ProximaCentauri

19 hours ago, MigL said:

A point is, by definition, dimensionless, and without extent.
The early universe, even at Planck scale, might not have applicable spatial and a temporal dimension, but it would still have an extent.
( just an extensive, non-causal quantum foam )

So no way the early universe in its hot, dense state at the very moment of the (supposed) Big Bang could have been infinite at a quantum level? (Eternal) inflation caused infinite expansion? Can you please elaborate?

I think the universe has either always been infinite in extent at all sizes or it has not. 

On 4/7/2020 at 1:36 PM, Strange said:

Why would it be pseudoscience? Inflation and the cyclic universe are just two ways of explaining various aspects of the early universe: mainly the uniformity (the "horizon problem").

Do you have scientific evidence in favour of one model over the other? Or is this just a personal preference for one model?

As far as I can tell, they both have the same amount of evidence; i.e. both are consistent with the existing evidence.

I have no scientific evidence in favour of one model over the other. I'm just a lay person with an interest in cosmology, but I trust wizard mathematicians like Penrose who have shifted in their views from believing in the standard Big Bang cosmological model and come up with something which is far superior,  the Conformal Cyclic Cosmology (CCC). 

CCC is treated with ridicule by the herd, and Penrose is treated like a heretic in the scientific community for dissenting from the mainstream almost religious-like orthodoxy - since he no longer bows down to the standard cosmological model which places the Big Bang as the beginning of this universe - with the question of what came before deemed a 'silly question to ask'.

I saw a video in which Sean Carroll became very upset - you could see from the look on his face - when Penrose basically dared to rubbish inflation for the absurd idea it is. He was denounced of course, as you may expect, by an emotional Carroll committed to the standard model orthodoxy. 

I always pay more attention to the dissenters who once were with the herd and held the mainstream consensus. Because they're usually on to something.

Though I am not a mathematician and will not pretend to understand any of the maths behind CCC , but I trust someone like Penrose when he says he never liked inflation and that the standard model is wrong. So this is why I believe in the cyclic universe or CCC model which says that the universe is not only infinite in extent and in its expansion, but is eternal - there will never be an end to the universe ; there will never be a final 'cycle'.  And there was never a first one, either - which is hard to get our heads around, but the universe doesn't care about that. Not being able to understand how the universe could have had no beginning (or rather how there could have been no first cycle) won't make the universe change to suit what we would rather want just so it's easier for us to understand. 

7 minutes ago, Strange said:

Not all. Some might have died or exploded or merged or fallen into black holes or ... 

For example, Betelgeuse is due to go supernova sometime in the next few thousand year. It might have already happened but we won't know until the light reaches us.

You probably want to find the thread(s) by Michael123456 on this forum. He also struggles with the concept of light taking a finite time to reach us and what "now" means. His argument might make sense to you. (It makes no sense at all to me.)

 

Hi no I understand fully about the speed of light being finite - and I was 100% certain that things in space could not exist at all but due to light's finite speed, we could still see them looking the billions of light years away through our telescopes. I only became puzzled when MigL said that everything we see in the universe still exists/is still out there. I knew that wasn't right but didn't know if that's really what he meant to say.

16 minutes ago, MigL said:

As Ghideon and Strange have explained, what you see in the distance/past, is what is actually out there.
The speed of light is also the speed of ANY information transfer, and causality depends on it.

There is no universal now, so what you 'see' is what can actually affect you.
The fact that a star 100 LY away has gone nova, will not affect you for 100 years ( if you live that long )

Trying to consider what is happening 'now' to that star 100 LY away, is like trying to consider what will happen to you 100 years from now.

So when we look through the Hubble telescope and see nebula billions of light years away, or at galaxies in the Hubble Deep Field, they are all still there today? And all the stars we see in the night sky are all really there right now in our Earth time? 

We know that the further we look into space, the further back in time we are looking. So for example, when we look thousands of light years into the distance from planet Earth, we see things like incredible giant gas clouds (nebula), stars, galaxies. But we know that some of those stars we are looking at may not actually even be there anymore, as they may have since collapsed and died, maybe even become black holes which we cannot see and wouldn't be able to see for billions of years. Some of the galaxies may look completely different right now to how they appear and some of the nebula may have long disappeared. We cannot know because we can't see these things as they are now but only as they were millions or billions of years ago (however far away they happen to be). Due to light and how long it takes from certain points in the universe to reach us here on Earth. 

Now let's say I wanted to go and visit a nebula gas cloud. In this hypothetical situation I create the fastest spacecraft ever made. I choose to go to the nebula while a friend watches my whole journey from an observatory. My friend watches through a monstrous telescope (which we will say is the largest and most powerful one ever built) as I make my journey to the nebula. I arrive at the nebula and just as I do so, my spacecraft is cooked by the heat of a nearby star and I die. Considering what we know about the speed of light:

 I know my friend will be able to see my spacecraft still on its way to the nebula long, long after the spacecraft has actually been destroyed and I am dead, due to the time delay in light travel. But he was watching my entire journey to the nebula, so as what point does he not see things live in Earth real-time? 

Another spacecraft from a distant galaxy whizzes past the nebula and has a device which picks up my destroyed spacecraft containing my dead body inside it just seconds after this horrific event occurs. It travels faster than the speed of light (nothing can, but in this hypothetical situation, it does) so it is able to instantly get to Earth. The alien life form who was flying the spacecraft delivers my body to my friend.

My friend looks through the massive telescope and sees my spacecraft still on its way to the nebula - and because this telescope is the most powerful ever constructed, it can pick up the tiniest detail, and he sees me looking out of the window of the spacecraft, very much alive. He turns away from the telescope and sees my dead body lying next to him.

If we had the spacecraft which could get me to the nebula so fast in time that I would reach it during the lifetime of my friend back on Earth - and if the alien ship from the other galaxy could travel so fast so as to instantly get to Earth with my wrecked spacecraft and the deceased me - would this situation actually happen? Would my friend be able to see, at the same time, a dead me and an alive me? 

2 hours ago, Strange said:

 

Nonsense. It was proposed my several people, based on General Relativity. The astronomer and physicist Lemaitre used data (later known as Hubble's Law, and now as the Hubble-Laemaitre Law) to estimate the rate of expansion and age of the universe.

If it had been proposed purely for religious reasons then it would have been ignored or quickly abandoned. The reason it is still the accepted cosmological model is because of the evidence.

(Bizarrely, a lot of fundamental religions are opposed to the Big Bang model, possibly because it is based on relaitvity which they associate with moral relavitiy. But who know. It is hard to understand the motives of people that stupid.)

The Big Bang is a class of models based on the clear evidence that the universe is expanding and was, therefore, once much hotter and denser than now. There are multiple explanations for how it got into that hot dense state. 

So the first of your models IS (a version of) the Big Bang. There is no evidence for that version of the model yet. Penrose has supported this model and claimed that there were patterns in the CMB that support it but this is not generally accepted (yet).

The second appears to pseudoscientific nonsense. I don't know where it comes from but does not appear to be consistent with any of the evidence.

 

Penrose rejects the idea of inflation. I remember him saying during an interview "When inflation was first proposed [by Guth], I thought 'oh this thing isn't going to last five minutes!" and he went on to say that he is basically dumbfounded that so many have bought into inflation. The Cyclic universe model does not allow for inflation (Penrose's conformal cyclic cosmology model, anyway). Do you consider this to be psuedoscience, because it doesn't allow inflation? Also, he states there would never have been a first universe or first cycle and there will never be a final one. The cycle is infinite and eternal in both directions of time. This what the cyclic models tell us about the universe and they make much more scientific sense than the universe just coming about due to a quantum fluctuation in a vacuous state. This is of course my opinion and I accept that it is a dissenting one from the herd.  

Two cosmological models involving the universe as never having had a beginning and never having an end (eternal), and having no boundaries (infinite) are really interesting me:

The Cyclic universe in which the universe has always been (for an infinite amount of time into the past) and always will (for an infinite time into the future) go through cycles of massive expansion and then contraction. Our Big Bang being the last bounce back from the previous contraction and the cosmic microwave background radiation (CMBR) the result of the rapid expansion from the last epoch.

The universe of dynamical equilibrium. The universe is not expanding. Redshift has been misunderstood - it is not down to the Doppler effect and Hubble himself never even stated that this was so, and treated that idea with skepticism/caution. The universe never had a beginning, it has always existed and always will (eternal) and is infinite in extent. 

To me these models are more attractive because the Big Bang model I think was initially pushed by a Catholic priest (Lemaitre) so as to conveniently have the universe as having had a beginning and therefore very easy to argue that in order for there to be a beginning there would have had to have been a creator. I think big bang cosmological model was initiated to ensure a way to keep religious dogma within the scientific arena. 

What are other people's thoughts on these two cosmological models? Has anyone seen any good mathematics to back them up? I think the Big Bang model is coming under more and more scrutiny these days - and rightly so. We don't want to have that one particular model become like a religious orthodoxy!

38 minutes ago, Kartazion said:

The creation is however intelligent. How to explain this?
 

The first law of thermodynamics states that energy cannot be created or destroyed, but can only be changed form or transferred. Matter can be transformed into energy. And Einstein established that energy can be converted to matter and this was proved in an experiment by physicists at Imperial College London in 2014 when they changed the photon into an electron and positron. 

This means the universe of which is consisted of this energy and matter simply could not ever have been created. 

Of course the universe can exist without a creator. I assume the universe is what you were referring to? 

It is very egoist of human beings to apply anthropomorphism to the universe. We think that just because we can create things and that nothing that we can create can exist without our having created them, this must means surely that the universe - because it exists - must have a creator. How egoistic this attitude and way of thinking is. The universe does not need to have been created at all, just because it exists. And just because you cannot get your head around that, and cannot possibly even begin to understand - doesn't mean there had to be a creator. Again, this is egoist and anthropomorphic. The universe doesn't care, by the way, what you want or what you think. And you wanting something to be so (the universe having a creator) won't make that so or doesn't mean that is so. Imo, like most rational thinking people with a deep respect of science, I don't think the universe owes its existence to a creator. 

Imagine an ant. It lives in a (relative to the ant) extremely large colony with lots of other ants. This is the whole universe according to the ant. The ant has no thinking brain or consciousness, and so is oblivious to the rest of the world. It can only see so far and is limited by its sight. It cannot see up into the sky and doesn't even know that whatever is 50 miles away exists. Not only can it get there and will it never get there - but it does not and cannot know that that part of the world exists. It doesn't even know the world exists as the world - a sphere in space - as it does not have the consciousness to know this or work this out, as previously mentioned. 

If the ant could indeed think, it may (would?) think that it knew everything there was to possibly know. It's life in the confines of the colony and in the nest are the whole universe - including the 200 metres or so they travel from the nest. There would never be any awareness of anything else. The ant may think it knows everything and this is the world.

But humans are aware of the whole planet on which they live - we know it is indeed a planet which orbits the Sun at roughly 108,000 km/h, and that we have a moon which orbits around us at approximately 3,683 km/h. We are able to see all parts of the Earth and travel across the whole planet, we know about the ants who do not and cannot know anything about the universe more than about 200 metres from their nest. We can study the ants and know about their behaviour and their anatomy. We have traveled to our moon and we study the universe, using mathematics to make sense of it all.

Now what if we are the ant? What do I mean by this? Well, we are conscious and aware of our limitations - this is true. Whereas the ant is not. So you may think we have advantage here and I suppose that's right. And yes we know the universe is vast - that it involves distances which the human mind struggles to comprehend - even our most skilled mathematicians say the distances involved in space are just so unfathomable. Indeed, they tell us that the universe may very well be infinite. And WMAP has confirmed that the universe is flat - with a margin of error of about 0.4% - which means physicists can confidentially say, pretty much, that the universe is infinite (it has no boundary and it just goes on, forever and ever and ever - it never ends). Since we know this, and we are aware that what we can see is only the observable universe and not the entire universe, it could be concluded that we have an advantage over the ant we were previously discussing. Because we know our knowledge is limited. That we cannot know beyond the observable universe.

And unlike the ant, we can study our world. We can use physical laws and mathematical calculations and equations to understand and know our universe. But here is where we could indeed be ignorant, like the ant. Indeed, here is where we could know nothing at all about our universe, like the ant!? What if, the laws of physics and the mathematics we use to learn about and make sense of this universe in which we live - this physics and mathematics -  only make sense to us and are valid to us as humans? And to take this even further - what if the results from which are derived from the physics and mathematics are, in fact totally wrong? Is it possible, that because the mathematical methods employed and applied to physics make sense to us and work for us in that they deliver results and conclusions - evidence, in fact - that also makes perfect sense to us in relation to the mathematics - could actually be wrong?

It could be tricky to really explain properly the question I am asking and the point I'd like to make. So let us consider an intelligent life form trillions of light years away from us in some other part of the universe we could never reach. They use different tools - which we cannot imagine - instead of physical laws and mathematics - which make 100% sense to them and deliver results which fit well with those methods and which, to alien life form, answers questions about the universe in ways which make absolute perfect sense. They are not using our physics or mathematics. They arrive at different conclusions but they are absolutely true conclusions to the aliens as much as our conclusions through physics/mathematics are to us. Whose interpretation of the universe is correct?

In this sense not only could we think we know the universe is infinite in extent, when it could be something even beyond infinite, and there could be something totally beyond our universe other than the universe itself as we know it - but we could be totally wrong in everything we know, could we not? We only make sense of things with what we have (mathematics) to understand the universe and this is all we can do and we should just accept that, whatever results our experiments and theories yield, are what we have to go with as being true? When, in fact, they may not be objectively true. They may only be true to us?