Shape__Shifter
Shape__Shifter t1_j26ibfh wrote
I watched a video about the birds a while back, the researchers said the birds don't seem to have any awareness of the overall shape they make, each bird is just paying attention to the nearest (maybe) 5-7 birds and doing what it can to not crash into them.. this makes it a near constant change in direction to wherever they'll fit and not crash.. I'd imagine it's similar with fish (though I think I remember Nova showing sometimes they group up to appear larger to predators, no mention of 'how')
Shape__Shifter t1_j2315u2 wrote
Reply to ELI5 why do electric vehicles have one big battery that's hard to replace once it's expired, rather than lots of smaller ones that could be swapped out based on need (to trade off range/power/weight)? by ginonofalg
According to Google, if you replace the battery with AA batteries, you'd need 25,000+ batteries... that'll take some time to replace... also the more batteries you have, the more potential failure points you have
Shape__Shifter t1_j1lbmiy wrote
Wikipedia has the origins and probably links to more info, but says 'witching hour' has its origins in a poem from 1775 called "Night, an Ode".. but it could go further back to 1535 when the catholic church banned activities between 3-4am due to fear of witchcraft spreading and using 3am as its the inverse of when Jesus supposedly died (3pm)
Another folklore thing with it is the hour after midnight and it's sometimes called the "devils hour"
Shape__Shifter t1_iy6t8xr wrote
It gets mixed with air just before going into the engine, once it's mixed with air and is no longer a liquid, it's pretty flammable.. at a certain time a sparkplug creates a spark that sets off the burning (about the highest point in the pistons motion so the expanding flames help push the piston down with extra force, enough to rotate a shaft attached to the tires)
The thing mixing the liquid with air is called a carburetor, there's plenty of videos about them on YouTube for free, a channel called smarter every day did a whole deep dive and built a clear one that he shows working up close and in slow motion and I think it'd answer all questions about them
Shape__Shifter t1_j9stptj wrote
Reply to ELI5: this has probably already been asked but why do guys get morning wood? by mean_beanz
Google says hormones, they're highest in the morning..
Or just a result of sleep cycles with healthy nerves and blood flow
Or a change in nervous system during REM sleep..
There doesn't seem to be an agreed upon answer, more just something that happens