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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

#71

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.

Consider a bubble rising to the surface of a pond. As the bubble breaches the surface, it extends beyond the surface and expands as the pressure reduces.

If you consider the surface of the water as a 2D plane, the bubble expands into a third dimension perpendicular to the others. The bubble's surface is made of the same water as the surface of the pond, and there is no hard boundary between them. The bubble pushes part of the 2D plane into the third dimension, which results in the water having more surface area than the total possible area of the 2D plane.

Area (space) has been created without creating matter or energy. The surface is simply extended into an extra spatial dimension.

The way I like to interpret the big bang is as a higher dimensional structure folding or knotting itself such that a bubble is forced into a 3D space. The bubble expands and thus creates more volume than is possible in the lower-dimensional surface the bubble was formed on. This is my ill-informed interpenetration of M-theory.

Dunno why, but much of mathematics and the universe in general makes much more sense to me when viewed in terms of dimensionality. Our universe is 'just' a 4D slice of a higher dimensional structure, and I find a certain kind of beauty in that. In another life, I'd have been a string theorist

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

#72
post #20

Earlier quoted context omitted.

This is very close to an idea known as "Black hole cosmology" -- basically the idea being that the visible universe is inside a black hole, leading to a sort of "nested multiverse". https://en.wikipedia.org/wiki/Black-hole_cosmology A related theory, rather than being inside a black hole, is that the other side of a black hole is a "white hole". As matter collapses into a black hole, it is emitted from the white hole…

I'm sure it's not practical, but I always thought it would be interesting if instead of living "inside" a black hole, the visible universe was simply being consumed by a black hole so large it just encompassed everything outside the visible part. So no nesting, the universe just eventually gets consumed entirely by one black hole.

Unsure if the math actually checks out on this, but I was told that if you add up the observable mass/energy in our universe with the same average density we see now, you get a black hole with a Swarzchild radius around the size as the observable universe.

One could then quite reasonably argue that our universe is indeed inside or is itself a black hole.

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

#73

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…

You may have heard that a black hole is the most efficient way to convert matter to energy apart from antimatter annihilation. This is that.

In the accretion disk, friction and collision between fragments, molecules, atoms cause things to reach incredible temperatures. The matter gets so incredibly hot that the radiation it emits is actually enough to offset the black hole's gravity and prevents more matter falling in faster. The innermost section of the disk is so ludicrously hot that matter dissociates into subatomic particles and becomes a plasma. This plasma is very energetic and moves very fast and creates a very strong magnetic field. This interacts with the electric field produced by the black hole. This plus the stupendous distortion of spacetime caused by the black hole's rotation causes the magnetic fields to twist up tightly in a vortex about the axis of rotation.

Again, the energies involved are impossibly huge. We're converting matter into energy at something like 95% efficiency. Just through gravity!

Because the plasma is so highly charged, the magnetic vortices are so powerful, and the twist is so tight, it essentially creates a particle accelerator on a galactic scale. Plasma from the accretion disk is sucked into the vortex by the insane magnetic fields. Particles spin round and round in the vortex until they get as close to light speed as is possible. The vortex also confines the jet into a cone, blasting out charged particles with impossible velocities along the axis of rotation.

These jets convert matter into pretty much every kind of energy. Radiation across the entire spectrum, lightspeed particles, magnetic and electric fields. It's really impossible to overstate just how much energy these things throw out. It's just a few degrees shy of a sustained matter/antimatter reaction on stellar scales running for millenia.

These things can extinguish entire galaxies. Not sterilize, extinguish. They can blast away any free gas in a galaxy, immediately and irrevocably halting star and planet formation. Not even just in the host galaxy. Exceptionally powerful quasars can extinguish galaxies lightyears away.

And again, this is only driven by gravity. Nothing else. All of the impossibly huge energies are produced by nothing more than matter falling into a gravity well.

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

#74

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?

Yes, but only if the black hole is rotating. Fortunately, all known black holes do rotate.

There's a concept for using exactly this idea for interstellar propulsion. You fire a laser around a black hole, it gains energy, then hits you, imparting more kinetic energy than you spent firing the laser.

In essence, you're executing a gravity slingshot with photons.

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

#75
post #50

Is it possible for these jets to hit other galaxies/stars/planets?

Yes. A poweful enough quasar can halt star formation in nearby galaxies by blasting away free gas.

Most quasars emit enough gamma radiation to sterilize all of space within a hundred lightyears or so.

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

#76
post #53

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.

From an outside observer, the black hole is finite in width though, though. and if the speed of light is constant, isnt that a contradiction? Or is a black hole somehow of infinite width?

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

#77

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?

> Just by symmetry, shouldn’t it blueshift on the way in, gain some preposterous amount of energy — enough that it can escape? Escape requires a certain critical speed (escape velocity), and light always travels at the speed of light regardless of it's energy, so light's ability to escape a black hole is not energy dependent. At some radius (the event horizon), space itself falls into a black hole faster than the spe…

Here’s something else that I’m concerned with with about black holes. If a mass is one nanogram below that of a black hole, how similar is it to a black hole?

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

#78
post #53

Earlier quoted context omitted.

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.

From an outside observer, the black hole is finite in width though, though. and if the speed of light is constant, isnt that a contradiction? Or is a black hole somehow of infinite width?

It is finite in circumference, yes, but its geometry is not the usual geometry so diameter does not equal circumference divided by pi.

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

#79

Earlier quoted context omitted.

From an outside observer, the black hole is finite in width though, though. and if the speed of light is constant, isnt that a contradiction? Or is a black hole somehow of infinite width?

It is finite in circumference, yes, but its geometry is not the usual geometry so diameter does not equal circumference divided by pi.

It must be infinite then?

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

#80

Earlier quoted context omitted.

It is finite in circumference, yes, but its geometry is not the usual geometry so diameter does not equal circumference divided by pi.

It must be infinite then?

Yes.
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