Exactly why does water cool down so much slower than it heats up?
Asked by:
Seamus Hodgkinson
Answer
Water cools down and heats up at exactly the same rate under ideal conditions.
The specific heat capacity of water is 4200 J/KG/C. That is, it takes 4200 Joules to raise the temperature of 1Kg of water by 1 degree Celsius.
Conversely, the water must lose 4200 Joules of energy to cause a drop in temperature of 1 degree in 1Kg of water.
Water may seem to cool down much slower than it heats up because the heating up is an active process. I.e., when heating up water, you are putting it on a heat source which gives out a lot of energy in a short space of time. If you were able to create a 'cold' source which extracted energy at a similar rate, the temperature would drop just as quickly.
Answered by:
James Kilner, Music Technology, University of York (England)
'The strength and weakness of physicists is that we believe in what we can measure. And if we can't measure it, then we say it probably doesn't exist. And that closes us off to an enormous amount of phenomena that we may not be able to measure because they only happened once. For example, the Big Bang. ... That's one reason why they scoffed at higher dimensions for so many years. Now we realize that there's no alternative... '