Space Station Threshold

Say the word "antimatter" and immediately people think of science fiction – anti-universes, fuel for the Enterprise's warp-speed engines and so forth. But Captain, we can't change the laws of physics; antimatter is the real deal. Antimatter is made up of elementary particles, each of which has the same mass as their ...

Cosmologist Stephen Hawking will retire from his post at Cambridge University next year, but he still intends to continue his exploration of time and space. University policy is that officeholders must retire at the end of the academic year in which they become 67. Hawking will reach that age on Jan. 8, 2009. Hawking [...]

Just as unseen dark energy is increasing the rate of expansion of the universe, there's something else out there causing an unexpected motion in distant galaxy clusters. Scientists believe the cause is the gravitational attraction of matter that lies beyond the observable universe, and they are calling it "Dark Flow," in the ...

We've all wondered at some point or another what mysteries our Solar System holds. After all, the eight planets (plus Pluto and all those other dwarf planets) orbit within a very small volume of the heliosphere (the volume of space dominated by the influence of the Sun), what's going on in the rest of the [...]

On large scales, the Universe is homogeneous and isotropic. This means that no matter where you are located in the cosmos, give or take the occasional nebula or galactic cluster, the night sky will appear approximately the same. Naturally there is some 'clumpiness' in the distribution of the stars and galaxies, but generally the density ...

One of the biggest questions that occupy particle physicists and cosmologists alike is: what is dark matter? We know that a tiny fraction of the mass of the universe is the visible stuff we can see, but 23% of the Universe is made from stuff that we cannot see. The remaining mass is held in [...]

What happened before the Big Bang? The conventional answer to that question is usually, "There is no such thing as 'before the Big Bang.'" That's the event that started it all. But the right answer, says physicist Sean Carroll, is, "We just don't know." Carroll, as well as many other physicists [...]

An international team of astronomers from the Sloan Digital Sky Survey unveiled a new detailed map of the chemical composition of more than 2.5 million stars in the Milky Way. This new map could help reveal the unknown ancient history of our galaxy. "With the new SDSS map, astronomers can begin to tackle many [...]

We're getting the numbers down pretty well now about how much we don't know about the universe: Only about 5% of our universe consists of normal matter, made of atoms. The rest of our universe is composed of elusive matter that we don't understand: dark matter (23%) and dark energy (72%). And [...]

Hopefully you've all recovered from part 1 of this set, where we make you sad about the future of the humanity, the Earth, the Sun and the Solar System. But hang on, we're really going to bring you down. Today we'll look far far forward into the distant future of the Universe, at timescales that [...]