One of Albert Einstein's greatest insights was realizing that time is relative. It speeds up or slows down depending on how fast one thing is moving relative to something else. How much does it change ...

Time travel has shifted from pure fantasy to a serious, if highly constrained, topic in modern physics. The equations that ...

Traveling to another star isn’t just difficult—it might be physically impossible with today’s technology. Learn about the ...

Einstein said that clocks that are moving through space at dramatically divergent speeds will measure time differently, and he used his famous “twin paradox” to illustrate the point. But there are ...

Alfredo has a PhD in Astrophysics and a Master's in Quantum Fields and Fundamental Forces from Imperial College London.View full profile Alfredo has a PhD in Astrophysics and a Master's in Quantum ...

Albert Einstein’s “twin paradox” is a famous counterintuitive implication of the special theory of relativity, but it also reveals deep links between physics and philosophy, as Robert P Crease ...

I have a question regarding time dilation that I thought of last night listening to an audiobook, Project Hail Mary. I am an amateur astrophotographer, and marvel at the distance to deep-space objects ...