Light beam for burning?

[Ethator]

i was thinking last night.... if you got 100W halogen bulb and focused all the light into a small point using mirrors and lenses could you burn with that?

Kind of like this

 

[bob12345]

Yes you can, in fact Archimedes is famed to have done something exactly like this.

 

[chido]

Yeah, I saw that on MythBusters.

 

[wooooooolazer]

You can focus it all to a very small spot but you cant have a beam like that, since the light is not coherent it will diverge very badly.


...lazer... ;D ;D ;D

 

[styropyro]

There is going to be a tiny black spot in the middle of that beam because the lightbulb itself will make a shadow.

 

[Amnizu]

It's obviously possible, as this is how the Wickedlasers Torch works. It has a very, very powerful 4100 Lumen bulb with an adjustable focus.

 

[nikokapo]

yes u can, but indeed there would be no "beam" as it would diverge from the dot when focused to another place, as if it would be a full cone