How to measure 35 million Celsius?

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This topic has been posted but me and another fellow are curious how such a temperature can be measured. I think I know but I cannot explain it. I think it has to do with measurable "safe" distances then using math to determine the core temperature.

a reply to: Gyo01

Easy, they measure the heat by checking what's the spectral frequency (colour) it emits.

Take for instance a flame. The hotter areas of a flame are blue, the cooler areas are red. We can extrapolate the temperature of objects by the frequency of the light they emits - even hotter than a flame (over 10,000 Kelvins) will give off ultraviolet radiation; even hotter than all that (around 10 millions Kelvin) will give off X-rays; and yet even hotter will give off gamma rays.

a reply to: swanne

Thanks.

a reply to: Gyo01

Anytime mate! BTW I love your avatar!

originally posted by: swanne
a reply to: Gyo01

Easy, they measure the heat by checking what's the spectral frequency (colour) it emits.

Take for instance a flame. The hotter areas of a flame are blue, the cooler areas are red. We can extrapolate the temperature of objects by the frequency of the light they emits - even hotter than a flame (over 10,000 Kelvins) will give off ultraviolet radiation; even hotter than all that (around 10 millions Kelvin) will give off X-rays; and yet even hotter will give off gamma rays.

The spectral frequency does give an indication of blackbody temperature of an ideal blackbody. If you had an ideal blackbody that would be a good way to measure temperature, but the fusion reactor isn't an ideal blackbody, so there are other methods used in addition to measuring spectral frequency distribution.

If you put a thermometer in water, and it doesn't have many impurities, it's mostly water molecules bouncing against the thermometer and they all have different energies in a distribution but any molecules with way higher or lower energy than the rest will tend to move toward the average.

Plasma temperature is different because you've got a huge mass difference between the electrons and the ionized nuclei so the electrons can and will move a lot faster, so you could say the electrons have a higher temperature than the ionized nuclei, thus there are at least two different temperatures. Because of the physics involved in measuring them, researchers don't use a single measurement to determine both temperatures, they use multiple types of measurements from different types of "thermometers" as described here.

This diagram shows the 4 different types of thermometers used in an actual fusion experiment:

A stripped-back model of the JET experiment, showing only the temperature-measuring systems.

-Electron cyclotron emission (pale purple),
-LIDAR / Thomson scattering (red),
-charge exchange (bright green), and
-X-ray spectroscopy (pale green).

These technologies get a little technical and are explained in the article, but the LIDAR is kind of like the "speed guns" use to measure the speed of motorists, ok not exactly like that, but it's a similar concept and it only works on the electrons so they need other thermometers to measure the nuclei. I tried to find a simplified source to explain it, but it's still a little technical.

originally posted by: swanne
a reply to: Gyo01

Easy, they measure the heat by checking what's the spectral frequency (colour) it emits.

Take for instance a flame. The hotter areas of a flame are blue, the cooler areas are red. We can extrapolate the temperature of objects by the frequency of the light they emits - even hotter than a flame (over 10,000 Kelvins) will give off ultraviolet radiation; even hotter than all that (around 10 millions Kelvin) will give off X-rays; and yet even hotter will give off gamma rays.

Thus the fallacy of science.

originally posted by: odzeandennz

originally posted by: swanne
a reply to: Gyo01

Easy, they measure the heat by checking what's the spectral frequency (colour) it emits.

Take for instance a flame. The hotter areas of a flame are blue, the cooler areas are red. We can extrapolate the temperature of objects by the frequency of the light they emits - even hotter than a flame (over 10,000 Kelvins) will give off ultraviolet radiation; even hotter than all that (around 10 millions Kelvin) will give off X-rays; and yet even hotter will give off gamma rays.

Thus the fallacy of science.

"...scientists are condemned by their unexamined assumptions to study the nature of mirrors only by cataloging and investigating everything that mirrors can reflect. It is an endless process that never makes progress, that never reaches closure, that generates endless debate between those who have seen different reflected images, and whose enduring product is voluminous descriptions of particular phenomena." - The Adapted Mind

In a nutshell and to put this in a more tenable framework, extreme heat of this nature produces a great deal more than the ratio of infra-red energy you would measure at temperatures near the melting points of iron. The extra energy of course, comes out of the system, so what we call heat, or infra-red, is no longer measurable as a linear effect at extreme temperatures such as 35 million Celsius . The infra-red energy level changes in proportion to the increased production of X-Rays, Ultraviolet and Gamma Rays. It kind of re-defines what we normally think of as heat, even though they are all forms of heat.

a reply to: namelesss

On the other hand, here's the complete list of functioning technology given to us by meditation and spirits:

A fifth way of measuring electron temperature in a plasma is to scan it with radio waves up and down the spectrum, you'll get reflections back at various frequencies that will tell you the electron temperature.

The plasma electron temperature and the frequency of radio waves reflected are linked. It's how you build an ionospheric radio mirror.

originally posted by: Bedlam
a reply to: namelesss

On the other hand, here's the complete list of functioning technology given to us by meditation and spirits:

I didn't say anything about 'meditation' or 'spirits', but, it wouldn't take much to prove your premature and ignorant dismissal completely wrong about 'meditation'.

originally posted by: namelesss

originally posted by: Bedlam
a reply to: namelesss

On the other hand, here's the complete list of functioning technology given to us by meditation and spirits:

I didn't say anything about 'meditation' or 'spirits', but, it wouldn't take much to prove your premature and ignorant dismissal completely wrong about 'meditation'.

Let's see it then.

The criticism from "the Adapted Mind" is the usual drivel of someone who knows nothing about how science works.

I guarantee you any sophomore physics student can tell you more about mirrors than every guru spouting inane crap.

Subjective internal examination of your navel doesn't build semiconductors.

a reply to: Gyo01

By how fast it would cook an order of chicken wings?



Wrong answer!

originally posted by: Bedlam
Let's see it then.

The criticism from "the Adapted Mind" is the usual drivel of someone who knows nothing about how science works.

I guarantee you any sophomore physics student can tell you more about mirrors than every guru spouting inane crap.

Subjective internal examination of your navel doesn't build semiconductors.

I think that your sarcastic (comes from fear) 'challenge' to make you aware of the deeper things in life would be wasted time.
I really don't care what you think, and I won't rise to your sarcastic and dismissive bait.
You have your Perspective, enjoy it.
Had you demonstrated any capacity or "willingness" to learn/understand, perhaps I might have shared a bit, but...
I think not. And your ignorant 'guarantees' mean nothing to me.
Yeah, it's all hocus-pocus.
Peace...

originally posted by: namelesss

I think that your sarcastic (comes from fear) 'challenge' to make you aware of the deeper things in life would be wasted time.

How do you know they're 'deeper'?

Maybe they're 'illusory'.

That's the problem with subjective issues. You can never know if it's just mental masturbation or not. I go by results. And "revealed truth" topics like religion, under any guise you want to cast it, are generally in the class of things that by their very nature can never produce tangible results. Including meditation and the like.

originally posted by: swanne
a reply to: Gyo01

Easy, they measure the heat by checking what's the spectral frequency (colour) it emits.

Take for instance a flame. The hotter areas of a flame are blue, the cooler areas are red. We can extrapolate the temperature of objects by the frequency of the light they emits - even hotter than a flame (over 10,000 Kelvins) will give off ultraviolet radiation; even hotter than all that (around 10 millions Kelvin) will give off X-rays; and yet even hotter will give off gamma rays.

I'm pretty sure White is hotter than blue.

originally posted by: Bedlam

originally posted by: namelesss

I think that your sarcastic (comes from fear) 'challenge' to make you aware of the deeper things in life would be wasted time.

How do you know they're 'deeper'?

Maybe they're 'illusory'.

That's the problem with subjective issues. You can never know if it's just mental masturbation or not. I go by results. And "revealed truth" topics like religion, under any guise you want to cast it, are generally in the class of things that by their very nature can never produce tangible results. Including meditation and the like.

ah there it is right there. 'Illusory'.

a reply to: Encryptor

Don't get me wrong, I meditate to clear pointless crap out of my head. Like when you're working on a dozen things, finish half of them, and find your mind's still wasting cycles solving things you've moved on from.

I see it as sort of like doing a reboot on the OS. But it's more of a way to get all your horses back in the corral than it is an analytical tool.

a reply to: Encryptor

and it's the daily double!

originally posted by: Bedlam
a reply to: Encryptor

Don't get me wrong, I meditate to clear pointless crap out of my head. Like when you're working on a dozen things, finish half of them, and find your mind's still wasting cycles solving things you've moved on from.

I see it as sort of like doing a reboot on the OS. But it's more of a way to get all your horses back in the corral than it is an analytical tool.

That totally resonates.