Optics

[aaa16797]

Hey I am a new member here at the science forum! I recently have been doing some research on optics and started experimenting with laser lights. I started to place mirrors around my room and reflecting laser beams off of them. After a while of just random experimenting, a thought came into my head. What would happen if I could collect light from the sun using a mirror that would reflect the light at one point? I researched this topic and found out about parabolic reflectors and parabolic troughs. So if I were to concentrate sunlight at one focus, which would be better (in terms of more heat): a parabolic reflector (like a bowl shape), or a parabolic trough?

[studiot]

Collecting and focusing solar energy can produce substantial power. See solar furnace.

 

https://www.google.co.uk/search?hl=en-GB&source=hp&q=solar+furnace&gbv=2&oq=solar+furnace&gs_l=heirloom-hp.3..0l10.1469.4860.0.5125.13.10.0.3.3.0.125.1124.1j9.10.0....0...1ac.1.34.heirloom-hp..0.13.1248.VlefBCYx98U

Edited July 11, 2014 by studiot

[Strange]

So if I were to concentrate sunlight at one focus, which would be better (in terms of more heat): a parabolic reflector (like a bowl shape), or a parabolic trough?

 

A bowl shape will focus the light at a single point. A trough will focus it in a line (which is more practical for extracting the energy).

[aaa16797]

Thanks. Just one question though. Will the line be visible light or will it seem invisible( for the trough)?

[Strange]

Thanks. Just one question though. Will the line be visible light or will it seem invisible( for the trough)?

 

As it is sunlight it will be visible light (although, as with all light, you will only be able to see it if it hits something - which is normally something carrying a fluid to convert the incident radiation to heat and carry it away to do something useful).

[aaa16797]

As it is sunlight it will be visible light (although, as with all light, you will only be able to see it if it hits something - which is normally something carrying a fluid to convert the incident radiation to heat and carry it away to do something useful).

Sorry I think I stated the question incorrectly (scientifically). I was trying to ask with a parabolic trough, will the light be in one complete beam or will you only see light at the point in which it comes from and the point at which it hits

[Strange]

Sorry I think I stated the question incorrectly (scientifically). I was trying to ask with a parabolic trough, will the light be in one complete beam or will you only see light at the point in which it comes from and the point at which it hits

 

I'm afraid I don't understand the question. You can only see light when it hits something and is reflected into your eyes.

[aaa16797]

 

I'm afraid I don't understand the question. You can only see light when it hits something and is reflected into your eyes.

OOHHH oops my bad I was thinking about laser beams not beams of sunlight my bad never mind that question.

[Strange]

OOHHH oops my bad I was thinking about laser beams not beams of sunlight my bad never mind that question.

 

Note that you can only see laser beams (in the air) because there is dust or mist and some gets reflected into your eyes.

[aaa16797]

 

Note that you can only see laser beams (in the air) because there is dust or mist and some gets reflected into your eyes.

ok thanks

[Acme]

... What would happen if I could collect light from the sun using a mirror that would reflect the light at one point? I researched this topic and found out about parabolic reflectors and parabolic troughs. So if I were to concentrate sunlight at one focus, which would be better (in terms of more heat): a parabolic reflector (like a bowl shape), or a parabolic trough?

One isn't better than another except in regards to your exact use/purpose. As to amount of heat, it depends on the size. One advantage to a trough reflector is that it doesn't have to be continuously moved in the same way as a parabolic 'bowl'.

 

I built this experimental solar trough for producing bio-char in the receiver. The reflecting surface is silvered cardboard & the receiver is a section of metal stove pipe. It worked great, but it was too small to reach the necessary temp in the receiver. Edit: Too small in the top-to-bottom measure as seen in the photo. This unit was ~ 4ft top-to-bottom.

 

Edited July 13, 2014 by Acme