The Sagnac effect, first observed over a century ago, remains central to our understanding of relativistic kinematics and the operational definitions of simultaneity. Fundamentally, this effect arises ...

Neutrinos, the most ghostly particles we know of, are hitting far above their weight class. Recent evidence from the European physics mecca known as CERN and an affiliated group in Lyon suggests that ...

In his 1986 book, Was Einstein Right? Prof. Clifford Will, physics, Washington University in St. Louis, declared anyone who questioned Albert Einstein’s special theory of relativity to be a crank or ...

When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Albert Einstein's theory of general relativity has held up pretty well after a century out in the ...

The conventionality of simultaneity at distant points is defended partly by reference to Einstein's 1905 paper founding special relativity. His famous light-signaling definition takes the transit time ...

It stands among the most famous theories ever created, but the general theory of relativity did not spring into being with a single, astonishing paper like the special theory of relativity in 1905.

Scientists are using observations of black holes to test the limits of general relativity, aiming to identify potential inconsistencies or incompleteness in Einstein's theory. Multiple methods are ...

Margaret Wertheim does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond ...

When the theory of relativity appeared in the early 1900s, it upended centuries of science and gave physicists a new understanding of space and time. Isaac Newton saw space and time as fixed, but in ...