It’s True: Hot Water Really Can Freeze Faster Than Cold Water

[The Straight Story]

It’s True: Hot Water Really Can Freeze Faster Than Cold Water

Hot water really can freeze faster than cold water, a new study finds. Sometimes. Under extremely specific conditions. With carefully chosen samples of water.

sciencenewsNew experiments provide support for a special case of the counterintuitive Mpemba effect, which holds that water at a higher temperature turns to ice faster than cooler water.

The Mpemba effect is named for a Tanzanian schoolboy, Erasto B. Mpemba, who noticed while making ice cream with his classmates that warm milk froze sooner than chilled milk. Mpemba and physicist Denis Osborne published a report of the phenomenon in Physics Education in 1969. Mpemba joined a distinguished group of people who had also noticed the effect: Aristotle, Francis Bacon and René Descartes had all made the same claim.

On the surface, the notion seems to defy reason. A container of hot water should take longer to turn into ice than a container of cold water, because the cold water has a head start in the race to zero degrees Celsius.

But under scientific scrutiny, the issue becomes murky. The new study doesn’t explain the phenomenon, but it does identify special conditions under which the Mpemba effect can be seen, if it truly exists.

“All in all, the work is a nice beginning, but not systematic enough to do more than confirm it can happen,” comments water expert David Auerbach, whose own experiments also suggest that the effect does occur.

Read More http://www.wired.com/wiredscience/2010/03/icy-hot/#ixzz0j7fRSu88

[CTyankee]

1. ANd I used to laugh back in the day when people put hot water in their ice cube trays

because they'd "freeze faster." It never made sense to me...

[meegbear]

2. I think these people should've used the grant money to buy The Straight Dope ...

Which freezes faster, hot water or cold water?

[HughMoran]

6. Mixed results there as well

:shrug:

[ashling]

3. I always get annoyed when Alton Brown says that the roast will

get hotter AFTER you remove it from the oven. I don't question it - it is sacriligious to question Alton Brown - I just wish it wasn't so damn counter-intuitive or, should I say:

kitchen counter intuitive







no, I guess I probably shouldn't say that

:rofl:

[ashling]

4. I always get annoyed when Alton Brown says that the roast will

get hotter AFTER you remove it from the oven. I don't question it - it is sacriligious to question Alton Brown - I just wish it wasn't so damn counter-intuitive or, should I say:

kitchen counter intuitive







no, I guess I probably shouldn't say that

:rofl:

[ret5hd]

5. especially not twice.

[ashling]

7. Sorry,

must be the cooking wine :shrug: