3 ms·
Genuine question: what are the “long line” or the phase space of the cosmic fluid? I found the Wikipedia page https://en.m.wikipedia.org/wiki/Long_line_(topolo
by carl_dr 5y ago
Genuine question: what are the “long line” or the phase space of the cosmic fluid?
I found the Wikipedia page https://en.m.wikipedia.org/wiki/Long_line_(topology) https://en.m.wikipedia.org/wiki/Long_line_(topology) but like a lot of such pages, they are opaque unless you are familiar with the topic. Consequently, I have no idea if this is the long line you are referring to.
Oh, and which xkcd comics?
- Y_Y 5y agoGood questions. You got the right long line. The normal number line, the "real line" can be thought of as taking a half-open unit interval [0,1) and putting one at each integer to "fill in the gaps". This is already very long. If you did the same thing, but stuck together each point on the real line, then you'd get the long line. Cosmic fluid is a model of the universe as a fluid, like an ideal gas or something. The phase space is is the space of all the possible states it can get in to (shape, flow, pressure etc.) You may call this state space depending on how you think about spacetime. See e.g. https://en.m.wikipedia.org/wiki/Equation_of_state_(cosmology) https://en.m.wikipedia.org/wiki/Equation_of_state_(cosmology... . xkcd: 435, 794, probably others