news sciences: Comments of the Week #169: from a theory of everything to discovering today’s Universe [Starts With A Bang]

“Your assumptions are your windows on the world. Scrub them off every once in a while, or the light won’t come in.” -Isaac Asimov

Just like every week, we’ve had a slew of new stories to share with you here on Starts With A Bang! It’s been great fun to put these stories together, to share a new corner of the Universe with you, and to explore what’s going on at the frontiers of science together. Want to take a look at everything that’ happened, in case you missed anything? Let’s take a look:

Do you want a fun announcement? I bet you do! For those of you excited about my upcoming book, Treknology, I’ve just finalized that I’ll be at two days of the official Star Trek convention in Las Vegas next month, on August 3rd and 4th, and if you’re there, make sure you come and see me and say hello!

And finally, it looks like there are some problems with a couple of plugins on Scienceblogs: Jetpack (for anyone on the back-end) and Wordfence (for anyone trying to comment). Until the admins get things in order, the best I can recommend is to wait ~10 minutes and try and comment again if you get blocked. With that out of the way, let’s all enjoy the best of our comments of the week!

If you remain outside the event horizon of a black hole, escape is possible; if you fall inside, is there any possible way out? Image credit: The Simpsons / Fox / Treehouse of Horror; deviantART user 15sok.

From Naked Bunny with a Whip on falling into a black hole:
“ES: Are you telling me that your ship must be torn apart by the event horizon’s existence.
NBwaW: No, I was asking why that isn’t the case.”

I want to paint a picture for you. Imagine you’re crossing the event horizon, and part of you is inside and part of you is outside. You’re in free-fall, so in theory, you can’t tell the acceleration due to gravity apart from any other type of acceleration. But you also have this issue that any particle inside the event horizon that emits a boson, even a massless virtual boson, will have that boson be directed towards the central singularity. So why can inter-atomic forces still work? Or inter-particle forces, for that matter?

It’s because there aren’t just two options. (This is the same problem with every Socratic dialogue; the answer isn’t always A or B, Socrates, and you don’t prove A by showing that B is absurd.) The setup implies that either these particles go to the singularity, or they escape to outside the event horizon. Clearly, that latter option is absurd, and so you might think that going to the singularity is inevitable. But what if there are other particles inside the event horizon, too? Is it possible that a particle falling towards the singularity, when it emits a photon, has that photon encounter another particle that’s also falling towards the singularity before it reaches the singularity?

Yes, yes it is. That’s the resolution. Either you tear something apart (i.e., your tether goes “snap”), or you go to the singularity, or you run into something else that’s also inside the event horizon, including something that’s been newly pulled inside the event horizon. Don’t underestimate option C!

The fabric of the Universe, spacetime, is a tricky concept to understand. But we’re up to the challenge. Image credit: Pixabay user JohnsonMartin.

From Elle H.C. on what spacetime is: “At LIGO we can eventually reduce and escape as much noise as possible by setting LISA up in space, but for the LHC there’s no escape.”

So it occurs to me, as we retread this ground again, that you are of the mindset that spacetime fabric is a thing, rather than nothingness itself. We can create visualizations of it; we can write down the laws that govern it; we can quantify the interrelationships of its various components. But it’s not a physical thing that you can poke holes in or tear apart; it’s a mathematical structure that’s well-defined, and the conditions where that structure breaks down — Planck scales — are also well-defined. The LHC doesn’t reach those scales, so we’re positive that we’re fine. Your analogy isn’t applicable here.

The fabric of spacetime, illustrated, with ripples and deformations due to mass. Image credit: European Gravitational Observatory, Lionel BRET/EUROLIOS.

From Pentcho Valev on what science is and isn’t: “This is wrong. Logic comes first – a physics theory should be DEDUCTIVE (general relativity is not). If the theory is not deductive, it is an empirical model that can be endlessly adjusted, and looking for supportive evidence makes no sense.”

You are entitled to your wrong opinion. But it is wrong, as I’ve explained to you; you cannot demand that the logical structure you would impose on the Universe describes the Universe. The Universe is full of examples of things that “make no sense” actually, physically happening. Do please stop spamming my blog with the same screeds, or I’ll have to ban your commenting privileges.

Kasim and Axil: you aren’t far behind.

If you allow a quantum wavefunction to spread when it’s near a false vacuum in inflating space, it could expand for an infinite time into the future, which is the idea behind eternal inflation. Image credit update: Narlikar and Padmanabhan, retrieved from Ned Wright, edits by me.

From CFT on whether it could be infinity: “Sir, you yourself play pretty fast and loose with the whole ‘infinite’ concept yourself.”

I suppose I can count on you to tell us all how to make cosmology great again?

An artist’s impression of the three LISA spacecraft shows that the ripples in space generated by longer-period gravitational wave sources should provide an interesting new window on the Universe. Image credit: EADS Astrium.

From rich r on something I’m not used to: “By the way Ethan, I love the your articles and writing. As an engineer i have just enough science background to be dangerous and your topics keep my interest and keep my brain bubbling!”

What is this, unequivocal praise? Damn… I don’t even know what to do with myself. Thank you. This may be the antidote I need to some of the frustrations of working hard with little thanks. A little thanks goes a long way!

Oh, I know how to fix things! Let’s address only the comments, for the rest of the Comments of the Week, that have something relevant to say about the physics/astronomy/science that we’re talking about!

The pattern of weak isospins, weak hypercharges, and strong charges for particles in the SU(5) model, also known as the Georgi-Glashow charges. Image credit: Wikimedia Commons user Cjean42 under a c.c.a.-s.a. 3.0 license, created from Garret Lisi’s Elementary Particle Explorer.

From Anonymous Coward on low-energy signatures of new high-energy physics: “Besides proton decay (which is so far coming up empty), are there other low-energy consequences to GUTs and string theory and these other attempts to stretch the frontiers of physics? Only neutrino physics so far seems to be yielding any results that go beyond the Standard Model.”

Yes! And it’s thanks to the non-observations of many phenomena that we can constrain GUTs, string theory, and other beyond-the-standard-model (BSM) physics. For example, flavor-changing-neutral-currents are predicted in many BSM models, where a charm quark could decay to an up quark… but such decays don’t happen. Neutrinoless double beta decay is a feature of a neutrino extension… and that’s not observed. Baryon and/or lepton-number violating interactions should be seen… and they’re not. There’s also the “doublet–triplet (splitting) problem” arising in GUTs, the prediction of additional Higgs particles, and those are unresolved, too.

Yes, I would agree: dark matter, dark energy, and the neutrino sectors are the best evidence we have for BSM physics. But there are other outstanding problems to solve, like baryogenesis, the strong-CP problem, and the hierarchy problem, among others. There’s no doubt new physics out there, but whether further unification is part of the solution is not yet known.

Images from the Hubble Space Telescope show the Great Red Spot shrinking in extent and changing in shape even from 1995 (top) to 2009 (middle) to 2014 (bottom). Image credit: NASA, ESA, and A. Simon (Goddard Space Flight Center).

From dean on getting data from Juno’s flyby of Jupiter: “How long is required for the data to arrive back here?”

Not long! The other eight non-visual instruments sent their data with higher priority, and it was less than 48 hours before the JunoCam images came down. Lucky for you, I got my hands on them pretty fast and you can see them here!

Three members of the Star Trek crew beaming down off the ship. If a planet-to-ship transport of quantum information has been successful, could human beings be next? Image credit: CBS Photo Archive / Getty Images.

From Naked Bunny with a Whip on how transporters work in Star Trek: “Transporters break the subject down and beam its atoms along with a reference pattern to the destination, where the original is put back together. The process is spelled out in chapter 9 of the TNG tech manual in excruciating detail.”

What’s been interesting in learning about all the various incarnations of Star Trek, from the various series to the technical manuals, is how contradictory the various explanations are. This makes a ton of sense, of course, since for the most part these were dreamed up as “we need to make this happen, let’s come up with an explanation that sounds plausible.” And so the term Treknobabble was born.

Early incarnations refer to a matter stream; in other series, there is no matter stream and the information is simply stored in the pattern buffers.

What about actual physics? If you have the full quantum state of a macroscopic system encoded, and particles like electrons, protons, nuclei, etc., are identical to and indistinguishable from one another, does it matter which particles are used? The “you” of today has no atoms in common with the “you” of 10 years ago, yet it’s still identifiable as you… isn’t it? The “you” a minute after you become a corpse (someday) and the “you” the minute before have virtually the same composition, yet one has the “you-ness” of the living you and the other doesn’t. So what is it that defines who you are? What you are?

Book cover for my new book: Treknology. Image credit: Voyageur Press / Quarto Publishing Group.

These are among the fun issues I get to explore in Treknology, in the context of the full suite of science as is known in early 2017. I like to think this is what sets it apart from any other treatment of the physics of the Star Trek Universe ever created… and if you get yourself a copy, I think you’ll agree.

Combining Juno’s three main images of the Great Red Spot and enhancing the color and contrast has yielded a spectacular view of the Great Red Spot. Image credit: NASA/JPL-Caltech/MSSS/SwRI/Kevin M. Gill.

From PJ on the first images of the Great Red Spot: “Interesting to note the ‘surface’ of the GRS is much lower than the average surface of the planet. This may indicate some form of subduction caused by the cyclonic action of the spot.”

It’s a very complex system, and whether what you say is true or not depends on what you mean by “surface.” The great red spot is much colder than the rest of the planet, which we have learned from infrared observations, and therefore it should be higher in altitude than the rest of the cloud-tops. The GRS’s cloud-tops are about 8 kilometers higher in altitude than the other, surrounding clouds.

But in the upper atmosphere above the cloud tops, there’s excess heat found over the GRS. (Way over, by the way: like around 800 kilometers up.) What gives? It’s possible that there are pressure waves rising from the spot itself, causing this heating phenomenon. This is part of the mystery that Juno’s other 8 instruments will help solve. In the meantime, let’s enjoy the pictures and marvel at the possibilities!

The two main models for Type Ia supernovae. Image credit: STSCI, NASA; NASA/T. Strohmayer (GSFC)/D. Berry (Chandra).

From Michael Richmond on a Universe without deuterium: “Suppose two 3-solar-mass stars form in close proximity. One evolves into a white dwarf after a common-envelope phase, the orbit shrinks, mass transfers from the main-sequence star to the white dwarf, and *poof* Type Ia supernova. The ejecta from the explosion contains plenty of heavy elements.
Why wouldn’t this scenario create the makings for some planets, even without Type II SNe?”

I mean, that is a possibility. Also a possibility: that two white dwarf stars collide somewhere in space. Or inspiral and merge. Your scenarios are realistic and would happen in a Universe with no deuterium.

But they would take a long time, and they would also produce very, very small amounts of heavy elements compared to the type II supernovae we have, compared to neutron star-neutron star mergers, and compared to the very large numbers of type Ias (relatively) that we have today, due to stars up to about 8 solar masses. As it is, Type IIs are about four times as common as Type Ias, the vast majority of Type Ias had higher-mass progenitors than we can have without deuterium, and the siphoning mechanism you describe would have to be very efficient and long-term to trigger a supernova with such a low-mass white dwarf to start with.

I (crudely) estimate a metallicity about two orders of magnitude less than the Universe we have at present. We might get planets, but they’re going to be very different than the ones we know today!

Image credit: Wikimedia Commons user 28bytes, via CC-BY-SA-3.0.

From Omega Centauri on what elements we’d get: “Though the cosmic abundance chart would be different (would there be Gold and Uranium, or would things stop after Iron?”

Oh, you’d go up past iron without a problem. As you say, Type Ia supernovae get you produce the full gamut of these heavy elements through the r-process, and once you get the initial seeds of these heavy elements, you can then form new stars that produce planetary nebulae.

The Butterfly nebula, perhaps the most beautiful of them all: Planetary Nebula NGC 6302. Image credit: NASA, ESA and the Hubble SM4 ERO Team.

Neutron-capture elements, through the s-process, can fill in the gaps and create significant amounts of elements all the way up to lead/bismuth. The abundance will be low, but the elements will be there. If the rules of fusion were different.

The timeline of our observable Universe’s history, where the observable portion expands to larger and larger sizes as we move forward in time away from the Big Bang. Image credit: NASA / WMAP science team.

And finally, breaking my rule, here’s dean: “Very interesting.
Related note: ignoring science deniers like PV is getting difficult.”

Yup. And if people keep beating a dead horse, they’re going to be doing it somewhere else on the Bulgarian internet.

Thanks for a good week, everyone, and see you back here on Monday for more!

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