# Question from the game MindTrap regarding boiling water physics **URL:** \ **Category:** Factual Questions\ **Created:** [July 22, 2009, 2:27am UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811 "2009-07-22T02:27:29Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [July 22, 2009, 4:51pm UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/21 "2009-07-22T16:51:59Z")
> [@Munch](#): > > Hang on. > > How much of a head start would Mountain Mike get? Presumably his pot of water begins boiling sooner, right? > > Or do people hardboil their eggs by putting the eggs in with the water and heating the whole thing up? 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. ---
**Author:** ![StinkyBurrito](https://avatars.discourse-cdn.com/v4/letter/s/b9e5f3/32.png) [@StinkyBurrito](https://boards.straightdope.com/u/StinkyBurrito)\ **Post date:** [July 22, 2009, 4:58pm UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/22 "2009-07-22T16:58:03Z")
> [@Munch](#): > > How much of a head start would Mountain Mike get? Presumably his pot of water begins boiling sooner, right? > > Or do people hardboil their eggs by putting the eggs in with the water and heating the whole thing up? 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… ```auto Time TempCoast TempMountain 1 110 110 3 130 130 5 150 150boiled 7 170 149 9 190 148 11 210 147 13 211boiled 146 15 210 145 17 209 144 19 208 143 21 207 23 206 25 205 27 204 ``` 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. ---
**Author:** ![zut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zut/32/2875_2.png) [@zut](https://boards.straightdope.com/u/zut)\ **Post date:** [July 22, 2009, 5:09pm UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/23 "2009-07-22T17:09:52Z")
> [@StinkyBurrito](#): > > 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. From [Baking911.com](http://www.baking911.com/pantry/eggs_baking.htm): > [@](#): > > Egg white proteins coagulate first at about 140 degrees F, with the white no longer flowing near 149 degrees F. It becomes opaque and forms a gel. Heating the egg white much beyond this temperature shrinks and toughens the coagulation of the white. Coagulation of the yolk begins near 150 - 151 degrees F, and the yolk thickens and no longer flows when the temperature nears 158 - 160 degrees F. From [here](http://www.hi-tm.com/Documents/Calib-boil.html): ```auto Altitude Pressure Boiling pt. (ft.) (in. Hg) (° F) -500 30.466 212.9 0 29.921 212.0 500 29.384 211.1 1000 28.855 210.2 2000 27.821 208.4 2500 27.315 207.5 3000 26.817 206.6 3500 26.326 205.7 4000 25.842 204.8 4500 25.365 203.9 5000 24.896 203.0 5500 24.434 202.0 6000 23.978 201.1 6500 23.530 200.2 7000 23.088 199.3 7500 22.653 198.3 8000 22.225 197.4 8500 21.803 196.4 9000 21.388 195.5 9500 20.979 194.6 10000 20.577 193.6 ``` ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 22, 2009, 5:11pm UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/24 "2009-07-22T17:11:13Z")
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. ---
**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\ **Post date:** [July 22, 2009, 5:43pm UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/25 "2009-07-22T17:43:19Z")
> [@Enright3](#): > > I agree that water boils at a lower temperature the higher you go… but who cares? To me the only way the above answer would matter is if the water stopped getting hotter once it started boiling. 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. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [July 22, 2009, 5:51pm UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/26 "2009-07-22T17:51:52Z")
> [@Smeghead](#): > > Now, what if the water is being boiled on a treadmill at the bottom of the Marianas Trench? At the bottom of the trench, ambient pressure is around 15,000 psi. Weird things happen at these kinds of pressures. The [critical point](http://en.wikipedia.org/wiki/Critical_point_(thermodynamics)#Vapor-liquid_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,](http://en.wikipedia.org/wiki/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. ---
**Author:** ![Kevbo](https://avatars.discourse-cdn.com/v4/letter/k/e47774/32.png) [@Kevbo](https://boards.straightdope.com/u/Kevbo)\ **Post date:** [July 22, 2009, 11:01pm UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/27 "2009-07-22T23:01:26Z")
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. ---
**Author:** ![Yookeroo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yookeroo/32/323_2.png) [@Yookeroo](https://boards.straightdope.com/u/Yookeroo)\ **Post date:** [July 23, 2009, 10:17am UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/28 "2009-07-23T10:17:38Z")
> [@Enright3](#): > > Are any of you familiar with the game MindTrap? To quote Wikipedia on the game: “The puzzles are logical, trick-type questions. Some are simply riddles to be thought out, and some give unnecessary information in order to distract the answerer from a simple, common sense solution, and play on common assumptions.” > > So, my wife and I were sitting on our deck tonight enjoying the awesome weather we’ve been having in Georgia, while sipping some Gentleman Jack, and reading MindTrap questions to each other. We happened across this doozie: > > It was a warm summers evening when Sid Shady and Sam Sham robbed the till at the ‘Soul-Ace Hotel’. Knowing the police were not far behind, they agreed it would be a ‘colder trail’ if they split the loot and parted company. Sid Shady took the high road far up into the mountains and Sam Slug headed for the coast. 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. ---
**Author:** ![scm1001](https://avatars.discourse-cdn.com/v4/letter/s/c4cdca/32.png) [@scm1001](https://boards.straightdope.com/u/scm1001)\ **Post date:** [July 23, 2009, 11:29am UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/29 "2009-07-23T11:29:35Z")
> [@The\_Librarian](#): > > So you are saying that an egg is ‘hardboiled’ in exactly the same amount of time at 97 degrees celcius as on 100? > That doesn’t ring true. > > I would guess it takes 3% longer at the high altitude. NITPICK 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. ---
**Author:** ![Irishman](https://avatars.discourse-cdn.com/v4/letter/i/b487fb/32.png) [@Irishman](https://boards.straightdope.com/u/Irishman)\ **Post date:** [July 23, 2009, 1:37pm UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/30 "2009-07-23T13:37:16Z")
**Enright3** said: > [@](#): > > The first morning on the run, they each woke with a craving for hardboiled eggs. Since water boils at a lower temperature at higher altitudes, which of the two will get hardboiled eggs first? I would say the question is unanswerable. Who woke up first? 😉 **Yookeroo** said: > [@](#): > > 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 suspect that’s part of the distraction, the superfluous information used to keep you from figuring out what the problem really is. ---
**Author:** ![JerseyFrank](https://avatars.discourse-cdn.com/v4/letter/j/bcef8e/32.png) [@JerseyFrank](https://boards.straightdope.com/u/JerseyFrank)\ **Post date:** [July 23, 2009, 2:24pm UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/31 "2009-07-23T14:24:13Z")
> [@Yookeroo](#): > > 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? 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. If you’re a MindTrap fan, check out “[Professor Layton](http://en.wikipedia.org/wiki/Professor_Layton) [and the Curious Village](http://en.wikipedia.org/wiki/Professor_Layton_and_the_Curious_Village)” for Nintendo DS. There’s also [a sequel](http://en.wikipedia.org/wiki/Professor_Layton_and_the_Diabolical_Box) due out in late August if you have trouble finding the first one. 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. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [July 23, 2009, 2:31pm UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/32 "2009-07-23T14:31:11Z")
> [@Joe Frickin Friday](#): > > At the bottom of the trench, ambient pressure is around 15,000 psi. Weird things happen at these kinds of pressures. The [critical point](http://en.wikipedia.org/wiki/Critical_point_(thermodynamics)#Vapor-liquid_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,](http://en.wikipedia.org/wiki/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. 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. > [@Smeghead](#): > > Now, what if the water is being boiled on a treadmill at the bottom of the Marianas Trench? Once, for twenty minutes? ---
**Author:** ![WarmNPrickly](https://avatars.discourse-cdn.com/v4/letter/w/d78d45/32.png) [@WarmNPrickly](https://boards.straightdope.com/u/WarmNPrickly)\ **Post date:** [July 23, 2009, 2:46pm UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/33 "2009-07-23T14:46:04Z")
> [@Lumpy](#): > > 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. > Once, for twenty minutes? 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. ---
**Author:** ![GameHat](https://avatars.discourse-cdn.com/v4/letter/g/ed655f/32.png) [@GameHat](https://boards.straightdope.com/u/GameHat)\ **Post date:** [July 23, 2009, 6:29pm UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/34 "2009-07-23T18:29:17Z")
> [@CurtC](#): > > 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. 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](http://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 😃 ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [July 23, 2009, 7:28pm UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/35 "2009-07-23T19:28:22Z")
> [@Ruken](#): > > 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. “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](http://discovermagazine.com/2006/feb/cooking-for-eggheads/article_view?b_start:int=1&-C=). > [@Discover](#): > > About an hour later—timing isn’t critical, and the eggs can stay in the oven for hours or even overnight—he retrieves the first egg and carefully shells it. “The 65-degree egg!” he announces. The egg is unlike any I’ve eaten. The white is as delicately set and smooth as custard, and the yolk is still orange and soft. It’s not hard to see why l’oeuf à soixante-cinq degrés is becoming the rage with chefs in France. (The article has some poor coding so it doesn’t look right to me in IE 7.0.) ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 23, 2009, 7:33pm UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/36 "2009-07-23T19:33:44Z")
> [@](#): > > 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. 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. ---
**Author:** ![Enright3](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/enright3/32/2897_2.png) [@Enright3](https://boards.straightdope.com/u/Enright3)\ **Post date:** [July 28, 2009, 6:30pm UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/37 "2009-07-28T18:30:46Z")
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? ---
**Author:** ![Hilarity\_N.Suze](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hilarity_n.suze/32/6223_2.png) [@Hilarity\_N.Suze](https://boards.straightdope.com/u/Hilarity_N.Suze)\ **Post date:** [July 28, 2009, 6:43pm UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/38 "2009-07-28T18:43:29Z")
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. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [July 28, 2009, 6:45pm UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/39 "2009-07-28T18:45:21Z")
> [@Enright3](#): > > 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? 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. > [@](#): > > What would happen to water in space? Would cohesion exist or would the water just turn into mist? 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 dispersive[BLEVE](http://en.wikipedia.org/wiki/BLEVE); no cohesion of the whole body of water. ---
**Author:** ![Bosstone](https://avatars.discourse-cdn.com/v4/letter/b/22d042/32.png) [@Bosstone](https://boards.straightdope.com/u/Bosstone)\ **Post date:** [July 28, 2009, 6:49pm UTC](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811/40 "2009-07-28T18:49:23Z")
> [@Enright3](#): > > 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? Yep. [Here’s](http://www.newton.dep.anl.gov/askasci/chem99/chem99558.htm) the explanation of what happens to water in a vacuum, and [here’s](http://www.engineersedge.com/h2o_boil_pressure.htm) 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](http://en.wikipedia.org/wiki/InHg). 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. [Previous page](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811.md?page=1) [Next page](https://boards.straightdope.com/t/question-from-the-game-mindtrap-regarding-boiling-water-physics/503811.md?page=3)