Friday, February 22, 2008

A Smoggy Day on Venus


Before telling where I've gone this week, there is news from Venus. ESA's Venus Monitoring Camera has found mysterious hazes that appear and disappear in a few days. The hazes are composed of sulfur dioxide and water vapour, source unknown. Like the polar hot spots seen on other worlds, the haze begins at the South Pole and moves outward.

In the islands we learn to recognise volcanic activity when we see it. Kilauea Volcano issues water vapour from the Steaming Cliffs, and sulfur from vents. These hazy clouds probably issue from Venus' interior. We have previously seen geysers on Enceladus' South Pole and hydrocarbons gushing from Titan. These diverse worlds could all have internal heat powered by central Black Holes.

I'm staying at a place known for smog and haze, but more about that soon. More Space news at the new Carnival of Space!

6 Comments:

Blogger nige said...

"These diverse worlds could all have internal heat powered by central Black Holes."

Hi Louise,

I've got a huge number of questions about this. If planets have black holes in their centres, why doesn't the mass get sucked in, how does it produce just the right about of heat?

Since Hawking radiation in the mainstream picture is just gamma radiation with a blackbody (Plank) radiation spectrum resulting from the gamma rays which originate near the event horizon from the annihilation of charged virtual fermions, small black holes would evaporate quickly by emitting radiation (according to the mainstream model), unless mass endlessly falls into them.

Are you sure that this is a stable system? It looks pretty unstable to me: either the black hole will get converted completely into gamma rays (Hawking radiation) ans disappear quickly, or it will grow rapidly by swallowing up the planet and then other planets, the sun, etc.

I think that one thing that needs a lot of careful thought is a conflict between facts from quantum field theory and black hole theory.

According to quantum field theory, Schwinger shows that pair production doesn't occur in the vacuum at any distance around matter.

It only occurs in electric fields which are stronger than Schwinger's threshold for pair production. This is well established experimentally, because the polarization radially of virtual fermions from pair production around a charge accounts for the renormalization of charges, by shielding core charges in part.

If there was no limit to the amount or range of pair production, the vacuum would be able to totally shield (not partly shield) all electric charges, so that all electric fields would be quenched within a short distance (not by just geometric divergence of field lines which gives the infinite range inverse-square law).

Schwinger's threshold is 1.3*10^18 v/m, which occurs out to a radius of 33 femto metres from the middle of an electron. Electrons will therefore be black holes radiating some kind of "photons" from their black hole event horizon radius of 2GM/c^2, assuming that they have no larger scale structure (string theory is based on the idea that electron cores are strings of Planck scale, but there's no evidence for anything existing at the Planck scale, it's just a size based dimensional analysis and isn't physically based; it's not even the smallest unit of physical length, which is actually the event horizon radius for an electron's mass, which is far smaller than the Planck length).

If you apply Schwinger's threshold field strength for pair production to black hole Hawking radiation, you can see that no Hawking radiation can occur from an electrically neutral black hole.

In order for Hawking radiation to be emitted, pair production must occur all the way out to the event horizon, so that virtual pairs of fermions created near the event horizon can become real by the mechanism of one of the pair falling into the black hole, while the other particles escapes beyond the event horizon.

This is only possible if there is an electric field of over 1.3 x 10^18 v/m at the event horizon. (equatuon 8.20 in the http://arxiv.org/abs/hep-th/0510040 lectures on quantum field theory, equation 359 in Dyson's http://arxiv.org/abs/quant-ph/0608140 book on QED).

Hence, the whole basis of Hawking's theory is undermined by QED, which implies that charge renormalization demands a cut-off to the amount of pair production and vacuum polarization.

The vacuum is not full of virtual charges; these only occur in the case where a static electric field exceeds 1.3x10^18 volts/metre.

Large black holes which are electrically neutral therefore emit exactly zero Hawking radiation, because there is no electric field at the event horizon and consequently no mechanism for Hawking's pair production mechanism to create annihilation gamma rays.

But it is more interesting is when you treat the electron as a black hole.

It does radiate, and it an interesting way. Because it is charged, it has an adequately strong electric field at its event horizon to enable it to radiate, but - also because it is electrically charged - it doesn't radiate by the same mechanism as envisaged by Hawking.

Hawking's mechanism for black hole radiation is completely fictional, because there is no fermion pair production without a strong electric field. Fermions of opposite charges must accumulate beyond the event horizon radius in Hawking's model, to enable them to annihilate forming gamma rays (Hawking radiation). This can't happen in reality.

Because only electrically charged black holes can radiate, the electric charge on the black hole will prejudice which charge escapes.

E.g., pair production of fermions near the event horizon of a negatively charged black hole will result in fermions of electric charge opposite to the black hole tending to fall into it, while the fermions of the opposite sign will tend to escape.

This mechanism will act towards neutralising the electric charge which exists within a black hole, while charges accumulate outside the event horizon which are of similar sign to the original charge of the core of the black hole.

Once this has occurred and the core of the black hole has become electrically neutral while it's charge has in effect been transferred beyond the event horizon by the subtle pair production process, the black hole will no longer possess an electric field capable of causing pair production at its event horizon.

Specifically, once a black hole electron causes one virtual electron-positron pair to be created near its event horizon, the virtual positron will tend to fall into the event horizon and neutralise the real electron's core.

The virtual electron will escape and become a real electron, then will repeat the process.

If this process is occurring all the time to electrons, it would go some way towards explaining the lack of determinism of electron motions on very small scales, such as inside the atom.

9:12 AM  
Blogger L. Riofrio said...

qHello nige: I always appreciate your very thoughtful comments.

In the case of Earth, the Black Hole would have mass on the order of 10^22 kg, slightly less than the Moon. It would be centred in a cavity of radius 300 km. (This boundary has already been detected.) The gravitational force at the edge of this cavity is about 7 m/sec^2, less than we feel at Earth's surface.

The cavity's interior would act as a blackbody. Radiation originating from the singularity opposes gravity's inward pull. We end up with a neat equilibrium at the cavity boundary. Increasing the cavity temperature would decrease the amount of materiel falling into the singularity, lowering temperature back into equilibrium.

Black Holes within planets would not evaporate because something is feeding them, namely us. Because of the high cavity temeprature, only a tiny amount of mass reaches the singularity. The amount eaten is far less than the mass Earth acquires from meteorites.

Hawking radiation is an widely accepted yet unproved theory, since no one has directly observed it. There are other methods by which Black Holes produce radiation, evidenced by the many active galactic nuclei.

Treating the electron as a Black Hole is an approach I have tried before. Einstein wondered what the lowly electron really is. Like a Black Hole the electron can be described by charge, mass and spin. In the electron they are restricted to quantum values.

My brief reply does not do justice to your comment. I hope you don't mind that I had dinner with the author of a 1998 supernova paper, for I am aware what someone predicted back in the 90's.

9:40 PM  
Blogger nige said...

Hi Louise,

Thank you very much for your reply, which is very thought provoking.

"Treating the electron as a Black Hole is an approach I have tried before. Einstein wondered what the lowly electron really is. Like a Black Hole the electron can be described by charge, mass and spin. In the electron they are restricted to quantum values."

I think that the mainstream objection is that the black hole event horizon for an electron is so small, way smaller than the Planck scale, that they're sure that quantum field theory can't apply there.

The high energy cutoff (UV cutoff) needed to make quantum field theories ignore the unphysically massive momenta of virtual particles as you reach very high energies such as the Planck scale (very small distances between colliding particles) seems to suggest that there is a grain size to the vacuum (assumed to be the Planck scale), and that smaller sizes than the Planck scale are meaningless because there is nothing on smaller scales.

However, from the equations of quantum field theory I've seen, there is no real evidence for this at all. It's clear that there is a need for a cutoff on a logarithmic term for a force coupling strength, but there is no evidence that the reason for such a cutoff is that nothing exists at smaller distances than the Planck scale.

If you look at a plot of how the three fundamental forces of the standard model approach each other (either with or without supersymmetry), they appear to approach one another at a size much bigger than the Planck scale.

I think the whole problem there is mathematics symmetry-searching winning out over physical laws like conservation of mass-energy.

What they should be doing (instead of assuming that standard model forces can all be the same at one point using supersymmetry, implying that forces "unify" because the strengths of the forces become similar) is to concentrate on where how conservation of the field mass-energy is occurring.

E.g., an electromagnetic field of given strength has a given amount of energy per cubic metre, as will weak and strong force fields. What is the physical reason why the strong force strength coupling increases with increasing distance (up to a certain point), while the electromagnetic force coupling decreases? Clearly, from conservation of mass-energy and the mainstream model of a force field as mediated by exchange of gauge bosons, the mechanism is that the polarization of the vacuum attenuates some of the electromagnetic field, and this attenuated energy is used for pair-production of short range particles in the vacuum. Presumably some of this energy transferred from the electromagnetic field to virtual short-ranged particles, eventually is converted into the gluon and meson fields which are powering the strong nuclear force. This would explain why the strong force coupling parameter varies in the opposite way to the electromagnetic force coupling parameter as you get closer or further away from a quark. Instead of investigating such physical mechanisms, the mainstream approach is to search for mathematical beauty, and after failing to find it, to attempt to fabricate such mathematical beauty where it doesn't exist by constructing string theories which can't connect to reality.

12:55 PM  
Anonymous Samh said...

The vog here has been really intense, they have closed access to one of the craters as it is emitting so much gas. I have never really noticed it before, but the vog really does effect the health of those living here. I find it both fascinating and irritating at the same time ;O)

The sky is practically white it is so hazy and with the bright sun it is blinding.

Apparently it will not last much longer, Hilo will do what Hilo does best, and wash all that SO2 out of the air in a flush of acid rain.

So Louise, when you coming to da kine ?

8:49 AM  
Blogger CarlBrannen said...

I suspect that a 300km cavity would appear as an artifact in earthquake measurements that pass through that spot. They would be anomalously slow and weak on paths directly through the earth.

So the specific gravity for that 300km sphere would be around 88 grams/cc, which is considerably higher than what is thought to exist at earth's core, but I suspect that this is not detectable.

A third place where this might show up is in neutrino studies, which oscillate differently depending on mass densities. But I suspect a void that small won't be detectable.

Where does the 300km come from?

9:11 AM  
Blogger Parvulus said...

To Carlbrannen

Hi. Possibly from the last page of

http://arxiv.org/PS_cache/gr-qc/pdf/0008/0008006v1.pdf

but of course only Louise can tell where she got it from.

5:46 AM  

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