The mind-bending concept of time dilation results from a seemingly harmless assumption—that the speed of light is the same for all observers.

ASML's Q2 shines, but weakened guidance and rising risks signal caution. Read why I rate ASML a Sell and prefer to wait for ...

Explore news and insights on climate change, environment policies, global warming and sustainable practices with The New York Times Climate and Environment section.

<p>News about private equity, including commentary and archival articles published in The New York Times.</p> ...