I’m no lavatorial expert, but I’d guess the thermal conductivity of lava is relatively low. The high temp and high mass will keep it warm for a while, but water has a pretty high conductivity and capacity on its own. The agitation is distributing the heat too, well beyond the regular convection rate.
Bruh. Someone else on this thread has already clarified to you the easy and what I was expecting question: what happens to the water and lava in the water bucket.
You already answered that question in this thread.
Heat capacity of lava per degree Celsius per unit of mass
Multiplied by temperature differential vs ambient, multiplied by mass = total extra heat energy
Then you calculate the sum of heat capacity multiplied by mass for lava and for water, and calculate from that how many degrees above ambient the two masses will land at when combined as the extra energy above is divided over both (assuming water starts at ambient temp)
It won’t be exact because heat capacity varies in materials as temperature changes, both steam and solidification of lava (state change) will contribute significantly, but it’s a decent first estimate
Okay. Then they add more and it will boil quickly. I guess the question boiles (huehue) down to how much water you can turn into stream per amount of lava or the inverse, how much lava you can cool down per amount of water.
The phase change from liquid water to stream will, by the way, not just contribute significantly but be by far the majority of energy needed. Simply heating water up, ignoring the phase change and changes of the heat capacity, with the same energy as it takes to go from liquid to gas (2257 kJ/kg) would result in a temperature rise of… dT = 2257 kJ/kg / 4.2 kJ/(kg*K) = 537 K
Assuming enough water that most of it doesn’t boil, then my math would still check out, but yeah, any substantial amount of boiling forces you do do the math in multiple steps to handle that
I’m a software engineer, not a physicist, but I’m not sure that makes sense for this. Heat does transfer much more quickly in oil than water, so it can cool something off more quickly, but oil can also get way hotter than water. That little bucket isn’t going to hold enough for a lot of thermal mass, so it’s pretty quickly going to get as hot as the lava (or as close as oil can get). Water turns to stream and boils off, so kind of caps the temp under normal conditions.
Plus if they’re doing sampling, I doubt they want the sample covered in oil.
He might just be shielding his face from the heat. That said, I saw a little plant that almost survived the lava flow, and it was much closer than he was, so idk.
Normally when I see geologists standing around lava they have masks on, so I’d assume he has one under whatever he’s got on his face. Either that or maybe he was getting a couple quick scoops and wasn’t going to be standing around long enough for a mask to make a huge difference.
What surprises me is no way to carry the bucket away afterward; You would have to put your hand over the bucket, in the steam. Gloved or not, it does not seem very safe.
If it really is just getting the lava down to boiling water temperature, or even a bit higher, that thin metal handle will dissipate that heat pretty quickly. A glove should be fine.
The hottest lava gets about 200C lower than the melting point of what looks like stainless steel. And the water inside will actually wick that temperature from the outside into the water pretty effectively.
That's also why you can boil water in a paper cup by placing it over a flame. The water eats the eat like a hungry jiraffe.
Ooo, you can use a plastic bag, like the kind supermarkets still use, in place of a pot too! Granted, I wouldn’t recommend it because god knows what plastics are leeching out of your makeshift pot and into the water, but if you need to boil water and all you have is a plastic bag, well, there you go!
Considering how plastic trash is literally everywhere now, a survival situation where you have a reasonably intact walmart bag but no pot is more likely than you’d think.
A vital detail you forgot to mention is that water can store an absurd amount of heat even before it boils, and when it starts boiling it stops getting warmer and instead simply takes boils faster and faster the more heat is applied.
and when it starts boiling it stops getting warmer and instead simply takes boils faster and faster the more heat is applied
Isn’t that how most matter behaves? An example of a process that seemingly relies on that, is distillation, which I imagine would be impossible to do, if once the boiling point is reached, the heat didn’t [stop going towards raising the temperature and instead going towards the vaporization enthalpy]
Is it even lava after it cools in the bucket of water? Chemically, yes (or maybe? Wouldn’t the water change it just a bit?), but definition wise does lava not imply that it is still molten?
That’s so weird. Why doesn’t he just fill the bucket with lava? That way he can place a lava source block wherever he wants! Maybe set fire to his friends creations in the process.
Oh man, he’s going to be so disspaointed when he gets home and it’s all just rocks. It’s like the time I bottled a piece of a cloud in Costa Rica and opened it up to just find a slightly damp bottle.
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