Since Einstein developed his theory of relativity, and Rutherford and Bohr revolutionised physics, our picture of the world has radically changed.
One of the most exciting things about dark energy is that it seems to live at the very nexus of two of our most successful theories of physics: quantum mechanics, which explains the physics of the small, and Einstein's Theory of General Relativity, which explains the physics of the large, including gravity.
In the context of general relativity, space almost is a substance. It can bend and twist and stretch, and probably the best way to think about space is to just kind of imagine a big piece of rubber that you can pull and twist and bend.
Relativity can, for instance, explain that the universe had once been clumped into a dense fireball. But it can never explain how matter actually behaved.
Typically in science, individual scientists make up their minds about scientific fact or theory one at a time. We don't take votes. We just don't vote on quantum mechanics, the theory of relativity, why the sky is blue, or anything else.
Science doesn't work by voting. Did people vote on the theory of relativity? No! It's either right or it's wrong. Do we vote on whether genetics is a good theory or not? Of course not.
The star S0-2 orbits around Sgr A* every 16 years and will go through its closest approach in 2018. That's an opportunity to test Einstein's General Relativity theory through very precise measurements of this star's short period orbit.
I always found it satisfying that gravity was described by Einstein's geometric theory of general relativity.
At some point we must realize that actively defending against radical Islamic teachings is not a matter of cultural relativity. It is a matter of universally recognized human rights.
One of the main successes of string theory is that it has been able to unify the general theory of relativity, which describes gravity, and quantum mechanics.
