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Biggest ever seen black hole jets; blasting plasma well beyond their own galaxy

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Re: Biggest ever seen black hole jets; blasting plasma well beyond their own galaxy

#51

Post by chasil »

doctorwho42 wrote: post #42
JumpCrisscross wrote: post #33

Earlier quoted context omitted.

> it makes me wonder if there isn’t an upper limit to energy density Yes, in a sense. The point at which the energy bends space-time into a black hole.

Actually, in theory there is one place denser but our models show it can never happen. The moment right after the big bang. As energy can never be created nor destroyed, all the energy in the universe was practically in one point in space-time a femtosecond after the big bang.

At that moment, why didn't the entire [mass of the] universe collapse into a black hole?

Perhaps gravity evolved.

Re: Biggest ever seen black hole jets; blasting plasma well beyond their own galaxy

#52

Post by chasil »

LarsDu88 wrote: post #4

If the plasma jet is wildly larger than our entire galaxy, I wonder if some sort of exotic life could evolve inside the jet. Some sort of life that would be totally rare in the universe.

You are getting a single plastid. No more, no less.

Re: Biggest ever seen black hole jets; blasting plasma well beyond their own galaxy

#53

Post by kadoban »

thehappypm wrote: post #25

I have a question about black holes, HN. Let’s say you have a black hole. You fire a laser beam straight into it. Just by symmetry, shouldn’t it blueshift on the way in, gain some preposterous amount of energy — enough that it can escape?

It will gain energy.

There _is_ no amount of energy it could gain to escape though. It goes no faster, gets no closer to escape. It just splats into the black hole and we'll never see it again no matter how much energy it started with or gained.

Re: Biggest ever seen black hole jets; blasting plasma well beyond their own galaxy

#54

Post by sa1 »

doctorwho42 wrote: post #42
JumpCrisscross wrote: post #33

Earlier quoted context omitted.

> it makes me wonder if there isn’t an upper limit to energy density Yes, in a sense. The point at which the energy bends space-time into a black hole.

Actually, in theory there is one place denser but our models show it can never happen. The moment right after the big bang. As energy can never be created nor destroyed, all the energy in the universe was practically in one point in space-time a femtosecond after the big bang.

This is a misunderstanding. All the energy in our « observable » universe was compressed in that small size. We do not have any estimates of the size of the actual universe now, nor at a time shortly after Big Bang. For all we know, the universe might be infinite, both now and back then.

Re: Biggest ever seen black hole jets; blasting plasma well beyond their own galaxy

#55

Post by ijk »

southernplaces7 wrote: post #5

I thought that only hawking radiation could escape a black hole. Now a paper describing a vast jet of emitted plasma?? The article doesn't quite clarify this point. It mentions the jets shooting from below and above the black holes, but does this mean they're emerging from their interior or being created by the accretion of superheated material that forms in orbit around black holes? The article simple states this, w…

If you track down the original source, there's a video of the lead author of the Nature paper explaining how it works:

https://www.caltech.edu/about/news/gargantuan-black-hole-jet...

Re: Biggest ever seen black hole jets; blasting plasma well beyond their own galaxy

#56

Post by mkl »

dyauspitr wrote: post #45
doctorwho42 wrote: post #42

Earlier quoted context omitted.

Actually, in theory there is one place denser but our models show it can never happen. The moment right after the big bang. As energy can never be created nor destroyed, all the energy in the universe was practically in one point in space-time a femtosecond after the big bang.

The whole concept of the Big Bang is a mind warp. The whole explosion must have happened in some… space-time thing to begin with. What was that immense point of matter and energy in? What was “around” it? We’ll never know.

It wasn't an explosion. Space itself expanded, so there wasn't anything to expand into. https://en.wikipedia.org/wiki/Expansion_of_the_universe

Re: Biggest ever seen black hole jets; blasting plasma well beyond their own galaxy

#57

Post by gitanovic »

chasil wrote: post #51
doctorwho42 wrote: post #42

Earlier quoted context omitted.

Actually, in theory there is one place denser but our models show it can never happen. The moment right after the big bang. As energy can never be created nor destroyed, all the energy in the universe was practically in one point in space-time a femtosecond after the big bang.

At that moment, why didn't the entire [mass of the] universe collapse into a black hole? Perhaps gravity evolved.

That's a question that I always also asked myself, from my layman understanding space time expanded quicker than gravitational collapse

Re: Biggest ever seen black hole jets; blasting plasma well beyond their own galaxy

#59

Post by meroes »

chasil wrote: post #51
doctorwho42 wrote: post #42

Earlier quoted context omitted.

Actually, in theory there is one place denser but our models show it can never happen. The moment right after the big bang. As energy can never be created nor destroyed, all the energy in the universe was practically in one point in space-time a femtosecond after the big bang.

At that moment, why didn't the entire [mass of the] universe collapse into a black hole? Perhaps gravity evolved.

I’m a layman but I think I’ve understood this enough to repeat. The early universe is hypothesized to have been so uniform (gravity pulling in every direction) there was no net direction for anything to collapse to. Because the expansion was so quick, before the uniformity could be ruined due to quantum randomness, it expanded away from there being tons of or one giant black hole.

You also must remember the universe was always infinite (in this model). So for every particle there were particles in every direction from them, ie the universe not a point or point like because points have edges. It was (much much) denser, but still infinite and expanding from all regions.

Re: Biggest ever seen black hole jets; blasting plasma well beyond their own galaxy

#60

Post by meroes »

gitanovic wrote: post #57
chasil wrote: post #51

Earlier quoted context omitted.

At that moment, why didn't the entire [mass of the] universe collapse into a black hole? Perhaps gravity evolved.

That's a question that I always also asked myself, from my layman understanding space time expanded quicker than gravitational collapse

Yes and it was never a point, it was just much much denser but still infinite. And so uniform there was no net direction for collapse before expansion took over.
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