I just checked, Polaris is about ten times younger than sharks. The other two stars of its ternary star system are older, but not visible to the naked eye, so early sharks would not have been able to use them for purposes of navigation.
I just checked, Polaris is about ten times younger than sharks. The other two stars of its ternary star system are older, but not visible to the naked eye, so early sharks would not have been able to use them for purposes of navigation.
It’s just that normal gravity on earth feels exactly like being in an accelerating elevator in space. So you can’t tell the difference from the inside. Like in the elevator you can ask them, whether you’re still on earth or accelerating in space. Einstein used this thought experiment to develop the general theory of relativity.
Basically Einstein thinking about that weird feeling you get in your gut when an elevator starts upwards led to him concluding that mass bends spacetime making light from distant stars go in curves around the sun, which was confirmed during the next available solar eclipse.