Interesting Links for 24-08-2023

[andrewducker]

1. When did galley slaves become common, and why?

(tags:history boats war sea europe slavery viaDanielDWilliam )

2. Would *you* like to know about the racist birth centrifuge?

(tags:childbirth gravity history patent viaPatrickHadfield )

3. LEGO officially offers Braille Bricks for sale for the first time

(tags:blindness lego )

4. It's Getting Too Hot for Tropical Trees to Photosynthesize

(tags:trees plants doom globalwarming )

Comments

[nancylebov]

2. You can call it racist, but it would have put white women at risk rather than women of color.

_The Frailty Myth_ has it that upper class Victorian women were expected to move so little that they had trouble giving birth, so special lightweight exercises were invented for them.

Shades of Heinlein: I think it was _Time Enough for Love_ which had the idea of a pulse of high gravity (artificial gravity on a spaceship) to get the baby out.

[andrewducker]

I'm fairly sure it was in "The Tale of the Twins Who Weren't" in that book. Based on (IIRC) Inuit women using poles to give birth?

[anna_wing]

It's still racist, though.

[channelpenguin]

So, "Victorian women were expected to move so little that they had trouble giving birth"

What about now? When many (more?) people in the western world move very very little ...

[channelpenguin]

Wait, did you mean specifically "move during childbirth"? Or in life in general?

[nancylebov]

In life in general.

[nancylebov]

I think the Victorians were more extreme. I recommend the book.

[bens_dad]

Took me a while to think why you need language-specific Braille bricks.

[liv]

4. A friend of mine who is a grass specialist has been involved in experiments that found empirically that parts of Africa are now regularly too hot for important crop seeds to germinate. That's not as devastating as no photosynthesis because it's not that hot constantly so there might still be a window in which you can get germination. But it's an experimental result, not just modelling. And there's nothing you can do about altering conditions other than temperature to compensate for, it's too hot to germinate.

[andrewducker]

Well that's not at all terrifying.

[andrewducker]

When they publish, let me know

[armiphlage]

4. With respect to survival (and thriving) at high temperatures, plants using C4 photosynthesis cope better than plants using C3 photosynthesis. Unfortunately, only a few trees (all from Hawaii) use the C4 pathway. Either we have to massively seed tropical rainforests with currently-endangered Hawaiian trees, or they will turn into grasslands.

https://www.llifle.com/Encyclopedia/TREES/Family/Euphorbiaceae/28967/Chamaesyce_olowaluana

[hairyears]

What's the upper limit for grassland?

You can see where I'm going with this: what's the upper limit for cereal crops?

This is a harder question to answer online, than I had thought: all the data I can find is about overall climate, and conflates high temperatures with low rainfall.

[armiphlage]

Unless we have robotic or air-conditioned tractors to harvest the cereal crops (or sugarcane! it's C4), it'd be a moot point; before it gets too hot for C4 grasses, there won't be any living mammals in the region. Many insects would be dead too (bees kill wasps by huddling around them and warming them to 45 C). Without insects for pollination, the variety of C4 crops that could propagate would be reduced. We might end up with just lichens before it got too hot to actually kill off the grasses.

My grandfather's tractor didn't have air conditioning, just fans; it was sometimes too hot to harvest even in relatively cool Nova Scotian summers.

[hairyears]

The good news is that honeybees aren't the only game in town - they're not eventhe dominant pollinator.

Mining bees can and do survive temperatures in the high forties; they don't forage during these conditions, but they'll breed successfully if flowering plants are photosynthesisising and producing nectar for part of the day.