Thursday Throughput: Big Black Hole Edition
The masses of black hole binary components and their final product (connected by upward arrows) for mergers detected by LIGO-Virgo. GW 190521 is by far the highest-mass final black hole seen, and even one of its components is one of the largest ever detected. Credit: LIGO/Caltech/MIT/R. Hurt (IPAC)
[ThTh1] When the Laser Interferometer Gravitational Wave Observatory (LIGO) detected the first ever gravitational waves — ripples in the fabric of spacetime created by massive objects moving at incredible speed — it represented a huge breakthrough. The culmination of decades of work, it opened up a new way of looking at the Universe. Astronomy is unique among the sciences in that we don’t get to touch the things we study. We rely on the messengers they send out — light, subatomic particles and now gravitational waves — to bring us information about them. This was a new messenger.
The detection was an amazing event and won the Nobel Prize for Physics. One thing I noted at the time though was that we would soon move to an era where such detections were routine, and we began to learn about entire categories of gravitational wave sources. LIGO has now detected over 50 gravitational wave events, mostly colliding black holes.
Last week, they announced the detection of their biggest black hole yet. Two black holes — one massing 85 times that of the Sun and one massing 66 times smashed together leaving a black hole massing 142 times that of the Sun. The remaining mass was converted into energy in the explosion.
This isn’t just a matter of a winnah and new champeen though. We’re learning how massive black holes are built. Black holes are generally created by the remnants of massive stars that explode. But they only start out at a few solar masses. In the center of galaxies are black holes massing millions of even billions of times that of the Sun. How did they get there? Probably by mergers of intermediate-sized black holes. But we’ve never detected those before. This is a big step in our understanding of how supermassive black holes are formed. And an example of the kind of science that happens when the astonishing becomes “routine”.
[ThTh2] I was going to make a joke about running into a room then running back out to see if something follows you, but decided that would be tasteless.
Yesterday I had a lot of retweets and reddit posts and such for playing Doom on a pregnancy test.
But as I explained then, it wasn't really PLAYING on a pregnancy test, it was just a video being played back, not an interactive game.Well, now it is. It's Pregnancy Test Doom! pic.twitter.com/Nrjyq07EVv
— foone (@Foone) September 7, 2020
[ThTh3] The DOE has given permission for a company to build small nuclear reactors. I’ll be keeping an eye on this story, both to see if it happens and how well it does. Nuclear power has to be part of our energy solution and small reactors may be the wave of the future.
[ThTh4] A study came out this week claiming that the Sturgis motorcycle rally caused 250,000 COVID-19 cases, one-quarter of the new cases over the last month. While the rally was a danger and there may have been a spike, this claim seems … dubious and the paper has not yet been peer-reviewed. This is one of the dangers of the COVID Era: papers are released before they are vetted.
[ThTh5] You may have heard something about a “heartbeat” being detected in space. It’s not an alien. It may be something more amazing: the pulse of a black hole lighting up a gas cloud 100 light years away.
[ThTh6] The nearest large galaxy to our own — Andromeda — looks like a tiny cloud if you glimpse it with the naked eye. But that’s just the core a truly gigantic structure.
Sweet, sweet NASA press release describing our most recent ProjectAMIGA paper on the gaseous halo of the Andromeda galaxy: https://t.co/3JjB4WYbmG pic.twitter.com/pb7fNjE0Xs
— Chris Howk (@jchowk) August 27, 2020
[ThTh7] I’ve sometimes told my students that a really close supernova could be an extinction-level event (there are no stars close enough to worry about). Well … that may have happened 360 million years ago.
ThTh3: Not only given permission, but provided a site on federal land that bypasses the state having any say in the the project, and makes cooling water available using the federal government’s authority to preempt state water laws. This will be tied up in court for a few years settling whether the reactor violates the INL agreement with the state of Idaho to not bring additional commercial nuclear waste into the state until the INL cleanup is complete. Myself, I expect the group of small Utah utilities that have agreed to fund this will go bankrupt before a single watt is delivered.Report
ThTh4: While I would be more than happy enough to believe that large gatherings of people are likely to be superspreader events, the whole issue of how it’s seems to only be worth reporting that *FUN* gatherings of people transmit the virus seems to undercut the case.Report
I also am not seeing much digging into correlation versus causation. If X people went to Sturgis already sick and X people left Sturgis still sick and no new people got sick, then Sturgis caused zero cases, not X cases. But that isn’t how those events are being talked about everywhere I look.
How many people got sick at Sturgis who wouldn’t have gotten sick had they never gone? And how many of those people got other people sick who wouldn’t have gotten sick if the initial people never went to Sturgis? That seems to be the important numbers and maybe we don’t have the tools in place to find those numbers… which is a problem. But the solution isn’t to just make up numbers.Report
I like pointing out the sheer hypocrisy of the Narrative pushers as much as the next guy, but I still think people are underestimating how important the indoors-outdoors distinction is. Indoors the virus just keeps bouncing off walls and getting recirculated by the air conditioning system until it flies up someone’s nose. Outdoors it blows away.
I don’t doubt that you can get some spreading outdoors, especially in very dense crowds, and to be fair some of the Fiery But Peaceful Protesters did do a fair bit of indoor looting (after breaking windows to keep everyone safe and healthy!), but I do think it’s plausible that the Sturgis rally, which apparently involved a lot of large indoor gatherings, really was a more significant cause of transmission than the Peaceful Protests, at least on a per-capita basis.Report
I haven’t seen anybody outside of amateur epidemiologists (like us in comment sections!) make that distinction, though. Has anyone argued that it’s probably okay to do stuff like go outside, hang in a park, go to the beach?
I’ve only seen: Stay Safer At Home and Wear A Mask If You Must Leave versus Racism Is Important Enough To Risk Disease.
No “hey, go someplace with good ventilation!”Report
I can’t remember where I originally saw this (scroll down to the red/yellow/green matrix), but this model explicitly takes ventilation into account.
I found this NYT article as well, which stresses the inside-outside angle pretty hard.
This chart got picked up by local news all over the country, though I didn’t find a national news source.Report
Well, in NY/NJ outdoor dining was allowed well before indoor dining was. So someone somewhere decided that an activity that requires the removal of masks can probably be done safely outdoors but not indoors.
My (NY-state based) camp had different rules for indoor versus outdoor activities, so we did everything outdoors.
So while we are still learning about this coronavirus, I do believe there is enough established evidence about how airborne respiratory viruses spread to determine policy about indoors versus outdoors.
My understanding is that the reason we have a cold-and-flu season is not to do with the weather itself but because the weather often forces us indoors to spaces with limited air flow.
So, least ’round these parts, the people with the power are saying, “Indoors bad, outdoors good,” as it relates to coronavirus transmission.
Related to cold-and-flu season, I heard (though didn’t dig into) that the southern hemisphere was experiencing record low rates of the flu during their cold-and-flu season because of all the social distancing practices employed to halt the spread of Covid. So we may just avoid the double whammy of a winter wave and a flu wave? We’ll see.Report
ThTh4: I’m not sure I’d say COVID is to blame for this. Peer Review By Press Release was a thing before COVID.Report
And honestly, peer review isn’t all its cracked up to be. It helps, of course, but deeply flawed papers make it past peer review all the time.Report
I did peer review for the IEEE for a couple of years. Doing it well is an enormous amount of work. My managers were willing to let me do most of it on company time, which helped. Doesn’t help that so many of the papers are written by people in publish-or-parish mode, and you feel guilty about rejecting them.Report
Under what circumstances is a paper flat-out rejected? Major methodological issues that can’t be addressed without starting all over? Just not very interesting?Report
Speaking just for myself, my short list for recommending a paper be completely rejected were (a) so badly written I couldn’t tell if there was anything new and interesting in it, (b) didn’t have anything new and interesting, and (c) didn’t fit the theme an editor had set for a special-topic issue. In the last case, I’d add a note that said it might be perfectly fine in another situation.
In hindsight I was fortunate that I was reviewing engineering papers where measurements of smaller/faster/stronger/more accurate are generally straightforward (which is not the same as simple or easy). I would really dislike having to judge papers where the effects being measured are so small that most of the discussion is about measurement methodologies and/or subtle statistics.
Another point that Oscar Gordon raises from time to time is the publishing bias towards positive results, particularly for medical stuff. It’s much harder to publish papers whose conclusion is “the null hypothesis that there’s no effect/benefit is not rejected.” I suspect that one of the most valuable tools some of the big drug companies have is a database built over decades identifying molecules that didn’t work, almost none of which has been published.Report
It seems to me that one problem with eliminating the publication bias in favor of positive results is that the correct interpretation of small studies with negative results is that they’re inconclusive.
There was a recent study of the effects of Arkansas’ Medicaid work requirements on employment, and the abstract says “work requirements did not increase employment over eighteen months of follow-up.” But if you read the full study, you’ll see that what they actually found for the employment effect was a 95% confidence interval ranging from -8.5% to +6.5%. The correct interpretation of that is that we have no idea what the effect on employment was, other than that it was probably in that range.
Big studies with negative results generally get published because they’re expensive and generally have enough statistical power to rule out a substantial intervention effect.
Maybe the solution here is not to pay more attention to studies with negative results, but to stop taking small studies with positive results so seriously, and just treat them as preliminary results that need larger preregistered replications before we start acting like the results are true.Report
We still need to pay attention to negative results. If nothing else,we should have a public database of negative results, if only to avoid blindly treading over the same ground over and over.
Otherwise, yes, small studies that suggest positive results, but are inadequate to confirm such should not get much press. When the institution pushes the PR hard, that’s when I suspect they are trying for peer review by press release.
I mean, I give a lot of science reporters credit in that they do state clearly that it’s a small study, or a preliminary study, and it should not be taken as gospel. But others are not so honest, and a lot of media consumers are just fecking clueless regarding what constitutes significant results, and what is just a positive lead.Report
ThTh3 is some of the best news I have heard in a while. Not only is nuclear the best short term option for combatting AGW, I also like the way the new reactors are smaller, cheaper and more flexible.
In Ridley’s new book How Innovation Works, he makes an interesting observation on nuclear. He notes that successful innovation usually comes about via trial and error and incremental tinkering, and that this is the antithesis of the nuclear energy model.Report
More today’s model of how electric power delivery is going to be organized, for which we can blame FERC. FERC’s particular market (and to a lesser extent, reliability) models leave no room for nuclear tinkering. They leave no room for the kinds of network management needed to make renewables successful. There’s no hope of a no- or low-carbon power grid unless Congress imposes drastically different goals on FERC.Report
ThTh5 [“heartbeat”]:
I don’t know. I think a heartbeat from an actual alien would be pretty amazing.Report