If infinite, would the Universe be too hot?

[weeman]

Ever since the idea of the "Big Bang" was taken seriously, many astronomers have been searching for evidence supporting that it actually happened.<br /><br />Some evidence we see is the motions of galaxies moving away from us in every direction; also, we are able to witness the cosmic radiation background.<br /><br />However, I would think that the properties of thermodynamics should also be another sign of the Universe starting with with a BANG, and not being infinite. According to scientists, just after the big bang the Universe was very very very very hot. Fractions of a second after the blast, it may have been in excess of a quadrillion degrees Kelvin! Over the next 300,000 years after that, it became much much cooler. <br /><br />This is where I get confused. Many people still speculate that the Universe might be infinite. If all matter in the Universe were infinite, meaning its density is infinite, wouldn't thermodynamics give it infinite heat? How would so many astronomers say that it has cooled since its beginning if it were indeed infinite?<br /><br />If anyone can fill me in on this subject please do <img src="/images/icons/smile.gif" /> <br /><br /> <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>

 

[SpeedFreek]

The speculation is often that space might be infinite, but the amount of mass in it is finite. As Einstein put it, "finite but unbounded".<br /><br />But even if there was infinite mass in the universe, this doesn't mean it's density is infinite. If it was, the whole universe would be a black hole. I would take infinite in this case to mean "the stars go on forever" rather than "space is infinitely full of stars". <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[docm]

Matter isn't infinite else there wouldn't be empty space, hence no infinite heat. In fact the universe's expansion has caused the universe to cool.<br /><br />Also; look up M-theory, which turns the big bang into a big bump between two 11th dimensional membranes (aka: 'branes), eliminating the singularity and letting us look back in time to before the big bang. It also postulates a <i><b>multi-verse</b></i>; multiple parallel universes.<br /><br />M-theory primer;<br /><br />http://en.wikipedia.org/wiki/Introduction_to_m-theory<br /><br />PBS "Elegant Universe" mini-series online episodes;<br /><br />http://www.pbs.org/wgbh/nova/elegant/ <div class="Discussion_UserSignature"> </div>

 

[SpeedFreek]

<font color="yellow"> Matter isn't infinite else there wouldn't be empty space </font><br /><br />Infinity is a strange thing. If I use an example of a single line of rocks spaced 1 metre apart, the line being infinitely long, I have an infinite number of rocks. But there are empty spaces between them.<br /><br />I know current thinking is that there isn't an infinite number of stars in the universe, but if there were, that doesn't mean there wouldn't be any empty space. The stars would just go on forever. <br /><br />This is probably why infinity is often referred to as an irrational number! <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[alkalin]

<font color="yellow">Ever since the idea of the "Big Bang" was taken seriously, many astronomers have been searching for evidence supporting that it actually happened. </font><br /><br />Some people have not taken Big Bang seriously because it never came close to make any accurate prediction of anything. A good theory stands up if its predictions are accurate.<br /><br /><font color="yellow">Some evidence we see is the motions of galaxies moving away from us in every direction; also, we are able to witness the cosmic radiation background. </font><br /><br />There is no evidence that the universe is expanding. There is an assumption that due to the red shift we see in the distant universe that it is caused by Doppler. The red shift can be caused by what is called the Wolf effect. The CMB is very likely not due BB but to another cause as well. So the universe needn’t be expanding at all, or not in the way of current theory. <br /><br /><font color="yellow">However, I would think that the properties of thermodynamics should also be another sign of the Universe starting with with a BANG, and not being infinite. According to scientists, just after the big bang the Universe was very very very very hot. Fractions of a second after the blast, it may have been in excess of a quadrillion degrees Kelvin! Over the next 300,000 years after that, it became much much cooler. </font><br /><br />Here is where we can get in big trouble in this thought that the universe was very hot and started cooling immediately aft of the big bang. What caused all this heat in the first place?<br /><br /><font color="yellow">This is where I get confused. Many people still speculate that the Universe might be infinite. If all matter in the Universe were infinite, meaning its density is infinite, wouldn't thermodynamics give it infinite heat? How would so many astronomers say that it has cooled since its beginning if it were indeed infinite? </font><br /><br />Oh yes

 

[bonzelite]

right, as well an expanding and <i>accelerating</i> universe violates the laws of physics but is somehow allowed by turning a blind eye to myriad contradictions. <br /><br />big bang theory is the best they can come up with. so instead of admitting they have no idea how the universe came to be, they remain comfortable with a theory that is highly nonsensical upon closer scrutiny.

 

[weeman]

Seedfreak, I understand what you're saying. The emptiness of space might be infinite, but the matter that is in our Universe may not be. This is the exact way that I have thought of the Universe for many years. <br /><br />Now lets say that the matter in the Universe is infinite. Why would we see galaxies appear to be younger and younger as we gaze further in space? If indeed matter were infinite, it has no real beginning, so galaxies shouldn't show a steady decrease in age, with an increase of distance from Earth. We might be able to see new galaxies forming anywhere, or see galaxies that are incredibly old, very far away. So, it could be true that the doppler shift may not tell us anything about their velocity. However, it is important to keep in mind that light is known as the "cosmic messenger", without it, we would know nothing of the Universe. So we must trust light, and the rest of the electromagnetic spectrum, that it will give us the most accurate information possible of the universe around us. <br /><br />It's obviously hard for us to say that the Universe has a beginning when we can't see it. Light cannot travel instantly through space, so we are limited to our knowledge that we can see within our observable universe.<br /><br />Lets say that distant galaxies are indeed moving at very high velocities away from us. We could then conclude that galaxies about 13-14 billion lightyears away might have doubled that distance in the time it has taken their light to reach Earth (roughly speaking). That would mean our observable universe would be more on the order of 26-28 billion lightyears (if light could travel instantaneously), giving an estimated diameter of the Universe to be about 56 billion lightyears present day. This of course has to depend on the Big Bang model, and that the Universe could have had a single beginning at some point in time. <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>

 

[vandivx]

"Now lets say that the matter in the Universe is infinite."<br />---------<br />this quote is as good as another posters' here (as everybody on this thread is making the same mistake)<br /><br />no mater how much matter there is, it is always some finite (i.e. definite) amount of matter that is out there, no more and no less<br /><br />infinity is not an 'amount' of something and can never be, in fact infinity can never be used to quantify anything since it is not a number but an abstract concept which is meant only to be used within mathematics in connection with limits, it should NEVER be applied to concrete reality existing out there which is always finite in all respects, everything that is physical is by definition finite<br /><br />some time back I posted a link to my paper on infinity but nobody made a comment on it, like if nobody went to look, I suppose some may have visited but found it uninteresting, most people find real serious physics/mathematics uninteresting and dull unless it is obscure (and therefore 'deep') and can't be understood, only then it ignites some interest LOL<br /><br />I could answer that query on another thread why can't matter move faster than light and supply physical picture of gravitation that goes beyond Einstein as well as provide physical explanation for special relativity - why the speed of c is constant and why matter can't move faster than it - but I feel nobody would be interested in that because it wouldn't read in the style of Star Trek<br /><br />vanDivX <div class="Discussion_UserSignature"> </div>

 

[SpeedFreek]

I have to admit that infinity intrigues me, and I obviously do not truly understand the concept.<br /><br />From what you say, I take it I cannot state as true the abstract example of a line of rocks spaced 1 metre apart, with the line being infinitely long, meaning I have an infinite number of rocks? <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[rfoshaug]

I don't know much about infinity, but i know this: If there were an infinite number of stars in the universe and each star produces some amount of light, then combined they should produce an infinite amount of light.<br /><br />But it is dark at night. Hence there is not an infinite number of stars in the universe. <div class="Discussion_UserSignature"> <p><font color="#ff9900">----------------------------------</font></p><p><font color="#ff9900">My minds have many opinions</font></p> </div>

 

[SpeedFreek]

But would it not be the case that <b> if </b> there were an infinite number of stars in the universe, and yet we could only see a finite amount of them in our observable universe due to the expansion of space, the speed of light and the age of the universe, there would <b> not </b> be an infinite amount of star-light in the night sky? The night could theoretically look just as it does? <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[Mee_n_Mac]

<font color="yellow"><i>"I don't know much about infinity, but i know this: If there were an infinite number of stars in the universe and each star produces some amount of light, then combined they should produce an infinite amount of light. <br />But it is dark at night. Hence there is not an infinite number of stars in the universe. "</i></font><br /><br />See Olbers' paradox. <div class="Discussion_UserSignature"> <p>-----------------------------------------------------</p><p><font color="#ff0000">Ask not what your Forum Software can do do on you,</font></p><p><font color="#ff0000">Ask it to, please for the love of all that's Holy, <strong>STOP</strong> !</font></p> </div>

 

[alkalin]

Wikipedia’s explanation badly needs revision. Maybe there was an assumption at one time that stars should be visible everywhere, and in the past the stars in our galaxy were the only known ones. Olber’s ideas are out of date. Go out on a clear night and observe the Milky Way, then compare it to Andromeda. Andromeda is very comparable to our galaxy in size and brightness. Yes, you can see Andromeda with the naked eye, but it only appears as a faint blob barely visible. Why? The explanation is rather easy. Andromeda is about one or two million light years from us, while the center of our milky way is only about 25 thousand light years away. <br /><br /><font color="red">THERE IS AN INVERSE SQUARE LAW TO CONTEND WITH.</font><br /><br />Some people will argue the Earth is flat also.<br />

 

[bonzelite]

olbers paradox isn't true. <br /><br />even if stars were infinite, we wouldn't see them all. <br /><br /><br />

 

[vandivx]

"From what you say, I take it I cannot state as true the abstract example of a line of rocks spaced 1 metre apart, with the line being infinitely long, meaning I have an infinite number of rocks?"<br />---------<br />the line would always be only as long as you made it (extended it) to suit your needs at the moment, that is, it would always be some given definite length at any moment and could be made longer as required without any limit and any number of rocks laid on it (spaced one meter appart) would always be some concrete, i.e., definite number of them at anyone moment even if it was openeded how many you could lay out on that line, you could always lay out more<br /><br />the actual, the real, the physical is always finite even if you make an abstract thought experiment like this one in which you don't have to consider how to implement it in a real physical experiment<br /><br />the point where you smuggled a fatal flaw into your argument was when you said "line being 'infinitely long'... " <br /><br />'infinitely long' is a false premise which renders your whole argument false since you can't meaningfully explain what you mean by that, it is like a sleigh of hand by which magician does the 'magic', once he gets away with it, everything that follows after that looks like true magic, like there is an argument out there I believe which ends with the nonsensical but inescapable conclusion (if you missed the false premise early in the argument) that 1=2<br /><br />how long is 'infinitely long'? that term on the one hand claims on it face 'how long' that line is but on the other it doesn't say how long it is, it just says that the length of that line is 'not finite' (that's what the prefix 'in' means - a negation), i.e., that the line has no finite length, that is in other words it has no definite (de-finite) length and that is how 'long' it supposedly is !? <br /><br />'infinitely long line' is a logically impossible (false) term in that it claims on its face a 'definite leng <div class="Discussion_UserSignature"> </div>

 

[nova_explored]

hey vandivx, okay i took the time to read your paper, or a bulk of it, and i just don't know what you are trying to say here or with it. it seems like the thrust of the paper is to discount infinity as a real or practical system in a field of study, namely mathematics and argue for infinity's abstract structure as its sole purpose, unusable in real-world situations, again, that being mathematical theory. <br /><br />what are we talking about here?<br /><br />infinity is a concept. but get this, PI is an inifinite number for a finite system, a circle. a closed system. the fact that PI is inifinite is pretty significant. <div class="Discussion_UserSignature"> </div>

 

[oscar1]

Onassis once said "you are not rich if you can count your money". Who knows, a derivative may be "there would be no universe if we could count all the stars". But an infinite universe or not, I don't find it too difficult to understand that mortals such as us cannot ever comprehend infinity, mathematically or otherwise.

 

[vandivx]

"it seems like the thrust of the paper is to discount infinity as a real or practical system in a field of study, namely mathematics and argue for infinity's abstract structure as its sole purpose, unusable in real-world situations, again, that being mathematical theory."<br />----<br /><br />on the contrary, the whole thrust of that paper is that infinity is to be used solely for mathematical purposes - the way it is used in mathematics since the time it was invented<br /><br />where it shouldn't be used is in the description of physical reality like when we talk about infinite number of stars or infinite universe, that's total nonsense - the stars that exist as of now are some finite number of them and it will always be finite number, never mind we can't ever count their multitude, same for universe, if one can actually talk about its size and lets assume we can, then the universe must have some definite size at a given instant of time whatever it may be, it cannot be infinite, that's just non sensical, everything in reality must perforce be finite, definite, that is hallmark of reality if anything is<br /><br />otherwise thx for reading it, I did the same myself now also because I wrote it many years back and didn't quite remember all I wrote there after all that time and I see now that I should rewrite it a bit, some sentences need rebuilding and the grammar is not without faults either (English is not my native language) but the basic thrust is there, perhaps not as clear as it should be I admit, when I rewrite it I will make sure it is more clearly stated<br /><br />the thrust of the paper is that infinity is a tool of mathematics for use solely within mathematics (as it always was used in mathematics) where it has definite purpose, outside mathematics it represents misuse<br /><br />mathematics can use infinity in its calculation in physics or astronomy (it can be applied to real world that way) but it doesn't have any meaning when it is applied directly to describe phy <div class="Discussion_UserSignature"> </div>

 

[vandivx]

"I don't find it too difficult to understand that mortals such as us cannot ever comprehend infinity, mathematically or otherwise."<br />-----<br />but you do realize that us mortals are the only ones who can ever comprehend anything...<br /><br />my opinion is that if something seems incomprehensible it means we made a mistake somewhere in our approach in thinking of it and that we should rethink our ways<br /><br />vanDivX <div class="Discussion_UserSignature"> </div>

 

[vogon13]

As noted in the HST views of the Andromeda galaxy, with sufficient magnification we note discrete stars in Andromeda. We are still seeing in that direction, a significant quantity of black sky. <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[vandivx]

"infinity is a concept. but get this, PI is an inifinite number for a finite system, a circle. a closed system. the fact that PI is inifinite is pretty significant."<br />---<br /><br />I will comment separately on this one<br /><br />observe that Pi is a ratio of circumference to diameter, that is a ratio of a curved line to a straight line, each of which of itself is a perfectly definite, finite quantity<br /><br />the fact that Pi is an infinite non-repeating decimal does not mean that the circle is somehow an example of a physically existing infinite or indefinite object (at least that's how I interpret your objection), right triangles exist that have one unit long sides with hypotenuse equal to square root of two - the irrational number - but that also has no bearing on actual reality which is totally rational the last time I looked (the hypotenuse of such right triangle has perfectly definite length)<br /><br />vanDivX <div class="Discussion_UserSignature"> </div>

 

[oscar1]

"but you do realize that us mortals are the only ones who can ever comprehend anything..."<br /><br />No I don't, because I don't know if we are the only ones.<br /><br />"my opinion is that if something seems incomprehensible it means we made a mistake somewhere in our approach in thinking of it and that we should rethink our ways"<br /><br />Like all of us, you like to find the answer. You feel however, that we should find the answer in mathemetics. Perhaps the answer will ultimately be found there, but in the interim we need 'infinity' to toy with. <br /><br />But I do agree that 'infinity' carries a similar paradox as does time travel:<br /><br />-If the universe was 'created' (by God?) at some point, that what created it must be infinite. Yet, if the universe is infinite, it never needed creation.-<br /><br />In other words, that what began the universe, if it did begin, must have been there, and that what caused 'that what began..' must have been there before it, before it, before it,......<br /><br /><br />

 

[SpeedFreek]

Thank you for that explanation <img src="/images/icons/smile.gif" /> I will try not to misuse infinity in future. <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[kmarinas86]

http://en.wikipedia.org/wiki/Olbers%27_paradox#Myths_and_alternative_explanations<br /><br />I added some math to provide quantitative support for the idea that some types of fractal distribution of stars in an infinite cosmos do not lead to infinite brightness.

 

[bonzelite]

<font color="yellow"><br />Point of fact, how could ANY scientific observation EVER conclude that the universe was 'infinite'? </font><br /><br />good point. <br /><br />our science is very limited in scope, particularly with the (allegedly) empirically derived, often abstractly "model based," cosmology of today. it cannot supply nor stand as the ulitmate measure of reality. the cosmos is beyond ultimate direct human observation and conclusion. it is beyond human understanding; it is beyond the infinite. our science when faltering with explanations can indeed <i>imply</i> the infinite, as it does so when necessary anyway! <br /><br />to steadfastly claim that a current model of the cosmos' shape, size, age, nature, is accurate is beyond the laughable; to dismiss a possible infinite state of the comsos is likewise premature.