Infinite or finite

so what do you think?

finite, everything ends	33.3%	[ 3 ]
infinite. AND SO AM I	66.7%	[ 6 ]
Total Votes:			[ 9 ]

[Elskeleton]

(1) is the universe infinite?
(2) is matter infinite?
(3) is energy infinite?
(4) if the universe is infinite, does that mean the other two are too?

I've been reading a lot on energy and matter lately and it's pointing to finite, regardless of whether or not the universe is infinite. I just can't wrap my head around it properly I mean, yeah, the law of conservation of energy, but doesn't that mean we won't run out? Which means it is ...immortal?

I'm reading a lot of contradicting things like the mass-energy equivalence for example. Someone mentioned that all mass is matter, but not all matter is mass. Then there's the fact that space is never empty. So aren't they heavily related after all? Regarding finiteness?

I suppose the main thing is that I'm confused on this whole conservation thing.

[Morberticus]

Recent results from the BICEP2 experiment imply (but don't prove) our universe is future-eternal. Our observable region of space and time is one of many, which are constantly produced by an eternally-inflating universe.

BICEP2 Results

Eternal Inflation

It doesn't, however, imply the universe is past-eternal.

[edit] - Also, as an aside:

Matter can be difficult to define. It's not always helpful in explanations. Mass is the measure of the relation between a system's energy and momentum. More specifically:

Mass^2 = Energy^2 - Momentum^2

Sometimes you will hear people mention relativistic mass, which follows the simpler relation

Mass = Energy

Sometimes you will see people mention c, the speed of light, in these relations. That's just the result of using bad units for length and time.

[Elskeleton]

Morberticus

Recent results from the BICEP2 experiment imply (but don't prove) our universe is future-eternal. Our observable region of space and time is one of many, which are constantly produced by an eternally-inflating universe.

BICEP2 Results

Eternal Inflation

It doesn't, however, imply the universe is past-eternal.

Thank you! That's a very interesting take, this future-eternal. Does this also include the other two (it mentioned fractals, see), or is this strictly just the volume and expanding of the universe? Also, Is this only for our observable universe? It says "region".

[Elskeleton]

Morberticus

Recent results from the BICEP2 experiment imply (but don't prove) our universe is future-eternal. Our observable region of space and time is one of many, which are constantly produced by an eternally-inflating universe.

BICEP2 Results

Eternal Inflation

It doesn't, however, imply the universe is past-eternal.

[edit] - Also, as an aside:

Matter can be difficult to define. It's not always helpful in explanations. Mass is the measure of the relation between a system's energy and momentum. More specifically:

Mass^2 = Energy^2 - Momentum^2

Sometimes you will hear people mention relativistic mass, which follows the simpler relation

Mass = Energy

Sometimes you will see people mention c, the speed of light, in these relations. That's just the result of using bad units for length and time.

Oh yeah, so as energy in fact. So it all boils down to having to define these things properly to actually understand anything. Crust.

(This is pretty irrelevant, but what's with the ^2 in the equations, couldn't they do without?)

Mass = Energy? Or only in special relativity? I thought energy and mass are just interconvetible? Isn't Photon a type of energy that is massless? Oh wait oh wait oh wait yeah, only with mass-energy equivalence, hahahaaaaa thank you! I feel a little farther from confusion!

[Morberticus]

A photon has the same amount of energy as it has momentum, so its mass is:

Mass^2 = Energy^2 - Momentum^2 = 0
Mass = 0

It wouldn't be correct to call a photon a type of energy. Rather, a photon is a quantised excitation of the electromagnetic field that obeys the energy-momentum relation.

Quote:

I thought energy and mass are just interconvetible?

Don't think of energy and mass as fundamental "things" or "substances". Rather, they are properties that things have. E.g. If you have some system at rest, and you know its mass property "m", then you know the energy of the system too, thanks to Einstein's mass-energy equivalence.

A video on mass that might be of interest to you:

Quote:

That's a very interesting take, this future-eternal. Does this also include the other two (it mentioned fractals, see), or is this strictly just the volume and expanding of the universe?
Also, Is this only for our observable universe? It says "region" lol

I'm not sure I understand the question.

[Elskeleton]

Morberticus

A photon has the same amount of energy as it has momentum, so its mass is:

Mass^2 = Energy^2 - Momentum^2 = 0
Mass = 0

It wouldn't be correct to call a photon a type of energy. Rather, a photon is a quantised excitation of the electromagnetic field that obeys the energy-momentum relation.

Quote:

I thought energy and mass are just interconvetible?

Don't think of energy and mass as fundamental "things" or "substances". Rather, they are properties that things have. E.g. If you have some system at rest, and you know its mass property "m", then you know the energy of the system too, thanks to Einstein's mass-energy equivalence.

A video on mass that might be of interest to you:

Quote:

That's a very interesting take, this future-eternal. Does this also include the other two (it mentioned fractals, see), or is this strictly just the volume and expanding of the universe?
Also, Is this only for our observable universe? It says "region" lol

I'm not sure I understand the question.

Thanks for the video!!!!

what I mean by the question is, it says that the universe regarding volume is future-eternal
does this include energy and matter as well?

[Morberticus]

dissolve me

What I mean by the question is, it says that the universe regarding volume is future-eternal
does that include energy and matter as well? as future eternal? surprised

It would, yes.*

*Energy can be tricky to define in a cosmological framework. It is often described as the quantity that is conserved due to a particular symmetry of physical laws, and that symmetry can be hard to construct in an expanding universe without additional assumptions about how the universe behaves at infinity, and if you naively try to calculate the energy density of the universe in the context of a dynamical space and time, you will get 0.

In our observable pocket of the universe, mass might not last forever. If all of the mass in the observable universe is swallowed up by black holes, and these black holes "evaporate" into massless particles (via Hawking radiation), then the observable universe would contain no mass.

[Elskeleton]

Morberticus

dissolve me

What I mean by the question is, it says that the universe regarding volume is future-eternal
does that include energy and matter as well? as future eternal? surprised

It would, yes.*

*Energy can be tricky to define in a cosmological framework. It is often described as the quantity that is conserved due to a particular symmetry of physical laws, and that symmetry can be hard to construct in an expanding universe without additional assumptions about how the universe behaves at infinity, and if you naively try to calculate the energy density of the universe in the context of a dynamical space and time, you will get 0.

In our observable pocket of the universe, mass might not last forever. If all of the mass in the observable universe is swallowed up by black holes, and these black holes "evaporate" into massless particles (via Hawking radiation), then the observable universe would contain no mass.

Thanks so much you've been very helpful! ^^ I'll now play with that and turn it around my head.

[Vannak]

Morberticus

dissolve me

What I mean by the question is, it says that the universe regarding volume is future-eternal
does that include energy and matter as well? as future eternal? surprised

It would, yes.*

*Energy can be tricky to define in a cosmological framework. It is often described as the quantity that is conserved due to a particular symmetry of physical laws, and that symmetry can be hard to construct in an expanding universe without additional assumptions about how the universe behaves at infinity, and if you naively try to calculate the energy density of the universe in the context of a dynamical space and time, you will get 0.

In our observable pocket of the universe, mass might not last forever. If all of the mass in the observable universe is swallowed up by black holes, and these black holes "evaporate" into massless particles (via Hawking radiation), then the observable universe would contain no mass.

Its possible that hawking radiation would allow the emission of neutrinos, which would be an issue. Even if you don't have that, there should still exist virtual forces which only make sense in the context of massed particles.

To me, if you want to get rid of mass, it seems like you'd want to turn off the higgs field.

[Torixed]

dissolve me

These are simply my opinions based on some things i've learned in the past but...
(1) The universe is not infinite but it is ever changing.
(2) Matter is not infinite.
(3) Energy is also not infinite.
(4) Already answered...

If we agree that E=Mc^2 is true and we agree on the theory of conservation of matter, then we agree that matter can not be created or destroyed. However it can be changed. This theory has already been proven in the past in the "coal bed" experiment. Basically measured a liquid, the coal bed, and then streamed the liquid through the coal bed. After that the weight of the liquid was notably changed, however the difference in weight lost from the liquid, was equivalent to the gain of weight in the coal bed added to the "gas" or "vapor" that was captured from the coals as it escaped.
To clarify:
Coal bed (1) + Liquid (2) + Gas (0) = Coal bed (1.5) + Liquid (1) + Captured gas from coals (0.5)
1 + 2 + 0 = 1.5 + 1 + 0.5
3 = 3


Then their is E = Mc^2 which basically means Energy equals Mass multiplied by the speed of light squared.
Energy = (Mass) x (Speed of light)^2

Here is a documentary on it that i loved: https://www.youtube.com/watch?v=YgpD4XZP0uM

This shows their IS a way to change mass into energy in some sense and vice-versa. Though the amount of energy to create mass is enormous, it is possible. Human's have used this to transmute other materials into things like gold. However the process costs more than the gold is worth and the gold also ends up radioactive. On the other hand, splitting matter a mass into energy releases enormous amounts of energy. The atomic bomb is the perfect example of such, or nuclear reactors if you prefer to be less destructive.

Anyway this leads me back to the original question: "Is the universe Finite?"
Well That depends what you consider the "universe." If you consider the universe to be only where their is "matter" than yes it is finite. If you consider it to be any spot where there is a black void than honestly I'm not sure, but If i had to guess I'd still say it's finite.

My view of the universe is as follows: The big bang occurred, energy was dispersed rapidly from the "center" of the universe. The heat and energy created yatta yatta yatta, created the planets and stars. You already get how that works. Some theorize the universe than expands infinitely...
but I'm not so sure abut that.
One thought i came to was "black holes." Basically a mass with a gravitational pull as strong as a sun, but so small that it is incredibly easy to get close to the center of that pull and become trapped. Many people imagine a black hole as a "hole in space" or a "Well" that things fall into but that's incorrect. It's actually more like a miniature sphere on it's own that pulls things in from ALL directions. Some say that black holes "move" some say "they pull things towards itself". Though motion is all relevant to the things around the object your observing... I'd argue it does both. *shrug*

Anyway, my theory is that black holes are the REVERSE of the BIG BANG.
Eventually i figure the black holes will collect everything in the universe and pull themselves together. Then with so much energy collected the black hole will become unstable and collapse. Causing another "big bang." Thus the cycle repeats continuously. No matter is lost, none is gained. Simply changed over and over into something new.

"I mean, yeah, the law of conservation of energy, but doesn't that mean we won't run out? Which means it is...immortal?"
To clarify on this... if you mean that it never is used up, then your right to some degree.
Even after we breath in oxygen we still emit carbon dioxide. I'm not sure the exact ratios but the oxygen isn't simply destroyed. It's instead changed into carbon dioxide and our bodies use the oxygen and release some of it back out. Then the plants have at the CO2 and make Oxygen again. The cycle just repeats. Sure if their were no plants we would eventually "run out" of oxygen, but the original atoms that made up the oxygen would still be in the air, they would just be in Carbon dioxide instead of Oxygen [O2].

[OhDearie]

Infinity is a funny thing.

Imagine a library, with an infinite amount of red books and an infinite amount of blue books. One day, a man decides to check out all of the red books, throwing practicalities like transporting all those books into the wind. As he leaves with all the red books, the interesting thing is: the library has just as many books as it had before he arrived.

I don't think infinity exists outside the realms of maths and art.

1) The universe is very, very, very large and we haven't seen all of it yet, but I cannot say for certain that it is infinite. It certainly is infinite, for us. We are going to die out as a race before we touch a fraction of these worlds

The rest have already been answered and I have no more to add on those.

[calgarian]

lol jk, it prolly is finite. rolleyes

I got no facts, just opinion.

[Shokushu]

The Universe has been shown to be about as flat as we can measure it to be, meaning that it doesn't wrap around on itself.

So that means a finite universe must have edges. Edges would mean that material near the edge would have the gravity of the entire rest of the universe tugging in one direction, so it would be quite different from something in, say, the center of the universe. Likewise the material just past it would have some unique mix of forces working on it and so on all throughout the universe. Instead of seeing all sorts of differing configurations in this sort of stripe or ring when we look out to those distant galaxies they all seem to be rather homogenous.

By this reasoning we would expect the universe to be infinite. This would mean infinite mass, matter, energy, and probably quite a few sombreros.

Phiday

Infinity is a funny thing.

Imagine a library, with an infinite amount of red books and an infinite amount of blue books. One day, a man decides to check out all of the red books, throwing practicalities like transporting all those books into the wind. As he leaves with all the red books, the interesting thing is: the library has just as many books as it had before he arrived.

I don't think infinity exists outside the realms of maths and art.

1) The universe is very, very, very large and we haven't seen all of it yet, but I cannot say for certain that it is infinite. It certainly is infinite, for us. We are going to die out as a race before we touch a fraction of these worlds

The rest have already been answered and I have no more to add on those.

No, the library doesn't have the same amount of books. It still has an infinite amount of books, which is to say that we don't have ways of writing down how many books there are that distinguish between different sorts of infinity.

To take this more simply just look at a number line. That are infinitely many positive integers on it. We will call that A.
There are infinitely many negative integers on the line. We will call all of the positive and negative integers B.
B is clearly not the same as A. B=2A. These are both infinite, but of a different sort. You can't ever count off the final entry in either list, but because B contains everything that A does, and more, we know that it contains a different sort of infinity than A.

Likewise we can do the same thing for many other sets of numbers on the number line. Rational numbers and Irrational numbers being the next two logical steps. In a way we are looking at powers of infinity for those infinities.


So now for a concession: Yes, I understand fully that you were taught that all infinities are the same. This is very much the preferred model used in public education in the states, and probably many other countries with public education. What this isn't, is the only way to deal with infinity, and mathematicians have spent quite a lot of time dealing with infinity differently.

[Ask Jappleack]

Technically gravity is infinite energy alone if I think about it.
Like, everything constantly condensing, there doesn't need to be an energy input for that output of pressure.

[chainmailleman]

No-Mi-Jutsu-Yu

Technically gravity is infinite energy alone if I think about it.
Like, everything constantly condensing, there doesn't need to be an energy input for that output of pressure.

Gravity is a force. We still need distance (displacement), time, and mass to be considered energy...