The Student Room Group

Hotter the source, less the light emitted?

"Experimental science demonstrates that the purer the flame and the hotter the fire, the less light will be emitted from the fire."

Is this true or bunk?
Please explain (I'm not a physicist)
(edited 9 years ago)
Original post by NJA
"Experimental science demonstrates that the purer the flame and the hotter the fire, the less light will be emitted from the fire."

Is this true or bunk?
Please explain (I'm not a physicist)


You need to post the original source with context for an explanation.
For example, what do they mean by a "purer" flame.
Reply 2



Oh dear. I think I'll pass on this one.
Original post by NJA
"Experimental science demonstrates that the purer the flame and the hotter the fire, the less light will be emitted from the fire."

Is this true or bunk?
Please explain (I'm not a physicist)


Taking the same logical approach, heaven is full of light and therefore must be an extremely cold place.

A case of religion masquerading as psuedo-science.

SB is being the diplomat as ever!
Reply 5
Original post by uberteknik
Taking the same logical approach, heaven is full of light and therefore must be an extremely cold place.

A case of religion masquerading as psuedo-science.

No, the person is quoting something in an attempt to explain an obscure text.

If you are a real scientist please shed what light you have on the matter instead of this noise/heat!
Original post by NJA
No, the person is quoting something in an attempt to explain an obscure text.

If you are a real scientist please shed what light you have on the matter instead of this noise/heat!


Since this is a physics study help forum, I will decline to answer here. If you care to post in the religious forum, that will be a different matter entirely.
Reply 7
I'm not really sure what they mean. Visible light?

You might say that when you have a bunsen burner on safety the fire is "brighter". This is a "cooler" fire that releases less heat than it's hotter, dimmer, blue counterpart. Who knows?
Original post by Stonebridge
Oh dear. I think I'll pass on this one.


LOL xD
Original post by NJA
"Experimental science demonstrates that the purer the flame and the hotter the fire, the less light will be emitted from the fire."

Is this true or bunk?
Please explain (I'm not a physicist)


Surely the hotter the object, the more wavelengths of visible light it emits.
A white glowing object is very hot.

Maybe the hotter the fire, the more wavelengths of visible light is emitted, we can only see the transition from red to white.
So if an object is even hotter than this, it may emit wavelengths in the gamma and x-ray region, which we cannot see...
So yes, hotter the object less visible light is emitted.
(edited 9 years ago)
Well, if we take the example of stars, we find that blue stars are hotter than white stars, but that's because the spectrum 'shifts' as such (more high frequency light such as UV is produced), so this only applies when referring to visible light.

However, I think it's rather evident that your source is bending the facts to the scripture (as opposed to the scientific methods), and it is poorly referenced so I'd dismiss it if you can't find other sources.
Reply 11
OK students of physics.
I asked the same question on Yahoo Answers and got what seem to me to be good answers.

Any comment?
Original post by NJA
OK students of physics.
I asked the same question on Yahoo Answers and got what seem to me to be good answers.

Any comment?


Yes, age 49, you should have better things to do.
Original post by NJA
OK students of physics.
I asked the same question on Yahoo Answers and got what seem to me to be good answers.

Any comment?
It's the statemnents 'religious' connotation which is deterring people. Yahoo patrons do not have the knowledge of TSR's religious forum history. lol!

What the heck, I rescind my original decline. :colone:

The problem is with the statement. It uses words which are far too vague to give an answer without forcing the use of assumptions about certain words: Purer, flame, light and the definition of heat.

e.g. :

Purity can apply to flame colour (wavelength range of the light emitted), as well as combustion efficiency if produced by an oxidation chemical reaction, etc.

Flame implies light produced by burning and burning can be produced (not exclusively) by an oxidation reaction with air. The reaction can be slow as in smouldering or rapid as in explosive.

Light can be described by both electromagnetic waves or as photon particles. Both exhibit different behaviour as observed in quantum mechanics and observations can be contradictory depending on the conditions of the experiment.

The human eye is receptive to a very narrow range of light. Flames can be classed as hot or cool, both of which will produce the 'effect' of reducing light output (but not necessarily heat) as perceived by the human eye and skin:

At the cool end of the light spectrum, the light tends to infra-red which is felt as heat (human sense) as well as seen. Infra-red can still be felt as strong heat long after the flame has extinguished. (A hot radiator will burn even though there is no flame).

The statement starts with 'Experimental science demonstrates'. This is an invitation for scientists to request disclosure of the reference source of the experiments for dissection and validation.

Physics does not like dealing with assumption.

The original statement is therefore vague and can be interpreted in too many ways to give a definitive answer.

Which is why Stonebridge requested clarification and why there will be a reticence to reply given that any comment made can be validated or refuted depending on the assumptions made about the original statement.
(edited 9 years ago)
Reply 14
Original post by Zenarthra
Yes, age 49, you should have better things to do.


So 49-year olds shouldn't take an interest in physics?

What should I be doing with my spare time?

What do you imagine you will be doing at that age?
Original post by NJA
So 49-year olds shouldn't take an interest in physics?

What should I be doing with my spare time?

What do you imagine you will be doing at that age?


I usually respect my elders, but just some words you used seemed quite demanding.
I am not here to argue so, i apologize for my response. :biggrin:

And to answer your questions, you should definitely take an interest in Physics its great! :smile:
And maybe you could play golf of something, and elders should sleep more. xD
At that age, hopefully ill be quite rich so i can do alot of charity work to help others in need. :smile:

Any how, uberteknik and Stonebridge are the experts to ask here. :biggrin:
(edited 9 years ago)
Reply 16
Original post by Zenarthra
I usually respect my elders, but just some words you used seemed quite demanding.
I am not here to argue so, i apologize for my response. :biggrin:

And to answer your questions, you should definitely take an interest in Physics its great! :smile:
..

I forgive you, I can be bolshie at times.
I may play gold when I'm too decrepit to do anything else.

Quick Reply

Latest