/sci/ - Science & Math

[Anonymous No.11650635]

Why does everyone assume that the big bang hypothesis is correct?

[Anonymous No.11650642]

>>11650635
it's their religion

[Anonymous No.11650646]

>>11650635
They didn't assume. They tentatively accepted the big bang because it explained previously current observations while predicting others that later were found to be correct.

[Anonymous No.11650647]

>>11650635
It makes predictions that can be tested. Like the existence of microwave background radiation.
https://en.wikipedia.org/wiki/Big_Bang#Observational_evidence

[Anonymous No.11650663]

>>11650635

>hypothesis

We have pretty strong evidence up to the 10^-43 seconds. We know because we have reproduced the result in laboratories, computer simulations and particle accelerators. We also have direct evidence up to 13 and a half billion years ago thanks to the Cosmic Background Radiation.

Note that classical Big Bang theory is obsolete as it has 3 major flaws:

>The Horizon Problem
>The Flatness Problem
>The Magnetic monopole problem

Which lead to the development of the concept cosmic inflation. Also, it doesn't say anything about the origin of the big bang itself. It runs Einstein's equations all the way back until the equations predict a singularity and enters into conflict with quantum mechanics. Is this approach valid? It is better to think of the big bang as a theory of the earlier universe rather than its origin.

[Anonymous No.11650684]

>>11650663
Thanks for the good post. How do we know the age and origin of CBR? If big bang or whatever you want to call it is true, why hasn't it dissipated? Why is it almost equal in all directions?

[Anonymous No.11650714]

>>11650663
>>11650684

Let's start with the irrefutable:

The universe is expanding. Light from distant galaxies is red shifted, stretched to longer wavelengths. And the further away the galaxy is, the more its light is stretched. In the context of Einstein's theory of general relativity, the only sensible interpretation for this fact is that space itself is expanding and light traveling through expanding space is stretched. The more distance traveled, the more it's stretched. The universe is definitely expanding now. And so we know that once upon a time, it had to be much smaller.

See, this is the wonder of physics. We can look at the current state of the universe, or even just a tiny part of the universe, and run the laws of physics forward in time to predict the future. Or run those laws backwards and predict the past. If we rewind the universe using the mathematics of general relativity, then the further back you go, the smaller the universe is. In fact, with raw general relativity, we get that the entire observable universe was once compacted into an infinitesimal point, a singularity at time t=0, the hypothetical instant of the Big Bang. Now, that initial singularity is not something that most cosmologists believe in. While general relativity is incredibly successful, it doesn't contain the machinery to describe the quantum scale gravity of that first speck. So we know that at some point in our rewind, pure general relativity will give us the wrong predictions for the behavior of space time. But we understand those limitations really well, and we know that we can be confident in our predictions down to a certain point.

[Anonymous No.11650717]

>>11650663
uh

in line with all current physics models you need a bunch of dark events for the system to work

so I'm not exactly holding my breath that our current theories are correct

[Anonymous No.11650721]

>>11650714

For times after that point, our understanding is good enough to make some pretty bold and testable predictions about what the universe must have looked like at various times. One such prediction is that the entire universe was once as hot and dense and opaque as the inside of a star. It was a searing ocean of protons and electrons. A plasma. As the universe expanded, this plasma cooled. And at a very particular moment when the universe was around 400,000 years old and about 1,000 times smaller than it is today, it hit a critical temperature of 3,000 degrees Kelvin, at which point the entire universe slipped from plasma to gas as the first hydrogen atoms formed. In the same moment, the infrared light that had previously been trapped in this fog was free to travel the width of the cosmos. It's still traveling today, carrying with it an image of that early time. And we see it. It's no longer infrared. Having been stretched into microwaves as it traveled through an expanding universe, it's the cosmic microwave background. This ubiquitous radiation is almost impossible to explain without a universe that was once much smaller, hotter, and denser.

[Anonymous No.11650730]

>>11650721

So at least that far back in time, the Big Bang theory is right. We see some amazing clues in the image imprinted on the CMB. Firstly, it's incredibly smooth and even. But this mottled pattern shows there are imperfections, tiny differences in temperature of 1 part in 100,000 from one patch to the next. These represent regions where there's a bit more stuff here, a bit less stuff there. Very, very tiny fluctuations that would let it collapse on themselves to form galaxies and clusters of galaxies. That process, the evolution from a smattering of tiny fluctuations to a network of giant galaxy clusters, is also evidence that the Big Bang picture is right. When we look to vast distances, we're also looking back in time and we see the very first galaxies soon after they collapsed from these blobs. Now, we expect them to be violent places with galaxies colliding and merging with each other, rich in the raw materials of star formation but poor in the heavy elements released by generations of supernovae. And they are. We see galaxies back when the universe was 5% its current age. And they look very different to galaxies today. The universe is clearly evolving. But there's another amazing clue in the CMB. The pressure results in spherical sound waves of both baryons and photons moving with a speed slightly over half the speed of light outwards from the overdensity. We see ripples of "sound waves" in the pattern of those fluctuations. The fancy name is baryon acoustic oscillations which cause ring-like clustering of the CMB fluctuations. . If the Big Bang theory is right, then those ripples should have been frozen into the distribution of matter at the moment the CMB was created, and those ripples should still be visible in the way that galaxies are spread out on the sky. And yep. We see that, too.

[Anonymous No.11650735]

>>11650730

But all of this only gets us back to 400,000 years after the Big Bang. We can rewind further. At an age of a few seconds, we predict that all of the universe was much hotter than the very center of a star and remained so for around 20 minutes. During this time, nuclear fusion raged across the cosmos, baking some of the existing protons into heavier elements in a process that we call primordial nucleosynthesis. The Big Bang theory tells us how long these elements were baked and at what temperature, and so predicts the proportions of deuterium, helium, and lithium that should have been produced. It's in startling agreement with what we see when we look out there. The Big Bang theory has powerful, direct evidence, almost down to the first second. Although we don't have direct evidence for what the universe looks like in its very first second, our understanding of physics is still good down to a crazily early age of 10^32 seconds, when the entire current observable universe was around the size of a grain of sand, give or take. How can we be so confident? Because we've recreated the conditions of the universe at this time. We've recreated those insane energies in our particle accelerators. We can check that our physics works in these conditions, and so we have a lot of confidence in the predictions of that physics.

However, this is where our certainty ends. Earlier than 10 to the power of minus 32 seconds, we just can't produce the energies needed to test our understanding of physics in those conditions. But there are clues to that earliest of times. Some are also imprinted in the cosmic microwave background, and they may lead us back to the instant of the Big Bang itself.

[Anonymous No.11650755]

>>11650684
>why hasn't it dissipated?
It has. It red shifted from high energy wavelengths to microwave in the intervening time.
If you went way way back in time the CMB was in the visible wavelength and the universe would have been glowing.

[Anonymous No.11650771]

>>11650635
Doesn't add up according to Barry Scott.

[Anonymous No.11650772]

[Anonymous No.11650775]

>>11650684

CBR is the light from when the first atoms formed. It's literally the first light of the universe.

[Anonymous No.11650797]

>>11650717
Don't be a moron.
If the models work time and time again if you keep a variable for something you haven't discovered yet that acts within theoretical constraints that is pretty good evidence that maybe the theory isn't wrong but there is just a missing piece.
Just look at things like quarks. They were thought to exist because you needed them to make the math work, so they looked for them, and sho'nuff we found them in high energy particle colliders.
Whats really spooky is the whole concept of a dark sector of physics, there could be an entire zoo of particles that don't interact with the electromagnetic forces which means it would be nearly impossible to ever detect them.
And science would love for a better theory to come along that explains everything better but every candidate does a worse job than the current model.

[Anonymous No.11650811]

>>11650635
just get off the board and read a book bitch

[Anonymous No.11650816]

>>11650775
>It's literally the first light of the universe.
Not exactly. There was light prior to that but the universe was opaque with hot plasma so all of the light before a certain point was constantly being absorbed and reemitted.
Once the universe cooled enough to become transparent then the light from the CBM started.to shine through.
If you could figure out how to take the cosmic neutrino background you could see back even farther, and if you could analyze the cosmic gravity wave background you could see back almost to the moment of creation. Unfortunately both of those things will be well outside of our reach for quite some time.

[Anonymous No.11650819]

>>11650735
>Because we've recreated the conditions of the universe at this time. We've recreated those insane energies in our particle accelerators.

How did the experiment not expand and fuck us up?

[Anonymous No.11650825]

>>11650735

Now, The Big Bang Theory suggests that once the entire universe was compacted into an infinitely small speck at the beginning of time. But was this really the case? What parts of this theory are still under serious question? Direct and convincing evidence tells us that the universe was once much smaller, hotter, and denser
than it is now. We're actually pretty sure we know what happened all the way down to approximately 10^-32 of a single second after the hypothetical beginning of time. And at that point, the entire observable universe was around the size of a grain of sand. Now, we got down to that size by rewinding the laws of physics, and in particular running the math of Einstein's general theory of relativity backwards. But how much further can we rewind until we run into trouble?

Well, things get pretty weird before that 10^-32 seconds. Now, remember, when the universe was younger than 400,000 years it was too hot for atoms to exist. Well, before 10 to the minus 32 seconds, it was too hot for the fundamental forces of nature as we know them to exist. The Higgs field gives particles mass. Well, at temperatures above 10^15,
01:48 or a quadrillion Kelvin, it stops doing that. It turns out that when you take this Higgs mass away from the particles that carry the weak nuclear force, they become just like the photon, which itself carries the electromagnetic force. This means that the weak and electromagnetic forces sort of merge into the one electroweak force. For a very brief period soon after the beginning of time, these forces are combined. It's called the electroweak era.

[Anonymous No.11650833]

>>11650825

Sounds weird. But perhaps weirder is that it's not really a mystery at all. We pretty much know this happened because we can actually make bits of the universe do this. We can create energies needed to produce the electroweak states in the Large Hadron Collider. Yep, we can simulate the instant just after the Big Bang. Our theories look really good to that point. But once you get to a crazy 10^29 Kelvin at an age of around 10^-38 seconds, it's expected that this electroweak force and the strong nuclear force-- that's the force that holds atomic nuclei together-- also become unified into one force.

There are a lot of ideas of how this might happen. And we call these grand unified theories, except they aren't theories in the same sense as relativity or evolution because we don't know which, if any, are actually correct. The problem here is that we can't test them yet. We need to produce energies a trillion times larger than is possible with the Large Hadron Collider. Nothing we could build on the surface of the Earth could do this. Perhaps that's for the best. So this is still a huge unknown.We do think that we can describe gravity and the shape of space time at these densities and temperatures. But we can't confidently describe this stuff that the universe contained, the weird state of matter that far back.

[Anonymous No.11650840]

Duh. Everything started as light, dummy.
God said "let there be light" and there was light. This has been known for thousands of years.

[Anonymous No.11650844]

I really like you posts here. But I am not a physics graduate, my formation is math/CS.
How do you guys define space time in the time of the singularity and expansion?
Do you accept there it was a pure mathematical vector space where the universe expanded unto? How is the topology of this space?

[Anonymous No.11650846]

>>11650833

OK, rewind a bit further to 10^-42 seconds of age. And pack all of the galaxies in the entire observable universe into a space 10^-20 of the width of a proton. That's the Planck length. And here, physics kind of goes out the window. See, at this point, general relativity comes into serious conflict with quantum mechanics. And we need a theory of quantum gravity, a so-called theory of everything, to go further. These theories don't play nice together. We leave it alone because we don't actually know whether the universe was really ever this small. Remember, we've been rewinding the universe using basic general relativity. Is that valid? Well, we don't yet have direct evidence from those very early stages. But there are some clues still visible at later times. And those clues tell us we've missed something huge.

[Anonymous No.11650874]

>>11650846

Let's undo our rewind a bit, fast forward again to 400,000 years after that crazy first fraction of a second. The universe is space sized. But it's still 1,000 times smaller than the modern universe. It's full of this hot glowing hydrogen plasma. But at 400,000 years, it's cooled down just enough to form the very first atoms, and in the process, release the cosmic background radiation. We now see this light as an almost perfectly smooth microwave buzz across the entire sky. That smoothness tells us that all of the material in the universe when the CMB was released was almost exactly the same temperature, around 3,000 Kelvin, varying from one patch to the next by at most one part in 100,000 across the entire observable universe. This is weird.

Why is this so weird? If you have a cup of coffee, and drop in some cold milk, it will all smooth out and become the same temperature after a bit of time. Well, the universe works in the same way. But based on the simplistic expansion you predict from general relativity, when the CMB was released, there just hadn't been enough time for this mixing to have occurred. See, in order for the most distant patch of the universe we can see in that direction to have the same temperature and density as the most distant patch in that direction, there needs to have been enough time for something to travel between those points to diffuse and even out that heat. And there just wasn't, not even for light, the fastest thing that there is.

[Anonymous No.11650889]

>>11650874

Let's take this grain-of-sand-sized universe at 10^-32 seconds. A photon emitted on one side of that grain wouldn't have time to get to the other side, not even in 400,000 years. See, although light is fast, those opposite edges of the universe were traveling apart even faster. Another way to say this is that those edges of the universe have always been beyond each other's particle horizons. So those edges shouldn't be in each other's observable universes, not then, not now. This serious issue is called the Horizon Problem And it's a big deal that we need to sort out.

The only way around this problem is somehow have the universe, once upon a time, be small enough so it could easily get all nicely mixed together, and then pow!, blow it up in size much faster than general relativity would normally allow. The theory that describes this is called Inflation. The idea is the universe started subatomic, small enough that it was able to even out its temperature and then enter the state of insane, exponentially accelerating expansion in which it increased in size by a factor of at least 10 to the power of 26. So 100 trillion trillion to something like our grain of sand size at which point it slowed down to its regular expansion rate. But its edges are thrown way out of causal connection. Yet, they look the same because they were once causally connected.

This whole idea fixes our horizon problem. In fact, inflation solves a number of vexing problems with the Big Bang Theory so well, in fact that most cosmologists accept that something like this must have happened even though we don't have any direct evidence for it. There are a number of explanations for how inflation might have happened. And some of them actually call into question our understanding of that very first instant of the Big Bang.

[Anonymous No.11650898]

>>11650663
>We know because we have reproduced the result in laboratories,
Unless they exhausted all other methods, that does not prove anything

[Anonymous No.11650913]

>>11650874
Dont cosmic horizon A and B intersect at the point where the milky way is?

[Anonymous No.11650925]

>>11650889

The horizon problem isn't the only troubling feature of the CMB. We can use the apparent size of the very subtle fluctuations in the CMB to measure the flatness of the fabric of the universe, of spacetime. And the answer we get is very strange.

Let me explain:

A flat sheet of paper is flat.

>Duh!

Draw any triangle on one and add up the angles. It's always 180 degrees. Draw the same triangle on the surface of a sphere, which has what we call positive curvature, and the angles add up to more than 180. On a negative curvature hyperbolic plane-- a saddle-like structure-- they add up to less. Triangles in 3D space obey exactly the same rules as on 2D surfaces, and their geometry measures the curvature of space.

So now, think of those blobs in the CMB as the ends of very, very long triangles. We know the size of the brightest of those blobs. They're defined by how fast sound waves could have traveled by the time the CMB was created. And we know how far away they are. They're really, really far. Using basic trigonometry, those distances tell us what the little angle at this end should be. It should be 1 degree, assuming the universe is flat. It should be larger if the universe is positively curved, smaller if negatively curved.

It's pretty much exactly 1 degree.

Based on the precision of our measurements so far, we know that the curvature is within 0.4 of 1% of perfect flatness.

[Anonymous No.11650930]

>>11650925

>So what? The universe is flat.

No, actually, it's extremely weird. An expanding universe doesn't tend to stay flat, even if it starts that way. Analogy-- one way to bowl a strike is to keep the ball near the center of the alley all the way to the pins. If the ball isn't moving fast enough, then any initial deviation from dead center will send it towards the gutter.Same with the universe.If the center of the alley represents a flat universe, then the gutters represent extreme curvature in the positive or negative directions. If the universe starts out even a little bit not flat, then that not-flatness will amplify quickly. So if our universe is flat to within 0.4 of a percent now, then in the first instant, the universe had to be flat to one part in 10^62. That's like rolling your ball really, really slowly and having it stay within 0.4 of a percent of the center of the alley, and the alley is a light year long. Nice bowling, universe

[Anonymous No.11650946]

>>11650930

So it turns out that we can fix both of these problems with a single, elegant idea called inflation. It goes like this-- start with a universe so crunched down that the entire currently observable part of it was all causally connected. Then, for a very short period of time blow it up much faster than the speed of light so that most of it appears causally disconnected, at which point inflation stops and regular expansion takes over. This works because even a very blotchy, curvy universe is going to be much smoother and flatter on its smallest scales. Inflation takes a very tiny, smooth, flat speck of that blotchy, curvy greater universe and blows it up to a macroscopic volume really, really fast. That inflated speck subsequently grows into the universe that we know, but retains its once subatomic smoothness and flatness.

That's right. According to inflation, the universe that we see is a tiny part of a vastly larger universe that itself may well be curved. The neatness with which this inflation solves both the horizon and flatness problems really has most cosmologists thinking that something like this must have happened. For this to work, that inflationary expansion had to throw neighboring regions of space apart at many times faster than the speed of light. It needed to increase the size of the universe by a factor of at least 10^26 in less than 10^-32 seconds, ending when the universe was just macroscopic, something you could hold in your hand. In the subsequent 13.7 billion years since, the universe has expanded by about the same amount that it did during inflation.

[Anonymous No.11650958]

>>11650946

So what sort of mad physics could do something like that? Actually, Einstein came up with the exact mathematical description that we need-- an antigravity term called the cosmological constant. In the field equations of his general theory of relativity, he added this as a way to allow his theory to describe a static space time, a universe that's neither expanding nor contracting. When it was later discovered that the universe is indeed expanding, Einstein retracted his constant. But this bit of math gives us exactly the type of expansion that we need for inflation. Incidentally, it also describes the effect of dark energy, and that may not be a coincidence. The cosmological constant represents something that can happen to our spacetime. Einstein is right, even when he's wrong. The cosmological constant adds some energetic stuff to empty space. It doesn't tell us what this stuff is, just that it's a property of space itself and that it acts to drive expansion. The more space, the more of this stuff. And so the more space, the more expansion.

What could cause such a weird sort of energetic vacuum? Inflatons, scalar fields, forced vacuums, all of that. For now, let's just go with the fact that empty space can propel its own expansion and will do so if the vacuum contains a ubiquitous constant energy density. Another really important thing about the driving mechanism if inflation is that it stopped. The universe slowed down from exponential to the regular old expansion that we see today, what we call Hubble expansion. And while we know the minimum amount of inflation needed before that stopping point, we don't really know when it began or even if it had a beginning. It may have, and there are some ideas about what got it started. But it's also possible that inflationary expansion is the default state of the greater universe-- I should say multiverse at this point. This is the idea of eternal inflation.

[Anonymous No.11650967]

>>11650958

With inflation, the Big Bang theory takes on new meaning. When first conceived, the inflationary period was thought to have started at a particular point after the instant of the Big Bang. But once you accept inflation, there isn't necessarily a good reason to think that there was a normal expansion period before, if there was even was a "before inflation." In fact, the instant that inflation ended can perhaps be thought of as the moment that our universe as we know it came into being. In that sense, inflation is the initial kick of the Big Bang. We don't need to talk about an exploding singularity at all. Time may not have begun with the Big Bang.

[Anonymous No.11650978]

>>11650913

Yes, but they never reach each other's region. The Milky Way is at the edge of their relative Cosmic Horizons. For all purposes, Region A and Region B may as well be on different universes.

[Anonymous No.11651021]

>>11650819

There are natural phenomena much more energetic than we can produce in a particle accelerator. They still haven't caused any vacuum metastability event or anything that could destroy the universe.

[Anonymous No.11651034]

>>11650663
What are the good cosmogony theories/hypothesis that deal with its direct origin?

[Anonymous No.11651060]

>>11650635
Only brainlets and pop scientists accept the big bang.

[Anonymous No.11651063]

>>11650663
simulations are not proof dumbass

[Anonymous No.11651070]

>>11650635
I'm tired of literal retards who think that scientists just sit in a room and make shit up.

[Anonymous No.11651100]

>>11651034

Eternal Inflation model may be a candidate. It suggests that there is a vastly larger (infinite) universe out of there that has never ended its inflationary epoch with no beginning and no end. We are just a tiny region of this universe where inflation stopped and there may be others.

[Anonymous No.11651111]

>>11650635
because the alternative is so wrong

[Anonymous No.11651119]

dude our calculations are missing 85% of stuff...
dude lets just call our error "dark matter" LOL

[Anonymous No.11651130]

>>11650967
Very good writing. I'm a brainlet and physics noob but I found this very informative and interesting.

[Anonymous No.11651138]

>Globulal

[Anonymous No.11651143]

>>11650647
But is that making predictions or is it observing what is here and then making the hypothesis fit? I mean the biggest question is if the big bang happened, what happened before it? What caused it?

[Anonymous No.11651198]

>>11651143

Inflaton field.

[Anonymous No.11651211]

>>11650642
>>11650635
This. There are plausible alternatives to the Big Bang, even ones that are phenomenologically indistinguishable. But modern physics is about politics and bandwagons, not about exploring possibilities; lots of mediocre physicists climbing over each other so they can be the first to agree with whatever is popular right now; all desperately trying to recover their long-lost sense of dignity. Anyone with an ounce of self-respect will become jaded and leave academia after graduating. Meanwhile, affirmative action, corporate funding, and the integration of poorly educated foreigners requires academic standards to slide ever-lower over time, and nowadays graduate students are effectively used as slave-labor for outsourced corporate R&D. But then you wouldn't know any of this by looking from the outside because the system does such a great job of portraying science in America as being in a perpetual Golden Age.

[Anonymous No.11651292]

>>11650663

What is the Magnetic monopole problem?

[Anonymous No.11651329]

>>11651021
Although I was not talking about destroying the universe, I was indeed talking how could we hold the energy as not to, for example, destroy part of the LHC?

[Anonymous No.11651339]

>>11651211
dangerously based

[Anonymous No.11651396]

>>11651143
And what are the mathematical properties of what existed before.
"Before the universe, there it was C^n"

[Anonymous No.11651452]

>>11650635
read a book on introductory cosmology and you'll understand why
now be gone simp

[Anonymous No.11651458]

what was there before the big bang

[Anonymous No.11651587]

>>11650889
>There are a number of explanations for how inflation might have happened
Like this?

[Anonymous No.11652316]

>>11650717
>in line with all current physics models you need a bunch of dark events for the system to work
true. isn't it funny that whenever the models didn't predict something, they just adjusted the models? why never consider the possibility that maybe the models are wrong

[Anonymous No.11652322]

>>11652316
"all models are wrong"

[Anonymous No.11652327]

>>11651587
ugh, dear christ why

[Anonymous No.11652489]

>>11651198
Field of what?

[Anonymous No.11652637]

>>11650958
thank you for your service.

[Anonymous No.11652718]

>>11650840
>"let there not be foreskin"
go fuck a goat

[Anonymous No.11652729]

>>11650635

It's not. But it agrees with Scripture so they go with it, and it sort of matches observation.

Reality: universe is infinite in time and space, depth and scope. Atoms are galaxies and inward (and outward) for infinity. Our local cluster is a gas at cosmic scale, around the size of a period in a sentence. That gas is expanding and so people think it came from an origin. It didnt.

[Anonymous No.11652766]

>>11650635
Because it's a product of Catholic theology, the world's official religion.

[Anonymous No.11652794]

>>11652729
>what it entropy

[Anonymous No.11652798]

>>11651143
there was nothing before it, its always been happening, the big bang wasn't like one event, it's just a really dense point shitting out waste.

[Anonymous No.11652800]

>>11651211
woke as fuck

[Anonymous No.11652802]

>>11650958
Excellent posts

>we don't really know when it began or even if it had a beginning. It may have, and there are some ideas about what got it started. But it's also possible that inflationary expansion is the default state of the greater universe-- I should say multiverse at this point. This is the idea of eternal inflation.

As far as I know, eternal inflation is only eternal and self-sustaining into the future (and indeed may have been ongoing for a very long time by the time it created our local universe), but it is not eternal into the past. Due to entropy it still must have a beginning. Something like this maybe:

https://en.wikipedia.org/wiki/Hartle%E2%80%93Hawking_state

[Anonymous No.11652819]

>>11651587
my brain refused to understand this for a good 30 seconds. oh dear god why

[Anonymous No.11654283]

>>11651458
nothing

[Anonymous No.11654336]

>>11652819
Sorry, my typesetting was kind of off. I fixed it.

[Anonymous No.11654884]

>>11650635
I don't. The Big Bang is just another form of Creationism. It's silly nonsense.

[Anonymous No.11654902]

>>11650663
>WMAP_2010.png
Cringey unscientific meme.

https://youtu.be/i8ijbu3bSqI?t=118

https://www.youtube.com/watch?v=O13ApQvUfb8

https://www.youtube.com/watch?v=5i6mCNgJNZs

https://www.youtube.com/watch?v=cqM6lZOvZcs

>Big Bang

https://www.youtube.com/watch?v=p8lKQMEYYLw

https://www.youtube.com/watch?v=kz-Bwi5xTTs

https://www.youtube.com/watch?v=rZspAmawIpc

https://www.youtube.com/watch?v=xUC_a-IMmGs

https://www.youtube.com/watch?v=_c9M33FLH40

https://www.youtube.com/watch?v=FIgmsQOKnmk

https://www.youtube.com/watch?v=UlFVUozGWyU

https://www.youtube.com/watch?v=Z8shxpZJ30Q

https://www.youtube.com/watch?v=SeIHTCdOGWs

https://www.youtube.com/watch?v=4IdMz8PkGZM

https://www.youtube.com/watch?v=hC_KkLvG22A

https://www.youtube.com/watch?v=Ox3_tJcPy2M

https://www.youtube.com/watch?v=uQu5iff2F3o

https://www.youtube.com/watch?v=ot-9R2GZxp8

https://www.youtube.com/watch?v=Q4wVGhS72xU

https://www.youtube.com/watch?v=DdNopoXhEuk

[Anonymous No.11654907]

>>11650714
>Light from distant galaxies is red shifted
Redshift is not an indicator of distance, so the rest of your post is meaningless as it's fundamentally flawed.

[Anonymous No.11655028]

>>11654907
That's not what they do. Some stars have certain properties such as how often they pulse. Based on that you expect a certain brightness and blackbody profile. From the difference in brightness and spectrum you can then determine their distance and redshift. Turns out galaxies farther away have a bigger shift, thus the assumption that the universe is expanding.

[Anonymous No.11655038]

This is why JWST will be so important. We have so much riding on that clusterfuck of a project. Let's hope all goes well when its deployed.

[Anonymous No.11655063]

>>11650635
Because it's one hell of a banger!

[Anonymous No.11655071]

Couldnt this flatness be explained by holographic universe theory? Similar to a hologram sticker on a flat credit card, the 3d is just an illusion.

[Anonymous No.11655089]

>>11655028
In terms of expected observations, it all works out the same if, instead of accelerating expansion via dark energy, the Planck mass increases at an exponential rate causing atomic radii to shrink over time. Since the ratio we're comparing is intergalactic distances to atomic radii, there's no reason to assume one or the other.

[Anonymous No.11655119]

>>11652316
The models are obviously "wrong" in the sense that they don't fully describe reality, that much is conventional among physicists, hence the search for physics beyond the standard model.

[Anonymous No.11655126]

>>11654907
>Redshift is not an indicator of distance
It's an indicator of speed, with the degree of redshift increasing as distance increases, indicating that more distant objects are moving away faster than nearer objects.

[Anonymous No.11655132]

>>11654902
ah yes the schizo youtube dump, you're a big boy use your words

[Anonymous No.11655138]

>>11655089
> the Planck mass increases at an exponential rate causing atomic radii to shrink over time
Setting aside everything else, that would predict that the greatest shifts should be closest to us, rather than farthest from us.

[Anonymous No.11655150]

>>11654884
If we only knew now what Aristotle knew 2300 years ago. Sad!

[Anonymous No.11655232]

>>11650967
Thanks for the writeup, I read hawkings brief history of time and Iarge parts went over my head, this tied up some things nicely.
One question, does this mean there is something faster than the speed of light? whatever induces inflation, or maybe inflation itself, since the edges of the universe are expanding (or were expanding?) faster than light?

[Anonymous No.11655297]

>>11650930
Wouldnt a gigantic and curved surface (neg or pos) appear flat to a tiny observer

[Anonymous No.11655304]

>>11650797
>If the models work time and time again if you keep a variable for something you haven't discovered yet that acts within theoretical constraints that is pretty good evidence that maybe the theory isn't wrong but there is just a missing piece.
You seem to be justifying speculation of this missing piece with the idea that it sticks around while the rest of the model changes. It seems that in order for this to make any sense, the "rest of" the model would need to change such that this persistent thing is defined. If it remains amorphous and just defined as something like "that thing that is missing in these equations," then you are indeed assuming for no good reason that math that does not accurately describe things, does.
>And science would love for a better theory to come along that explains everything better but every candidate does a worse job than the current model.
What "science would love" is irrelevant. Explain how this is not the exact same sentiment as the following
>this is the best model and we need a model therefore best model
How good of a job other models do compare to your model is irrelevant. Theories should be treated as such -- not believe and propounded by turbobrainlets who can't handle the existential dread of feeling like they just don't know.

[Anonymous No.11655309]

>>11650797
>If the models work time and time again if you keep a variable for something you haven't discovered yet that acts within theoretical constraints that is pretty good evidence that maybe the theory isn't wrong but there is just a missing piece.
You seem to be justifying speculation of this missing piece with the idea that it sticks around while the rest of the model changes. It seems that in order for this to make any sense, the "rest of" the model would need to change such that this persistent thing is defined. If it remains amorphous and just defined as something like "that thing that is missing in these equations," then you are indeed assuming for no good reason that math that does not accurately describe things, does.
>And science would love for a better theory to come along that explains everything better but every candidate does a worse job than the current model.
What "science would love" is irrelevant. Explain how this is not the exact same sentiment as the following
>this is the best model and we need a model therefore best model
How good of a job other models do compare to your model is irrelevant. Theories should be treated as such -- not believed and propounded by turbobrainlets who can't handle the existential dread of feeling like they just don't know.

[Anonymous No.11655600]

>>11650967
So in a hundred years when they throw out this made up garbage like they have to do every hundred years or so what do you think the new epic theory of everything marvel origin story science theory will be?

[Anonymous No.11655606]

>>11654902
>EU trash
into the trash can it goes

[Anonymous No.11655608]

>>11652316
>whenever the models didn't predict something, they just adjusted the models
To be fair, this is the explicit purpose of the scientific method. It is working as intended if they are earnestly and in good faith using new observations to make better and more precise models. Of course, most scientists and the fknlovescience syncophants are just brainless bootlickers but thats not relevant to the intended execution of the scientific method.

[Anonymous No.11655650]

>>11651143
Both, but remember that most of science is just making models that fit our observations. Coming up with a hypothesis that explains everything before doing any experiments isn't something that usually happens for the big questions.

[Anonymous No.11655658]

>>11651211
I'm a lefty, but the definition in that picture is incorrect. Bigotry is intolerance to ideals, not demographics. Islamaphobia and fist-fights over politics are bigotry, not racism.

Although that picture could also be photoshopped. Half of the SJW rage-bait containing pictures of powerpoints end up just being great photoshops.

[Anonymous No.11655685]

>>11655658
Kys

[Anonymous No.11655708]

>>11655685
Only if you buy me dinner first

[Anonymous No.11655718]

>>11652316
Because dark matter is a better explanation than all the "our model is wrong" approaches. Modified gravity theories are a mess. Dark matter behaves EXACTLY like we would expect an electromagnetically neutral collection of particles to behave. Considering we have experimentally confirmed the existence of some EM-neutral particles like neutrinos, there's not much reason to assume dark matter is something radically new.

[Anonymous No.11655721]

>>11652316

Note that any following model must explain not only the new phenomena but also all phenomena that came before it previously explained by the now obsolete theory.

[Anonymous No.11655734]

>>11654336
I can fap to this

[Anonymous No.11655743]

>>11655038
This. If private aerospace can pull off massive fairing ships we could see dozens of jwst sized scopes all over fuck yeah

[Anonymous No.11655747]

>>11650635
>Why does everyone assume that the big bang hypothesis is correct?

It’s a theory, not a hypothesis, because it has made verified testable predictions. Any alternative model will have to conform to known observations while also making testable predictions that the model of cosmic inflation doesn’t. If you can formulate a model that does that, be my guest.

[Anonymous No.11655749]

>>11650684
>If big bang or whatever you want to call it is true, why hasn't it dissipated?

It is dissipating, but it will take a while still for it to become undetectable.

> Why is it almost equal in all directions?

Why would you expect it to not be almost equal? The universe is mostly homogenous.

[Anonymous No.11655750]

>>11655138
No, lighter, larger, distant, ancient atoms would emit lower energy, longer wavelength light than heavier, smaller, closer, contemporary atoms.

[Anonymous No.11655764]

>>11655126

What if the speed of light is just getting faster. Light from distant objects travelled longer because it started off slower

[Anonymous No.11655797]

>>11655750
Which would still predict that the greatest differences in magnitude should be observed closest to us.
Not to mention that trying to change the nature of subatomic particles and atoms changes their interactions in a way that would heavily show up at the macroscale. Those atoms would be less dense, which would heavily affect star and galaxy formation i.e. they wouldn't just be redshifted.

[Anonymous No.11655799]

>>11655764
Photons are the carriers of the electromagnetic force. If the speed of light were meaningfully changing, basically every electromagnetic interaction would be altered as well.

[Anonymous No.11655858]

>>11655797
Nope, as long as dark energy isn't a cosmological constant you get quantum scale symmetry, and from local particle interactions, to nucleosynthesis, to the CMB, to the evolution of the largest structures are absolutely indistinguishable between a universe with expansion and a universe without it.

[Anonymous No.11656346]

>>11655718
To add to your good point, there is historical precedent for the "model is right, but invisible shit is skewing observations" approach. When people noticed beta decay didn't seem to obey the conservation of momentum rules, Pauli proposed what we now call the neutrino to make the math add up. Or the discovery of Neptune; astronomers noticed that Uranus's orbit didn't follow good'ol Newtonian gravity, so some proposed there was a difficult to detect planet was messing stuff up, while other's suggested that the model was wrong & gravity worked differently far away from the sun. So in a way, Neptune was dark matter for a time. Granted, later on a new theory of gravity was need to explain other observations, so such things shouldn't be ruled out; both ideas (model is wrong/model is right with invisible stuff added) need to be considered when we see things that don't match our current models.

[Anonymous No.11656376]

>>11654283
not possible

[Anonymous No.11658055]

>>11656376
God?

[Anonymous No.11658630]

>>11652794

Entropy? An infinite universe will never reach equilibrium. Furthermore it is clear as day that the Universe becomes more ordered, not less, over time.

[Anonymous No.11659025]

>>11650635
Tell us which other theory is better.

[Anonymous No.11659051]

>>11650735
>gravity froze out
More on what this means?

[Anonymous No.11659070]

>>11650874
>when the CMB was released, there just hadn't been enough time for this mixing to have occurred
Can't it be as simple as everything in those earliest times being highly symmetric?

[Anonymous No.11659072]

>>11650898
Is anyone claiming PROOF? It's evidence that supports the theory.

[Anonymous No.11659084]

>>11650930
>That's like rolling your ball really, really slowly
I don't get this part of the analogy. What is the speed of the ball analogous to?

[Anonymous No.11659099]

>>11652316
>whenever the models didn't predict something, they just adjusted the models
Which is admitting/accepting that the previous models were inaccurate
>why never consider the possibility that maybe the models are wrong
HUH? That is what happened.

[Anonymous No.11659110]

>>11655232
>faster
No, not in the sense of actual MOTION. Expansion is not movement. 2 galaxies may be expanding away from each other at a greater rate than speed of light, but not MOVING at anywhere close to speed of light.

[Anonymous No.11659117]

>>11655309
>What "science would love" is irrelevant.
Nitpicky nonsense. Of course science would 'love' a theory that does fit all observations.
The rest of this post seems to be saying that every part of an imperfect theory should be immediately thrown out and ignored so everyone can start again from scratch.

[Anonymous No.11659281]

>>11655799

Not if the rate of change is imperceptably small

[Anonymous No.11659290]

>>11655799

What about if the speed change was happening at an individual scale, ie a single photon accelerates after creation but all photons start at the same speed. Afaik we only bothered to measure the speed of light from relatively "fresh" sources and are just assuming that speed is static.

[Anonymous No.11659877]

>>11659290
>we only bothered to measure the speed of light from relatively "fresh" sources
Bruh the CBM is the stalest source of photons its possible to have.