Was the big bang really the beginning of time? or did the universe exist before then? Such a question seemed almost blasphemous only decades ago. Most cosmologists insisted that it simply made no ...

String theory began over 50 years ago as a way to understand the strong nuclear force. Since then, it’s grown to become a theory of everything, capable of explaining the nature of every particle, ...

Why strings? What are they made of? How did physicists even come up with this bizarre idea? And what’s all this nonsense of extra dimensions? PBS Space Time is available to stream on pbs.org and the ...