How big should a lens be to focus enough light to reach 1000 Celcius???

by Panthera Leo
Tags: 1000, celcius, focus, lens, light, reach
Panthera Leo
Panthera Leo is offline
Aug15-11, 06:33 PM
P: 110
I was wondering how big should a glass lens be to focus enough light to produce a temperature of about 1000 celcius at its foci???

What if the lens was made up of sth with higher refractive index, doesn't this reduce the size of lens?

A rough guess will do... I am just curious

Thanks in advance :)
Phys.Org News Partner Physics news on
The hemihelix: Scientists discover a new shape using rubber bands (w/ video)
Mapping the road to quantum gravity
Chameleon crystals could enable active camouflage (w/ video)
CJames is offline
Aug15-11, 07:19 PM
CJames's Avatar
P: 355
Take a look at this thread:

Also have a look into fresnel lenses:
HallsofIvy is offline
Aug15-11, 07:25 PM
Sci Advisor
PF Gold
P: 38,898
So we have yet another post (three or four of then today) that seems to assume that a specific amount of energy translates to a specific temperature. That is NOT true.

Register to reply

Related Discussions
Convex lens. If it receives light and the lens is twisted will it guide the light? General Physics 0
Contact Lens: How to focus light 1mm away General Physics 2
Lens can focus the light to a smaller spot by ...?? General Physics 3
What lens shape gives perfect focus? General Physics 9
Question on light intensity at the focus of a lens. General Physics 2