BT21 Interceptor

Superstring Theory

One reader requested this, so I finally wrote the chapter on the string theory. Have fun.

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I described how an atom looks like earlier and mentioned the electrons and quarks. Electrons and quarks are particles that belong to the category elemental particle. There is nothing smaller they are made of, they are the smallest fragment of matter. Of course, there are more of those elemental particles: neutrinos (mass-less, traceable during nuclear beta decay), gluons (mass-less particle that glues together the quarks to build protons and neutrons), myons and tauons (like step-brothers of the electron), photons (mass-less particle of light), gravitons (mass-less particle that transmits gravitation), and the whole bunch of their anti-matter siblings (there is no anti-graviton though). Just to list some of them. They predicted the Higgs boson, by the way.

Basis of the string theory is that every elemental particle is a small, closed, 1-dimensional string that is vibrating. The string-loop has a length of at least 10^-35 meters (Planck length). That's what I mentioned when I talked about black holes. Now, a black hole is no longer a 0-dimensional point with infinite density, but a sphere of at least the circumference of the Plank length. However, the vibration defines things like the mass and the charge; and the little string vibrates not only in our well-known three dimensions of room, but in nine dimensions of the room and the time dimension. (Sheldon's 25 dimensions are also right. It's simply another one of the five string theories. But you can transform one into the other. I prefer the 10d version and will explain only that one.)

But how come there are six dimensions we can't perceive? That works the following way: The other six dimensions are rolled-up and scattered over the time-space regularly in distances of the Plank length (That's the shortest length existing. Nothing goes beyond. For physicists not for mathematicians... The last kind can depict the whole universe into a dot and create a world with gravitation and anti-gravitation by using a Möbius strip.). But they are not just rolled up randomly, but in the form of so-called Calabi-Yau manifolds. And the form of those manifolds defines the physical laws of our universe. Mathematicians have to find the one form that leads to our universe by working themselves through thousands and thousands of those manifolds. Until now, they found out that the Calabi-Yau manifold can have multi-dimensional holes, and every hole stands for one family of particles. Our universe knows three particle families, so it should be a Calabi-Yau manifold with three holes, but there are still hundreds of them. So, long way to go.

For those who are interested, let me sum up the three families:

Family 1

electron, electron-neutrino, up-quark, down-quark

That are the particles our touchable matter is made of. The other two families are heavier and therefor rare. They have only been found in circular accelerators like the LHC in Cern, Switzerland. Those could have existed naturally when the universe was smaller and hotter.

Family 2

myon, myon-neutrino, charm-quark, strange-quark

Family 3

tauon, tauon-neutrino, top-quark, bottom-quark

So, we have 1D strings that vibrate in the time dimensions and nine dimensions of space, of which six are rolled-up in Calabi-Yau manifolds. But why is it called superstring theory?

To explain that, I will have to give you another kind of intel first: Particles are divided in fermions and bosons. Fermions are the particles of matter (electrons, neutrinos, quarks), and bosons are the particles of force, meaning they transmit different kind of forces like the electromagnetic force, gravitational force, the weak and the strong nuclear force, and the electroweak interaction.

Now, back to the super in superstring. The string theory predicted a bunch of particles. One of those was the tachyon, a particle that was moving faster than light. As you might now by now, that is impossible. Another flaw was that there were no fermions predicted what is plain stupid because we already found them, we CONSIST of them. But scientists are clever, so they added a new kind of symmetry to the theory, the supersymmetry. So, now there was no tachyon but fermions, and every fermion had a supersymmetric boson-partner, and every boson had a supersymmetric fermion-partner:

Quark (f) and squark (b), electron (f) and selectron (b), neutrino (f) and sneutrino (b); gluon (b) and gluino (f), graviton (b) and gravitino (f), photon (b) and photino (f).

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This is just a fragment of the giant, colorful and funny world of strings, but I guess it is enough to get an idea. If you dive into it more deeply, you will find branes (string membranes), several multiverse theories, several big bang theories, cuts in space-time and flops, virtual strings and interaction of strings in general and so much more mind-blowing stuff.

If you're interested I recommend:

Brian Greene: The Elegant Universe, 1999

Greene explains Einstein's theories of relativity and all the phenomena around strings and the 10-dimensional superstring theory in a really easy and enjoyable way. He was my door into the realm of string theory.

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Now, that I'm at it. I have to confess something:

The QGCS propulsion I used in my story does not work. Just as warp, it is a nice idea but that is all. Traveling faster than light would also cause other unmanageable consequences like traveling back in time what would lead to chaos regarding coming back to earth in the same century you headed off. But what would a scifi story without over-light-speed be like? Boring, right?

I'm sorry for sneaking this tiny bit of unrealism into the book. Be assured, it really ate at my physicist mind.

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