For over 100 years, two theories have shaped our understanding of the universe: quantum mechanics and Einstein’s general relativity. One explains the tiny world of particles; the other describes ...

Albert Einstein's theory of general relativity—which explains gravity as the product of the distortion of space and time—may not be universally applicable. This is the conclusion of physicists from ...

Tachyons are hypothetical particles that travel at speeds greater than the speed of light. These superluminal particles, are the "enfant terrible" of modern physics. Until recently, they were ...

It might not be obvious to those of us only grappling with more mundane concerns, but for cosmologists bent on unlocking the universe’s deepest secrets, there’s no shortage of problems keeping them up ...

Black hole singularities should not exist, according to theories of quantum mechanics. New tweaks to Einstein's equations of general relativity could finally do away with them, and explain what truly ...

A new theory suggests that gravity could possibly be the result of entropy. If true, this would mean that everything in the universe would fall apart if it all remained unchanged. This theory tries to ...