the film Interstellar.
John: Yeah, not so much made known. I mean these are concepts and ideas that have been around for quite a long time even as early as the 1930s and 1940s, but really what we see with the movie Interstellar which I have not seen yet, we see just a kind of popularization of those ideas. Not to say that Interstellar is the first one to do so, but due to the popularity, especially here in the Mainland, without it we cannot talk about some of them. I want to take the time right now to first describe some very fundamental concepts in the world of mathematics, in physics that informs much of what we saw in Interstellar. So the first is general relativity and a simple explanation of general relativity is the idea on large scales, what happens with large bodies and their influence on other things. So by large bodies, I mean planets, suns, other stars, comets, and things like that. Large massive things in space and how they affect each other, mostly looking at gravity and time.
Xiaohua: 广义相对论general relativity基本上讲的就是在广大的空间内的一些高密度的天体是怎样互相之间作用而影响我们的。
John: Then there is quantum physics. So general relativity is attributed to Einstein in the 1930s and 1940s somewhere around there. And then there was quantum physics which was popularized especially in the 1960s and 1970s. So general relativity has everything to do with large massive bodies, again planets, stars, things like that. Quantum physics has everything to do with small things. Things that we cannot perceive with the naked eye, so quantum physics tries to answer the question how is it that an atom stays in atom, how does a molecule stay a molecule, even going future down how does a proton stay a proton.
Xiaohua: 在相对论之后，又有了著名的量子理论quantum physics。
John: The problem for theoretical physicists so the people who are doing all the math and trying to figure how the math works is that if you try to apply the ideas in mathematics of general relativity to very small things, everything breaks down. And if you try to apply the mathematics of quantum physics and quantum theory on a larger scale, everything breaks down. And so what theoretical physicists had to do was come up with a completely separate system of math and a completely separate idea of how things work. And they call that string theory. So string theory has not been experimentally proven. However, this point is accepted by a wide number of theoretical physicists and mathematicians as a very elegant way of bringing general relativity and quantum physics together.
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Xiaohua: 由于广义相对论和量子理论在很多地方是不能同时成立的，于是理论物理学家们又延伸出一个新的学科，那就是弦理论，也就是string theory。
John: Right, so the idea behind string theory is that you have strings of different shapes and sizes vibrating at certain frequencies. This can be very, very small, smaller than electron, than the smallest particle we know of. Everything basically is made up of different types of strings vibrating at different frequencies and this is where the ideas of branes or membranes and worm holes really start to take shape and actually start to make sense in terms of the mathematics and the actual theory.
Xiaohua: 弦理论的一个基本观点就是说自然界的基本单元不是点状粒子，而是很小很小的线状的弦string，而弦之间的不同震动就产生出不同的基本粒子。另外在弦理论里面还有一个brane, right?
John: Yeah, brane. It’s just the shortening of the word membrane. The idea there is that the membrane is actually a very elongated string that also has its own vibration. And the idea is all theory. None of this is proven. It’s that our universe in fact could be either just on one brane or could be that we are on many different branes, so the idea is that somehow you take one membrane and you fold it around. It should be theoretically possible to create some kind of gateway between those two. That’s really where the idea of a worm hole really starts to make sense, so people used to think there was this science fiction idea that black holes could somehow be a worm hole, but as far as we know, the physics of that just make no sense, because the black hole is a star that collapses upon itself so quickly because of the way that these forces work, that it just sucks in everything else around it and the thing is as far as we can tell, if everything is actually sucked into the black hole, there is no way that a human could actually survive.
Xiaohua: 而弦理论的存在使得平行空间，也就是虫洞的存在产生了可能。以前有人认为黑洞和虫洞也许是一种东西，但其实我们现在知道黑洞是一种超高密度的天体，那么所有的物体在被吸入黑洞之后都没有办法逃脱出来，所以黑洞和虫洞其实是不一样的。
John: I want to talk about the speed of light, in about relativity in that sense, because the whole thing with one of the big discoveries of Albert Einstein in terms of relativity was the speed of light. So a lot of science fiction looks at faster than light travel, sometimes abbreviated into FTL. The thing is right now, and this is why worm holes and things like that are so attractive, because according to the physics that in our understanding of the universe now it is virtually impossible to ever actually travel at the speed of light or even faster than the speed of light using what we now have in terms of propulsion technology. Because according to E=mc*2, as you get closer to the speed of light, the energy required increase in such an exponential fashion.