Maybe not what you were asking, but let’s say we have two pots of water, both at 25 °C but at different pressure. We stick each pot on a 200 °C hotplate and plot water temperature vs time. How do the plots differ?
I would guess that the rate of heating is slower for the low-P pot because there is more evaporative cooling.
re: your last question, I heat the eggs from a cold pot of water. When it boils, I remove the heat, wait 15 minutes, then cool quickly. Works wonderfully. I didn’t always do this, and only read about it in a cookbook a few years back. I’ve never had any trouble, other than the usual caveat of using too-fresh eggs.
And somewhat unrelated, I read somewhere of a chef who determined what makes and egg “cooked”. Length of heating didn’t really do much. It was all about maximum temperature achieved. I guess the proteins denature rapidly once they reach some threshold.
While there are various ways of hard cooking an egg, I think the generally accepted way of doing it is to put the egg in a pot of water with a lid then put the whole thing on the stove. When it comes to a boil, turn off the burner and let it just sit there for about 15 minutes at which point you should cool the eggs as quickly as possible with running water, etc.
At sea level, the water in the pot will only get to 212 (because if it gets to 213 it will no longer be “water” and it wouldn’t be in the pot), and on the mountain, the water in the pot will only get to 150 (a number I just pulled out of my ass).
If both people have the same burner that can heat water by 10 degrees a minute and they both start with 100 degree water, then…
So I have no idea what this proves… I guess I just wrote that out so I could see it myself. But it is clear that while the mountain egg and the coast egg are heated exactly the same up until the 5 minute mark, the coast egg continues to get hotter and hotter after the mountain egg has reached it’s plateau temperature. So I don’t think it matters that the mountain egg actually boils first, the coast egg will still get more heat and will therefore cook faster.
On Preview, I see Ruken’s post. Yes, the protiens in eggs “cook” or coagulate or whatever at a certain temperature, so for all I know you could cook and egg forever on a mountain and never have it hit that temp simply because the water can never get that hot a that pressure.
Just to nail down this coffin lid thoroughly: I’m at about nine-tenths of a mile, here, and if I follow a hard-boiled egg recipe exactly, I end up with incompletely cooked eggs. I don’t need much extra time, but I do need a little.
This hasn’t been satisfactorily explained IMHO. To answer directly, yes, water does stop getting hotter once it starts boiling. If you added energy at a constant rate, the temp will increase linearly until it hits the boiling point, then stays at that temp while the water turns to vapor.
The egg at sea level will be immersed in 100 C water, the egg in the mountains will be immersed in water that’s maybe 94 C. The sea level egg will cook faster as a result.
At the bottom of the trench, ambient pressure is around 15,000 psi. Weird things happen at these kinds of pressures. The critical point for water is 3200 psi, 705 degrees F. Beyond this point (at higher temps and pressures), you end up with a supercritical fluid, which is kind of neither liquid or gas. “boiling point” kind of loses its meaning here.
But as far as the egg is concerned, at the bottom of the trench you would be able to heat the water to 705 F while still having it remain a liquid; the egg would cook pretty goddam quick. Hell, you’d probably burn it.
As a person who has never lived (well except for a few months abroad) below 5000’ MSL, I am suprised that this is even a question. 3 minute eggs?..you better use a glass to serve them in.
Rice and pasta don’t cook much slower though…I think it is more a matter of giving hot water time to soak into the starch than actually having to cook it.
I’ve never played Mindtrap, but I’m curious. Is there a reason why there’s a robbery and loot-spltting? Couldn’t they just ask whether an egg will cook quicker at a high altitude?
I have to say that I love that someone answered the Marianas Trench question. I actually found that more interesting than the original.
100 is not 3% (approx) hotter than 97 as the 0 point is purely arbitary. You should be using Kelvin e.g. 394 vs 397 which is not so different (less than 1%). And chemical reactions (including cooking) generally have an exponential (nonlinear) dependence on temperature anyway.
And it’s a recurring theme. I got the impression that these names were common placeholders in these sorts of puzzles, but that might just be me playing a lot of mindtrap or hearing a lot of the mindtrap puzzles repeated.
Japan has 4 games in the series, but the game has loads of work in translation/localization. They did it right (i.e., it doesn’t seem like a game with all the text run through an internet language translator). But the ‘expense’ has been that we don’t have all 4 games in the series.
Burn it? My uninformed guess is that in the presence of water at that temperature and pressure the proteins of the egg would completely decompose into amino acids.
I think that is a pretty good guess. OTOH, I don’t think the egg shell would survive at that pressure since the egg white itself will compress. Chemically though, at super high temperatures entropy rules which means more and smaller molecules.
Nitpick: It’s not linear, for at least two reasons. In fact if you plot it it’s pretty far from linear. I’m speaking from having heating acetone in lab flasks that have temperature probes (acetone for cleaning) and watching the temperature rise on a plot.
First - the heat transfer rate is directly proportional to the difference in temperature between the egg and the boiling water. So the heat transfer rate slows as the egg increases in temperature.
Second - heat capacities are temperature dependent as well. I’ll grant that for a lot of common materials they don’t vary much with temperature (example - C[sub]p[/sub] for water at 25 C, 1 atm is 75.328 J/mol K. At 99.974 C (bp at 1 atm) the C[sub]p[/sub] for liquid water is 75.946 J/mol K (source: www.nist.gov). Granted, this is not quite 1% difference but heat capacity is not a constant. I have no idea if anyone’s ever modeled the heat capacity of an egg
“Molecluar gastronomy” chefs experiment with this, with very precise and evenly-heating ovens. This results in the “65-degree egg”. Here’s an article in Discover Magazine.
(The article has some poor coding so it doesn’t look right to me in IE 7.0.)
To elaborate, a liquid is a fluid with the equation of state (relationship between pressure and density) “density equals a constant”. A gas is a fluid with the equation of state “pressure is proportional to density times temperature”. One or the other of these two equations of state works pretty well for almost all familiar Earthly fluids, but in principle, there’s no limit to the crazy sorts of equations of state you could have. Any fluid with an equation of state other than one of those two is neither a liquid nor a gas.
Once again, in my 10+ years on the dope I’ve learned something new.
So my followup questions is: so could you theoretically put water at a high enough altitude so it boils at virtually any temperature? i.e. ‘room temperature’ of 70 degrees Fahrenheit?
Does high altitude change the freezing point of water too?
What would happen to water in space? Would cohesion exist or would the water just turn into mist?
I live in Denver. In Denver there is no such thing as a 3-minute egg. It’s a 4-minute egg or it’s not done. (And that’s a SOFT-boiled egg.)
A fun thing we do when we get up early to hike in the high country is, as soon as we get to about 10,000 feet, we open up the thermos. The coffee we poured in in Denver is…boiling.
I think we can assume it did not get any hotter after an hour in the thermos.
At 70F, the saturation vapor pressure of water is 0.363 psi. Atmospheric pressure is this low at about 83,000 feet above sea level.
Just to nitpick terminology, “mist” implies a collection of superfine liquid water droplets dispersed in air. This is technically called an aerosol, colloquially called fog. In space, I suspect most of the water would rapidly evaporate/boil away, leaving the remaining molecules cold enough to freeze (not sure on whether the remainder would actually freeze, or just slowly evaporate). That rapid vaporization would take place throughout the body of water, causing a dispersiveBLEVE; no cohesion of the whole body of water.
Yep. Here’s the explanation of what happens to water in a vacuum, and here’s a chart showing how lower air pressure affects the boiling point. “Vacuum inHg” is something I had to look up, but that’s a unit of pressure. Standard pressure is 29.92 inches Hg, so the chart is essentially showing from sea-level at the top to a near-complete vacuum at the bottom. To get the boiling point at room temperature requires dropping pressure to about 1 inHg. Since I’m just learning about this myself, I can’t say what that’s comparable to, but given that we’re talking about a scale of 0 to 30, that’s damn little pressure. I’d guess very near the upper bound of the atmosphere, then the boiling point plunges below 0 as soon as you cross into true vacuum.
