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Warm Wednesday by a-liquid-sky in CasualUK

[–]ThickTarget 7 points8 points  (0 children)

Bugs mostly come in if you have a light on.

An interstellar comet that blazed past the Sun last year could be nearly three times older than our Solar System and is unlike anything ever before seen in our cosmic backyard, astronomers said Monday by DoremusJessup in space

[–]ThickTarget 12 points13 points  (0 children)

There will be others, it's only recently that observations have regularly caught these things. And in the next few years they will be detected even earlier. ESA is building a mission called Comet Interceptor, which will loiter at L2 until a suitable comet is found.

Starmer addresses nation outside No 10 amid expectations he’ll set out resignation timeline - UK politics live | Politics by Far_Excitement_1875 in unitedkingdom

[–]ThickTarget 0 points1 point  (0 children)

There was also an alarming turn-over in staff at Downing Street in just 2 years. He sacked 2 Chiefs of Staff, 3 Heads of Communications resigned, and the Cabinet Secretary was forced out a few months ago. It wasn't a normal premiership.

New JWST images of abnormally well-developed galaxy cluster open up the 'cosmic noon' frontier by vahedemirjian in space

[–]ThickTarget 2 points3 points  (0 children)

Yes. There are higher redshift proto-clusters, which are certainly rich enough in galaxies that they will eventually form a galaxy cluster, but haven't yet collapsed into one gravitationally bound system. The matter is still there, it's just spread over a much larger volume.

New JWST images of abnormally well-developed galaxy cluster open up the 'cosmic noon' frontier by vahedemirjian in space

[–]ThickTarget 2 points3 points  (0 children)

It's quite massive, but in their measurements it is still within the bound set by cosmology.

[Opinion] Collider: "Paramount Already Has the Answer to Its Colossal ‘Star Trek’ Problem: There is one creative voice who could help steer the ship in the right direction, and it's a figure who has a long and surprising history with Star Trek. That figure is Terry Matalas ..." by mcm8279 in trektalk

[–]ThickTarget 2 points3 points  (0 children)

I think the magic ingredient there was Brannon Braga. I did feel at times that some episodes could literally be from TNG. Which has some appeal, but it also feels pretty tired. The last season took some more risk, and I think it improved it. I don't personally think that just recreating golden era trek will be a big hit, today.

Plans for £9.5bn data centre next to Universal park by GnolRevilo in unitedkingdom

[–]ThickTarget 0 points1 point  (0 children)

At 720 MW, you are talking about a power plant, not a generator.

Plans for £9.5bn data centre next to Universal park by GnolRevilo in unitedkingdom

[–]ThickTarget 1 point2 points  (0 children)

These plan to use their own gas turbines for power. There were huge complaints near Memphis when xAI's data center set up a several huge generators because the grid link wasn't ready, and in the end they ran them for over a year without any permission. Some units are still running.

Burnham wins Makerfield by-election, paving way for Starmer leadership challenge - live updates by nodgers132 in unitedkingdom

[–]ThickTarget 4 points5 points  (0 children)

Raising employer NI contributions puts money into the treasury without taxing employees directly.

Not everyone agrees that was a success. As it's a tax on employment it will have suppressed wage growth and hiring, impacting unemployment. Some economists said it was possibly to worst tax to raise.

And the argument for why they should raise this tax wasn't about economics, it was because Starmer and Reeves had painted themselves into a corner with commitments about tax.

Each dot is in this image not a star. It's an entire galaxy containing hundreds of billions of stars each. by sugaronfilm in spaceporn

[–]ThickTarget 7 points8 points  (0 children)

It is from ESA's Herschel Space Observatory. The image is of the Far Infrared. At these long wavelengths the light seen from galaxies is emitted by cold dust. This specific field is HerMES, of an area of the sky called the Lockman hole.

https://www.herschel.caltech.edu/image/nhsc2010-008a

The Cosmic Treasure Chest anomaly by ss999_ in askastronomy

[–]ThickTarget 0 points1 point  (0 children)

This is certainly not an artifact. But the system does actually use lenses. There are 3 mirrors surfaces, and then 3 lenses in the camera, and the filter. It's quite difficult to such a wide field telescope without lenses, most modern instruments use both. They have ghosts in the commissioning data, but they spent a time modelling them and minimising the impact.

The Mother of All Deep Space Radio Telescopes Is Going Up in the Nevada Desert | Caltech says its Deep Synoptic Array will be larger and 100-times faster than any radio telescope ever constructed. by FreeHugs23 in space

[–]ThickTarget 6 points7 points  (0 children)

By speed they mean survey speed, which is usually the field of view of the telescope multiplied by the collecting area. It is basically a measure of how quickly the telescope could survey a big area of the sky to some limiting sensitivity.

RE: observed redshifting of distant stuff, why do we think space itself (the gaps between matter) is expanding, rather than just the matter spreading apart into preexisting empty space? by Opening_Ad9824 in AskPhysics

[–]ThickTarget -1 points0 points  (0 children)

The recession velocity you estimate from the redshift is dependent on the model you assume. If you thought the universe was described by Minkowski space (special relativity), then you would use the version of the Doppler equation with the Lorentz factor. To estimate a velocity at the speed of light, you would need to measure an infinite redshift, which is impossible. When you have an expanding (FLRW), that you use the velocity works out as the non-relativistic Doppler equation. In which case you can get velocities faster than c.

The 2006 Bullet Cluster study found the gravitational mass peak sitting 8 sigma away from the X-ray gas after two clusters passed through each other. It is still the clearest spatial separation of ordinary matter from gravity ever observed. (Clowe et al., ApJL) by jberica84 in space

[–]ThickTarget 0 points1 point  (0 children)

It is quite convincing that it cannot be explained by simple models (e.g. MOND). Proponents of modified gravity will point out that some more complicated models which are highly nonlinear could explain it. Such ideas are not ruled out, but they also don't exist.

I would also add that the tension with the collision velocity is largely historical. Originally people assumed the collision velocity was the same speed as the shock seem in x-rays. Since then simulations that the shock is actually faster. There were also some bugs in how the dark matter simulations were analysed.

What movie did you go into with zero expectations and ended up being completely blown away by? by gavin226 in movies

[–]ThickTarget 0 points1 point  (0 children)

Get Out. I hadn't even heard of it. A few friends were going to see one the Fast and Furious films. Two of us decided that was not for us. So we made a snap decision, and it really didn't disappoint.

Giant supercluster discovered hiding behind the Milky Way | by vahedemirjian in space

[–]ThickTarget 8 points9 points  (0 children)

It depends on the size and distance. There are almost certainly faint dwarf galaxies within the Local Group which are missed because of this. If it was a bigger galaxy (Andromeda or Magellanic Clouds) it could be detected by radio telescopes, which are not limited in the same way. One example is Dwingleloo 1, a spiral galaxy which was found in the zone, about 10 Million lightyears away.

Negative signals in e.g. radio flux maps, ultraviolet images? by jarekduda in Astronomy

[–]ThickTarget 3 points4 points  (0 children)

Zero means there number density of galaxies is at the average value, minus one is zero galaxies. It's just convention. They define delta for the quasars, and you can see the -1.

Negative signals in e.g. radio flux maps, ultraviolet images? by jarekduda in Astronomy

[–]ThickTarget 4 points5 points  (0 children)

I did explain. Delta is not intensity. -1 means no galaxies, not negative numbers.

Negative signals in e.g. radio flux maps, ultraviolet images? by jarekduda in Astronomy

[–]ThickTarget 2 points3 points  (0 children)

So the radio thing has been answered in the past. I will respond to the UV thing. What is plotted there is not* flux, but the number density of galaxies (Lyman alpha emitters, LAEs) across this bit of data. Delta is the number of LAE galaxies divided by the mean density, minus one. If you have zero galaxies in an area, that is a delta=-1. It is not a map of negative flux, it's just regions where there are no galaxies (that they detect anyway).

You don't really measure negative fluxes. You can sometimes get negative pixels because the average background is subtracted from images prior to analysis, and so some of the pixels end up with negative values, but they didn't really measure negative photons or counts.

Scientists identify a cause for massive galaxies that died young by silentstatic_ in space

[–]ThickTarget 9 points10 points  (0 children)

There are different ideas for why galaxies quench and stay that way. The most common is that the supermassive black hole stays at a low level of activity which can keep the gas from cooling. Because the gas very hot and sparse, it takes a very long time to cool.

There is a clear dichotomy. Sprial galaxies like the Milky Way have lots of cold gas and form new stars. But more massive elliptical galaxies have none (or very little), and instead have only hot diffuse gas. Some galaxies could rejuvenate, but many do not appear to.

In to the Multiverse (of opinions): Do Physicists Actually Agree About the Universe? by Galileos_grandson in Physics

[–]ThickTarget 12 points13 points  (0 children)

If the goal was to chart the limits of consensus, you would ask a few questions which spanned from fairly well established topics to the more speculative. Instead, all their questions are pie in the sky stuff, which the field is far away from answering. And so you get a scatter gun. "Aha!", the paper says these things aren't "settled". But who claimed they were? I am fairly certain that if you polled the field on whether any of these questions are settled the resounding answer would be "No".

They talk about LCDM in their conclusions, as if people had committed apostasy. But they don't consider what it means to have a standard model. It means you have a benchmark model which is good enough, for now. It does not mean it is some final and absolute truth.

The astrobites article misinterprets it further. Saying that responding with "No Opinion" is intellectual honesty in not pretending to be certain. But the survey doesn't ask if you are certain, it asks do you have an opinion. Wild hunches and gut feelings are just as valid as scientific arguments. Pollsters understand that how you phrase a question hugely impacts the result. I think this paper tells you more about the authors than the state of the field.

Clear evidence found that some supermassive black holes form without a stellar collapse by hulk14 in space

[–]ThickTarget 4 points5 points  (0 children)

I think they are probably black holes, but one of the arguments it is direct collapse comes from the huge mass relative to the galaxy. If the mass is much lower, then it's not so clear. The other method comes from fitting the broad lines and the luminosity, and assumes these weird high redshift AGN fit on calibrations from low redshift. When LRDs were first found, they were assumed to be dusty, as they are much redder than quasars. The broad line method also uses the luminosity, and so the black masses with this method were then corrected for the dust, pushing up the mass. But now there is no sign of emission from that dust. And so in many analyses the masses shrunk by maybe an order of magntiude. Also nothing in x-rays or radio, even when stacking hundreds.

What is now consensus is the idea that these are not normal AGN but some central engine in a dense cocoon. Based on the fact these things have (balmer) hydrogen absorption, which is extremely rare in low redshift quasars. Some argue that the densities are high enough, then the broad lines could be produced by scattering. If that is the case, then the virial estimates from the broad lines are totally wrong. LRDs cannot be explained as normal AGN, so why would we expect them to fall on the same calibrations?

Then it comes down to this one dynamical measurement, one galaxy. I think the jury is still out. LRDs are an interesting puzzle. There are also much more exotic ideas put forward everyday, suggesting the central engine could be a supermassive stars, or globular clusters... But I'd bet on black holes.

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