Contrabang #33 Dark Charge

Output for this blog suffered as I got lazy over the holidays, but we're back with a fairly long 2-week version of Contrabang! and posts should return to the normal pace.

This Is How Eta Carinae Survived A Near-Supernova Eruption (link)

In all of astronomy, no stellar event releases more energy than a supernova. ... The most famous ‘supernova impostor’ of all could have died back in the 1840s. Here’s what we think kept it alive.

The hardest part of being a modern astronomer is explaining away all the evidence that doesn't fit. The standard model for supernovae is that they are sudden explosions caused by runaway nuclear fusion who power output temporarily matches that of entire galaxies. The star is destroyed in the process, with vast quantities of the outer shell scattered into the cosmos, and the heavier core collapses into a neutron star or black hole.

The Milky Way's Eta Carina system is puzzling because it exhibits the power of a supernovae - and many of their visual characteristics - but also violates a number of rules.

1. The power increased gradually over years
2. The event has occurred at least three times since the 19th century, with many small-scale variations within the larger cycle
3. The core star has not been destroyed

Scientists are at a loss to explain how a minor star can go through a supernova-like event and emerge as a much more powerful system.

In 2005, observations revealed that Eta Carinae isn’t a single star, but a binary system in a ~5.5 year mutual orbit.

These statements must be handled carefully, because it is natural to assume they mean that a binary companion was directly observed. Rather, a binary system has been assumed in response to some periodicity in the spectral signal, but no other star has actually been observed.

The 5.5 year binary orbit of the Eta Carinae system consists of a hydrogen-rich star of approximately 100 solar masses in orbit with a hydrogen-free star of 30 solar masses. This type of mass inversion, where the less massive star has lost its hydrogen, suggests a mass transfer that’s difficult to explain.

A 5.5 year periodicity in hydrogen emissions lines is what drove the hypothesis for two stars: one hydrogen-rich and the other hydrogen-depleted. However he admits that even the preferred hypothesis of a binary system is "difficult to explain." Which means they don't actually know and they are resulting to the normal trick of picking what is believed to be the least bad hypothesis and promoting that as scientific knowledge.

It’s possible that a specific cataclysm triggered this outburst: the devouring of a third star.

It's starting to become common to see unexpected celestial events explained by adding stars to systems and invoking complex gravitational scenarios. Eta Carinae had been observed for at least 150 years before the nova event, having been described by Edmond Halley in 1677. There was never any observation of a second or third star. It will be interesting to see what is proposed in response to any future eruptions.

NASA’s NICER Mission Reveals An Unexpected Neutron Star Surprise (link)

We discussed the NICER results in the very first installment of the NASA News segment. Now Ethan has something to say about it, although you already know what his position is.

The low-energy X-ray observatory measures timing signals down to 300 nanoseconds and at unprecedented sensitivities.

True.

NICER enables measurements of neutron stars’ sizes, masses, cooling times, stabilities, and internal structures.

False. Measurements implies a direct observation. NICER does not directly measure any of the attributes listed. Those numbers are coming from models, which can be just about anything.

For one pulsar in particular, J0030+0451, they determined its mass (1.35 Suns) and diameter (25.7 km) explicitly.

Not just false, but a lie. The mass and diameter were not determined explicitly, nor did the researchers convey it as such. The numbers come implicitly from a probabilistic model based on the pulse data and many assumptions about how pulsars work. If Ethan is indeed an expert in this field, then he is a liar.

For context, when I read the original article, it became immediately apparent what was going on when they described the diameter of a star a over a thousand light years in increments of tenths of a mile. We can't even resolve our own sun to that degree. Apparently, that was not obvious to Ethan, who thinks they actually measured the radius of an asteroid-sized star quadrillions of miles away to a resolution of hundreds of feet.

They detected “hot spots” on the surface and constructed the first-ever neutron star map.

Another lie. From the original paper.

In this paper we assume that there are two separate hot regions on the stellar surface; this choice was motivated by the presence of two distinct pulses in the observed (phase-folded) pulse-profile. However, we considered a number of different possible configurations for the shapes and temperature functions of the hot regions: circular spots, annuli (rings, both centered and off-centered), and crescents; with one or two temperature components. These choices were motivated by contemporary theories for pulsar surface heating distributions as a result of magnetospheric return currents.

It says it right there. They didn't detect hot spots. "In this paper we assume..." They were an assumption. This demonstrates a live example of my major beef with the mainstream astrophysics community in action: the promotion of assumptions to facts. Hot spots were not detected, at all. If there are hot spots, they could not possibly be resolved by NICER, a small instrument attached to the ISS. This should be obvious to a prominent blogger of astronomy with a PhD in astrophysics.

They concluded that pulsar magnetic fields are more complex than typical, naive two-pole models.

The answer is always to add more complexity to the models.

 What Is The Ultimate Fate Of The Loneliest Galaxy In The Universe? (link)

Just as stars are mostly found clustered in galaxies, galaxies themselves are organized into larger structures. However, one galaxy is notable for having no neighbors within 100 million light years. Ethan provides an analysis of the mechanics of the galaxy by on the standard assumption that there are only two forces of significance that act on celestial bodies - gravity and dark energy.

To understand what this galaxy is going to do, first we have to understand what it’s like from the inside out. When the Universe was much younger than it is today, it was almost perfectly uniform, with regions that are only slightly overdense or underdense compared to the large-scale average. The regions with more matter than average will self-gravitate, drawing in matter from the surrounding volumes of space and eventually leading to the formation of stars, galaxies, and groups and clusters of galaxies on even larger scales.

Regions that are underdense, however, tend to give up their matter to the surrounding overdense regions, leading to vast cosmic voids between the strands of the cosmic web. Contrary to popular belief, however, even the regions of below-average density still tend to hang on to some amount of matter — both normal and dark — and with enough time, that matter will collapse to form structures, too.

That's the theory. Out of nearly uniform initial soup, matter condensed into the cosmic web, driven by gravity alone.

He then offers a five-step understanding of extremely isolated galaxies.

1. The regions that fail to give up all of their matter to the filamentary network that comprises our large-scale structure will gravitate towards their mutual center-of-mass, determined by the presence of both dark matter and normal matter.

This is a confusing way to phrase it. All matter in a particular region should move in the direction of the net gravitational force.

2. The dark matter forms a large, diffuse halo of mass, while the normal matter sinks to the center, colliding with other normal matter particles and collapsing in the shortest dimension first.

The only force acting is gravity, and dark matter is said to exhibit the exact same gravitational mechanics as normal matter. There is no explanation given as to why dark matter would act differently and form a diffuse halo, rather than continuing towards the mutual center-of-mass as described in step 1. It is just magic that one must believe to be a proper academic these days. (The diffuse halo is required because dark matter was invented to explain the unpredicted rotational dynamics of galaxies.)

3. The normal matter “pancakes,” which is the scientific term for “goes splat,” and forms a disk that starts rotating.

More magic. Why does the 3D structure collapse into something that is nearly 2D? Why does nearly everything in the universe rotate? The gravitational collapse model does not explain why such polarity is ubiquitously observed throughout the cosmos, which is why he tries to gloss over the deep mystery with a single sentence.

4. Inside the disk, stars form, leading to the familiar spiral structure we recognize.

Even more magic. Claiming that stars forming leads to spiral arms is a non sequitur that intends to gloss over another mystery that goes unexplained by the standard model.

5. Dark matter gets dynamically heated, changing its density profile somewhat, while low-mass neutrinos eventually fall into the halo, adding to the mass.

If you can understand this you're doing better than me, but again it's vagueness hints that something is being covered up.

Looking past all the mysterious mechanics that are brushed under the rug in this explanation, the overall gist is...what? That some matter didn't get formed into the larger filamentary structures and became an isolated galaxy. But that's just re-stating what we already knew.

Not content with just an phenomenally terrible explanation of the past of the loneliest galaxy, he gives an explanation of the future as well, which is that it will get even lonelier as the universe expands.

For galaxies like our own, we’ll remain bound to our local group, including Andromeda, Triangulum, and about 60 additional galaxies, until they all merge together many billions of years in the future. Galaxies beyond our gravitationally bound group, like those in the Virgo cluster, will remain bound to their own parent groups, but will accelerate in their recession from our own.

While dark energy is said to be a fundamental aspect of all space, it somehow does not affect "gravitationally bound" systems - otherwise we'd detect its effect within our own solar system. He alleges that our local cluster is not gravitationally bound with the Virgo cluster, thus it is receding and that trend will only accelerate. How he came up with that example I do not know, but it seems to be ludicrous even by his standards, as it is directly contradicted by conventional astronomy. The local cluster is not being drifted away from Virgo by dark energy, but is moving towards it so swiftly that astronomers even have a name for it: Virgocentric flow.

The Virgocentric flow is the preferred movement of Local Group galaxies towards the Virgo cluster caused by its overwhelming gravity, which separates bound objects from the Hubble flow of cosmic expansion.

I believe he may be confused, because at the next level up - the Laniakea supercluster - astronomers believe that the system is not bound and will be pulled apart by dark energy.

The article then goes on for a number of paragraphs giving the normal doom-filled prophesies of the inevitable heat death of the universe.

The eventual fate of the last galaxies in the Universe will be a skeletal dark matter/neutrino halo, far outlasting anything else we’ve ever observed.

The Universe Really Is Fine-Tuned, And Our Existence Is The Proof (link)

Modern astronomers are always surprised when their exotic formulas are shown to reveal a universe that is tuned the way it would be if it was not exotic at all.

Somehow, the Universe began with just the right mix of cosmic ingredients to make life possible. It sure doesn’t seem likely.

Of all the things he's said that I do agree with, that one must be at the top of the list.

When you take stock of what’s in the Universe on the largest scales, only one force matters: gravitation.

That's their theory. The primary premise of the Electric Universe people is that this assumption is false, and accounts for the bulk of the current crisis in cosmology. The observe that the electric force is much stronger than gravity and ignoring it at cosmic scales is probably a mistake.

While the nuclear and electromagnetic forces that exist between particles are many, many orders of magnitude stronger than the gravitational force, they cannot compete on the largest cosmic scales. The Universe is electrically neutral, with one electron to cancel out the charge of every proton in the Universe, and the nuclear forces are extremely short-range, failing to extend beyond the scale of an atomic nucleus.

That the universe is electrically neutral is an assumption he is making because of the Big Bang Theory. That theory also predicts that equal amounts of matter and anti-matter should have been created, which hasn't been observed and is one of the big mysteries they've left unexplained. Thus, there's no reason to assume that prediction of equal numbers of electrons and protons is valid. But even if they were, it wouldn't matter. The earth is supposedly neutral and yet we have powerful charge differentials that discharge through the atmosphere as lightning bolts, into space as sprites, and are lately being shown to be related to weather and seismic patterns. The solar system is said to be electrically neutral and yet the sun sends streams of charged particles to the earth that power the aurora - basically neon lights in the sky - and powering aurorae on Jupiter so powerful that they emit X-rays. The galaxy is said to be electrically neutral yet astronomers have detected polar jets of charged particles that have even been shown to connect intergalactically. At what scale, we have to wonder, does the claim of an electrically neutral universe actually hold?

He then describes the universe as being in an unstable equilibrium, and that the probabilities required for it to randomly be so precisely tuned are impossible.

But if that’s the case, we’d hate to simply take that assumption at face value. In science, when faced with a coincidence that we cannot easily explain, the idea that we can blame it on the initial conditions of our physical system is akin to giving up on science. It’s far better, from a scientific point of view, to attempt to come up with a reason for why this coincidence might occur.

Exactly so. (Even though that's what they do with the Big Bang Theory, but no matter.)

One option — the worst option, if you ask me — is to claim that there are a near-infinite number of possible outcomes, and a near-infinite number of possible Universes that contain those outcomes. Only in those Universes where our existence is possible can we exist, and therefore it’s not surprising that we exist in a Universe that has the properties that we observe.

There are some scientists who entertain the perfect tuning of our universe as proof that there are infinite multiple universes out there which aren't so perfectly tuned. To his credit, Ethan dismisses such logic, showing that even his capacity for suspension of doubt has limits. (But if the Multiverse ever wins a Nobel Prize he'll suddenly be its biggest advocate.)

He then goes on to state that a good explanation is that cosmic inflation preceded cosmic expansion, thus the universe is flat. To me, that sounds like creating some hypothetical scenario to create the desired initial conditions to make the theory work, which he just said is bad.

What The 3 Biggest Physics Discoveries Of The Decade Mean For The Future Of Science (link)

The three biggest physics discovers of the decade about to end are given as

1. Discovery of the Higgs boson
2. Detection of gravitational waves
3. Observation of a black hole's event horizon

These are given in decreasing order of significance. I suspect the second two claims will ultimately be thrown out. They both suffer the same problem, which is a matter of tuning. The LIGO detector works by filtering a noisy signal and then comparing the results to a large catalog of theoretical signal patterns. Thus, the filtering is "tuned" whenever the output looks like one of the things on their list.

As similar thing happens for the infamous black hole picture. Using a vast amount of data and an algorithm of around a million lines of code, they came up with the picture they expected. Is anyone surprised? Now, I'm not a cosmology expert, but I did study artificial intelligence at the graduate-school level. Parameter tuning is something that must be done with care. When developing, say, a neural network to perform face recognition, developers must take to use separate sets of data for training and testing. It is fairly trivial to train an AI algorithm to respond as desired to a small training set - it is much harder to train it to respond to arbitrary data as desired. In the case of the black hole photo, there is no training set. There is no set at all, it's just one object. There is no way to independently verify the tuning, such as by resolving another object in the cosmos of known appearance. It's hard to know that they didn't just hard-tune the algorithm to the expected output, and would have seen the same image no matter what telescope data was provided.

Ask Ethan: Can Black Holes Ever Spit Anything Back Out? (link)

Watching the astrophysicists try to explain why black holes are frequently the opposite of black is always amusing. I'll leave this one as an exercise to the reader, except for one aspect which is worth pointing out again in light of some of the other claims made during the week.

The same physics is at play — charged object in motion create magnetic fields, and those fields accelerate particles along one particular axis — which is what creates the relativistic jets we observe from a distance.

The prevailing theory of black holes is that there is gas rotating around them which heats up from friction (somehow) and becomes so energized that it ionizes into hot plasma. Then, that rotating plasma generates an enormous magnetic field, which tends to propel the infalling charged particles along the axis of rotation. Before Ethan said the universe is electrically neutral. In this case he says it isn't, but according to his explanation it should be. If neutral atoms dissociate into equal amounts of ions and electrons that rotate, their effects should cancel and no magnetic field will be generated. So, in effect, Ethan claims the universe is electrically neutral where it's not, but then makes an exception for it when needed but isn't even logical. He has invented a Dark Charge where needed and hopes no one notices. (Or, more likely, doesn't even realize it himself.)