Big Bang 1of4: Expanding infinity

[SuperMagnetizer]

IF the Universe is infinite and IF the Universe is expanding, then IF it is accelerating as it does so -- all of which I accept -- then the conservation of mass and energy is meaningless, is it not? New matter and energy could be continuously being created all the time (somehow), thereby keeping the Universe "full", right? Forget the Big Bang, it no longer makes any sense. And please don't bother me with dark matter & dark energy either.

[ultrakool]

dark energy? dark matter? really? it's amazing however ludicrous a concept may be, if it's couched in sufficiently "scienticfic" terminology, it will pass for feasibility. this is illogical nonsense. hypothetical entities? things that we have never observed, all passing for explanations of an exposion that should be coming to a halt instead of accelerating. it's time to shelf this outdated model

[BasqueGranBeats]

"It turns out there's lots of room at infinity" - my favortie quote haha

[foathkent]

this is totally stans dad out of southpark

[Guitarlots]

This guy is amazing, I have absolutely no idea what he's talking about, but it sounds fantastic. It makes me want to bake up huge., take the final and flunk out huge.

I am humongous ruler of the waste land. Give me the oil, the pumps, and the whole compound, and I'll spare your lives

[hyrenata]

I dont know whether to believe this, it is slightly out of date. WMAP seems to measure the universe background radiation fromt he big band and using light years we can approximate the size?

[blardosplats]

So then, the Universe is expanding into nothing?

Nothing must be something.

Is 'the Universe' expanding into 'the Universe'?

Then the Universe might be something finite, and what then is outside of the Universe?

Is there anyone that can show that the raisins in the bread are getting further apart, yet the bread remains the same size? Otherwise, that whole analogy makes no sense.

[Guitarlots]

@blardosplats Nothing from nothing leaves nothing. But you gotta have something if you want to dance with me...or pay bills

[theboombody]

Consider the infinite real number sets (0,1] and (0,2]. ANY real analysis book will tell you they have a 1 to 1 ratio so are essentially the same size, but they're also a 2 to 1 ratio as well. Just add 1 to each number in the first set. The books I've seen don't mention that for some reason. Maybe because it's too intutive, but I think it's still important to bring up. I'd say one is twice the size of the other because it has intuition to back it up as well. Intuition isn't negligible.

[shamalbaba]

Is the expansion of universe having an impact on the density of matter in universe? If not then more matter must be constantly forming. In this case do we know what the format of the new matter is?

[theinquisitor]

As I understand it, the expansion of space is indeed decreasing the overall density of matter. Formation of new matter would violate the law of conservation of mass, and as far as I know has not been observed.

The expansion will continue into the far future until it tears apart galaxies and solar systems. Even the atoms and subatomic particles will be torn apart in what's called the "Big Rip", leaving only an increasingly dilute volume of energy. However this much is far from certain as of yet.

[EvReSbOMyName]

Thereis no "law" of conservation of matter as I understand. The one better describing this is the law of conservation of mass-energy desrcibed my Einstein's equation E=mc2

[Fredder132]

I have a sincere question. Where can infinity expand to if it's already infinite?

[theinquisitor]

Infinity is a funny thing. Imagine you have a hotel with an infinity of rooms and an infinity of guests. Then an infinity of new guests arrives and wants accomodation. No room right?

Well just ask each current guest to move to a room number double their current room number. 1 to 2, 2 to 4, etc. Then have the new guests fill in the intervening rooms. It's counter-intuitive but infinity is not like a large finite number.

Check wikipedia for "Hilbert's paradox of the Grand Hotel" for more detail.

[Fredder132]

Because it's a paradox can you really have two infinites in that single dimension? Rooms vs people being the dimension.

[theinquisitor]

Not quite sure what you're asking, but infinity x 2 is still infinity. Infinity x infinity is still infinity.

To go back to the problem of infinite space expanding, it's important to realise that it's not expanding into some more empty space around it. The space itself is expanding.

There's no reason our evolved finite brains can intuitively understand the infinite. We have to rely on the maths. I don't get it in my gut, but apparently the maths works out, although maths is not my strong suit.

[Fredder132]

Alright I just realized the problem with Hilbert's Paradox. You can't ask everyone to move into the room 2x the number because there will always be somebody in the room 2x that number EVEN if you ask EVERYONE to move up one room. It would only work if there were a finite number of people.

[theinquisitor]

While the room that the guest is moving to would have an occupant, that occupant will himself be moving to another room. If they were moving simultaneously it wouldn't be a problem.

The room you're moving into will always have a previous occupant, but that occupant will always have just left to go to his new room. You'll never run out of rooms that have a guest just leaving.

[Fredder132]

Anyways does Hilberts Paradox really compare to space? When you expand space you can have room number such as .5 to expand into 1 and .25 to expand into .5 etc. down to the infinitesimal. Then, all the figurative rooms of space will remain occupied even if doubled. Doubling the infinite space will also still yield the exact same amount of infinite space. Unless expand is not used traditionally, no matter how much space expands, it's still the same infinite. Am I rambling or do I make any sense?

[theinquisitor]

I think the problem lies with the phrase "exact same amount of infinite space". Since infinite means without limit, it doesn't make much sense to talk about an exact amount of something unlimited. It's not an amount, it's limitless. Unmeasurable in principle.

The effect is that objects inside space are moving further apart, with a speed that is proportional to the distance. At a certain distance, the speed is greater than light speed, and so is effectively cut off from our part of the universe.

[Fredder132]

Alright, well I'm going to stop trying to understand these things for a little bit and let my mind rest on these questions. Who knows maybe my subconscious will conclude something, it seems to work most of the time. Thanks for your help.

[theinquisitor]

I have a hard time getting my head around it too. We evolved to understand things on a terrestial scale, so there's no reason to expect that our minds would easily conform to contemplation of the infinite. That's why we need science. Through mathematics and logic and the scientific method, we can divine truths that our intuitions never could. Apparently it all works out in the equations, but even the best physicists don't understand it on a gut level. Except maybe Einstein.

[powercore0]

Can these scientists prove that life was created from the big bang theory? Hence the word THEORY which is pretty much saying it what the scientists believe happened and they cant actually prove the big bang theory created life that's why the call it the BIG BANG *THEORY* Id like to see some one physically prove that the big bang theory actually happened .

[theinquisitor]

Ah the tired old ignorance about the scientific meaning of the word theory. You know the germ theory of disease is just a theory too? I'm sure you'll not be needing any antibiotics any more now you know that since it's *only a THEORY*.

Oh and gravity, that's just a theory too, same with electromagnetism. So feel free to jump off a building after sticking a fork into an electrical socket because they're JUST theories.

But if you want to hear the evidence, then listen to the rest of the lecture.

[ipLelouch]

Well thats what we have so far so deal with it. I don't see you coming up with anything better and everything is based on Theories.....

[kanchi2015]

Why the hell are you talking about abiogenesis when this guy is talking about big bang theory?

big bang theory was not made to explain why you forgot to lace your shoes this morning, it's to help understand the big bang.

go bother other people with your crap.

[theinquisitor]

I can't believe I actually missed that. I was so distracted by his irritating misuse of the word theory I didn't even mention that he actually thinks the big bang theory is about the origin of life.

Some people's scientific illiteracy is just depressing. In the age of information, when people have the opportunity to really answer some of the greatest questions ever asked, people retreat into ignorance and superstition. History will call this the stupid age.

[weetbixngluten]

a bowl of paradoxes with milk

[weetbixngluten]

in order for things to be possible things also need impossible, trying to 'figure out','everything' is the same as trying to evade dying, if it were possible would you ultimately really want to anyway, and if you knew everything you would be equal to a rock or a piece of lint, also, how can anybody disprove that either of those have infinate wisdom :)

[MrKappaBeta]

So... If we have not found the finite "edge" to the universe. The "Dark Ages" between the formation of the galaxies and the instance of a "Bang" has no direct observational evidence to my knowledge and the CMB is isotropic. I cannot see why anyone could use the CMB as evidence for a finite universe. The boundaries clearly have not been found or defined. It is currently infinite until proven finite. Does anyone have anything which suggests otherwise?

[francoisgbergeron]

To theinquisitor. Actually then, every atom in your body should jump simultaneously to the left an infinity of times.

[theinquisitor]

Well, it should happen to some fraction of the infinite number of instances of me, but the odds for any individual instance of me are still astronomical.

[francoisgbergeron]

If space and therefore events are infinite, is there anything that can NOT happen? Over and over again in fact?

[theinquisitor]

If the universe is infinite, then everything that's possible must happen somewhere, sometime. I suspect there are things that are beyond the limits of physics, but given quantum effects, that's not much. It's possible that every atom in my body will simeltaneously jump one foot to the left, but probabilistically, it would take longer than the age of the universe for it to have a good chance of happening, but in an infinite universe, that kind of thing would have to happen at some point.

[theinquisitor]

And yeah, everything would also necessarily have to be happening over and over again, an infinite number of times. Seems pretty redundant doesn't it? Such things would be happening so far away that none of their effects could ever reach us (at least not for a very very long time), since nothing travels faster than light and so in that sense they are as removed from us as if they were in a different universe. There may also be an infinite number of other universes.

[theinquisitor]

One thing that we know hasn't happened anywhere in the infinite universe (if it's infinite), is some alien evil genius inventing and employing an instant universe destroying machine. Such a thing must not have happened yet, or we obviously wouldn't be around talking about it.

[halcyonyear]

Berkley Physics?

I hope it's Physics 101, for dummies...

[theinquisitor]

Well, it's physics for future presidents, and some of them are dummies, so perhaps.

[weetbixngluten]

i think we can never have all the answers if there is such a thing as infinity, no matter how much wisdom you gain there will never be a time when we can say we understand infinity

[EdgeStormcrow]

This lecturer is horrid.. He drops random science terms like they are hot.. he speaks of the paradigms of science to be absolute.. which would stretch photonic wavelengths. he produces no math for his claims in any of his lecures.. he drew differently separated dots on 2 sheets of paper and presupposed implications of hubble's law from that.. A typical armchair scientist in my opinion..

[QuantumMaths]

This is a Physics for Future Presidents lecture... I think (I hope) it's a layman lecture.

[theinquisitor]

"I think (I hope) it's a layman lecture."

It is, although I think he does refer to some concepts covered in previous lectures. The whole course is available on the ucberkeley channel, link in description box.

[WolYou]

Room? The universe doesn't expand "into something". Without universe, there is nothing. So the universe expands expands into nothing not into some "infinit" room.

[dudevenom]

this dude is onto something :D

[Metallic7Dust]

I love these lectures, Richard is a brilliant professor, when he says that there's "no problem" to the "what is the universe expanding into?" question I don't think he really answers the question... he just says infinity has a lot of space to expand into. So in essence, the universe is expanding into infinity... but if the universe is inifinite, how can that be... etc. etc. I don't think he really answered this question very well because I don't think we really have any good answers for it yet

[SnowConeStudios]

Hey Inquisitor, i've got a question that's been bothering me. if the universe started out with all the matter of the universe in a small, infinitely dense region of space, wouldn't that just result in singularity? so how could expnsion occur if the universe were just pretty much a black hole?

[theinquisitor]

As far as I know, that's one of the unanswered questions in science. The problem is that quantum physics applies to objects that are very small, and relativity applies to objects that are very massive. We can make predictions about the behaviour of these two in isolation, but when both are combined in a black hole or the big bang singularity, the theories don't work together and the answers become meaningless, the theory breaks down...

[theinquisitor]

However, there have been speculations based on the similarity between black holes and the big bang singularity. There were ideas that black holes had other ends to them called white holes from which matter and energy spew out. These haven't been found. However a white hole sounds a lot like the big bang. Perhaps our universe formed inside a black hole in another universe, and that black holes in our universe give birth to "baby universes" which continuously "bud off".

[Metallic7Dust]

I hate to be the one to do this, but if that is the case... and I think this white hole theory actually makes good sense... then what are the origins of that original black hole?... another black hole? Is there an original black hole? Is the universe eternal then?

[theinquisitor]

Indeed, the white hole idea doesn't really answer the question of origins, it just moves it back a step. Since this is conjecture as it is, further questions inevitably end up in philosophical arguments, as our knowledge of these things approaches zero. However, there is a phenomenon in quantum physics called pair production, in which a particle and anti-particle can spontaneously arise out of the quantum uncertainty or chaos.

[theinquisitor]

Perhaps there is an empty parent universe, which has some kind of fundamental chaoticness to it. "Nothing" cannot be bound, it cannot be defined, or known, and so it fluctuates. We see this in things like pair production of quantum particles. If you create an anti-particle and a particle, their energies even out to zero. So you can get something from nothing if you also get an equal amount of anti-something. Perhaps the ultimate origin of reality is in fundamental chaotic nothingness.

[rbolo29]

The Universe won't expand forever. It is expanding as a whole(decompressing from the big bang), while gravity slowly sucks in the fabric of SpaceTime on a small scale. Matter is using up SpaceTime to exist. We feel the sucking in of SpaceTime and call it gravity. So we are really being pushed against the Earth by the sucking action. SpaceTime is the fuel allowing matter to transition into the future.

[theinquisitor]

The latest measurements show that the influence of the dark energy exceeds the gravitational influence. The rate of expansion of the universe is increasing. The doppler shift in the frequency tells us the relative motion of the star emitting the light. The very light of the heavens itself is what tells us this.

Your ideas about space time being "used up" are nothing to do with physics I've heard about. Read up on relativity to learn about what gravity actually is.

[SIP100]

Hey inquisitor tell me if I got this right he's saying that the universe is infinitely large, and that the big bang was also then close to infinitely dense and at any relative point in it infinitely large and when it expanded "the bang part" it was an infinite subset expanding out in another infinite set but the relative pos. of all matter is now gaining room in between each other reducing the initial density, it explains why everything expands relative to every other thing quite nicely.

[theinquisitor]

Yeah I think that right, the expansion wasn't really an increase in size of the universe, but a decrease in relative density. It's useful to remember that because of relativity, space is subject to distortion. The particles are moving away from each I think mostly because the space itself is expanding. At the time of "inflation" it is thought that space expanded very rapidly, faster than the speed of light until it got to a significant size.

[Metallic7Dust]

I wish I understood what you just wrote because it sounds cool. How is expansion a result of decompression? You say gravity is slowly sucking in the fabric of spacetime... what is gravity sucking spacetime into?... itself? another dimension?

[eye8one2]

I wonder what this professor would have to say about Neil Adams and the Expansion theory related to planets? Just food for thought.

[ajeetkunedodude]

So as we can see. Science clearly falls behind the bible.

[ALogicalConstruct]

That syllogism was flawless..... hahahaha, that was rich.

[ajeetkunedodude]

However with only one exception. For something to come into existence there had to be something to produce its existence. And that something would have to be out with time space and matter. This is what your bible has been telling you all for thousands of years.

How slow can an evolutionist go. Good try though.

[Metallic7Dust]

Does the Bible say that "God exists outside space, matter and time"? Please don't use the word "eternal" either... I want to know where the Bible specifically talks about space and time. Seriously... if it does, could you point me to the verse because my friends and I argue about this all the time. If not, then please stop.

[akontistiss]

using the bible you will only get more confused.. You should be more openminded to understand these things and realise that there are further compicated theories than "GOD"

[ajeetkunedodude]

Number do not exist when there is no time or method. What is a number or time to someone who is dead or how long can you keep on calculating numbers when you have to come to an end.

You see science, observation and commonsense tells us that if something is expanding, it needs somewhere or something in which to expand. This guy does not have the answer. there is no beginning that cannot end.

[albapollonia]

well this is only a theory.nathing can be proved

[ALogicalConstruct]

That doesn't mean that a "god theory" is equal to a expansionary universe theory, or the theory of evolution.

God theory = Flying spaghetti monster theory

Those are not in the same league as scientific theories.

[aimgood]

God- how did you do it?

[armcon3012]

beutiful lecture!! post more of this. simple, clear and concise!. good for you!

[wfl17]

whats he talking about?

[ESImatrix]

gregjockca: I'm just wondering who you're calling a dork? What is your stance on the cause of the existence of the universe?

[num3ric]

Not the kind of response(gregjocka) I thought I'd get indeed, but I don't care. My question was actually quite mathematical. I'm going to repeat it again in hope someone a bit serious could help me. My manual of physics says, at the beginning (t=10^-43 s), the entire universe was smaller than a proton. HOW CAN THAT BE WHEN WE SAY THE UNIVERSE IS INFINITE? How could ANYTHING with a delimited size (or even smaller/earlier, a singularity) become infinite in the physical world?

[DVDjHex]

The universe near t = 0 would require extremely large spacetime curvature. How large no one knows since both general relativity and quantum mechanics become of no use near (or at) t = 0. The closer we get to thinking we understand the big bang, the further one is removed from the realm of science, until, at the origin itself, science fiction is attained.

[num3ric]

Ok, I'm reading the comments and if you talk about a singularity, it's basically the opposite of infinitely big. Then how can a point "expand" into infinity? I mean, if I reverse what is shown in this video, the result is a universe infinitely DENSE & STILL infinitely BIG, not infinitely SMALL. Does this imply something about the creation of space itself? Then, that would make everything incomprehensible, at least for me.

[Rocksteady3000]

This guy is a great lecturer. I have a couple questions about the big bang singularity:

1) if it had a diameter, what was it?

2) was it composed of matter or energy?

Does anybody know?

[theinquisitor]

The big bang singularity is much like a black hole. A point of infinite density and infinite smallness. There's no recognisable matter, the electromagnetic and nuclear forces are overcome and subatomic particles are crushed into things we don't understand yet. The concentration of energy causes the very forces of nature to change and merge. Predictions fail at a fraction of a second after the big bang singularity. Before that is the mystery they call t=0.

[ESImatrix]

theinquisitor: Much thanks for responding. This Muller series is great btw. Now I think you've already hinted at the answer to my next question when you mention the word "mystery", but I'll ask anyway.

At the beginning, was the universe in a state of non-existence? In other words, can the universe still be regarded as eternal, with no beginning and no end?

Thanks again.

[theinquisitor]

Well non-existence isn't a state of being so I'm not sure what you mean.

It's possible that the singularity was a result of something else in another universe or something. The resemblance of black holes to the big bang singularity might not be a coincidence. Maybe the big bang is the other side of a black hole in another universe. There could be universes spawning from other universes in a cyclical way. That's just wild speculation though.

[ESImatrix]

theinquisitor:(part1/4) Thanks again for your input. I'm in a debate with a apologetic over the existence of god. He's arguing for it's existence with the Regression Argument. Basically this argument is that "every cause has an effect". If you go far back enough, one realizes that something has to be eternal. The question is" What is that something?

[DVDjHex]

Great question. I'll take it: Eternal would be, e.g., the zero point energy fluctuations. Indeed they are irreducible and so always present. Secondly: spacetime would be eternal, since there can be no boundary condition without breaking down the natural laws of physics, without leading to irreconcilable paradoxes, i.e., regarding past and future events. Conclusion: the big bang theory along with the event itself anr not consistent with observations.

[ESImatrix]

DVDjHex: So would you conclude that the universe is "eternal, thus in terms of regression, an eternal entity is not required."?

[DVDjHex]

I'm not sure what you mean by "regression." If you refer to back in time you are correct. I conclude spacetime is infinite as time t tends to minus infinity and as time t tends to plus infinity. Thus there was no begining, or big bang-type event. There was no t = 0, no 'birth' of the universe, and finally, no eternal entity (like god) is required. The only thing that is eternal (irreducible) is the ZPE and ZPF (F is for fluctuations) or ground-state energy, along with spacetime.

[ESImatrix]

DVDjHex: Thanks for the feedback. I think we're on the same page when we're taking about "regression".

When I typed "regression", I was refering to the "cause and effect" argument of apologetics. They like to argue that every effect has a cause. If you go far back enough, at some point you must decide if either the universe is eternal, or there is a "divine cause", that is eternal. They argue that it was this "divine cause" that "pushed over the first cosmological domino".

[DVDjHex]

Yes, we are on the same page. From the moment we understand the something is irreducible (ground-state energy or ZPE) the chicken-egg argument vanishes, since there is no first-cause or initial condition. The big bang suffers in this sense. That is one reason why the big bang event was removed from the theory.

[Metallic7Dust]

How can something be irreducible? Is this "something" you're referring to supposed to be Time itself? First you couldn't get smaller than an atom, then a proton, then a quark, now a "string"... pretty soon we'll have theories for what strings are made up of.

[ESImatrix]

theinquisitor:(part2/4) He's arguing that that the universe is not eternal, thus in terms of regression, an eternal entity is required. Conversely, I'm arguing that the universe is eternal, thus in terms of regression, an eternal entity is not required.

[ESImatrix]

theinquisitor:(part3/4) My argument for an eternal universe is this:

1-the universe exists

2-the universe is made up of energy and matter

3-all matter is energy (E=mc^2)

4-energy cannot be created or destroyed (1st Law of thermodyanamics)

[ESImatrix]

theinquisitor:(part4/4)

5-because the universe is made up of energy and matter,

.....a) -the universe also cannot be created

.....b) -the universe also cannot be destroyed

Therefore, the universe is eternal, thus in terms of regression, an eternal entity is not required.

Does this argument hold strong, even during singularity?

[Sarastarlight]

Informative. Interesting. Thank you for posting this lecture.

[DoorwayToHeaven]

Expanding infinity?

ha ha ho ho hah haaaa...

How about, shrinking nothingness?

Dry water!

Wet fire!

The universe as nothingness...

And then one day, the nothing exploded!!!

boom!

And see kiddies, this is how it all began.

[theinquisitor]

Doorway, tell me what's less ridiculous about the idea that god could come out of nothing? I find it easier to believe that a disordered universe came out of nothing than a highly complex and intelligent entity came out of nothing. If we do need an uncaused cause then why does it have to be god? It could be anything. God hardly seems like a reasonable first thing.

[DVDjHex]

Oracle disappeared. Hopefully he is doing a little research. That way next time he decides to participate in a serious discussion on the topic of science he won't stick his foot in his mouth.

[theinquisitor]

I think he means go on forever in the spatial sense, not temporal. Because the geometry of space is flat, the universe is infinite and unbound. It was infinite in size at the beginning too, but the density was infinite too. The big bang is the decreasing of the density as it expands. The universe will expand forever, but all the matter will decay into radiation after a few trillion years, so it will be an eternity of cold infinite night. But that's just our universe...

[enave2]

Um, I've always heard that the universe is finite but unbounded (meaning, it goes on forever, but has finite volume). He seems to say the volume too in infinite. I've never heard another physicist say that. Is there a reference or something that someone can point me to that says this is now the consensus view?

[theinquisitor]

This is based on recent observations of the microwave background radiation. The geometry of space depends on the amount of matter. If the amount is above a certain threshold, then it will sufficiently warp spacetime into the shape you describe. But if the amount is below that threshold, then the warping of space by gravity isn't enough to curve it back around on itself.

[theinquisitor]

The background radiation shows the density of matter in the early universe, which has been used to determine that the finite unbounded model is most likely incorrect, and spacetime is in fact geometrically flat. Which means that it is infinite and unbound. Hard to imagine, but his metaphor of the elastic band is useful in trying to understand how infinity can expand. Search for Shape of Universe on wikipedia to see more.

[mistaspot1]

His expansion of the universe demonstration has stuck with me since the first time I first saw this video. Absolutely mind-bending.

[TheOracle2007]

This DVDjHEX nut is one of 2 things. Someone with a hidden religious agenda or a wingnut out on the fringe who thinks he's going to win a nobel prize by coming on YT to prove how an intro physics lecture at UCal Berkeley is wrong. Would anyone with credibility say "Don't bother reading the text."

[theinquisitor]

Yeah it seemed to me like he was just repeating what he'd been told and didn't really understand. Especially since he said things like that, and also "The creationist like to use good science" and when he went totally quiet after I asked him for evidence.

[DVDjHex]

Actually, I have no religious inclination or agenda. I am an atheist, 100%. For me there is no doubt that god does not exist. So too do I have no doubt that the big bang (or anything similar) never occurred. Is there anything wrong with that? Obviously not.

[theinquisitor]

You have <i>no doubt</i> that god doesn't exist? That's not a rational standpoint. That sounds almost like a religious faith that god doesn't exist, and even that the big bang never happened. That isn't skepticism. How do you arrive at a state of perfect certainty when you're imperfect? Are you sure you're an atheist? I've never talked to an atheist who had faith. That's something that theists think about atheists. Can you explain?

[DVDjHex]

Simply, I believe in a natural solution to the evolution of the universe, one where the physical laws do not break-down at some time t = 0. There is no faith involved. There is no room for a creator in a universe that is infinite spatiotemporally.

[DVDjHex]

This discussion is an important one. Oracle seems to have vanished. He didn't know the subject very well. That was obvious enough. theinquisitor, it is a good thing that you post these lectures. Don't get me wrong. I just feel that the alternative models figure far less than they should at university level. And so my comment...

[DVDjHex]

To be clear, there can be no beginning, no boundary condition, no something-from-nothing in a universe that evolves according to the physical laws (no need for a metaphysical entity or hot creation event). Energy is conserved, entropy increases with time and absolute zero temperature is unattainable. General relativity never breaks down. Science will eventually prevail, but there is a long way to go.

[TheOracle2007]

Inqiusitor, pay no attention to these nutjobs like DVDjHex. Your sense of smell is excellent. The static universe crowd is aligned with the Christian creationists as well. I've also seen this happen with modern evolutionary biology. de Sitter himself was an expanding universe proponent and co-authored a paper with Einstein hypothesizing "dark matter".

[DVDjHex]

The term dark matter (as in the nonbaryonic kind) did not exist during the life of de Sitter. If you refer to the cosmological constant, you must mean 'dark energy.' What is the paper to which you alude? Finally, there are plenty of stationary universe proponents that are not religeous, like myself. There are many believers that accept the big bang (see Pope Pius, 1952).

[DVDjHex]

Dark energy is metaphysics, i.e., it is not real.

Einstein's cosmological constant is real, and prevents the universe from expanding.

It is time to leave the dark ages behind.

A new contemporary cosmology is burgeoning.

[theinquisitor]

Prevents the universe from expanding? How do you explain the redshift then? We can literally SEE it expanding before our eyes, so you'd better have some really astounding evidence. What is this evidence?

Also since you're commenting on the first one, something tells me you haven't watched it all yet.

[DVDjHex]

We do not see the universe expand. Redshift z is a de Sitter effect in a static universe.

See de Sitter space in Wiki. Look at the static metric circa 1917.

BTW, no need for dark energy or nonbaryonic dark matter...

[theinquisitor]

Well according to wikipedia, unless I've misunderstood, it says that a de Sitter universe is one in which the universe is expanding so fast that non-accelerating points are moving apart faster than the speed of light, which would mean we'd be unable to see nearby galaxies, which we can. The wiki entry you've pointed me to that supposedly says the universe is prevented from expanding, but actually it says it's expanding faster than the speed of light. I'm confused.

[DVDjHex]

Don't both reading the text. Look at the static metric toward the bottom of the article. A similar version is what needs to replace the nonstatic FLRW metric for a new standard model. The universe is not expanding. The Doppler effect is not operational. Redshift z is due to a curved de Sitter spacetime phenomenon, called the de Sitter effect.

[theinquisitor]

Interesting, although the maths is way beyond me. Can you point me in the direction of a more qualitative description? I'm afraid I'll have to forfeit this argument since I don't know enough about it. Is there much evidence for this interpretation? Why do you think it's not been widely accepted?

[DVDjHex]

The de Sitter metric was shown to be a static solution to the Einstein field equations by Tolman. The expansion hypothesis prevailed. It was easier to calculate Doppler shifts. Hubble used Doppler for convenience. He was familiar with the de Sitter effect but did not fully understand it (especially the time element). Too, general relativity was more of a curiosity at the time. Most of the tests that would confirm Einstein's theory were carried out in the 1960s and 1970s.

[theinquisitor]

Hmm, is it a coincidence that I just found an Islamic creationism video that talks about de Sitter? I smell cherry picking.

[DVDjHex]

That meen nothing. Google for example Einstein and creationism and you'll find many more. The creationist like to use good science (and especially Einstein) to advance their cause (I've never seen de Sitter used, but it doesn't surprise me, after all, he was a true relativist, just George Braque was a true cubist). Every time though it falls flat on its face, just like the origin of the universe according to the big bang. Cherry picking, not.

[DVDjHex]

I just checked out that video. Modern cosmology has left the door wide open to that type of speculation. Why? Something outside of physics is required to explain the origin of the expanding universe model. That is the reason creationists have such a field-day with science. As long as all the laws of physics break-down at the outset, the door will always be open to the religious. In order to avoid that, the laws of nature must hold for all times t.

[theinquisitor]

Interesting. I'd definitely like to hear more about the idea, especially if you don't have a religious agenda. I want to know the truth no matter what it is, so I'd be very interested in hearing the evidence.

[nanogirl]

Thanks!

[MATIASFLORESTA]

Muy buena clase! Which is the name of the subjet? I am from Argentine. Kiss

[Mjhavok]

Great video. I like that universities put lectures up on the web. It's great.