【海外の反応】溶岩に落ちると沈まない？ 15年議論された「焼死か圧死か問題」の答えが意外だった

Lava is generally 700–1,200°C (1,300–2,200°F) at this temp, the layer of skin hitting the lava would vaporize immediately. That layer of vapor would create an initial barrier that would cause the fluids nd lipids behind it to only raise a certain amount, too little for combustion or even rapid evaporation. Think of putting a wet piece of meat in a frying pan, how it wont brown (the maillard effect). This layer of steam is what keeps the hands of people safe when they do the “touching” molten iron trick, it’s called the Leidenfrost effect. There would be pyrolysis (thermal degradation of cells and tissues) within seconds though as this effect would last fractions of a second.

The human body is less dense than lava, by a lot. Lava is also considered a “semi-solid.” Lastly, it quenches to a solid when contacted with fluid. The body would be mechanically trapped on the surface so it would not be crushed for a while, a lot longer than the second it would take to burn to death. So the clear answer is oyu would burn to death.

Let’s for the sake of argument, act as though it was not a semisolid yet had the same density. We would use Archimedes’ Principle for Buoyancy to determine if the human body would float or sink. Fb​=ρf​Vg is the formula. I wont bore you with the details but a human body even at 900 pounds of mostly bone is less dense than lava → it should float.

Thanks for giving me 5 minutes of “dicking around” time with math instead of working though!

You'd burn to death. You're not sinking in lava. If you were impervious to heat, you could just walk over it. The heat is going to kill you, though, and if it didn't, the toxic fumes coming off of it soon would.

The surface tension is so high, you wouldn't sink much and would burn to death, albeit slowly and painfully

Lava is very thick

Finally a thread where I feel like I have something relevant to say. Because I have been very close to falling into lava – several times.

I’ve both been involved in SAR operations with Iceland’s recent volcanic eruptions and I’m also a fairly irresponsible person myself.

Lava is a lot denser and thicker than people imagine. It is molten rock, it it is still rock. Depending on the temperature you could step on red glowing lava and it would hold your weight easily. And you can pretty much kick it with your shoes and they won’t turn into liquid or get seriously damaged or anything. And poisonous gasses aren’t going to kill you either (although I had one preeetty serious incident with that).

What would definitely kill you is the immense heat. As you approach glowing lava it feels like walking into a baking oven. Your uncovered face and hands immediately start to feel burning and it is physically impossible to stand right up against the lava for more than a just a second. I’ve made unsuccessful attempts to integrate coins into lava rocks that I could break off later and keep as souvenirs (the coins don’t melt, by the way) but this is almost impossible.

So yeah. As soon as you would jump into the lava, you would not sink in, but you would would catch fire within seconds and burn to death. Depending on the behavior of the lava flow, your remains would be crushed up by the flowing lava.

All I know is, If you ever drop your keys into a river of molten lava, let'em go…because man, they're gone.

I can answer your question by correcting the first part of your question: you don't jump *into* lava, you jump *onto* lava.