How much does antimatter weigh?

Antimatter is mysterious, dangerous, and rare. In fiction, it's at the core of Isaac Asimov's positronic brains, the engines on the Enterprise, and the bomb in Dan Brown's Angels and Demons. But in the real world, antimatter is fairly mundane stuff. If the entire universe turned into antimatter, we'd barely notice. Or… » 5/08/13 1:00pm 5/08/13 1:00pm

We must destroy Mars before it destroys us!

Let's face it: It's only a matter of time until Mars comes after us. We've got lots of water. It doesn't. We've got life. It doesn't. All this might have been okay, but then we alerted Mars to our presence with our various satellites and rovers, and now it's just a matter of time. Here are some ways we might destroy… » 12/22/11 7:00am 12/22/11 7:00am

Mysterious changing neutrinos could explain why we don't live in an…

There's nothing in the laws of physics that actually requires matter to dominate antimatter, and yet all our observations of the universe suggest that that's the case. But some unexpected behavior by ghostly neutrino particles could solve the antimatter mystery. » 6/15/11 12:20pm 6/15/11 12:20pm

The mysterious X particle might solve the mysteries of matter

Physics is still grappling with two basic questions about the nature of matter: why is there more matter than antimatter, and where and what is all the dark matter? Meet the hypothetical X particle, the potential answer to both questions. » 12/03/10 2:05pm 12/03/10 2:05pm