[QUOTE=JohnnyMo1;43478510]If there are, I don't really know anything about them. I know a decent bit about cosmology, but certainly not everything. It feel like it's likely matter is pretty evenly distributed throughout space, since all of space expanded at once, but that means there is likely an infinite amount of matter in the universe. I can't think of any theoretical problems with this off the top of my head, but there may be.
I wouldn't think you could tear them apart any further, since elementary particles are pointlike as far as we know.[/QUOTE]
Seeing as electrons have mass, wouldn't this make them infinitely dense?
[QUOTE=JohnnyMo1;43478455]What do you mean?[/QUOTE]
The universe is expanding; is the Earth as well? What about our human bodies? In other words; when space is expanding, does it mean that the space between the atoms in our bodies is also expanding?
[QUOTE=blehblehbleh;43478771]Seeing as electrons have mass, wouldn't this make them infinitely dense?[/QUOTE]
Not really. Mass = density * volume is great for extended objects, but those are made up of tiny particles so it makes sense to talk about density. It doesn't really make sense to talk about the density of something that isn't made up of anything.
[editline]9th January 2014[/editline]
[QUOTE=SGTNAPALM;43478787]The universe is expanding; is the Earth as well? What about our human bodies? In other words; when space is expanding, does it mean that the space between the atoms in our bodies is also expanding?[/QUOTE]
Yep. But like I said, small distances expand much slower.
snip
[QUOTE=JohnnyMo1;43478763]We don't really have a theory that tells us what space is like at distances near or smaller than the Planck length. Some people think space is broken up into blocks of the smallest possible volume, but I don't think that has widespread acceptance or strong theoretical justification.[/QUOTE]
If space isn't made up of blocks then the only other possibility is that it must be continously fluid, right? You say that hte block theories aren't widespreadly accepted or has strong theoretical justification, what about it being fluid? Is that more accepted and does it have better theories backing it up or do most people think we know way too little to even make assumptions?
[QUOTE=MrJazzy;43478849]If space isn't made up of blocks then the only other possibility is that it must be continously fluid, right? You say that hte block theories aren't widespreadly accepted or has strong theoretical justification, what about it being fluid? Is that more accepted and does it have better theories backing it up or do most people think we know way too little to even make assumptions?[/QUOTE]
Well, yeah, continuous space is the only other option besides discrete space. That's what most physicists think it is. We do at least know that things get weird below the Planck length though.
[QUOTE=JohnnyMo1;43478871]Well, yeah, continuous space is the only other option besides discrete space. That's what most physicists think it is. We do at least know that things get weird below the Planck length though.[/QUOTE]
Before I ask my next question I just gotta make sure I got the right idea; matter exists in a pointlike way and energy exists in a continious way right?
[QUOTE=MrJazzy;43478906]Before I ask my next question I just gotta make sure I got the right idea; matter exists in a pointlike way and energy exists in a continious way right?[/QUOTE]
The second part depends. Bound states of particles have discrete energy spectra. (that's what quantum mechanics is all about) Free particles have continuous energy spectra.
[QUOTE=JohnnyMo1;43479030]The second part depends. Bound states of particles have discrete energy spectra. (that's what quantum mechanics is all about) Free particles have continuous energy spectra.[/QUOTE]
Guess I gotta learn quantum physics, I'm watching a TTC video series on precisely that atm but I haven't got very far yet and a lot of things are simplified.
[editline]10th January 2014[/editline]
All of this is so weird to me
[QUOTE=MrJazzy;43479113]Guess I gotta learn quantum physics, I'm watching a TTC video series on precisely that atm but I haven't got very far yet and a lot of things are simplified.[/QUOTE]
they're always so simplified. I'm usually excited when I see some new physics special on and I watch it for a few minutes and get bored, because it's usually stuff I already know.
[QUOTE=MrJazzy;43479113]All of this is so weird to me[/QUOTE]
Anyone who doesn't think quantum mechanics is weird doesn't understand it well
[QUOTE=JohnnyMo1;43479205]they're always so simplified. I'm usually excited when I see some new physics special on and I watch it for a few minutes and get bored, because it's usually stuff I already know.[/quote]
I can definitely understand that, but in my case it's not so bad cause I don't know all the math and physics to really learn about it on a real level.
[quote]Anyone who doesn't think quantum mechanics is weird doesn't understand it well[/QUOTE]
Yeah this is true I guess
look at this fucking majestic galactic spiral
[img]http://i.imgur.com/345Ktjz.png[/img]
Amazing that, it doesn't matter how deep we look, there's always a ton of galaxies, even if matter is finite there's just so much of it.
Aren't there some stars that are even older (in lightyears) than the estimated time of the big bang? I always found that kind of weird.
[QUOTE=Stiffy360;43480201]Aren't there some stars that are even older (in lightyears) than the estimated time of the big bang? I always found that kind of weird.[/QUOTE]
No there are no such stars, that would be impossible.
[QUOTE=MrJazzy;43480850]No there are no such stars, that would be impossible.[/QUOTE]
Pretty sure I heard about some stars that were like that.
[URL="http://www.space.com/20112-oldest-known-star-universe.html"]Like the Methuselah star[/URL]
[QUOTE=Stiffy360;43481284]Pretty sure I heard about some stars that were like that.
[URL="http://www.space.com/20112-oldest-known-star-universe.html"]Like the Methuselah star[/URL][/QUOTE]
It says right in the article that when taking additional factors into account the star can be determined to be younger than the universe, which seems much more likely considering our current understanding of the universe :v:
[editline]10th January 2014[/editline]
Ofcourse that determination is uncertain too, but I doubt the estimated age of the universe is off by billions of years and I doubt even more that the star was created before the big bang
[QUOTE=MrJazzy;43481838]It says right in the article that when taking additional factors into account the star can be determined to be younger than the universe, which seems much more likely considering our current understanding of the universe :v:
[editline]10th January 2014[/editline]
Ofcourse that determination is uncertain too, but I doubt the estimated age of the universe is off by billions of years and I doubt even more that the star was created before the big bang[/QUOTE]
There may be stars even further than the Methuselah star though. We're always discovering new things, so something like that is not totally out of the question, especially since there are other travel time issues such as the Cosmic Microwave Background.
These are microwaves emitted from stars. However, what is weird is that the temperature is nearly equalized. Closer stars emit microwaves and heat source close to each other, then spread the heat to cooler more further regions. However, in the early universe, the temperature of the CMB would have been very different at different places in space due to the random nature of the initial conditions. The problem here is that the universe wouldn't have enough time to evenly distribute the CMB.
This has rather confused me quite a bit, especially since there doesn't seem to be any solution to this problem.
Also sources
Cosmology: The Origin and Evolution of Cosmic Structure
Possible solution to the horizon problem: Modified aging in massless scalar theories of gravity, Physical Review D (Particles, Fields, Gravitation, and Cosmology)
Hmm I don't know enough to say anything about that really, so I guess we'll just have to wait for JohnnyMo1 or someone else who might have a clue to give their opinion on it.
[QUOTE=Stiffy360;43482501]There may be stars even further than the Methuselah star though. We're always discovering new things, so something like that is not totally out of the question, especially since there are other travel time issues such as the Cosmic Microwave Background.
These are microwaves emitted from stars. However, what is weird is that the temperature is nearly equalized. Closer stars emit microwaves and heat source close to each other, then spread the heat to cooler more further regions. However, in the early universe, the temperature of the CMB would have been very different at different places in space due to the random nature of the initial conditions. The problem here is that the universe wouldn't have enough time to evenly distribute the CMB.
This has rather confused me quite a bit, especially since there doesn't seem to be any solution to this problem.
Also sources
Cosmology: The Origin and Evolution of Cosmic Structure
Possible solution to the horizon problem: Modified aging in massless scalar theories of gravity, Physical Review D (Particles, Fields, Gravitation, and Cosmology)[/QUOTE]
Uhmm, I might just have misunderstood this whole thing, but isn't the CMB evenly distributed since the universe was near thermal equilibirum at the time that photons could actually penetrate space?
[QUOTE=areolop;43466929]That doesnt even make sense. Its all going away from a point. If it wasnt a point, we'd see blueshift in some galaxies.[/QUOTE]
Funny thing about the universe. A lot of things don't make sense. That's why Religion came up with God and why science is full of smarty pants professors trying to figure it all out one step at a time.
Truth is, no one really knows how the universe came to be. The Big Bang is only one of several very likely explanations. I'm sure very complicated math can trace the direction galaxies are moving toward and thus finding out where they started, but since the universe is larger than we can see, for all we know the center is 15 known universe sizes in any direction. And because of that, we may never know.
[QUOTE=Stiffy360;43480201]Aren't there some stars that are even older (in lightyears) than the estimated time of the big bang? I always found that kind of weird.[/QUOTE]
Lightyears is a measurement of distance, not time
But yes, there are stars that are more than 13,8 billion lightyears away
Which is possible because he universe is expanding
[QUOTE=IceWarrior98;43483486]Funny thing about the universe. A lot of things don't make sense. That's why Religion came up with God and why science is full of smarty pants professors trying to figure it all out one step at a time.
Truth is, no one really knows how the universe came to be. The Big Bang is only one of several very likely explanations. I'm sure very complicated math can trace the direction galaxies are moving toward and thus finding out where they started, but since the universe is larger than we can see, for all we know the centre is 15 known universe sizes in any direction. And because of that, we may never know.[/QUOTE]
What centre?
[QUOTE=GoDong-DK;43484400]What centre?[/QUOTE]
Sorry, stupid auto correct changed center to centre...
[QUOTE=IceWarrior98;43483486]Funny thing about the universe. A lot of things don't make sense. That's why Religion came up with God and why science is full of smarty pants professors trying to figure it all out one step at a time.
Truth is, no one really knows how the universe came to be. The Big Bang is only one of several very likely explanations. I'm sure very complicated math can trace the direction galaxies are moving toward and thus finding out where they started, but since the universe is larger than we can see, for all we know the center is 15 known universe sizes in any direction. And because of that, we may never know.[/QUOTE]
Do you really have any clue what you're talking about?
[QUOTE=Falubii;43487604]Do you really have any clue what you're talking about?[/QUOTE]
To an extent yes. I'm no scientist but let's face it, how many of us here are? I go by what I read just like the rest of you.
[QUOTE=IceWarrior98;43487739]To an extent yes. I'm no scientist but let's face it, how many of us here are? I go by what I read just like the rest of you.[/QUOTE]
Obviously nobody knows everything about the beginning of the universe, but I'm not aware of any feasible alternatives to the Big Bang. As far as I know the standard model doesn't state anything about how the singularity came to be, only that it did exist and it started expanding. Also, you'd be surprised how many people here are scientists.
[QUOTE=Falubii;43487881]Obviously nobody knows everything about the beginning of the universe, but I'm not aware of any feasible alternatives to the Big Bang. As far as I know the standard model doesn't state anything about how the singularity came to be, only that it did exist and it started expanding. Also, you'd be surprised how many people here are scientists.[/QUOTE]
One of my favorite alternate theories (even though less likely than the big bang) is the multi-universe theory where scientists believe that our universe was created when two other universes touched each other creating an immense source of energy. It also ties into the big bang theory a bit by claiming that as how the big bang happened. This theory also suggests that if it were to ever happen again the immense energy would annihilate the universe as we know it.
It was even featured on a TV series. Forget which one. Probably one those crack pot documentaries, but hey it's all theory until one proves the others wrong.
[QUOTE=IceWarrior98;43487545]Sorry, stupid auto correct changed center to centre...[/QUOTE]
His point was there is no center.
[QUOTE=JohnnyMo1;43488813]His point was there is no center.[/QUOTE]
That we know of.
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