So when this [endosymbiotic fusion] is peer reviewed. And the experiment repeated.

To the best of my knowledge, nobody serious has claimed to observe the merger of an alpha-proteobacterium (IIRC) or a [I forget, some class of oxygenic photosynthesising bacterium] with some other class of bacterium to form respectively mitochondria or chloroplasts. That is what Lynn Margulis inferred to have happened in the early Proterozoic (twice, successively ; green plants have both chloroplasts and mitochondria).

all rational thought generally believes it happened at least 2 times before

Well, when Margulis proposed her endosymbiosis theory, in the late 1960s and early 1970s, it was derided as bullshit by a large proportion of the biological community. Funeral-by-funeral, the consensus has moved in her direction, but it is still a very new consensus.

Actually, Margulis has promoted the idea of around a half-dozen other symbioses in the same 2.5Gyr B.P. period. Which is not consensus yet. I was tempted, but dubious, of the idea when I met it several decades ago, and have moved the relevant book to my by-bed pile for re-reading. Don't hold your breath waiting though - it's not an important point to me.

Yet somehow now rationally thinking that it ever happens ever in a more or less permanent manner.

Cat got your "n"?

No one looks at the nucleus that way,

... for values of "no one" that includes Lynn Margulis (originator of the mitochondrial- and chloroplast- endosymbiosis hypothesis, in the late 1960s and early 1970s).

By coincidence, a mid-1980s text book she authored ("Five Kingdoms") recently made it's way back form a box in my cellar onto my bedside table, because I feel the need to re-read it. While I've lost my notes from first time round (device died ; hardware-linked software), I clearly remember her making exactly that claim about the origin of nuclei. Also, in almost the same breath, she proposed endosymbiotic origins for : the actin network that underlies muscles, cellular motility and the endoplasmic reticulum ; the Golgi apparatus ; flagellae ; the nucleolus ; and I think a couple of other types of organelle. This was, in fact precisely the point I wanted to check in the book, so I dug it out. (It's buried under 10cm of higher-priority reading though.)

When I read that assertion, a decade or three ago, I thought it worthy of note ; but I also thought that Margulis was in danger of becoming a "endosymbiosis solves everything" Cassandra-a-like.

I really need to go back to re-read what she actually said.

The version of this story that I saw (outside America ; less concerned with USian politics) plotted the rates of people taking long-term contraception (vasectomies, tubal ligation ; not condoms or IUDs which are short-term contraceptives) against time - seeing a sharp increase from early 2022 to today, resulting in approximately a doubling of the number of vasectomies being performed in a little over a year, and a near-tripling of the number of female sterilisations over the same interval.

In a year, the population of the US has barely changed - not even 1%. So those absolute numbers might as well be rates/100,000 people.

Declare legislative war on pregnant women - which is what the US "penis politic" has done - and this is the predictable result. I'm sure your ultra-RW, women-hating politicians, male and female, have an explanation for why they are choosing to do this. Personally I read the headline and thought "... and the problem is ?"

Very much, it's a problem America's politicians have inflicted on the American populace and American economy (in years to come). From the rest of the world - a big fat [shrug].

TFS states that one of the outputs will be the "same material as seashells" - which as a geologist, I interpret as calcium carbonate (two minerals, multiple microstructures), calcium phosphate (several minerals, but much less common, because phosphate is frequently a limiting nutrient), or ... well that's about it, unless you're an insect and make a shell out of chitin.

So, where, in "sunlight, electricity and seawater are you going to find the calcium ions?

Obviously, they're relying on calcium already dissolved in their seawater.

Which is already maintained at quite low levels because there are petatonnes of coral reefs, seashells and the like already taking Ca++ ions out of seawater. They already have problems with falling seawater pH (so, increasing seawater acidity) making it harder for them to maintain their shells, leading to thinned shells, reduced growth rates, and decreasing mechanical strength of individual shells, and coral banks in aggregate. So I suspect that the ultimate utility of this approach is going to be very limited.

And now that the linked articles have opened in another tab ... the unquoted bits of the headline read : Some scientists are raising red flags. Yep. They're trying to perform some sleight of hand about separating the acidic and alkaline fluids produced (so, they're doing electrolysis. Meh. But where they get their calcium ions from in one side, and what rock they crush on the other hand ... I bet they're going to put limestone in on one side, double-count it, and use it to provide calcium ions on the other side. Which will lead, molecule for molecule, to one molecule of CO2 going in, and one molecule coming out. BFD.

Does the other link say anything? Nope, it's just hydrogen boilerplate.

This process will do precisely zero for net CO2 emissions, and at best will move some emissions from exhaust pipes to distant power plants.

Don't they teach chemistry at school these days?

Oh, OU Phys.Soc.

Didn't know they had one that videoed lectures etc - but not surprised. I stumbled onto the OU Archaeology Soc. recently, and they had an interesting few hours of presentations there, so I think the Phys.Soc should repay a good search too.

Thanks for digging that out. I didn't come across that in my hunting (I was working from the RS end more than this guy's website.

Off to watch and write notes.

You haven't noticed any of the astronomical publications about refinements to the chain of "standard candles" across the observable universe over the last 40+ years? I remember reading about these things in the town library in the late 1970s, in the university library in the 1980s, the journals waiting, wedging the front door shut when I got home in the 1990s, and on ArXiv (it's a chi, not an "X", but Slashcode can't handle HTML) in the 2000s, 2010s and 2020s.

The process of refining those candles continues to this day. Each publication cycle approximately halves the uncertainties of the previous one. See above for the recent publication cycles.

Shrug. We can't do experiments in historical geology (what happened in the past), but that doesn't render the field unscientific - it just means we have to use more indirect arguments and slightly longer chains of inference.

Everything can't rotate because there's nothing else for it to rotate relative to.

Not only that, but if it was rotating, it would have an obvious centre and we would see everything orbiting it.

I don't think so. Not necessarily.

Consider a universe - the whole shebang, everything, no external reference frame. Separate it into two regions, of (approximately) equal size ; set one part rotating clockwise relative to the other, and the second part rotating anticlockwise relative to the first.

You now have a universe where everything (except that on the rotation axes) is rotating, but the net angular momentum is zero.

But yes, if (if) your local "observable" universe included one or other of the rotation axes, then you should have something to look at. If the axes are outside your observable section of the universe, maybe you'd be able to tell, maybe not. My maths isn't up to saying for sure, either way.

Bloody Slashcode can't even handle a perfectly reasonable HTML entity, "& chi ;" necessary to spell "ArXiv" correctly.

Found it via the 3rd name.

https://royalsociety.org/scien...

15 - 16 April 2024 09:00 - 17:00 The Royal Society ... ah, the GRauniad article is from the 14th!

Scientific discussion meeting organised by [names]

Is the universe simple enough to be adequately described by the standard [lambda]CDM cosmological model which assumes the isotropic and homogeneous Friedmann-LemaiÌtre-Robertson-Walker metric? Tensions have emerged between the values of cosmological parameters estimated in different ways. Do these tensions signal that our model is too simple? Could a more sophisticated model account for the data without invoking a Cosmological Constant?

Speaker abstracts will be available closer to the meeting date. Meeting papers will be published in a future issue of Philosophical Transactions of the Royal Society A.

There are abstracts of the presentations, but no details.

I guess, if I were really interested, I'd search Ariv for papers by the relevant names, but I'm not that enthused. I've got better things to do this evening.

Yeah, I'm hunting around the RS's website looking for some information about this meeting ... to find it has gone down the cracks. Their programme of meetings covers 25th Apr onwards, while the Grauniad item talks about "this week's meeting" ... and if it's going at the moment, then the videos won't be on YT, yet. (The most recent RS video is "Dr Anthony Fauci on the lessons from AIDS and COVID-19 , 1.6K views, 4 days ago"). (Not a particularly engaging set of lectures. The RI is better.)

The named organiser (https://www.physics.ox.ac.uk/our-people/sarkar) ... doesn't have anything on his website.

He's trying to play some "Say you don't have an argument without saying 'I don't have an argument' " game?

The Triassic wasn't particularly "lush". With Pangaea barely getting started on it's pre-breakup LIP and rifting, most of the Earth's continents were far form any oceans to produce moist air and rainfall, making it, on average, a fairly arid period.

Also, most oil deposits are considerably younger than the Triassic.

But a bigger problem is risk of a "Mars pandemic". There could be microbes on Mars that Earth life has no immunity to.

Meh.

If there is life on Mars, and if it can survive a few centuries/ million years in vacuum below the surface of a lump of rock, then samples have been raining down on Earth since the Hadean. Despite Fred Hoyle and Chandra Wickramasinghe's best efforts, nobody has yet been convinced of any cases of "Mars Flu", despite the constant (if thin) rain of such projectiles. We have found and identified hundreds, possibly thousands (I can't be bothered keeping count), of Martian meteorites, which means there are millions or billions out there on Earth's surface which haven't been identified. Yet.

If Mars had infective biota, and that can be naturally transferred between the planets, then it has already arrived here. Repeatedly.

Now, personally, I don't think it is very likely that such a transfer (of organisms)could happen, in the Solar system. And it's even less likely to happen between stellar systems. But the possibility is just possible enough that people don't get laughed at (much, in public) for suggesting that Earth life originated on Mars. It's about 99 times as likely as all Mars life having originated on Earth. But it's not quite an insane speculation - the mechanisms exist, even if the stack of probabilities against is pretty daunting.

But if you grant that possibility, then there is no way you can have that without Earth having been repeatedly inoculated with Martian organisms. Therefore, the surviving life on Earth today are descendents of survivors of, say, the last time that 96% of genera of life on Earth were wiped out. (Permo-Trias "Great Dying" Mass Extinction, I'm looking at you!) And since that "Great Dying" didn't get us (our ancestors), the next delivery of "Death from Martian Skies" is pretty unlikely to either.

(There are very good terrestrial-only explanations for the "Great Dying" - but not for all the major extinctions in the Phanerozoic Era ("Era of Evident Life"), and I'm not claiming that was the cause of that mass extinction - I'm just arguing that IF Mars had Earth-infective biota, then our ancestors have already have survived an encounter.)

I've also got a philosophical contempt for the concept of "panspermia" - but I grant that it's physical mechanisms aren't impossible, just bloody unlikely.