How did the primordial gas cloud form?

[Zomling]

@Der Trihs

Why ? Couldn’t planets have formed out of those three elements ? They wouldn’t have rocky or metallic cores, of course, and they’d have to be big enough to hold on to such light elements, but a planet sized mass of just those three elements would still be a planet, I’d think. Rather like a modern gas giant. Is it theorized that planet sized masses just wouldn’t form or be stable under those conditions ?

Prossibly, (See reply by Stranger on a Train above), but it is theorised that even gas giants have small rocky cores. Whether they need them to form I’m not sure, maybe someone else can answer that.

[Chimera]

Thanks Stranger, I appreciate your time and response.

@Stranger On A Train

What the frass is that supposed to mean?

The bit you quote was in response to Exapno Mapcase and an emerging pattern in his responses to me over several threads.

[Quartz]

Back to my OP. I’m afraid I still don’t see how you get from something like the Crab Nebula to the vast dust clouds of the Pillars of Creation. Okay, the ejecta gradually slows from the galactic wind and gets mixed up as it orbits the galactic centre, but it’s then spread out incredibly thinly. So how does it all coalesc back together into semi-stable dust clouds without fully coalescing into planetary systems until given a nudge? And remember that places like dust clouds, Bok Globules, etc, birth more than one system.

[Enola_Straight]

How about pseudo-gravity?

A particle of dust is acted upon by light pressure.
If another particle is being pushed around by light from the opposite side, the two particles will fall into each others’ shadow.

[Exapno_Mapcase]

@Chimera

The bit you quote was in response to Exapno Mapcase and an emerging pattern in his responses to me over several threads.

I have no idea of who you are or any memories of you in other threads. I responded to posts that got the physics wrong even after a thorough explanation of the correct physics had already been given.

You’re either right or wrong. If you’re wrong expect to be corrected. In any thread. By anyone.

[Exapno_Mapcase]

@Enola Straight

How about pseudo-gravity?

A particle of dust is acted upon by light pressure.
If another particle is being pushed around by light from the opposite side, the two particles will fall into each others’ shadow.

This falls into the same problem. It’s hard to imagine two equal yet opposed light sources whose energies would cancel one another out. If the light sources are at a distance from another and the particles just happen to come together, despite the extreme unlikelihood of this is the vastness of space, the lack of other particles with exactly the same trajectories would prevent any larger bodies from growing.

Gas clouds start out with immense numbers of particles moving under similar influences. That allows for small gravitational interactions over large numbers of years. That’s pretty much the answer to Quartz’s question as well. But anything else and the speeds, angles, and densities will be wrong for long-term growth.