Because cosmology tells us we can describe the entire universe in a model [ https://en.wikipedia.org/wiki/Lambda-CDM_model
Claimed without giving any evidence or references to peer reviewed work.
Instead you troll a self promoting "essay" from a predatory journal - we've been here before, and your comment is no less trolling than the last time.
Because cosmology tells us we can describe the entire universe in a model
This is a bold claim.
Anyway, what do you mean by 'universe' and 'entire universe'? Is this claim for the observable 'contents of the big bang' or the 'whole contents of the big bang' or the universe (dictionary definition).
The dictionary definition of 'universe' is "everything that there is". You, this web sites articles and most top scientists seem to keep referring to the big bang and the universe as one and the same thing. for example, statements like - "The universe
started with the big bang
". It is a huge assumption that the contents of the big bang are 'everything that is' ie the universe. There's absolutely no evidence to support this, I find it completely unscientific.
So until proven otherwise I think its equally good (no, better) to assume the universe is infinite and contains infinite 'stuff'. Meaning the contents of the Big bang is not
'everything that is' ie the universe. With this in mind, the contents of the big bang are expanding into the stuff of rest of 'The Infinite', as I like to call it. When it hits this 'stuff', the 2nd law will not be able to expand the contents of our big bang anymore. So no heat death!
Everything that exists, exists in a space. The big bang may have created space (space itself being a 'something' eg quantum foam etc), but at the same time, it must have existed in a space, even if just a void or geometric space. So, if you want to stick with the idea that the contents of the big bang is also the universe, you are assuming that the rest of space that the big bang existed in is infinite and void, in order to allow indefinite expansion and heat death. A bit absurd in my opinion.
For something to have a beginning, it must be a part of a greater whole or from something pre-existing, otherwise, it's just another something from nothing theory." Again with this proposition the contents of our big bang are expanding into the greater whole, and so can't expand forever - no heat death.
Altogether, with unknown dark energy, and the possibility that the contents of the big bang are expanding into a 'greater whole' or 'The Infinite', don't you think it's a bit unsafe to predict the end, (heat death) of 'everything that there is' just yet?
The observation of the accelerating expansion of the universe is explained with dark energy. We don't know what dark energy is or its full properties. Support for the end of the universe is dependent on something we know nothing about or even if it exists at all. Don't you think that something as important as the end needs something a bit more concrete than an unknown 'dark energy'?