General Science Thread

Humans don't cause climate change! ...well, not this time.

In half a billion years, the Sun will have warmed enough to threaten the extinction of life on the planet anyway, supercontinent or no. Humanity has a cosmic deadline for our tenancy on this planet.

We can extend that with megaprojects like a solar shield (or, for extra sci-fi points, changing Earth's orbit), but no matter how hard we work, we run into an even harder deadline when the Sun runs out of hydrogen in its core and goes into its red giant phase.

At that point, we are either living elsewhere — preferably in another solar system — or we go extinct.

Edited by Fighteer on Oct 1st 2023 at 2:01:13 PM

Half a billion years is longer than hominids have existed by a factor of fifty, let alone humans, and whatever form humanity's descendants take if any will not be predictable or recognisable over that much time.

500.000.000 years ago was around the invention of fish.

Yes, that's probably right. Chances are we'll die out long before we hit the 500 million year mark. But our far-future descendants will face that problem, or whichever species evolves sapience after we're gone.

Put another way, if Earth life hasn't moved elsewhere by then, Earth life is toast. Literally.

Edited by Fighteer on Oct 1st 2023 at 2:13:56 PM

Global warming and ocean stratification: A potential result of large extraterrestrial impacts meteorite impacts in the ocean can cause global warming because the impact explosion adds a lot of water to the stratosphere where it acts as a greenhouse gas. The resulting warming of the ocean surface slows down the vertical mixing, causing the ocean away from river mouths to starve of nutrients. Except in river mouths as noted, explaining why taxa (like turtles and crocodiles) living in them are more likely to survive a mass extinction.

Asteroid impact, not volcanism, caused the end-Cretaceous dinosaur extinction - the Deccan Traps didn't contribute to the mass extinction, on the contrary their carbon dioxide emissions might have mitigated the impact winter.

That article is behind a paywall. Can you provide the article title or author name so I can try to find it?

This one?

From the same source: Centipedes subdue giant prey by blocking KCNQ channels A giant centipede weighing 3 grams can subdue a mouse weighing 15 times that in half a minute. The researchers even got a video of the attack, which is linked at the bottom.

Yup, that's the one, thanks.

Centipedes are nasty predators. Thank God they are so small.

Yeah, they're nasty critters, alright.

Emphasis on are that small. They used to be as big as buses.

Not that big, unless there's some small buses around.

Maybe it was vans, yeah, but they got pretty big nonetheless. Certainly as big as a man or more.

The longest ancient specimen found was 6 meters long. They weren't bus sized, but maybe bus length. They still didn't get that big in terms of circumference.

Edited by Zendervai on Nov 29th 2023 at 2:01:40 PM

Huh, we've found ones that big? I thought Arthropleura and Jaekelopterus(sea scorpion, not centi/millipede) both reached around 3 meters tops.

Oh, sorry, I worded it wrong, then.

It's like, one fossil that they found.

One is all you need, though.

Which species was it? Cause I keep inputting 6 meter long centipede fossil and not getting much back.

It was a millipede, not a centipede, and thus a large herbivore. they were called arthropluridians or something like that.

And it wasn't eight meters by any fossil, it was 8 and a half feet. So probably around three meters when they got big during their peak.

Trends in planetary science research in the Puna and Atacama Desert regions: Underrepresentation of local scientific institutions? (Free link) An article about the phenomenon that articles about a particular area in the non-Western world often do not feature any participation from local entities.

Volumetric LED candle looks the same from any angle—and looks like amazing work: Re-creating a candle's multi-angle glow requires a lot of small-scale soldering.

Someone just made this amazing volumetric display of a candle. It's just a prototype, but man, it's amazing how good it looks already. This would be an amazing way to create holograms.

So, not sure if to ask this in the politics or police threads, so I'll begin here:

Is DNA phenotyping i.e deriving the appearance of a person from their DNA, in any way reliable? This year, Switzerland allowed its use in prosecuting certain serious crimes^note Intentional killing, murder, manslaughter, non-consensual abortion, serious body injury, female genital mutilation, robbery, extortion under aggravating circumstances, human trafficking, kidnapping under aggravating circumstances, hostage-taking, sexual acts with children, sexual coercion, rape, defilement, membership in criminal and terroristic organizations and war crimes but I dunno if it's in any way useful or reliable.

I imagine it'd be at best somewhat helpful if the person being analyzed isn't already registered? But it'd be extremely vague. Would definitely not be used well by police though.

Edited by alekos23 on Dec 22nd 2023 at 1:35:45 PM

Depends. What are Swiss prosecutors using it for?

Doesn't seem like we have many examples of its use yet.