f*******d
发帖数: 339 | 1 1. How to understand the expansion of the Universe?
Maybe you have heard that the Universe is expanding, but don't
understand how, here I will explain it to you.
Trust me, EVERYBODY who knows highschool math can understand it, it
does NOT require an understanding of
4 dimensional geometry.
When one heard of expansion of the Universe, three questions
immediately come to mind:
1. If the Universe is expanding, does that mean it has an edge or at
least is finite?
2. If the Universe is finite, what's | l**n
发帖数: 67 | 2 Oh, My God! i lose my job then.(kidding)
In my mind, what really confusing about the expansion is what
actually is expanding.
It's not good enough to say the space itself is expanding while
not having a clear definition of space. Do we still have space
if no matter exists? Or space is just the extension of matter?
Why space is not expanding in the gravitional bound system, like
our solar system and our galaxy? You can say that SR is not
violated because it's not true that any kind of speed canno | f*******d
发帖数: 339 | 3 I'll touch upon the question why bounded system does not expand in my
cosmo2. As for other questions, I'll refer the reader to your
future posts:-)
【在 l**n 的大作中提到】
: Oh, My God! i lose my job then.(kidding)
: In my mind, what really confusing about the expansion is what
: actually is expanding.
: It's not good enough to say the space itself is expanding while
: not having a clear definition of space. Do we still have space
: if no matter exists? Or space is just the extension of matter?
: Why space is not expanding in the gravitional bound system, like
: our solar system and our galaxy? You can say that SR is not
: violated because it's not true that any kind of speed canno
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