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YourWiseOldFriend t1_je1at86 wrote

Hawking radiation IS dark matter. If you calculate all the Hawking radiation you reach a total that's -precisely- the amount predicted by the Standard Model.

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Shrike99 t1_je1lpfi wrote

OP was talking about dark energy, not dark matter. Given that Hawking radiation is in the form of photons which have no rest mass, it's already a poor candidate for dark matter.

Then there's the minor detail that the combined Hawking radiation output of every black hole in the observable universe is less than than the power consumption of the tablet I'm typing this on. Indeed, black holes absorb far more energy than that just from cosmic microwave background radiation, so they're net energy absorbers even without actively feeding on matter.

Even if we ignore that, the the upper limit on thier total energy emited as hawking radiation since the big bang is on the order of a few joules, or less than a picogram of mass equivalence. Ignoring primordial black holes anyway, since we've got no solid evidence for thier existence.

Even if it was a signifcant amount it wouldn't matter since any amount of 'hawking-equivalent-matter' emited by a black hole will reduce the black hole's mass by that same amount.

Since the combined mass of all black holes theoreized to exist is insuffcient to explain dark matter, then so too will be any amount of hawking radiation emited by them.

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Anonymous-USA t1_je1gh01 wrote

Radiation isn’t matter, it’s energy. And hawking radiation is not dark energy either.

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YourWiseOldFriend t1_je1ha4t wrote

I totally disagree. I refer to the wave/particle duality of light.

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Anonymous-USA t1_je1v40n wrote

Duality aside, photons have no mass and cannot be dark matter.

As for duality, they act as energy waves except when interacting with other particles as they absorb or emit radiation. EM and photons are well understood and not related to dark matter.

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YourWiseOldFriend t1_je6qrqa wrote

>photons have no mass

How then are they redirected when in the proximity of a stellar gravity field? How does that happen when they have no mass?

>EM and photons are well understood

And here I was, thinking they call it black matter and black energy precisely because they don't understand what it is.

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Anonymous-USA t1_je6vujf wrote

They aren’t redirected. They travel in a strait line. It’s the space that is warped and the light curves with the space.

In fact, the escape velocity of any gravity well is dictated by the mass of that first body, not the second, because it’s a function of warped space. That’s true whether it’s the Earth, the Sun or a black hole. And the second body, whether it has the mass of a moon or a massless photon, isn’t a factor.

Dark Matter and Dark Energy are called “dark” for two reasons, they are both not directly observable and are poorly understood. So it’s apropos. But electromagnetic energy (EM), light and photons are neither dark nor misunderstood. There are full quantum particle and wave and field descriptions for them.

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TheBounceSpotter t1_je1luxs wrote

How could you possibly think we would be able to calculate the hawking radiation of the universe. There are probably a trillion different variables in determining the amount of matter in black holes. How many there are, and what size they are also affects the emanation rate of Hawking radiation. Even an estimate trying to get within an order of magnitude would be highly suspect.

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