Could you focus light from Sol's corona?

• negativzero
In summary, using the Second Law, one cannot heat an object to a higher temperature using the heat from a cooler object. However, since the corona is typically at a higher temperature than the surface, it seems feasible that one might be able to focus enough of the coronal light to get more than 6000 K concentrated in a small spot.
negativzero
For instance, if you put a big "magnifying glass" above the atmosphere in the shadow of a total solar eclipse thus blocking out light from the "surface of the sun", could you heat an object to a temperature hotter than the surface of the sun? Applying the Second Law, one can't raise the temperature of a hotter object using the heat from a cooler object, not even by focusing light from the cool object with a magnifying glass. However, since the corona is typically at higher temperature than the surface, it seems feasible that one might be able focus enough of the coronal light to get more than 6000 K concentrated in a small spot. I'm assuming that since it's a total eclipse the radiation from the surface wouldn't dominate the spread of energies focused. I can't imagine what device would be used for such an experiment, or what the utility of it might be except perhaps to explode a tritium BB or something.

Hmm - that's an idea. The snag is that the temperature achieved would have to relate to a mean temperature over a full sphere. The optics to achieve that would be a bit taxing. For a start, the Moon, getting in the way, is far cooler than the body of the Sun. You could possibly do better without the eclipse and use the focussed radiation from the main body to 'blanket' the object that you wanted to heat up to more than 6000K.

Sounds right. "Blanket"? Do you have a synonym?
I haven't thought about design. Assuming that one is projecting an image on a surface, it seems like it would a nice trick to somehow exclude any disc at all from appearing on the image. I have no idea how to bend light around corners but perhaps an object or series of objects and a series or cascade of light bends might shrink the appearance of any disc to a lesser significance. It also bothers me that i don't quiet get the significance of the "spread" of frequencies that make black body so important in heating. I assume coronal light is far from black body radiation, but I'm naive.

negativzero said:
Sounds right. "Blanket"? Do you have a synonym?
The 'hot spot' would be losing heat not only back to the Sun - just as it will not be getting all the available heat from the Sun. If you surrounded the hot spot with a 'blanket' of his temperature then there would be less heat loss. That's an entirely practical comment.
About "black Body' radiation, you need to read about it to get the full story but the notion was studied way back by Lord Rayleigh and Jeans. If you take a cavity and allow it to fill with EM energy until it's in thermal equilibrium, you will end up with a balance of all frequencies, sharing the energy. The classical approach to this gave the answer that there would be more and more energy with increasing frequency (The Ultraviolet Catastrophe). Planck solved this anomaly by applying Quantum theory to the problem and produced a shape for the spectrum that achieves a balance between the energies at all frequencies. If you take an ideal cavity and make a small hole in it, the hole will behave like an ideal black body. And, of course, if you look into the hole and if the cavity is only at room temperature, it will look black because any light that gets into the hole will never get out. The cavity will look red / orange / blue-white, depending on the temperature of the cavity.
Do some Googling!

negativzero said:
For instance, if you put a big "magnifying glass" above the atmosphere in the shadow of a total solar eclipse thus blocking out light from the "surface of the sun", could you heat an object to a temperature hotter than the surface of the sun?
No - the corona isn't opaque.

sophiecentaur
negativzero said:
For instance, if you put a big "magnifying glass" above the atmosphere in the shadow of a total solar eclipse thus blocking out light from the "surface of the sun", could you heat an object to a temperature hotter than the surface of the sun?
ohhh my gosh, seriously ?

russ_watters said:
No - the corona isn't opaque.

yup, and it is also VERY tenuous ( low density), it also has a temperature of over 1 million K
and finally it's primary radiative mode is in X-rays ... the visible light output is relatively low in comparisonDave

sophiecentaur

1. How is it possible to focus light from the Sun's corona?

Focusing light from the Sun's corona is possible through the use of specialized instruments such as telescopes and lenses. These instruments are designed to gather and manipulate light, allowing for the focused collection of light from the corona.

2. What is the purpose of focusing light from the Sun's corona?

The purpose of focusing light from the Sun's corona is to study and understand the behavior and dynamics of this outermost layer of the Sun's atmosphere. This can provide valuable insights into solar activity, radiation, and the effects on Earth's climate and technology.

3. What challenges are involved in focusing light from the Sun's corona?

Focusing light from the Sun's corona poses several challenges, including the extreme brightness and heat of the Sun, as well as the distance and turbulence of Earth's atmosphere. Specially designed equipment and techniques are necessary to overcome these challenges and obtain accurate observations.

4. Can focusing light from the Sun's corona provide any practical applications?

Yes, focusing light from the Sun's corona can have practical applications in various fields such as space weather forecasting, solar energy research, and communication technology. By understanding the behavior of the corona, we can better prepare for potential disruptions to satellite and communication systems caused by solar activity.

5. Are there any potential risks involved in focusing light from the Sun's corona?

Yes, there are potential risks involved in focusing light from the Sun's corona, including the risk of damaging sensitive equipment and the potential for eye damage if proper safety precautions are not taken. It is important to use specialized equipment and follow safety guidelines when observing the Sun's corona.

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