19FortyFive on MSN

The nearest world that might host life is just 4.2 light-years away — but at the speed of the fastest spacecraft humanity has ever flown, the trip would take 75,000 years ...

Just over four light-years away, the Alpha Centauri system holds the closest worlds beyond our own that might support life.
Wired

Einstein Showed That Time Is Relative. But … Why Is It?

So, you’re driving a car at half the speed of light. (Both hands on the wheel, please.) You turn on the headlights. How fast would you see this light traveling? What about a person standing by the ...
Astronomy

What is the speed of light? Here’s the history, discovery of the cosmic speed limit

On one hand, the speed of light is just a number: 299,792,458 meters per second. And on the other, it’s one of the most important constants that appears in nature and defines the relationship of ...
The Conversation

Do photons wear out? An astrophysicist explains light’s ability to travel vast cosmic distances without losing energy

My telescope, set up for astrophotography in my light-polluted San Diego backyard, was pointed at a galaxy unfathomably far from Earth. My wife, Cristina, walked up just as the first space photo ...