**Strings. (0.000000000000000000000000000000000001 meters in length)**- The smallest layer that we have theoretically predicted is the string, from string
theory. String theory predicts that, at the minute distances of the Planck
length, matter is comprised entirely of vibrating strings with a number of
unusual and mind bending properties.
**The Standard Model of Quantum mechanics (0.000000000000000001 meters in length)**- After string theory there’s a huge gap in our knowledge, until we arrive at quantum
mechanics, which is the smallest layer that we have experimentally proven to
exist. Strings eventually become two quantum particles with different spins,
called bosons and fermions, and the ways these two particles interact with each
other form the fundamental forces of matter as well as quarks and leptons, which form atoms.
**Atoms (0.00000000001 meters in length)**- When quarks and leptons bind together in the right way, they form atoms of different
kinds. Each type of atom has a different origin.
**Chemistry and materials science (0.00000001 meters in length)**- Most atoms, under the right conditions, form compounds. Each of which has different
properties and interactions with other chemicals. This is the foundation of the
familiar world of macroscopic materials like coffee cups, cars, plants and
animals, and your own body.
- Matter, light, waves, antimatter, and all the rest are all forms of energy. But matter
is a particularly complicated form. Light, for instance, is just a single
photon, which is an elementary particle.