WazWaz t1_jclqyke wrote

Easy, inject a little of each into an iguana. The sick/dead iguana got the human blood. Also works in reverse.

Indeed, this is how blood identification works: you inject a little human blood into a chicken, then harvest the antibodies it produces in response. These antibodies can then be used to check if a blood sample is human (eg. only the human blood would react, the antibodies would have no effect on iguana blood).


WazWaz t1_ja4pual wrote

Take a step back. Matter cannot be created or destroyed (let's ignore E=mc² for now). So you must know the water doesn't just vanish. You've presumably seen the difference between a green leaf and a dead one (hint: the latter is dry).

Trees don't grow forever nor do they live forever, so I don't understand why you thought the water was trapped in them forever.

This is in addition to the chemical processes others have described which convert the water to and from plant matter via photosynthesis and respiration.


WazWaz t1_j13gt4s wrote

Indeed, the only reason we use high G on liftoff is because any time we waste getting to orbit costs us 1G negative the whole time.

Note that Special Relativity means you won't reach light speed, though it will seem as if you blow right past it as your rapidity increases.


WazWaz t1_ixcqm8n wrote

Technically it would be twice as bright in interstellar space. Since it's lit by a sphere of stars, not a hemisphere. Of course, you can only see one side of an object at a time, so as lit from above in those places. Roughly half the side lighting.


WazWaz t1_ivemwl0 wrote

Just a minor qualifier on many of the examples here: humans (and all multicellular organisms, but we're particularly bad) evolve orders of magnitude more slowly than the microorganisms that cause disease (since we breed slower). So when it happens that a segment of the population survives a disease while another dies, it's not necessarily because some have "evolved resistance". The same tends to happen with even new diseases. We do have evolved immunity but it is by necessity broad, so a segment of the population might be immune because they're descendents of survivors of a similar disease, or it may be entirely coincidental - and that coincidence can go both ways (such as survivors of Plague now being more susceptible to auto immune diseases).