Dan B.

It depends on the temperature of that oven Well, the Oven itself does not contribute any heat. There is no heater inside. It is used as an isolator. No heat gets in and no heat goes out. Hence, without the galaxy or stars Its temp is virtually 0 K. However, in order to simplify the question - If we could set only the Milky Way in an Oven, what might be its temp? In other words, if we can close the Milky way heat radiation in an Oven, what might be the average temp?

Now that we know that our Universe is infinite, homogeneous and isotropic, let's take it one step further. Could it be that the CRM and all other measurements are simple reflections from this infinite Universe? In order to verify it: The Observable Universe is just a very tiny piece with regards to the Infinity Universe. Let's assume that we could set our whole observable Universe in an oven, what would be the outcome of its thermodynamics? Could it be that based on its density, its temp in this kind of oven should be exactly 2.7K? Could it be that a black body radiation is just a reflection of this infinite Universe and we might discover it in this oven?

They are both decreasing in temperature in the same way. This is basically the ideal gas law which relates temperature to volume and pressure. As the universe expands it naturally cools (think of an aerosol can, when you release the gas it gets cold - or the opposite when you squeeze a bicycle pump). 1. Aerosol can - Yes, I fully agree that when you release gas it gets cold. However, in order to set it we need to have two different segments of pressure. If the pressure in the can equivalent to the presure outside the can, there will be no gas flow and no gas gets cold. 2. It seems to me that we do not know how Infinity Universe really works. We might get a severe error by implementing an intuitive finite knowledge on the Infinity. 3. Thermodynamics - Do we have a chapter in thermodynamics which covers the infinity? If not, than it's the time to write it.

The Observable Universe is clear. However, 1. Infinite Universe vs Observable Universe A. Assuming that we could move 1 Trillion Light year away from Earth at any direction (Deep into the Infinite Universe): Should we see a similar space view as we see from our current location? B. Is there any characteristics change between the two? (CRM, Temp...) C. Can we assume that the Observble Universe is covered by the Infinite Universe? D. Is there any edge to the infinite Universe? 2. Temp - If the temp of the Infinite Universe is identical to the Obseravble Universe: A. Can we see it as an example of small oven inside a Huge oven (both at the same temp)? If So, by opening the door of the inside oven, Can we decrease its temp? B. In the same token. How could the Observable Universe decrease its temp if it is covered by an infinite Universe with the same temp?

I have asked: "However, if the Universe is infinite, than it's age must be infinite (or close to infinite)." Your aswer was: It isn't clear for me. Why we can't just assume that an infinite age is needed to set an infinity Universe? What is the expected age of the current Infinite Universe? I assume that a time frame of 13.8 B years isn't long enough for that process?

Thanks Do appreciate. Sorry - What is the meaning of the observable Universe age in an Infinite Universe? The age of the Universe had set as follow: Age of the universe - Wikipedia https://en.wikipedia.org/wiki/Age_of_the_universe "In physical cosmology, the age of the universe is the time elapsed since the Big Bang. ... the Big Bang, and measurements of the expansion rate of the universe can be used to calculate its approximate age by extrapolating backwards in time." I assume that this extrapolation was based on the observable Universe. However, if the Universe is infinite, than it's age must be infinite (or close to infinite). As we set the extrapolating backwards in time (For infinite Universe) - It is still there. It is there 20 BY ago, It is there 100 BY ago and even 1 Trillion years ago. Hence, if the Universe is there (at any age), than we can't claim that 13.8 BY ago the time of the Universe was Zero. How could the Big bang start without setting the time to Zero? How could it start while the Infinite Universe is already there - full of mass? How a Big Bang which took place 13.8 Billion years ago could affect an infinite Universe?

If the Universe is infinite old than its age must be infinite. If there is no evidence that the Universe was "created", than: 1. Why we can't just assume that the Universe was there forever. 2. Why do we need to use the idea of early infinite hot dense Universe? 3. Why do we still need to use BBT as an explanation for Infinite Universe?

So do you mean that: 1. The Universe had been created 13.8 B years ago from an infinite hot denser. Therefore, the idea (based on the BBT) that the size of the hot denser was compact and finite at the first second is just incorrect. or 2. The Universe had been created Infinite time ago and therefore it is infinite now

Few questions: 1. Why do we assume now that the Universe could be infinite? 2. Why an infinite Universe has no impact on the BBT? 3. How could it be that an infinite Universe had been set in only 13.8 BY?