On Sunday, 25 September 2016 16:52:23 UTC+1, Alan LeHun wrote:
In article ,
says...
If you place your finger below a kettle, to prevent it being affected by convection, it will feel warm because of the warm radiation, and if you place it above and ice cube it will feel cold because of the cold radiation.


No. It will feel cold because of the lack of warm radiation.

If the level of radiation that your finger is receiving is greater than
the level it is emitting, your finger will (feel) warm. Conversely, if
your finger is emitting more energy than it is receiving, it will (feel)
cool.

I thought we had cleared this up last time.

Your cold radiation and your warm radiation are the same thing. They are
just at different energy levels.

--
Alan LeHun

Hot water and cold water are the same thing. That does not mean cold water does not exist.

On 26/09/2016 16:05, Alastair wrote:
On Sunday, 25 September 2016 16:52:23 UTC+1, Alan LeHun wrote:
In article ,
says...
If you place your finger below a kettle, to prevent it being affected by convection, it will feel warm because of the warm radiation, and if you place it above and ice cube it will feel cold because of the cold radiation.


No. It will feel cold because of the lack of warm radiation.

If the level of radiation that your finger is receiving is greater than
the level it is emitting, your finger will (feel) warm. Conversely, if
your finger is emitting more energy than it is receiving, it will (feel)
cool.

I thought we had cleared this up last time.

Your cold radiation and your warm radiation are the same thing. They are
just at different energy levels.

--
Alan LeHun

Hot water and cold water are the same thing. That does not mean cold water does not exist.


What a strange argument.

In hot water, the molecules are moving faster than in cold water.
Therefore, for cold water to 'radiate' cold, that would require an input
of energy - where would than come from...

--

Paul Hyett, Cheltenham

On Monday, 26 September 2016 16:34:38 UTC+1, vidcapper wrote:

Hot water and cold water are the same thing. That does not mean cold water does not exist.


What a strange argument.

In hot water, the molecules are moving faster than in cold water.
Therefore, for cold water to 'radiate' cold, that would require an input
of energy - where would than come from...

--

Paul Hyett, Cheltenham

Hot molecules have no input of energy. Why do cold molecules need one?

The cold molecules are still moving and that provides the energy for them to radiate, just as it does for hot molecules. Put them in space and they would lose all that energy and cool until they reached absolute zero. Well, actuallly the temperature of the background cosmic radiation.

It has been known since the 18th Century that all bodies radiate. It just that cold bodies radiate less energy than hot ones. You do know that don't you?

On 26/09/2016 06:22, wrote:


Mockery? Hardly. It's simply astonishment and laughter from those of us that see Alastair proposing to change the laws of physics to suit his beliefs.
When his arguments fail - as, of course, they always do - he takes the
sulk road and attempts to end the conversation because he feels he's
being picked on,
as no-one believes him. It's happened every single time he's proposed
cold radiation. Oddly, people really do laugh then!

Well mockery means much the same as ridicule and you seem to advocate
that. I wouldn't mock/ridicule anybody for their beliefs, no matter how
outlandish I might find them. I have talked to Christians and discussed
what they believe and although I might strongly disagree with it I would
never just point and laugh. That's says far more about you than the
person you are mocking.

I don't however understand Alastairs's behaviour though, this thread
popped up again out of nowhere and he could have ignored it. People
(especially Asha) have attempted to debate with him reasonably, and most
certainly not abusively, yet he still flounces off.

--
Col

Bolton, Lancashire
160m asl
Snow videos:
http://www.youtube.com/channel/UC3QvmL4UWBmHFMKWiwYm_gg

On Monday, 26 September 2016 12:43:48 UTC+1, Alastair wrote:
Dawlish discussed the science for once and brought a point which I think is what is confusing everyone.

He wrote "'...heat *always* flows spontaneously from hotter to colder bodies, and *never* the reverse, unless external work is performed on the system'

https://en.wikipedia.org/wiki/Second_law_of_thermodynamics#Intuitive_meaning_of_ the_law"

But the sentence actually reads "FOR EXAMPLE, heat always flows spontaneously from hotter to colder bodies ...". That is not a statement of the second law, it is an example. Another example is that cold always flows from a colder to a hotter body unless external work is performed on the system e.g a refigerator.

Putting it another way hot objects always cool and cold objects always warm e.g, cup of coffeee and an ice cube. But hot cups of coffe are so common it is easy to forget about cold ice cubes. (Thanks Asha for reminding me.)

Moreover, as I have already explained, the difference in temperature between and ice cube and room temperature is much less than that between a boiling kettle and room temperature. It is only when you have a tray of ice cubes and you use the back of your hand that you can sense the cold radiation.

Pictet used a sensitive air thermometer and had cooled his ice with nitric acid when he discovered cold radiation. Count Rumford, the famous physicist, could not reproduce the experiment until he was shown how in Edinburgh.

Utter bilge. The net flow is always from warmer to cooler. Get a grip.

On 26/09/2016 09:05, David Mitchell wrote:
I have every sympathy with Alistair on this. Science, physics, whatever have their place and can't be argued with on this issue. (But should really, as that's what science is about).

However, sometimes in life there are ways of explaining things that challenge the accepted definition and I totally understand his point and it's actually a very interesting idea. Wrong but interesting. But it actually gets the point across well.

I'm pretty sure that last time this was discussed I drew an analogy with
phlogiston:
https://en.wikipedia.org/wiki/Phlogiston_theory
Quite an elegant theory that explained the experimental results but
ultimately turned out to be back to front, when materials burned they
didn't lose phlogiston, but *gained* oxygen!

Scientists will not comprehend that at all, but those with open minds will get it.

Incidentally, I have cold radiators.



--
Col

Bolton, Lancashire
160m asl
Snow videos:
http://www.youtube.com/channel/UC3QvmL4UWBmHFMKWiwYm_gg

On Monday, 26 September 2016 12:43:48 UTC+1, Alastair wrote:

The difference in temperature between and ice cube and room temperature is much less than that between a boiling kettle and room temperature. It is only when you have a tray of ice cubes and you use the back of your hand that you can sense the cold radiation.

Pictet used a sensitive air thermometer and had cooled his ice with nitric acid when he discovered cold radiation. Count Rumford, the famous physicist, could not reproduce the experiment until he was shown how in Edinburgh.

We are not discussing temperature. You began this thread dicussing heat content and radiation.
How much heat is required to produce steam from ice at 0C?

On Monday, 26 September 2016 18:50:02 UTC+1, wrote:
On Monday, 26 September 2016 12:43:48 UTC+1, Alastair wrote:
Dawlish discussed the science for once and brought a point which I think is what is confusing everyone.

He wrote "'...heat *always* flows spontaneously from hotter to colder bodies, and *never* the reverse, unless external work is performed on the system'

https://en.wikipedia.org/wiki/Second_law_of_thermodynamics#Intuitive_meaning_of_ the_law"

But the sentence actually reads "FOR EXAMPLE, heat always flows spontaneously from hotter to colder bodies ...". That is not a statement of the second law, it is an example. Another example is that cold always flows from a colder to a hotter body unless external work is performed on the system e..g a refigerator.

Putting it another way hot objects always cool and cold objects always warm e.g, cup of coffeee and an ice cube. But hot cups of coffe are so common it is easy to forget about cold ice cubes. (Thanks Asha for reminding me.)

Moreover, as I have already explained, the difference in temperature between and ice cube and room temperature is much less than that between a boiling kettle and room temperature. It is only when you have a tray of ice cubes and you use the back of your hand that you can sense the cold radiation.

On Monday, 26 September 2016 18:59:32 UTC+1, Col wrote:
On 26/09/2016 09:05, David Mitchell wrote:
I have every sympathy with Alistair on this. Science, physics, whatever have their place and can't be argued with on this issue. (But should really, as that's what science is about).

However, sometimes in life there are ways of explaining things that challenge the accepted definition and I totally understand his point and it's actually a very interesting idea. Wrong but interesting. But it actually gets the point across well.

I'm pretty sure that last time this was discussed I drew an analogy with
phlogiston:
https://en.wikipedia.org/wiki/Phlogiston_theory
Quite an elegant theory that explained the experimental results but
ultimately turned out to be back to front, when materials burned they
didn't lose phlogiston, but *gained* oxygen!

Yes and your thinking is still dominated with the idea that heat is like caloric. The theory that had to be abandoned when Pictet discovered cold radiation.

On Monday, 26 September 2016 18:33:35 UTC+1, Col wrote:
On 26/09/2016 06:22, wrote:


Mockery? Hardly. It's simply astonishment and laughter from those of us that see Alastair proposing to change the laws of physics to suit his beliefs.
When his arguments fail - as, of course, they always do - he takes the
sulk road and attempts to end the conversation because he feels he's
being picked on,
as no-one believes him. It's happened every single time he's proposed
cold radiation. Oddly, people really do laugh then!

Well mockery means much the same as ridicule and you seem to advocate
that. I wouldn't mock/ridicule anybody for their beliefs, no matter how
outlandish I might find them. I have talked to Christians and discussed
what they believe and although I might strongly disagree with it I would
never just point and laugh. That's says far more about you than the
person you are mocking.

I don't however understand Alastairs's behaviour though, this thread
popped up again out of nowhere and he could have ignored it. People
(especially Asha) have attempted to debate with him reasonably, and most
certainly not abusively, yet he still flounces off.

Col,

I responded to Asha because she said she was not taking sides and I assumed she had an open mind. But it became clear that she wanted me to choose between two questions, which if I answered yes to either would have made me appear a fool, much like the old standard. "Have you stopped beating your wife yet?" If you answer yes or no you are still admitting you are a wife beater.

Not content with employing the fallacy of the excluded middle https://en.wikipedia.org/wiki/False_dilemma she then accused me of not understanding logic. It was obvious to me that wasn't going to give me any credit for my knowledge logic or science so it seemed poitless to continue into a slanging match. Is that so bad?

Anyway I am about to flounce off again. We are now off the topic of cold radiation, and I have better things to do with my time than respond to insults such as "flouncing off."