The Sun

[homie12]

I love science programs, but my pet peeve is when they just state facts without giving a clue HOW they know it. For example, they will always say our Sun will last for a few more Billion years before swelling into a red giant and destroying the inner planets, probably including Earth. How do they know the sun will last so long? Maybe they are way off, and the Sun will become unstable in Millions or even thousands of years from now.

 

Oh boy, now you are talkin. I love this thread. why is the suns heat signature in reverse? How is it still holding onto the planets if its consuming itself? Why does the solar wind accelorate? Id like to know/ thanks for your responses

[swansont]

why is the suns heat signature in reverse?

 

Huh? Reverse of what?

[John Cuthber]

" How is it still holding onto the planets if its consuming itself?"

 

To a fair approximation the sun is converting hydrogen into helium and a lot of energy.

The best estimates say this will take something like ten billion years from start to finish

The change of mass is small because a helium atom weighs very nearly as much as the 4 hydrogens it's made from.

So, over the course of something like 10,000,000,000 years the sun's gravitational attraction will alter by about 0.7%.

The planet's orbits will shift a bit, but not much.

 

"Why does the solar wind accelorate?"

Who says they do?

Some of the hot gas from the surface of the sun diffuses off into space.

Some of it gets caught in the magnetic field of turbulent bits and whipped up to a rather higher speed.

Edited February 5, 2012 by John Cuthber

[homie12]

Huh? Reverse of what?

the corona is 2 million degrees the surface is approx 5000 degrees and sunspots are holes on the surface of the sun and are showing cooler regions below the suns surface. Thats indicative of energy arriving to the sun. Why is there a corona in the first place otherwise?

 

" How is it still holding onto the planets if its consuming itself?"

 

To a fair approximation the sun is converting hydrogen into helium and a lot of energy.

The best estimates say this will take something like ten billion years from start to finish

The change of mass is small because a helium atom weighs very nearly as much as the 4 hydrogens it's made from.

So, over the course of something like 10,000,000,000 years the sun's gravitational attraction will alter by about 0.7%.

The planet's orbits will shift a bit, but not much.

 

"Why does the solar wind accelorate?"

Who says they do?

Some of the hot gas from the surface of the sun diffuses off into space.

Some of it gets caught in the magnetic field of turbulent bits and whipped up to a rather higher speed.

 

When have did anyone convert hydrogen into helium? I thought that was still theoretical and hadnt been proven yet? I guess you want me to locate the site that can measure the solar winds velocity? Fair enough Ill get back to you thanks for asking and whereed u get those calcs?

[swansont]

the corona is 2 million degrees the surface is approx 5000 degrees and sunspots are holes on the surface of the sun and are showing cooler regions below the suns surface. Thats indicative of energy arriving to the sun. Why is there a corona in the first place otherwise?

 

AFAIK, understanding the corona is an ongoing issue.

[StringJunky]

From Wiki. This not the full answer but does highlight the distinction between "heat" and "temperature":

 

What Physics Explains Already

 

Physicists already explains the misconception between Temperature and Heat Energy. In his blog, Ethan Siegel, theoretical astrophysicist, explained the misconception about the Coronal heating problem as follows.[33]

 

"while the surface of the Sun is very hot, at something around 5800 K, the Corona comes in at temperatures over one million Kelvin.

Mysterious, mind-boggling and inexplicable by the laws of physics, right? "

 

Except that temperature is not the same thing as heat! The Sun's surface is much, much denser than the incredibly rarified corona, so that even though the Sun's photosphere is less than 1% of the corona's temperature, it emits energy at a rate that's over 40,000 times the amount required to heat the corona up to its high temperature. We even think we know why: the wave heating theory, where energy can be transferred over long distances from the solar interior to the corona.

 

Remember what temperature is: a measure of the mean speed of the particles. Similar to how two balls—a tiny one and a very massive one—dropped one-atop-the-other will lead the tiny ball to rocket upwards at an incredible speed, the problem isn't getting a few particles to have a very large speed. The problem also isn't unique to the Sun; if we take a look at Earth's upper atmosphere, where it gets really rarified (above 80 km), we find that it does the same thing in terms of temperature!

 

The problem is that we associate temperature with heat in our minds, but the "very high temperature" corona contains almost no heat! But if we look in terms of heat, the Sun's photosphere contains much more than the corona; the corona merely reaches higher temperatures.

Edited February 8, 2012 by StringJunky

[homie12]

AFAIK, understanding the corona is an ongoing issue.

 

This is how you sit in judgement of me? with diplomatic jargon instead of scientific content?Did a few of you get together and decide to see if you could set up a site that mimmicks an actual scientific site? You people that label ypurselves as experts and dont even have some fundemental knowledge how temperature is taken in space. Have you done any observations of radio telescope images? And please, psychology isnt your major , so your assumptions of my feelings have been insulting. But I'll be just fine. Are you alright?

[Moontanman]

When have did anyone convert hydrogen into helium? I thought that was still theoretical and hadnt been proven yet?

 

 

You are mistaken...

 

http://en.wikipedia.org/wiki/Fusor

[Phi for All]

This is how you sit in judgement of me? with diplomatic jargon instead of scientific content?Did a few of you get together and decide to see if you could set up a site that mimmicks an actual scientific site? You people that label ypurselves as experts and dont even have some fundemental knowledge how temperature is taken in space. Have you done any observations of radio telescope images? And please, psychology isnt your major , so your assumptions of my feelings have been insulting. But I'll be just fine. Are you alright?

!

Moderator Note

homie12, your reaction here is wildly disproportionate to the situation, leading me to think you read something into swansont's post that wasn't intended. And at no point does anyone assume anything about your feelings.

 

If you feel you've been personally attacked, please report any such posts. Please refrain from personally attacking any other members. We discuss ideas here, not the people who have them.

[homie12]

!

Moderator Note

homie12, your reaction here is wildly disproportionate to the situation, leading me to think you read something into swansont's post that wasn't intended. And at no point does anyone assume anything about your feelings.

 

If you feel you've been personally attacked, please report any such posts. Please refrain from personally attacking any other members. We discuss ideas here, not the people who have them.

I'd say a reset in direction is a better way to further the value in discussions here. So I'll accept your point. And thanks for your responses.

[John Cuthber]

 

 

 

When have did anyone convert hydrogen into helium? I thought that was still theoretical and hadnt been proven yet?

1951

http://en.wikipedia.org/wiki/Operation_Greenhouse

[david50]

I read a new explanation for what the sun really is at. advertising url removed by moderator

(I have nothing to do with the site... just found it while cruising)

 

What do you think of this new idea

 

dave50

[DrRocket]

AFAIK, understanding the corona is an ongoing issue.

 

 

Correct. The coronal heating problem is one of the better known open problems in physics.

 

 

http://solar-center....AQ/Qcorona.html

 

 

It has the unfortunate distinction of being regulary cited by "electric universe" wackos as evidence for all sorts of nonsense.

Edited February 11, 2012 by DrRocket

[John Cuthber]

I read a new explanation for what the sun really is at. advertising url removed

(I have nothing to do with the site... just found it while cruising)

 

What do you think of this new idea

 

dave50

I think it is dross.

It gets as far as the second sentence before saying something that's clearly false i.e. "To most people, it was an established fact that the earth was flat and sitting on a tortoises' back. Travel far enough and you'd fall off the edge.".

 

This bit "They don't tell us the purpose of the sun or have an explanation for the stars" is also nonsense.

The Sun doesn't need a purpose and we do have a good explanation of the stars.

[*puffy* japanisthebest]

Oh boy, now you are talkin. I love this thread. why is the suns heat signature in reverse? How is it still holding onto the planets if its consuming itself? Why does the solar wind accelorate? Id like to know/ thanks for your responses

i do not know...but i have to go... bells going to ring soon!

[Phi for All]

I read a new explanation for what the sun really is at. advertising url removed by moderator

(I have nothing to do with the site... just found it while cruising)

 

What do you think of this new idea

 

dave50

!

Moderator Note

dave50, we don't allow new joiners to take us offsite due to all the spam we get. If you wish to pursue the explanation, please give us a brief overview here.

[JohnStu]

Sun's heat signature is inreverse? I don't think so. They estimated age of sun through radioactive dating on astroids around the solar planet including the ones that later fell onto Earth. It is all estimate though, still fairly accurate.