[BetaAmyloid]

I was wondering, if an atom is made of quarks, what makes up a quark, what makes up what makes up a quark? Is it theoretical that everything is continually made up of other elementary particles?

Such as, an atom is made up of a quark. There are six quark flavors, top, bottom, strange, charm, down, up. Top is made up of a bottom, strange, charm, down, up. Bottom is made up of a top, strange, charm, down, up. And on and on until miniscule infinity.

Is this such a theory, or is it impossible/implausible that this is theoretical?

Thanks. 

[sjb]

Certainly I believe our current understanding is that the quarks are the fundamental particles. But that may be because we can only observe them fleetingly, and that we haven't developed ways to isolate them or break them up even further.

Remember, at one stage we thought atoms were indivisible (witness the derivation of the word), and then some clever people like Rutherford and Thomson showed that there were particles within the atom and we thought that protons, neutrons, and electrons were the fundamental particles. But then people like Zweig and Gell-Mann suggested quarks, and we have some evidence towards them, now. Who knows what may happen in the next 15 or so years. The particle theory is about "due" a revision (~1910 for Rutherford  ~1965 for Gell-Mann ~2020 ??, perhaps the LHC can help?

[cth]

There is a string theory http://en.wikipedia.org/wiki/String_theory where quarks are made of tiny strings that oscillate. The type of particle formed depends on the oscillation frequency.
The biggest problem is that to break up quarks and observe if the strings exist or not, you would need an enormous amount of energy far beyond anything we can get nowadays. So, until this theory is experimentally proved or disproved, it is more a mathematical construction than anything really physical.

All I know about it is what I read in a popularization science book. It was fun to read and worth any science-fiction book.