Hot water freezes faster than cold water (Mpemba Effect)

http://math.ucr.edu/home/baez/physics/General/hot_water.html

by smanek • 18 years ago

27 15 18 years ago

math.ucr.edu

ObieJazz• 18 years ago

And yet, cold water doesn't boil faster than hot water. Weird.

bdotdub• 18 years ago

Man, everything I did for my third grade science experiment was a lie. Sorry Ms. Mariano

cjc• 18 years ago

Except under very specific conditions, this is NOT TRUE.

Do not fill your ice cube trays with hot water thinking it will freeze faster.

adamc• 18 years ago

Sure, but the fact that it ever happens is fascinating.

ars2• 18 years ago

Are you sure about that? Maybe I should try it. The article certainly contradicts you.

delackner• 18 years ago

Indeed, cjc sounds like someone who has already tried this at home, right? What circumstances are different between ice cube trays and ice cream mixture? High surface area comes to mind. In the article the experiments described all involve volumes of water (or ice cream goo) that are in containers with low surface area to volume. SA and Volume do not scale linearly, thus the heat exchange rate would be faster for the ice cube trays. Of course, TRYING it out would not hurt. Several hundred years worth of scientists seem to have laughed at previous experimental results out of some egotistical belief that experimental results passed down from history are fairy tales.

aebj• 18 years ago

oh i will like i care what you say dumbo!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

sharkfish2• 18 years ago

My father showed me how much faster hot water freezes in an experiment we did when I was a kid. How many of us owe our fathers for what seems to be innate curiosity now that we are adults :)

whacked_new• 18 years ago

And/or you inherited the curiosity trait.

ars2• 18 years ago

I fall on the side of nurture with regard to curiosity. _Everybody_ has "the curiosity trait", but in some environments it's discouraged: "Stop asking so many questions.", or "I don't know and why do you care?", or simply giving wrong answers.

sharkfish2• 18 years ago

Or the "prove your mom wrong" trait. That seemed to be his motivation, heh-heh.

maximilian• 18 years ago

I've done it a bunch of times and never had hot water freeze faster. How did you (or your dad) set it up?

ujeezy• 18 years ago

Boiled water freezes faster because the impurities have been burned out

sniemyski2• 18 years ago

many people think many things. im doing this 4 a science project and so far hot water freezes faser then cold water except on artical

sniemyski2• 18 years ago

many people think many things. im doing this 4 a science project and so far hot water freezes faser then cold water except on artical

Hot water freezes faster than cold water (Mpemba Effect)

Related Stories