>> ^BoneRemake:

>> ^ant:
They better not burn ants!

stepping on them is quicker and more productive.


Bah!

>> ^ant:

They better not burn ants!


stepping on them is quicker and more productive.

>> ^jwray:

put a giant lens in orbit -- next best thing to a death star.


This!

I'd love to see some random places get burned! It's like winning the lottery, but with death.

>> ^rottenseed:

I hate that kids can't say their r's. I couldn't either...it's weally stwange.


A lot of kids can't do R or TH sounds properly till 2nd grade or something. A lot of ESL students never get those ones right.

[redacted]

>> ^Mcboinkens:

The most obvious question in my mind is what happens when you put an arm under it? I imagine it won't light up in flames, but it would probably induce a pretty serious burn, no?


I have a much smaller lens around here somewhere, about 6" diameter, that will also ignite anything you put under it pretty much instantly. It's a focusing lens from a spot-light that was salvaged out of an old theater.

My neighbor in high school, who was probably about as stupid as these kids are, told me he wanted me to focus it on his shoulder. He was certainly old enough to know what was going to happen, so I had no qualms in obliging him. The moment I brought it into focus, his shirt caught fire and he dropped to the ground screaming. There were no marks on his skin, just some redness.

Once he had recovered (and extinguished his shirt), he told me to do it again and said he wouldn't move this time. I was focusing on bare skin this time, so there was no shirt ignition. His skin did blacken within a few seconds, though, and a thin stream of smoke began to pour off of him, just as it does when you burn wood. He lasted maybe 4-5 seconds at most before he dove to the ground in agony again.

Did I mention he was pretty stupid?

Tags for this video have been changed from 'Fresnel lense, projection tv, kids, science, fire, focus, sun, combustion, ignition' to 'Fresnel lens, projection tv, kids, science, fire, focus, sun, combustion, ignition' - edited by lucky760

http://en.wikipedia.org/wiki/Fresnel


I was fascinated when I learned of this type of lens as well as the person who invented it. I did not find many videos that I thought where Vs quality, but this one passed the exam. There are not how its made, how it works or anything on these lenses, you just have to read on them pretty well. Really neat though.

Tags for this video have been changed from 'Solar, cook, cooking, vacuum, tube, stove, sun, power, earth, green' to 'Solar, cook, cooking, vacuum, tube, stove, sun, power, earth, green, fresnel, lens' - edited by kronosposeidon

Now you can interact with each other even less! I delight in watching stuff with my significant O. We also enjoy programming our Netflix queue together as well, so we might not be typical.

This thing has all the technology of one of those "lenticular" images, with a picture that changes because of interlaced images aligned with micro prisms, or Fresnel type lens. Y'know, the stuff that they used to put on lunchpails and cereal boxes.

I'm not sure if this is real. She suddenly disappears at the end after the set falls on her head. Remember the "fresnel light falls" video?