# Is light composed of strings ?

#### Chris Walters

Is light composed of "strings"?

I read Professor Michio Kaku book Hyperspace and have tried to
create an online paper asking if light waves are composed of
the elusive "strings" and if the light or strings could be manipulated
without the energies required by Plank constant:

http://www.geocities.com/certvolunteer/physics/index.html

I am a layman and have limited technical knowledge to understand
replies Many thanks Chris Walters

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#### Ouabache

Homework Helper
It has been a while since I last read Hyperspace. (yes i have read it more than once)..
I do enjoy reading about physics but am no physicist. (though I am trained in one of the applied areas "electrical engineering"). Therefore before sharing my opinions, lets address your question with a quote by Michio Kaku on the Theory of Everything I have italicized and highlit chosen words for emphasis.(follow the hyperlink to see his whole article)

Superstring theory says that, if we had a supermicroscope and could peer at an electron, we would see a string vibrating in a certain mode. The string is extremely small. (So small) that the electron looks like a point particle to us. If we shake the string, so it vibrates in a different mode, then the electron can turn into something else, such as a quark, the fundamental constituent of protons and neutrons. Shake it again, and the string could vibrate in the mode which describes photons (the quanta of light). Shake it again and it turns into a graviton (the quanta of gravity).
From his discussion, we may say that the same string vibrating in a different way (mode), generates a different fundamental particle (e.g. electron, quark, photon, graviton). Modes are fundamental patterns of vibration. Using this analogy it is clear how the same string can represent different particles.

As a sidenote, we know photons behave not only as particles but also as waves. Varying the wavelength of light yields different frequencies (in the visible spectrum we perceive them as different colors). In Kaku's description, it is not apparent how the same string can represent different frequencies of light. My own thought is, perhaps light frequencies are expressed by a nonfundamental or complex vibrational mode (analogous to a complex wave in sound, such as a musical chord).

Last edited:

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Ouabache said:
As a sidenote, we know photons behave not only as particles but also as waves. Varying the wavelength of light yields different frequencies (in the visible spectrum we perceive them as different colors). In Kaku's description, it is not apparent how the same string can represent different frequencies of light. My own thought is, perhaps light frequencies are expressed by a nonfundamental or complex vibrational mode (analogous to a complex wave in sound, such as a musical chord).
Perhaps instead of using the wave represention of photons it would help to use the particle representation. Then the color is proportionsal to the momentum of the particle. Now the vibration modes of the string carry, indeed are indexed by momentum - that is string momentum. But I could see how that momentum could effect the momentum of the particle generated by the mode.

It has to be said here that the simple picture given by Kaku has never really generated a photon or any other common particle. Stringy attempts to do that are much more complex, involving many strings, as well as branes. These attempts have not really succeeded either, but they are continually getting closer.

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