http://youtube.com/watch?v=Cldg_Hcp9-c
Is this true? How on Earth is this possible?
And is this "guy" trying to say we have the ability to go to another dimension?
http://youtube.com/watch?v=BWyTxCsIXE4
Wow, those are some great videos. Just please, don't tell me that they're from "What the Bleep Do we Know?" (and if they are, then Dr. Quantum is probably the only good thing to come out of those otherwise horrid movies).
So here's the deal with the first video. In the real world, we are used to matter taking a definitive position at all time. For example, if you want to know where a certain city is, I could give you a latitude and longitude, and you could locate it more or less exactly. It turns out that at a more fundamental level, this isn't how the universe works. Matter is somewhat delocalized, and it doesn't have a precise location. One can naively think of matter as existing as a "cloud," and we call this cloud the wave function. In the real world, we are dealing with objects so large that this effect is not noticable. But small, atomic and subatomic particles do not behave as we would expect. Instead of talking about where something is, we can only give probabilities. In the double slit experiment for electrons, it turns out that an electron that passes through a single slit interferes with
itself, which is why you observe the interference pattern. By observing the electron as it is passing through a slit, you affect it, and its wave function collapses to a single point. That wave function will eventually expand again, but not until the electron has passed through the slit.
so matter has that kind of intellegence? Matter (tiny matter, I don't mean the human body as a whole) has the ability to choose? I wonder what this could mean?
No no. It's not magic, and the electron certainly has no mind of its own. It is important to consider that it is impossible to observe anything without affecting it in some way. When an observer looks at an electron, it has to affect that electron in some way. The effect is that the electron's wave function collapses. And in the time it takes for the wave function to become distributed again, the electron has already passed through one of the two slits, and will thus not create any interference patter.
Is it cool? Certainly! But try not to read too much into this. Matter isn't alive, and it has no consciousness of its own, nor does it really choose to be in any specific state (in our human sense of the word "choose," anyway). This is a prime example of the fact that science only explains how, and not why. There aren't really too many philosophical consequences that we can draw from quantum mechanics.
Now as to the second video. This one seems to deal more with mathematics than physics. It is unfortunate that it gives the idea that we can actually go to other dimensions, and I think that this is one of the minor problems with "What the Bleep Do we Know?" (I say "minor" because that movie has far more serious problems than this). From science fiction, one might get the impression that alternate dimensions are different universes, parallel to our own. This video, however, is talking about the issue of spatial dimension. In mathematics, we generally talk about up to three dimensions. To find a location in any three dimensional space, it is necessary to specify a point of origin, and three coordinate values (so forget the seven point thing that you may have learned from Stargate). For example, to locate a point in a cubic room, one could specify a corner as the origin, and then specify the length, width, and height that one must traverse to reach that object. Or to locate a plane flying somewhere on the globe, one can specify its latitude, longitude, and altitude. So you can see that the three dimensions of space needn't always be length, width, and height.
The video seemed to emphasize that we live in a three-dimensional world. Most of the shapes to which we are accustomed cannot exist in two dimensions. For example, a sphere or a cube cannot fit into a piece of paper. To a hypothetical two-dimensional being who lived on a sheet of paper, the idea of a cube would be nonsense. In the same way, it is difficult for humans to visualize four-dimensional objects. Though to someone who has taken multivariable calculus, it is certainly possible!
I'm trying to study Quantum Physics on my own but it seems pretty difficult to understand. Does anyone have any good links to look at?
I certainly do. Here's a great site to look at:
http://www.ncsu.edu/felder-public/kenny/home.html
There are two papers on quantum mechanics. The first is intended for general consumption, the second is intended for physics students. I think you'll find that the first gives an excellent explanation of quantum mechanics for laypeople.
