I'm not talking about the whole universe, just the emtpiness, that they say is expanding or growing or whatever. How can it grow like that is what I mean?
-
I know it is counter-intuitive, but lots of physics and cosmology is that way, I'm afraid. On the smallest and largest scales, the world doesn't behave quite the way that non-specialists feel it should.
Let's start at the beginning.
In the beginning was the Big Bang (BB). Now, it is easy, but totally wrong, to think of the BB as being like an explosion here on earth. Something of which you can say that it took place at such and such a place, and such and such a time. BB wasn't like that. It was an explosion OF time and space, not IN time and space. What was before the BB? Wrong question! (Sorry.) There was no time before BB,a nd therefore no 'before'. Since there was no 'before', by the way, there was also no 'cause'. What caused BB? Wrong question again.
Shortly after BB (say around 10^-40 seconds after, so very shortly indeed), the universe was pretty small. There was very little space around. A bit later, around 10^-33 secongs into time, came the so-called 'inflationary era'. That had nothing to do with the value of money, but everything to do with how much space there was around. Space expanded far faster than the speed of light for a while (i.e. for a few tiny, tiny fractions of a second). This did not, repeat not, violate anything Einstein said about the cosmic speed limit, because it was space that was expanding, not objects moving through space. Still with me?
Ever since then, space has been expanding rather more calmly. We know it has been doing that because of CMB (Cosmic Microwave Background - look it up). The universe was unimaginable hot just after BB, but its expansion has cooled the original bang down to just a couple of degrees above absolute zero.
Now, if you are not any kind of phyics nut, the chances are that none of this makes all that much sense to you. I'm sorry, (and I dare say there are people who explain better than I do), but that is kind of the way life is. The days when non-specialists could understand the workings of the universe, and make far-reaching discoveries about it, seem to be over for good. As someone once said, the universe is stranger than we know, and perhaps stranger than we can know.
Let's start at the beginning.
In the beginning was the Big Bang (BB). Now, it is easy, but totally wrong, to think of the BB as being like an explosion here on earth. Something of which you can say that it took place at such and such a place, and such and such a time. BB wasn't like that. It was an explosion OF time and space, not IN time and space. What was before the BB? Wrong question! (Sorry.) There was no time before BB,a nd therefore no 'before'. Since there was no 'before', by the way, there was also no 'cause'. What caused BB? Wrong question again.
Shortly after BB (say around 10^-40 seconds after, so very shortly indeed), the universe was pretty small. There was very little space around. A bit later, around 10^-33 secongs into time, came the so-called 'inflationary era'. That had nothing to do with the value of money, but everything to do with how much space there was around. Space expanded far faster than the speed of light for a while (i.e. for a few tiny, tiny fractions of a second). This did not, repeat not, violate anything Einstein said about the cosmic speed limit, because it was space that was expanding, not objects moving through space. Still with me?
Ever since then, space has been expanding rather more calmly. We know it has been doing that because of CMB (Cosmic Microwave Background - look it up). The universe was unimaginable hot just after BB, but its expansion has cooled the original bang down to just a couple of degrees above absolute zero.
Now, if you are not any kind of phyics nut, the chances are that none of this makes all that much sense to you. I'm sorry, (and I dare say there are people who explain better than I do), but that is kind of the way life is. The days when non-specialists could understand the workings of the universe, and make far-reaching discoveries about it, seem to be over for good. As someone once said, the universe is stranger than we know, and perhaps stranger than we can know.
-
Yes you do mean the whole thing, it is the universe that is expanding.
They know this because of the doppler effect, compare witn sound of an ambulance that is moving away, the frequency changes. For light same thing happens, for objects that are moving away they call it red shift..
Read more at source below
They know this because of the doppler effect, compare witn sound of an ambulance that is moving away, the frequency changes. For light same thing happens, for objects that are moving away they call it red shift..
Read more at source below