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Are Black Holes Actually Dark Energy Stars?

nautil.us

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Re: Are Black Holes Actually Dark Energy Stars?

#121

Post by Sarki »

sorenn111 wrote: post #58
Sarki wrote: post #52

On another note a theory which seems to fit particularly well is called Janus. The concept lies in the existence of a twin universe (ours being matter based the twin being antimatter based) merged together where the black holes are basically where the antimatter is concentrated and thus repulses all the matter hence this seemingly void. This is a succint summary but I hope it makes sense to the more knowledgeable rea…

The predominance of matter over antimatter I thought was explained by symmetry breaking at the ultra extreme conditions of early universe? Would there be a twin universe for other broken symmetries?

That's what is explained in the Janus model, both universes coexist in the same space and are rejecting each other through gravity, matter "won" over antimatter only by a tiny bit but sufficient to allow large portions of matter to remain. Though the appearance of both at the early times of the universe was in beyond colossal amounts, both being annihilated by each other when they met.

edit: typos

Re: Are Black Holes Actually Dark Energy Stars?

#122

Post by chc »

econnor wrote: post #116
joe-collins wrote: post #17

Earlier quoted context omitted.

At least at the pop-science level, his ideas connect a lot of dots. He'd neatly resolve the weirdness and mystery of black holes, their jets, their information paradox, and dark energy. It feels good. Whether or not any of it makes a lick of sense once you start actually crunching numbers is another question. The lack of interest from other scientists leaves me skeptical (even if I'm silently enamored of the neatness…

There's a certain nominative-deterministic inevitability to all this. There are these things called black holes that apparently are a full of a lot of stuff and aren't completely understood. And there's this mysterious stuff called dark matter that has to exist but seems to be hiding. My mom would be yelling "'Come on guys, join the dots". And who would blame her.

You seem to be thinking that nobody considered black holes as dark matter candidates, but that's not the case. The two big theories around the origin of dark matter are called WIMPs (weakly interacting massive particles) and MACHOs (massive compact halo objects), and MACHOs include black holes. The reason MACHOs aren't widely accepted is because the evidence (e.g. lensing measurements) doesn't suggest there are nearly enough massive invisible objects to account for a significant portion of the dark matter.

Re: Are Black Holes Actually Dark Energy Stars?

#123

Post by econnor »

chc wrote: post #122
econnor wrote: post #116

Earlier quoted context omitted.

There's a certain nominative-deterministic inevitability to all this. There are these things called black holes that apparently are a full of a lot of stuff and aren't completely understood. And there's this mysterious stuff called dark matter that has to exist but seems to be hiding. My mom would be yelling "'Come on guys, join the dots". And who would blame her.

You seem to be thinking that nobody considered black holes as dark matter candidates, but that's not the case. The two big theories around the origin of dark matter are called WIMPs (weakly interacting massive particles) and MACHOs (massive compact halo objects), and MACHOs include black holes. The reason MACHOs aren't widely accepted is because the evidence (e.g. lensing measurements) doesn't suggest there are nearl…

I'd kinda worked out that people who know about this stuff didn't think it was a good account. Was more remarking that calling things dark and black (and, indeed, wimps and machos) sort of invites simplistic and erroneous pop-science assumptions.

Re: Are Black Holes Actually Dark Energy Stars?

#124

Post by codethief »

clubm8 wrote: post #104

I find the idea of a photo of a black hole more interesting than this dark energy star. It didn't seem to be mentioned in the article: when will this "Event Horizon Telescope" have enough data to show us an event horizon?

From their blog[1]:

> As the EHT team begins to analyze the 2017 data on Sgr A* and M 87 over the coming months, preliminary images will begin to emerge, and the searches for the signatures of orbiting material around the black holes will be conducted. It is the most exciting time of the project.

[1] https://eventhorizontelescope.org/blog/eht-status-update-may...

Re: Are Black Holes Actually Dark Energy Stars?

#125

Post by codethief »

dsnuh wrote: post #112
codethief wrote: post #97

Earlier quoted context omitted.

No worries, I hadn't watched the video yet, anyway. :) So feel free to rephrase your questions if you like!

My questions were based in the video I linked above, which it sounds like may be incorrect in the way it presents the topic?

Judging from the few minutes I watched, it is at least not very precise, yes.

What they mean when saying that "time and space switch roles inside a black hole" is that in standard Schwarzschild coordinates, the direction given by the time coordinate becomes spacelike at the event horizon and, likewise, the radial coordinate becomes timelike. This statement is specific to Schwarzschild coordinates, though, or, more generally, any coordinate system that is singular/ill-defined at the event horizon. There are coordinate systems, however, that don't exhibit this pathological behavior at the horizon and, there, no switching occurs.

Re: Are Black Holes Actually Dark Energy Stars?

#126

Post by codethief »

maze-le wrote: post #24
hinkley wrote: post #5

I managed to confuse myself into a Zeno’s paradox situation with how black holes grow. This is really exotic space. Time dialation immediately outside of the event horizon would make any matter fall so slow that it would take millions of years of time for an observer to see that material cross the horizon.

From the outside, it would never cross the horizon, it would look as if the matter would travel towards the horizon infintly long. After trillions of trillions of years the information that made up the inbound matter from the horizon will be radiated away by hawking radiation. If you are travelling with a probe towards the horizon though, you would be able to calculate your escape velocity, so you could tell if you a…

> After trillions of trillions of years the information that made up the inbound matter from the horizon will be radiated away by hawking radiation.

This is merely conjectured by some physicists. In reality, we have no clue what happens.

Re: Are Black Holes Actually Dark Energy Stars?

#127

Post by nikofeyn »

bsder wrote: post #87
diegoperini wrote: post #19

Earlier quoted context omitted.

If what LIGO achieved is not loud enough for the 21st century, then we are probably doomed. It is a NEW kind of telescope that has not even been utilized for 1% of its potential. PS: I'm not arguing with your statement, you have all the right to think that way. Maybe even people who lived during Einstein's earlier times thought the same for their previous century.

> If what LIGO achieved is not loud enough for the 21st century, then we are probably doomed. The problem is that it is REALLY hard to describe to the layman just how excruciatingly difficult it is to do what LIGO does. I like to think that I know a thing or two about electrical engineering and quantum mechanics, and even I probably don't get just exactly how amazing LIGO is.

kip thorne's talks are really good about explaining ligo's importance.

https://www.youtube.com/watch?v=Cxhp4GBr1Zg

Re: Are Black Holes Actually Dark Energy Stars?

#128

Post by diegoperini »

whatshisface wrote: post #107
admax88q wrote: post #64

Earlier quoted context omitted.

The thing I hate about this statement is it gives people an excuse to ignore things they don't understand at first glace by claiming the presenter doesn't fully understand it so it's probably not true. Its a good standard to hold yourself to when explaining things to others. But not one to hold others to when explaining to you.

"Be liberal in what you accept but conservative in what you generate."

Even that is up to debate.

https://cacm.acm.org/magazines/2011/8/114933-the-robustness-...

Re: Are Black Holes Actually Dark Energy Stars?

#129

Post by 0898 »

codethief wrote: post #96
0898 wrote: post #15

Earlier quoted context omitted.

Question if you don't mind. This "information being destroyed" thing. What do they mean by information? Isn't information a human construct? How is the universe supposed to know what information is?

There're different levels of making this statement precise. Here's one: Physics is a deterministic theory, even at a quantum level where we call determinism unitarity . (Leaving the measurement problem & collapse of the wave function aside for a moment.) Determinism means, we can start with one state of a given physical system and basically hit the "fast forward" or "backward" button to see what the state was like in…

Thanks for this answer. Appreciate it.
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