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"Book Review: “The Cosmic Cocktail” by Katherine Freese"

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Blogger Uncle Al said...

Central giant black holes seed spiral galaxies persisting over time (red shift), obeying the Tully-Fisher relationship. This requires a filled spherical ball mass distribution (thermally inflated, or dark matter is equatorial plane). Planck satellite: 13.82 Gyr age; 68.3% dark energy, 26.8% dark matter, 4.9% baryonic matter. Galaxy UDFj-39546284 formed ~380 megayears post-Big Bang, z = 12. Spirals' central black holes scrubbed no dark matter over 13 gigayears. Saturn's orbit encloses no dark matter, arXiv:1306.5534.

Physics cannot draw a flat map of the Earth's surface without distortion, cutting, or folding.

http://www.youtube.com/watch?v=QVuU2YCwHjw
Parameterization?
http://www.youtube.com/watch?v=z9pD_UK6vGU
Euclid is the wrong model.

MoND's Milgrom acceleration gives Tully-Fisher, arXiv1310.4009 Milgrom acceleration is measurably geometrically sourced in existing bench top apparatus as an Eötvös experiment, enthalpy of fusion, microwave rotation temperature, pawnbroker rotation; geometric Galilean drop. Look or "D'oh"!

10:59 AM, May 27, 2014

Blogger Phillip Helbig said...

"popular science book"

Minor gripe: the above describes a popular (i.e. many people like it) book about science without saying anything about its level of difficulty. (Newton's Principia is a popular science book.) Freese's book, on the other hand, is a popular-science book, i.e. a book about popular science (i.e. science described for a non-expert readership).

Another minor gripe: The age of the universe is a function of lambda, Omega and H. Without further assumptions, it is not clear that it has to be almost flat in order to be so old. (Otherwise, we would have known it must be almost flat before having measured Omega and lambda accurately enough to claim this.)

11:09 AM, May 27, 2014

Blogger Phillip Helbig said...

Some day I'll start a blog. In the meantime, those interested in books I have reviewed on astronomy, cosmology etc can find them here.

11:11 AM, May 27, 2014

Blogger Uncle Al said...

Astronomy has an unenviable record of its experts' dicta, arXiv:1405.2954 It is not real until it is empirically correct absent excuses.

PAM Dirac told Otto Stern that an idiot would attempt measuring (terrifically difficult) versus calculating (an afternoon) proton magnetic moment. Stern accepted his Nobel Prize for Dirac being sufficiently wrong.

12:26 PM, May 27, 2014

Blogger L. Edgar Otto said...

Uncle Al,

If the universe were to present an observation would it accept the Nobel Prize for the measure or the spirit of it? Would it smile that at least it was honored as a source of inspiration?

Can we compare flat and round if ultimately they describe the same higher concepts of space on some say dimensional level? Newton did write a popular book in terms of old geometry and not the new calculus but even the calculus can turn square maps into round ones over some concept of time.

What sort of popular book would the universe write?

12:55 AM, May 28, 2014

Blogger Giotis said...

"the possible vacua in the string theory landscape do not all have a different cosmological constant (p. 201)"

Why you are saying that? Can you elaborate?

2:41 AM, May 28, 2014

Blogger Sabine Hossenfelder said...

Giotis,

In my (admittedly somewhat sketchy) understanding, the value of the CC is one one of the criteria that distinguish the different compactifications, they may have the same CC but still differ in particle content or symmetry groups, correct me if I'm wrong. Some time back there was some talk about the 'string vacuum project' if you recall (and whatever happened to that?) and they'd sample a selection from the 10^500 to see which had a good CC or the right chiral symmetry, etc, but for all I know the CC doesn't necessarily have to be different for all of these. Best,

B.

3:10 AM, May 28, 2014

Blogger Giotis said...

Nope, there is a discretuum of flux vacua and the CC takes a different value in each vacuum.

Check the mechanism in this seminal paper that started the whole thing (multiverse, 10^500 etc):

http://arxiv.org/abs/hep-th/0004134

3:56 AM, May 28, 2014

Blogger Sabine Hossenfelder said...

Giotis: The question is whether that fixes the symmetry groups & particle content. My understanding is, no, it doesn't.

4:59 AM, May 28, 2014

Blogger Giotis said...

Well, You should embed the mechanism (or a version of it) in a larger context and a compactification scheme e.g. F-theory flux vacua but that doesn't change the fact that each string vacuum will have a different CC.

6:54 AM, May 28, 2014

Blogger Sabine Hossenfelder said...

Giotis: Do you realize that you are saying string theory predicts that the observed value of the CC can only have been produced with the particle content of the standard model? Saying that one should 'embed' the mechanism into the compactification scheme somehow just means to me that there are different ways to do this embedding, consequently different theories with the same CC.

9:11 AM, May 28, 2014

Blogger Uncle Al said...

What are this vacuum' symmetry groups? Photons offer 14 significant figures, bench top and billion lightyear paths. Matter violates photon vacuum symmetries. Parity violations, symmetry breakings, chiral anomalies, baryogenesis, Chern-Simons repair of Einstein-Hilbert action suggest vacuum trace chiral anisotropy acting only upon hadrons occurs.

http://www.cfa.harvard.edu/events/2014/sackler/
The corrections require unending corrections.

Perform the first matter-based chiral geometric test of spacetime geometry. Ignorance is not a form of knowing things, nor is faith - except in politics.

10:32 AM, May 28, 2014

Blogger Giotis said...

In general what you are doing is first to construct a model that reproduces roughly the SM gauge group and then try to fix the moduli via fluxes. But these processes are not independent; there is a very complicated interplay between the two and one affects the other in a non-trivial way (additional consistence conditions comes into play too). That’s why people often make simplifications for one process when they are focusing on the other and vise versa. To have the complete setup is a very complicated thing.

In any case the expression that ‘each vacuum in the string theory landscape has a different cosmological constant’ is legitimate; I wouldn't say that the author made a mistake in any reasonable sense.

12:38 PM, May 28, 2014

Blogger L. Edgar Otto said...

The question of if an imagined CC varies or not, even if a matter of thought, even if distinct grounds are not resolvable as a unified landscape driving life close to frontiers but not beyond chaos (those busy not being born are dying) is the essential one in our time facing physics in all its greater span and depths of complexity. (as we can cite in the recent literature). But the existence of BICEPS data or not as a reduced independent oriented plane of symmetry or intrinsic chiral spin is the same question if a complete description in all its simplicity.

3:27 PM, May 28, 2014

Blogger pete said...

Hi Bee,

Apologies for coming in a little late, but I was just wondering about the part of the article that states that quantum fluctuations do not cause Hawking Radiation. I have read in several places that one interpretation of Hawking radiation is virtual particles popping up near the event horizon, with one going in and the other escaping before they can annihilate and return the "borrowed" energy from the vaccum or whatnot. I've also seem an explanation from tunneling, where particles can escape because part of their wavefunction crosses the horizon (or something to that effect).

I'm not sure if one is actually true, both are true and contribute to different degrees, or both are entirely off base. Your comment helped ease worries I've had with the fluctuation idea (such as how the in-falling particle, which I assume still has positive energy even if it is an antiparticle, could somehow contribute negatively to the black holes mass), but I'm still wondering what exactly goes on and why so many popular science sources could get things so spectacularly wrong.

Any help in clearing things up would be greatly appreciated.

2:30 PM, May 30, 2014

Blogger Jerry Lisantti said...

Bee: Maybe its time to rethink about you writing a book. Maybe on the topic of quantum gravity? Your writing style is wonderful and you have a broad knowledge of the subject.

3:40 PM, May 30, 2014

Blogger Giotis said...

Pete,

Although Bee can explain better of course, allow me to say that I think she is talking about quantum fluctuations of space time (i.e. of the gravitational field i.e. of the metric) and not of quantum fluctuations in general. What Bee means is that Hawking radiation is not a QG effect. To derive the Hawking radiation you treat space-time as a fixed classical background; you don’t quantize it. You quantize instead the quantum fields living on the fixed classical space-time of a Black hole near its Horizon. The Horizon (the causal structure basically) is what is important for the radiation to be produced and this is a property of the metric of the classical Black hole.

So these various heuristic interpretations of the Hawking radiation you've read in popular books are legitimate; meaning that the Hawking radiation can be attributed to the vacuum quantum fluctuations of the fields near the Horizon.

Of course strictly speaking, if you want, you can quantize even the space time perturbatively (i.e. quantize small fluctuations of the gravitational field around the fixed classical space time of a black hole); then the gravitons as quanta of this field will contribute to the Hawking radiation as any other field.

So the author of the book could save herself embarrassment if she would have said:

“Hawking radiation is caused by quantum fluctuations of space-time as well” :-)

Seriously though, it is very strange that a professional physicist made such a huge mistake. I think it must be a misprint of some sort.

9:12 PM, May 30, 2014

Blogger Sabine Hossenfelder said...

Pete,

Giotis explanation is correct and is exactly what I meant. Freese writes explicitly "quantum fluctuations of spacetime... cause pairs of particles and antiparticles to pop in and out of existence". The problem is the insertion "of spacetime". Quantum fluctuations of spacetime would be treated in quantum gravity, yet particle-antiparticle production has in general nothing to do with that. Particle and anti-particle pairs are created by quantum fluctuations, period. I am picking at this sentence because it supports the common misunderstanding that Hawking radiation is a quantum gravity effect. It is not. It's quantum field theory in a classical spacetime background. Best,

B.

12:12 AM, May 31, 2014

Blogger Sabine Hossenfelder said...

Jerry,

Thanks, I appreciate the encouragement. If I were to write a book though, it would not be about quantum gravity. It's not that I don't want to, I can't see how to make the time to do it well, and if I don't have the time to do it well, I don't see why do it at all. Best,

B.

6:00 AM, May 31, 2014

Blogger Sabine Hossenfelder said...

Phillip,

Thanks, I see what you mean about the dash, will be more careful with these. About the age of the universe, the book is generally very sketchy on how these parameters are to be understood and how they are extracted from the data. Be that as it may "almost flat" is a vague expression, but mainly I stumbled over the sentence saying that it has to be flat. (And let me not get started on the problem that she doesn't explicitly distinguish between spatial curvature and space-time curvature which I know (mostly from writing this blog) tends to confuse people who come across this first time.) Best,

B.

6:04 AM, May 31, 2014

Blogger pete said...

Giotis and Bee,

Thank you very much for the responses. Definitely helps clear things up!

One final question, and this is in relation to the actual mechanism of reducing the black holes mass. I understand the idea of pair creation and capture by a black hole making the particles "real," but if they are both particles with positive energy (change in charge being the only difference), how does the outgoing particle "steal" mass from the black hole. I've yet to ever hear an intuitive explanation for this (I mean what the heck would negative energy for a particle even mean?).

3:59 PM, May 31, 2014

Blogger Sabine Hossenfelder said...

Pete,

The energy of the infalling particle is negative, roughly, because inside the black hole horizon time and space are interchanged. I don't think there really is a good 'intuitive' explanation for it. I mean, why do you expect to have an intuition about black hole physics? Best,

B.

12:36 AM, June 01, 2014

Blogger Zephir said...

/* inside the black hole horizon time and space are interchanged */

This is indeed well said and at all, but which of contemporary formal models of black holes (entropic, whatever) actually accounts into it?

4:54 AM, June 01, 2014

Blogger Sabine Hossenfelder said...

The Schwarzschild metric, Zephir, the Schwarzschild metric... Had you ever opened any textbook about General Relativity you should know this.

9:19 AM, June 01, 2014

Blogger Zephir said...

/* The Schwarzschild metric, Zephir, the Schwarzschild metric... */

This is just the matter of coordinate definition. At pictures of the Schwarzschild metric the space-time gets curved monotonously toward singularity as nothing would ever happen with time dimension. At least the gravitational potential is borrowed from global time coordinate at all derivations instead from observer local time.

The road to the hell is pawed with good intentions.

11:33 AM, June 01, 2014

Blogger Sabine Hossenfelder said...

Zephir,

No, it is not a matter of coordinates. You just continue to demonstrate your lack of understanding. Do yourself a favor and read at least this. It's a property of the space-time, not of the coordinates you chose.

12:36 PM, June 01, 2014

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1:00 PM, June 01, 2014

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