Will It Lens? Table of Contents

Welcome, all! Here are links to everything in the “Will It Lens?” series.

  • Part 1: introduction, melting pennies, dimes, toothpaste, Tylenol, milk, chalk, gourd, can.
  • Part 2: equipment upgrades, CDs, disposable silverware, brass penny, burned pennies.
  • Part 3 (Food Edition): popcorn, grape, kumquat, Frosted Mini Wheat, jelly beans, Reese’s Pieces.
  • Part 4: wood, quarter, soap, dishwasher detergent, bacon, egg, honey, seashell, almonds, gummy bears, M&Ms.
  • Part 5 (Temperature Breakthrough): marshmallow, peeps, copper, iron, sand, glass
  • More to come soon eventually!
  • Gallery of all pictures: This contains every picture we took. There’s a lot of junk in here; the good pictures are in the blog posts above.


  1. Can you melt glass?

    This surprised us, but yes! Normal glass is more properly called “sodalime glass,” which has a much lower melting point than pure silicon dioxide (which we originally thought glass was made of, and which we haven’t been able to melt yet). However, we have trouble melting clear things because they don’t absorb the sunlight. Nonetheless, we melted a dark brown glass in part 5.

  2. Can you melt sand?

    Kinda. The sand we tried is a mixture of quartz, feldspar, and iron. We can melt the last two, but we haven’t melted quartz yet. Look at part 5 for more details.

  3. Can you lens electronics?

    We probably could, but we don’t want to because the fumes are really noxious. There’s lead and other stuff that’s terrible for your lungs in there.

  4. Can you use a second lens to focus the light even more?

    No, that’s not how optics works. For a slightly more thorough answer, see the Light Sharpener FAQ over at cockeyed.com.

  5. Where did you get the lens? How much did it cost?

    I think we got it from here. When we ordered it, I think it was about $120, plus shipping. If you include the wood for the frame and stand, the welding goggles, and the skillet, we’ve probably spent over $200 on lens-related stuff so far.

  6. You should lens something that will burst and explode all over the place!

    That would be very entertaining, but we need to clean everything up before lunch is over, so we’re not doing anything too messy in the foreseeable future (no unopened pop cans, no aerosols, etc.). If we ever take the lens out to the middle of the desert, we will consider lensing messy things.

  7. You should lens an iPhone, iPod, or other hip status symbol.

    First, see question 3 about electronics. Then, remember that we’re paying for all of this with our own money. We’d prefer not to lens anything that costs more than a couple dollars. Everything we’ve tried so far has cost under $1 each (almost everything is under $0.25 each).

  8. Isn’t it illegal to destroy money?

    Not unless you do it with the intent to defraud someone. Remember the last time you went to the zoo? You probably saw one of those machines that will take your penny, flatten it out, and stamp an image of a penguin or something on it as a souvenir. Melting a penny is no more illegal than one of those machines.

Other articles that link to this series:

Leave a Reply


  1. Anonymous says:

    Lensing a solar panel

    Perhaps it would just melt the panel. Too bad, that.

    What a wonderful way to spend lunch time.

    • Anonymous says:

      Re: Lensing a solar panel

      i once melted a cheap solar panel’s cover just from an incandescent light bulb.

      for cooking, maybe you could distribute the heat more evenly by boiling water in a container and setting a second pan in/over it? cheaper than a copper plate. could make ganache for dessert…

      making ice cream with liquid nitrogen is fun too…

  2. Anonymous says:

    Rob Cockerham’s Light Sharpener

    This is in similar vein but potentially higher-powered:


    • Alan says:

      Re: Rob Cockerham’s Light Sharpener

      Livejournal emails me when people comment on my blog. Your comment was caught by my spam filter (presumably due to its title). Well done!

      I hadn’t seen that before, but it’s a pretty cool project. Thanks for the info!

  3. Anonymous says:

    Real Genius

    You guys got to reenact one of cinema’s greatest moments.


    So unfair.

  4. cculhanepsm says:

    Fun with a Fresnel

    I recently ahd the opportunity to play with one as well.

    Yes it does melt glass.

    We actually used a lens about the size you have to separate soldered pipe joints and actually soldered copper fitting with it for a thermosolar water heater.

  5. Anonymous says:


    Peeps. Peeps. Peeps.


  6. Anonymous says:

    Testing solar sails

    Just taking a toy car with a sail made with a reflective material could do the trick.


    • Alan says:

      Re: Testing solar sails

      Let’s do a rough calculation of how much force we could get from using the lens as a solar sail. We can get about a kilowatt of sunlight focused through the lens. The relativistic momentum of a photon is its energy divided by the speed of light. However, if we reflect the photons instead of just absorbing them, the change in their momentum is twice their absolute momentum. So the force we could get from using the lens as a solar sail is

      1 kilowatt / c * 2 = 0.000007 newtons

      That’s way too small to do anything because it is dwarfed by the force needed to overcome air friction (let alone the friction in the wheels of the car). Solar sails don’t become a plausible mode of transportation until you’re in the vacuum of space (no friction) with thousands of square meters of sail (reflects more light) and years to wait (you accelerate very slowly because the forces are so small).

  7. sorethumb says:

    Holy crap. A Googler with a LJ. I suppose it might be a bit more common than I think. :) I love looking at that seashell broken.. sahme, though, looked pretty.

    My thoughts: Did you have another goal in mind besides scientific experimentation? How much did the lens cost?
    I bet you aren’t in New England– you couldn’t do that here with sun at this time of year :3 (well, maybe on a warm day like today, but still!)

  8. Anonymous says:


    In high school my friends and I used one of these (for an overhead projector) to burn the following items:

    Mini-donuts (covered with wd-40)(it lit on fire)
    A modem
    Someone’s car stereo speaker

    That last one got us all suspended.

  9. Anonymous says:


    A Google employee with a Yahoo picture album.

  10. Anonymous says:

    more items to lens

    hard drive
    oven glove, welding glove
    coffee mug
    time how long it takes to boil a liter of water
    stainless steel frying pan vs teflon coated frying pan
    how about introducing another magnifying glass to focus the beam even further?

    • Alan says:

      Re: more items to lens

      Interesting ideas! We considered electronics in the past but decided not to do them because none of us want to breathe the fumes. Also, we don’t want to do Teflon because it’s mostly fluorine (which was used as a chemical weapon in World War One; definitely bad for breathing). The second magnifying glass won’t work because the incident light is not parallel (for a bit more explanation, see the Light Sharpener FAQ over at cockeyed.com.

      However, the rest of your ideas are nice; I’ll add them to our list. Thanks!

      • Anonymous says:

        Re: more items to lens

        But if you had another 200 dollars (minus the price of a second frying pan) just lying around (around your wallet, not the focused beam of death), would it make a difference to set another glass up in parallel with the current one, and point it at the same focal location? What kind of relation between number of lenses vs change in thermal energy would that theoretically make (such as twice as many lenses in parallel would give twice the thermal energy)? With enough lenses, would it be possible to completely melt a penny?
        Also, is there any legal difference between defacing a dollar bill and defacing a penny? Oh well, I suppose you are really just reshaping the face on the penny, anyways… not defacing.

        • Alan says:

          Re: more items to lens

          It’s something we’re already planning on trying. In Part 4, I mention that the lens company sent us a second lens for free because the first one came with a corner chipped off, and we’ve got mirrors to focus both lenses on the same point. However, we haven’t built a frame for the second lens, and we’re still working out the logistics of what has to be where to get it to work reliably. but it’s definitely something we’re looking into, and I suspect we’ll be able to melt copper with the second lens.

          It’s my understanding that defacing money is legal unless you’re doing it with the intent to defraud. Melting pennies with a lens is no more illegal than those machines at the zoo that turn pennies into souvenirs by flattening it and imprinting a penguin on one side.

  11. Anonymous says:

    Google search is down…again

    Hey, why don’t get yo-yos get back to work. Google search is down again!!!! Seriously, isn’t this supposed to be an available service, like, all of the time?

  12. Anonymous says:

    Try lensing …

    Aerosol cans

    Just kidding. You really shouldn’t lens tires or aerosol cans. :)

  13. lil_holwick says:

    Since you’re having troubles with it getting too hot too fast, try something like a frozen burrito or pizza.

    • Alan says:

      We’ve already considered trying frozen pizza, but we decided against it because the top is still likely to burn before the middle is even thawed. I think we want the rate of heat absorption into the food to be roughly the same magnitude as the rate of heat conduction within it, and changing the starting temperature isn’t going to help.

  14. Anonymous says:


    I know you guys must be having a blast with this, but is this an economically viable solution for alternate energy sources? Or could you just use it to store power in a super-light gun that you could instantly melt pennies with!?!

    • Alan says:

      Re: Power?

      Yes, solar power is economically viable if you live in a sunny place. It isn’t very popular yet because it takes about 8 years to recoup your investment and people are impatient, but it is viable.

      I’m not sure the light gun would work. :-)

  15. severoon says:

    Why not move the lens slightly closer or farther so the items are not at the exact focal point? This allows the light to be dispersed and not quite so powerful, so you can make a proper solar oven with variable temperature and even cooking.

    Or, you could go the other direction and figure out a way to collect & collimate the light coming through so that it forms a tiny, super-powerful beam. You could probably use that to build a lair. And then become a super villain. Just a thought.

  16. Anonymous says:

    What abt circuit boards & processors that dont work anymore

    I havent tried it out so I am not sure what happens. Just an idea.

    • Alan says:

      Re: What abt circuit boards & processors that dont work anymore

      We considered it, but none of us want to breathe the fumes.

      Several year ago when I was doing robotics research, we blew a power regulator (the chip was tiny, about a square centimeter), and our control module smelled vile for days. I don’t want to repeat that; it’s really bad for your lungs.

  17. Anonymous says:


    I just love you guys. Seriously

  18. Anonymous says:

    Light to Power Conversion

    Can this idea be used to generate power at all?

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