# Tag Info

2

To add to PM 2Ring's answer, there's also the phenomenon of microlensing. The point is, stars don't stay still on the sky. They move. Our Sun for example is moving around the center of the Milky Way. Therefore, even if two stars are completely aligned right now, they were not aligned in the past and likely will not be aligned in the future. In these ...

5

Nice thought, but as the saying goes, space is really big. Stars have a tiny angular size when viewed from even their nearest neighbours (except perhaps in clusters & galaxy cores), so not much starlight actually gets intercepted by other stars, relative to the amount of light that gets absorbed by interstellar (or intergalactic) gas and dust. And even ...

0

For phantom energy model we have $$H^2 = H_0^2\Omega_pa^{-3-3w_p}$$ such that $w_p < -1$ $$\dot{a}^2 = H_0^2\Omega_pa^{-1-3w_p}$$ $$\dot{a} = H_0 \sqrt{\Omega_p} a^{-1/2(1+3w_p)}$$ $$\int a^{1/2(1+3w_p)}da = \int H_0 \sqrt{\Omega_p}dt$$ Now at this part we should define the integrals upper and lower bounds. When we set time from $t → t_0$ \int_a^{...

Top 50 recent answers are included