Ask a Scientist


Over the years, people have sent questions to Fermilab on subjects from why the sky is blue to the speed limit of the universe. Here are a selection of the most interesting questions and informative answers. We no longer post answers to questions and we do not update the content of this website. Scientific understanding evolves, and the answers to some questions on this website may not reflect the latest scientific discoveries or the current operational status of an experiment or facility.

Physics Questions People Ask Fermilab

Particles and their properties

Quarks, leptons and bosons, spin and mass, antimatter.

Forces and interactions

Strong, weak, electromagnetic and gravitational, particle-wave dualism.

Particle theories

Quantum fields, superstrings and all that.


Bringing particles to almost the speed of light.

Particle detectors

Capturing the tracks of particles.

Physics of the universe

From the big bang to black holes, extra dimensions, space and time.

Special and general relativity

Physics at the speed of light.

General physics

From very cold to very hot — and everything in between.

For additional answers to particle physics questions, visit the Fermilab YouTube channel. In particular, you might be interested in the 35 short videos of the Subatomic Stories series produced by Fermilab scientist Don Lincoln and posted in 2020.