Recent comments in /f/askscience

saywherefore t1_jadf9gk wrote

The easiest way to see the effect of uncertainties in a calculation is to redo the sums with the extreme values of the range.

So let’s say your average value was 20cm^3 per 10 seconds. The limits are:

20 - 1 = 19cm^3 per 10 seconds = 19 x 6 = 114 cm^3 per minute

20 + 1 = 21cm^3 per 10 seconds etc

This also helps to see how uncertainties combine, by considering all the limits that affect the final result in the same direction, although as another commenter alluded to, you don’t necessarily need to combine all your uncertainties linearly.

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mfb- t1_jadbv3t wrote

> lepton flavor is conserved

It's not. And you found out why not.

If you try to apply this to e.g. a muon to electron+photon decay you get absurdly small branching fractions (10^(-50) or so, theorists don't bother calculating it more precisely because it's zero for all practical purposes).

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AndrewFurg t1_jad9mp9 wrote

Not likely. Insects as a group are exceptionally diverse and most reproduce quickly with large numbers of offspring. It will vary strongly from group to group, with heat-loving generalists doing well and specialists (e.g. obligate parasites with rare hosts) hurting the most.

Additionally, some are very susceptible to pollution, while others can survive nearly anywhere (e.g. mosquitoes in shallow, ephemeral pools).

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-Metacelsus- t1_jad961c wrote

> The gonads themselves react to the environment temperature epigenetically. This is the theory that is the biggest departure from the others as it doesn't specifically target a separate messenger hormone (even though one may or may not be present).

This has been proven pretty well, at least in one species of turtle: https://pubmed.ncbi.nlm.nih.gov/29748283/

But other species might be different.

Also, you write, "in humans, all babies start off development as females." But this isn't correct. A better way to say it would be that they start off as undifferentiated, and trigger male or female development depending on whether the SRY gene is present.

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Gederix t1_jad8j6z wrote

Species that use vision to hunt like wolf or jumping spiders do have vision behind them, and yes spiders can walk backwards, trapdoor spiders do this every time they drag a still struggling victim into their lair never to be seen again.

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Alex_877 t1_jad7aag wrote

All of current life on earth is mediated through reactions by enzymes. Each enzyme has a most active temperature region based on its specific protein structure, length and folding etc.

In this case the difference in temperature is enough to produce a cascade of effects to make the enzymes responsible produce a difference in the offspring.

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