sue me if you don't learn anything #2

these are some random facts i've written in my notes over the past weeks:

1. caffeine is a sort of natural poison. it evolved in plants to kill bugs and keep other plants away. (interestingly, it evolved independently in different parts of the world). bugs that eat plants with caffeine die because it overclocks their nervous system, so the bugs learn to stay away and the plants survive better.
caffeine works similarly in humans, just at a different scale, so 5+ grams of caffeine (50-something cups of coffee) would likely kill you through nervous system overload.

2. a calorie is the energy required to raise the temperature of 1 gram of water by 1°C. so a 80 kcals (80,000 calories) apple has enough energy to heat up 80 liters (80,000 grams) of water by 1°C. the calories are just the potential energy stored in the food.

3. the reason time "moves forward" (in one direction) is because of entropy. entropy measures disorder, meaning things always get messier, never more organized (on their own). eggs break but don't unbreak. heat spreads but doesn't gather back. this one-way increase in disorder defines the direction of time.

4. lizards, snakes, and komodo dragons can smell and navigate the world with their tongues. they have a forked tongue that collects particles from the air. inside their mouth are sensors, one on each side, that they dip each side of the tongue into after licking the air. this allows them to sense which direction prey is (there'd be more prey particles on that side of the tongue). this is why these animals keep sticking their tongue out all the time.

5. many ants use their saliva as medicine for other ants. they lick on fellow ants' wounds for a couple minutes and it heals through some fancy compounds in the saliva.
some ants also have internal step counters. as they walk, neurons track their leg movements to calculate the distance they've traveled. researchers famously tested this by adjusting the ants' legs length, and the modified ants overshot or undershot their destination.

6. the amur leopard is the rarest cat on earth. fewer than 30 of them existed on earth in the early 2000s. today there are ~130. damn are they beautiful...

7. in 1928, Alexander Fleming returned from vacation to find mold growing in a forgotten dish of bacteria. he noticed the mold was killing the bacteria around it. he isolated the mold and found it could kill many types of bacteria. he called the substance in the mold "penicillin" and accidentally created the world's first antibiotic.

8. a turkey mother will ignore or even kill her own chick if it doesn't make the correct sound effects. young turkeys are supposed to make a "cheep-cheep" sound, and this seems to be all the mother cares about: she will nurture an enemy animal if it makes the "cheep-cheep" sound, and she will get rid of her kids if they don't. (i got this from robert cialdini's book "influence". you should read it.)

9. clownfish can change gender throughout their life. all clownfish are born as males into a social group with one female, and when the female dies, the largest male transforms into a female and starts laying eggs.

10. if you had 2 more choromosomes you'd have the same chromosome count as a potato. you also share many of the same genes (for protein synthesis, glucose metabolism, etc.)

11. bees suicide when stringing.