Recent content by LeoChan

Thank you.That is quite straight forward.

In ΛCDM, H(t0) = 70km/s/Mpc, Ωd(t0) = 0.3, Ωr(t0) = 0 and ΩΛ(t0) =0.7, so that Ω(t0) = Ωd(t0) + Ωr(t0) + ΩΛ(t0) = 1and the universe is spatially flat. I want to know the t and z when the matter density equal to the vacuum energy density. By total energy density equation, I think Ωd(t) +...

Thanks. But just didn’t expect the answer to be irrational for a lamina, it made me so confused.

The moment of inertia tensor I found out is (1/3) (-1/2) 0 (-1/2) (4/3) 0 0 0 (5/3) The principal moment of inertia tensor I found out is (1/3-I) . (-1/2) . 0 (-1/2) . (4/3-I) . 0 0 . 0 . (5/3-I) det of principal of...

In the book "Guns, Germs, and steel", it said the wide usage and need of technology come after the invention. While we might feel like there are many examples of the invention is to resolve something, most of them are just out of curiosity. Necessity's mother is the evolution of technology.

Hello I am Leo:smile:. I hope I can get inspiration here for my study and future path.