Editing Openai/6921ae73-3700-8000-8ab7-90012976bb8a (section)

=== Assistant: Nice one, you’re basically asking: ===
Nice one, you’re basically asking:

: 

Let’s compare that to what actually happens, then flip it.

==== In our universe (as far as we can tell): ====
* At very early times, the universe was hot, tiny, and extremely dense.
* Then space expanded.
* As it expanded: - The same amount of stuff was spread out over more space. - So the average density went down over time. - Temperature dropped, particles slowed, atoms formed, then stars, galaxies, etc.

So: early = dense & hot, later = thin & cold.

==== You’re imagining something like: ====
* Early on: universe is not very dense (kind of “empty-ish”).
* As time goes on: it gains matter/energy, so density goes up.

That would mean one of two things has to happen:

===== For density to rise while space is expanding: =====
* Either new matter/energy keeps getting created everywhere,
* Or space shrinks (collapses), but you said “during the Big Bang,” which we usually think of as expansion.

Creating matter out of nowhere:
* Breaks energy conservation (unless some exotic mechanism balances it).
* This is kind of like the old steady-state theory idea, where the universe keeps expanding but new matter is magically created so density stays constant.

In your version, it’s even more extreme: density increases over time, so even more matter has to appear.

===== If space itself contracts instead of expands: =====
* Volume gets smaller.
* Same amount of stuff in a smaller space → density goes up.
* That’s basically like running the Big Bang in reverse: a Big Crunch.

So your scenario is a bit like saying:

: 

That’s kind of the opposite of what we usually call “Big Bang”.

==== If density slowly increased instead of decreased: ====
# No hot, dense early phase → broken Big Bang story In our universe: - Early high density + high temperature explains: - The cosmic microwave background (CMB) - How light elements (hydrogen, helium, a bit of lithium) formed If the universe started low density and only later got dense: - You don’t get the right early “nuclear furnace” conditions. - You wouldn’t get the same helium/hydrogen ratios we see now. - You wouldn’t get the CMB the way we observe it.
# Gravity behavior would be weird As density grows: - Gravity gets stronger overall. - The universe might start to recollapse, forming black holes and super-dense regions earlier. - Structure formation (galaxies, clusters) would happen differently or violently.
# Life probably doesn’t show up If the universe is: - Initially too empty → no stars form for a long time. - Later too dense → things get crushed, heated, or destroyed as gravity ramps up. You’d either get: - A long “boring” phase with nothing much, - Then a violent crunch phase where everything collapses. Not great for stable, calm environments where life can chill for billions of years.

==== We can actually measure how the universe behaved: ====
* The cosmic microwave background shows the universe was: - Much hotter and denser in the past.
* The way galaxies are distributed and how they move matches a universe that: - Started dense and expanded, with density decreasing over time.

So a universe that “slowly gained density during the Big Bang” doesn’t match:
* The CMB
* Element abundances
* Galaxy formation patterns

It’s like an alternate universe with totally different starting rules.

===== If the universe slowly gained its density during the Big Bang instead of starting super dense: =====
* You’d need matter to constantly appear from nothing or space to contract.
* You’d lose the normal Big Bang picture: no standard CMB, no normal element formation.
* Gravity would ramp up over time, likely causing a collapse, not a nice long-lived, star-filled universe.
* It probably wouldn’t make a universe that can host life like ours.

If you want, we can try another twist:

>