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Physics (Chapter 3): Gravity, Branes And Hidden Dimensions (The Fourth Dimension / 4D Tesseract)
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Why is gravity so weak? Why can a small magnet pull or push something away from the entire earth? There is an idea that may explain it, but before we go there, lets explore some preliminary ideas. The most popular quantum gravity theory of today describes all fundamental particles as vibrating strings of energy. And the theory is constructed in a whopping nine or ten spatial dimensions instead of the three that we experience in our everyday lives.
But what is a dimension? A line is a familiar geometric figure. It can be completely described by giving its length. It is a one-dimensional object. It can be imagined that the dimensionality of an object can be created by taking an object of one less dimensions and moving it at a right angle to that dimension. You can create a line in your imagination by thinking of taking a point and moving it.
Next consider a surface: A surface is also quite familiar. A surface has both length and width and requires two measurements to define it and therefore is a two-dimensional object. Similar to the generation of a line from a point, we can generate a two-dimensional surface by taking a line and moving it in a direction other than the direction of its length.
And a solid figure is the stuff of everyday life. It has length and width and depth and requires three measurements to describe it, and is a threedimensional object. And like the generation of a surface from a line above, we can generate a three-dimensional object like a cube by taking a square and moving it in a direction other than the directions of its length and width. Cylinders, cubes, and spheres are three-dimensional objects.
And now the hard part the higher dimensions are created by moving a threedimensional solid in a direction other than its length, width or height. And while that is easy to do mathematically, it is impossible for us to picture it.
Now back to strings If this membrane represents the three dimensions that we live in, then particles like quarks and electrons are strings that have their endpoints forever attached to those three dimensions. But the particle that is the force carrier for gravity, the graviton, is a closed loop.
It has no ends that are constrained to our three dimensions. So if there are other dimensions, gravity will propagate freely there as well as in our familiar three. And that might explain why gravity seems so weak to us. We experience only a tiny fraction of gravitys true strength because so much of it is leaking out into the other dimensions!
But where are these dimensions hiding? One possibility (but not the only one) is that they are all around us but are
incredibly tiny.
If you look at a wire or a string from far enough away, it looks like a line a onedimensional figure. But if you get closer or if you were a lot smaller than the thickness of the wire, then you would easily see that it has other dimensions. On the tiniest of scales, space has extra dimensions at every point. It might look something like this if we were small enough to see it.
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LHC (Large Hadron Collider): Accelerators like the LHC at CERN smash protons against anti-protons at enormous energies perhaps enormous enough to produce gravitons. And if they do, then perhaps we might just be able to see them form in our limited threedimensional world and slip quickly and quietly away into those hidden dimensions!
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The tesseract: In geometry, the tesseract, also called an 8-cell or regular octachoron, is the four-dimensional analog of the cube. The tesseract is to the cube as the cube is to the square. Just as the surface of the cube consists of 6 square faces, the hypersurface of the tesseract consists of 8 cubical cells. The tesseract is one of the six convex regular 4-polytopes.
A generalization of the cube to dimensions greater than three is called a hypercube, n-cube or measure polytope. The tesseract is the four-dimensional hypercube, or 4-cube.
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String Theory in Two Minutesby MegaFantastique122,288 views
@pliqhtify
Could the act of 3-D movement, be the fourth dimension?
seth917 22 hours ago
@seth917 but a 4-d object moving in 3-d space would be like a 3-d object moving in 2-d space
pliqhtify 1 day ago
gay
geennaamable 1 week ago
@lolkvadim
Yes but that might be OK. 2-D objects can move in 3-d space? and 1-d objects can move in 2-d space.
No?
seth917 1 week ago
@seth917 It would still be moving in three dimensional space.
lolkvadim 2 weeks ago
@meroxyersox
Not sure why the video says it is "impossible" to imagine a fourth dimension.
Wouldn't the image of the fourth dimension"be the movement of the 3D object in any direction e.g. demonstrating time.
seth917 2 weeks ago
@Shockszzbyyous
Because realty says there is a limit. But you don't think you believe in reality so lets leave it there.
seth917 2 weeks ago
@MediumNothinFull
Actually it makes sense the third time I listened to it but they didn't explain "why".
seth917 2 weeks ago
someone was way to stoned
XxJellyMulishaXx 1 month ago 2
that gets fuckin trippy
MediumNothinFull 1 month ago