How energy transfer in the sun from core to the surface?

Question

i need describe the basic mechanisms for the transport of heat energy inside solar star. And explain how the presence of matter impedes that flow.

Answer 1

The first answer is right.  In a star like our Sun, the heat (energy) is transported via to mechanisms:

- Radiation: this is the dominant mechanism that conveys energy from the core (where the thermonuclear reactions take place) to the outer layers.  As the first answer mentioned, this process takes a very long time as the photons emitted by one particle get almost immediately absorbed by another particle.  The process continues by means of a random walk, until the energy is able to reach the surface of the Sun.  The time quoted to completed the process varies on the source, but a generally accepted value is around 300,000 years (but we really don't know, this is only an estimate)

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- Convection is the predominant mechanism close to the surface to the sun (in the so-called "convection zone").

Answer 2

You have two mechanics: Radiation and convection.

Radiation gets used as long, as the temperature gradient (the change in temperature between two points) inside the sun is too low to allow convection.

The density of the radiation zone in the sun is so high, that, while the radiation travels at light speed, it gets reflected so often that it needs 171,000 years to reach the convection zone.

Answer 3

Aggggggh! ONLY 171,000 blah blah times? Come on! Get a grip!

The center of the Sun and any star resides outside time, in a separate universe. The energy is expressed at a barrier Event Horizon between the center and the exterior, which is what we see. The material beneath the Event Horizon is moving faster than light (outside of time), so it needs to be "demodulated" before it enters our universe.

Okay, this model is not yet accepted by the dudes like the first answerer, sooo you are going to have to rely on some blather from someone else other than me for a good grade. BUT, if you want to really find out what is going on, download the article listed below and discover a model closer to reality.

Answer 4

Urwumpe is correct.

from the core light (energy) travels as radiation. But it doesn;t move in a straight line. Every time a photon hits a particle (atom/nucleus) it will be scattered (reflected at some angle). So the photons do a random walk to get away from the core.

Consider fog - the reason you have a hard time seeing thru it is because light bounces off water droplets in all directions, so much of the light does not reach you directly. The more densely packed the water droplets, the less distance you can see into the fog - and that's because more light scattering occurs because there are more particles packed into a smaller space.

Once the gas is has cooled significantly, the photons can start to be absorbed and thus the energy is tranfered to an atom which then moves the energy by moving itself. It will collide with other atoms and transfer the energy. So the outer layers of the sun transfer energy by convection.