Like Fluoride or Oxygen.
Just about anything including water or salt
Not just about. Literally everything is lethal at a high enough concentration.
I’d argue gravitational force isn’t lethal. As long as you don’t arrive at whatever is pulling you & the gradient of gravity doesn’t change across your body length. You could be perfectly fine (for a while) orbiting a black hole at enormous speeds (assuming you don’t collide with matter in the accretion disc.
Wouldn’t a high enough force cause the gradient of gravity to differ?
Unless I misunderstood how that works. I’m picturing a downed powerline that causes large differences in voltage across the ground, which is why you are supposed to shuffle instead of taking a normal step. Would a high enough gravity cause a harmful gradient across the length of a human body?
I’d argue against that. For one thing it is impossible to imagine a situation where there is no change in the gravitational gradient across your body over time. Your orbiting a black hole situation is a perfect example of a situation where the gradient alone would tear you apart. The conditions you’ve specified are tautological. There’s no way to maintain a zero gravitational gradient while also simultaneously having extremely high gravitational field. The two are mutually exclusive in any conceivable scenario.
It’s like saying a human being in a hypersonic wind stream won’t necessarily hurt you, burn you alive and rip you to pieces (not necessarily in that order) as long as there is no turbulence and you have a sufficient boundary layer – but you’re a non-aerodynamic human body in a hypersonic wind stream, so of course there will be turbulence and the boundary layer will not protect you at all, you’re going to die, basically instantly.
I think General Relativity is based on the idea that a frame of reference that’s in freefall is equivalent to one that in a gravity free region of space (at least that was one of Einstein’s Gedankenexperiments that led him to his theory of GR).
Having said that, in reality a sufficiently strong gravitational field will cause a tidal effect, which will crush you along one axis and pull you apart along another.
LD50’s are fun!
Alle Dinge sind Gift, und nichts ist ohne Gift; allein die Dosis macht, dass ein Ding kein Gift ist.
All things are poison, and nothing is without poison; the dosage alone makes it so a thing is not a poison.
Paracelsus, 1538
The word for poison in German is Gift?!
The word has been used as a euphemism for “poison” since Old High German, a semantic loan from Late Latin dosis (“dose”), from Ancient Greek δόσις (dósis, “gift; dose of medicine”). The original meaning “gift” has disappeared in contemporary Standard German, but remains in some compounds (see Mitgift). Compare also Dutch gift (“gift”) alongside gif (“poison”).
Well that’s dumb.
I thought about this a bit and concluded that it only applies to physical materials and forces.
For example: There certainly are lethal ideas, but most of them are not, and much like bosons they can overlap, so filling a person with multiple copies of the same (benign) thought has a diminishing effect.
But yeah, anything physical has a lethal concentration.
dying is a pretty big red flag, you ask me.
Nicotine, small doses can be okay, but large doses and it’s really lethal
I’m not sure bout that. I know they say it, but on many occasions I’ve taken 80+mg orally in a day. Lethal dose is supposed to be 60.
Ld50 is usually in units per kg, so unless you are a pixie, 90 is well under that number.
Remember that the ld50 is lethal for 50% of people (healthy adults? Something like that.)
ionizing radiation, according to some hypothesis, vitamin E, selenium, zinc,
there’s no single “red flag” everything is different
The human body is pretty weak so anything in high concentrations can probably kill us. It’s no steel