… and how reliable is this measurement and/or calculation?

Modelling.

Directly we measure the e/m output, the alpha particle, neutrino output, beta particle, hydrogen output, its rotational speed and the amount of turbulence it experences, the dimensions and shape of its atmosphere down to the photosphere, we know its mass and the movement of its axis and its magnetic field. Observations of other stars gives us an idea of its past and future. We know from our direct experiments about quantum mechanics and hydrodynamics and thermodynamics and turbulence and gravitation and chemistry.

So yeah: iteratively model the inputs until you’ve matched the output, same as any modelling.

An overview of the history of the standard solar model.
https://arxiv.org/pdf/astro-ph/0209080.pdf

How accurate? Well how would we know. A good boost to the confidence in the SSM came with the advent of neutrino detection, as the output matched what was “predicted” by the SSM even though that was not part of the information used to develop the model.

dv said:

Modelling.

Directly we measure the e/m output, the alpha particle, neutrino output, beta particle, hydrogen output, its rotational speed and the amount of turbulence it experences, the dimensions and shape of its atmosphere down to the photosphere, we know its mass and the movement of its axis and its magnetic field. Observations of other stars gives us an idea of its past and future. We know from our direct experiments about quantum mechanics and hydrodynamics and thermodynamics and turbulence and gravitation and chemistry.

So yeah: iteratively model the inputs until you’ve matched the output, same as any modelling.

An overview of the history of the standard solar model.
https://arxiv.org/pdf/astro-ph/0209080.pdf

How accurate? Well how would we know. A good boost to the confidence in the SSM came with the advent of neutrino detection, as the output matched what was “predicted” by the SSM even though that was not part of the information used to develop the model.

Thanks for that.

The question was prompted by reading that photons from the Sun take up to a million years (or more) to reach the surface, which made me wonder how you’d go about calculating the temperature when you have to take effects of that magnitude into account.

We know the coldest temperature it is possible to reach, but is there a hottest temperature?

PermeateFree said:

We know the coldest temperature it is possible to reach, but is there a hottest temperature?

There is no widely accepted hottest temperature.

dv said:

PermeateFree said:

We know the coldest temperature it is possible to reach, but is there a hottest temperature?

There is no widely accepted hottest temperature.

It is not uncommon for scientists to claim in their experiments that temperature measured far exceeding the temperature of the sun. How is this possible?

PermeateFree said:

dv said:

PermeateFree said:

We know the coldest temperature it is possible to reach, but is there a hottest temperature?

There is no widely accepted hottest temperature.

It is not uncommon for scientists to claim in their experiments that temperature measured far exceeding the temperature of the sun. How is this possible?

Isn’t it inside particle accelerators and involves just a few particles colliding creating the temperatures

PermeateFree said:

dv said:

PermeateFree said:

We know the coldest temperature it is possible to reach, but is there a hottest temperature?

There is no widely accepted hottest temperature.

It is not uncommon for scientists to claim in their experiments that temperature measured far exceeding the temperature of the sun. How is this possible?

The sun is not that hot, in the scheme of things. 15 million K or so.
Hadron colliders routinely create temperatures over a trillion K.

dv said:

PermeateFree said:

dv said:

There is no widely accepted hottest temperature.

It is not uncommon for scientists to claim in their experiments that temperature measured far exceeding the temperature of the sun. How is this possible?

The sun is not that hot, in the scheme of things. 15 million K or so.
Hadron colliders routinely create temperatures over a trillion K.

Gosh, their measuring equipment must be of another factor.

The Rev Dodgson said:

… and how reliable is this measurement and/or calculation?

The name you want is Bahcall.

The solar neutrino problem led Bahcall to develop the standard solar model in more and more detail over the following 50 years. The result is startlingly accurate.

Let’s consider three sources of uncertainty.

The first uncertainty is (oh my God my memory is really playing up), um, the blockage of radiation and its conversion into convected heat. Opacity and mixing length.

The second source of uncertainty is swallowed planets.

The third source of uncertainty is the solar atmosphere model.

The central temperature is very well known.

mollwollfumble said:

The Rev Dodgson said:

… and how reliable is this measurement and/or calculation?

The name you want is Bahcall.

The solar neutrino problem led Bahcall to develop the standard solar model in more and more detail over the following 50 years. The result is startlingly accurate.

Let’s consider three sources of uncertainty.

The first uncertainty is (oh my God my memory is really playing up), um, the blockage of radiation and its conversion into convected heat. Opacity and mixing length.

The second source of uncertainty is swallowed planets.

The third source of uncertainty is the solar atmosphere model.

The central temperature is very well known.

Would swallowed planets contaminate the plasma ?

Cymek said:

mollwollfumble said:

The Rev Dodgson said:

… and how reliable is this measurement and/or calculation?

The name you want is Bahcall.

The solar neutrino problem led Bahcall to develop the standard solar model in more and more detail over the following 50 years. The result is startlingly accurate.

Let’s consider three sources of uncertainty.

The first uncertainty is (oh my God my memory is really playing up), um, the blockage of radiation and its conversion into convected heat. Opacity and mixing length.

The second source of uncertainty is swallowed planets.

The third source of uncertainty is the solar atmosphere model.

The central temperature is very well known.

Would swallowed planets contaminate the plasma ?

I’m no scientist but to me this question is probably one I would ask.

mollwollfumble said:

The Rev Dodgson said:

… and how reliable is this measurement and/or calculation?

The name you want is Bahcall.

The solar neutrino problem led Bahcall to develop the standard solar model in more and more detail over the following 50 years. The result is startlingly accurate.

Let’s consider three sources of uncertainty.

The first uncertainty is (oh my God my memory is really playing up), um, the blockage of radiation and its conversion into convected heat. Opacity and mixing length.
The Rev Dodgson said:

that’s the one that started me wondering about it

The second source of uncertainty is swallowed planets.
The Rev Dodgson said:

Hadn’t thought of that. Are they significant?

The third source of uncertainty is the solar atmosphere model.
The Rev Dodgson said:

Seems like a big problem to me

The central temperature is very well known.
The Rev Dodgson said:

How can it be? How can they overcome the uncertainties and assumptions in the models?

The Rev Dodgson said:

How can it be? How can they overcome the uncertainties and assumptions in the models?

This is the way the biblicists question me..

Hydrogen and helium don’t block radiation, only heavier elements do.

A star that swallows a planet has all this extra conversion of radiation into convection at the depth to which the planet’s material has penetrated, which can have an effect significant enough to alter the standard solar model.