Originally Posted by asgelle

Not quite. Air being a poor conductor of heat, your skin remains close to body temp in the oven. The pot being a good conductor raises the skin temperature almost immediately. The difference in how the two situations feel is a result of the difference in skin temperature. We know the skin temps are different because for the pot there is cell damage from the high skin temperature. In air, there is no immediate damage because skin temperature remains low at least for a while.

Originally Posted by genejockey

If a cyclist wears Rapha but nobody can see the stripe, is is still elitist?

Originally Posted by MinnMan

I profess no expertise regarding thermoreceptors, so unlike others here, I won't comment where I don't have expertise.

Originally Posted by genejockey

And yet, somehow, you did.

Originally Posted by MinnMan

Considering the embarrassing things you've written in this thread, it doesn't seem wise for you to be picking another fight.

Originally Posted by genejockey

You mean like when I said that reducing the amount of an insulating substance with high specific heat capacity would improve cooling because you don't have to cool it, too? Lordy, however will I live that down?

Originally Posted by MinnMan

That's an excellent example. The part about "you don't have to cool it down" proves that you know nothing about heat transfer.

Originally Posted by genejockey

Hmmmmm. Let's see whether that's true. Does the layer of sweat on the skin stay the same temperature as the water evaporates off the surface? Or does its temperature fall?



What do you suppose "the energy needed to change the temperature of water" meant?



Hmmm. But if someone makes the observation that wiping the sweat off his face makes his skin feel cooler, and your calculation doesn't explain why, is the flaw in the observation or the calculation? That is, If your hypothesis doesn't explain an observation, is your hypothesis actually adequate to the situation?

Originally Posted by MinnMan

I would think that it might have occurred to you that other people on this thread, and reading this thread, have a more formal background and that you might consider the shocking hypothesis that you are missing some understanding. But unfortunately, there are millions like you.

Originally Posted by MoAlpha

1. I submit that the only way a base layer can keep you cooler is by facilitating evaporation.
2. I further submit that only way to do that is
a. to increase the surface area over which evaporation can take place, i.e., by more efficiently diffusing moisture over the surface, or
b. by facilitating transport of moisture from the skin to the surface.

Originally Posted by Dean V

I can't see how this is even a discussion.
Forget the science. You don't need it.
Go for a ride on a hot day with a base layer on. Remove it mid ride and see if it is cooler.
I have always found it to be cooler without it.
Has anyone found otherwise? I am not talking about theory, but personal experience.
Anyone ever seen a Pro racing on a hot day wearing a base layer?

Originally Posted by MinnMan

Look, this is just sad. You have no technical expertise. You cannot distinguish calculation from "belief". You think that making stuff up based on your intuition is the same as studying a topic and having quantitative mastery over it. You ridicule people who point you to rigorous sources.

I would think that it might have occurred to you that other people on this thread, and reading this thread, have a more formal background and that you might consider the shocking hypothesis that you are missing some understanding. But unfortunately, there are millions like you.

Originally Posted by genejockey

That actually IS the Science. Promulgate an hypothesis, test the hypothesis. If the test doesn't disprove the hypothesis, it's likely to be right.

Originally Posted by WhyFi

Lookit that - we've covered the heat transference of sweating and the heat generation of pissing matches! Ya gotta love multi-tasking.

Originally Posted by guadzilla

Do pissing matches cool you, though? And would the heat radiating off the urine compensate for the heat that you have just expelled from your body?

Originally Posted by genejockey

that actually is the science. Promulgate an hypothesis, test the hypothesis. If the test doesn't disprove the hypothesis, it's likely to be right.

Originally Posted by Dean V

This is a rather dubious statement.
But putting that aside how about answering the OP?
Has anyone put a base layer on under their cycling top and thought it was cooler?
If so then maybe a bit of science could be justified in explaining how this might happen (if anyone cares).

Originally Posted by guadzilla

Do pissing matches cool you, though? And would the heat radiating off the urine compensate for the heat that you have just expelled from your body?

Originally Posted by asgelle

Not quite. Air being a poor conductor of heat, your skin remains close to body temp in the oven. The pot being a good conductor raises the skin temperature almost immediately. The difference in how the two situations feel is a result of the difference in skin temperature. We know the skin temps are different because for the pot there is cell damage from the high skin temperature. In air, there is no immediate damage because skin temperature remains low at least for a while.

Originally Posted by MinnMan

This isn't wholly true. I profess no expertise regarding thermoreceptors, so unlike others here, I won't comment where I don't have expertise. But regarding your oven analogy, whereas it is true that the temperature of the air and the temperature of the hot pot are the same, the nerves are not feeling the temperature of the external world. They are feeling the temperature at the nerve ending, inside your skin. The reason that you feel the greater signal from the pot is this case results in a larger increase in the temperature of the nerve ending - by the more rapid process of conduction from the steel handle.

Additionally, the process of heating from the hot oven air is still conduction, not convection. Convection requires that the air be in motion, but even if the air is stationary, you will feel the heating effect of the air. the reason you feel less of an effect is the vast difference in thermal conductivities of the two materials - air versus steel.

Additionally, for materials with the same thermal diffusivity, convection is MORE efficient at heat transfer than conduction. Here, its the difference in thermal properties between the materials that matters, not the heat transfer mechanism

Note that if you juxtapose two objects at a different temperature with one another (i.e, your cool hand and hot oven air, or your cool hand and hot pot handle), the instantaneous temperature at the interface at time = 0 is always half the difference (T1+T2)/2. So your hand does not feel the the exterior temperature instantaneously. In the case of contact with an excellent conductor, this changes - FAST.

Originally Posted by genejockey

That actually IS the Science. Promulgate an hypothesis, test the hypothesis. If the test doesn't disprove the hypothesis, it's likely to be right.