# What is faster than a supernova explosion?

Is a supernova explosion really fast or is it just fast, metaphorically speaking? Can you cite the fastest known phenomenon in astronomy (neutron stars, pulsars) besides supernovae in terms of explosions?

EDIT: yes, i mean the shockwave from supernova

• Would light fit into what you are asking? Or are you asking specifically for explosions. Aug 24 '15 at 2:17
• @CipherBot Specifically for explosions. Edited question. Aug 24 '15 at 6:28
• Most of the energy in a supernova explosion is actually neither in the shock wave, nor in the light, but in the massive amount of neutrinos emitted. Neutrinos travel almost at the speed of light. Does that count?
– pela
Aug 28 '15 at 9:46

If you count unique events as well, the fastest known event would be the exponential expansion of the Universe during inflation which lasts from about $10^{-36}\,\rm s$ to $10^{-32}\,\rm s$ right after the Big Bang. In this time, the Universe grew by a factor of about $10^{26}$.
The "fastest" pulsar found so far spins 716 times a second. If you really want fast, how about the standard for atomic clocks? The used transition is between two ground states of the element caesium that are very close together and lasts about $1\times 10^{-10}$ seconds. There are even better atomic clocks now.