Bending the Light

Ruled Hyperboloid CC Prof. William McCallum
Ruled Hyperboloid CC Prof. William McCallum

Everyone knows you can’t visibly bend light over short distances in free air. Or can you? [Jack Pearse] has figured out a way to do it though, or at least make it appear that way. He does it by combining a trick of math and a trick of the eye. The secret is the hyperboloid, a geometric construct described by a quadratic equation. [Jack’s] creation is more specifically a hyperboloid in one sheet. This type of structure allows straight lines to create a an overall curved surface.  Hyperboloids have been used by architects and in construction for years, often in tall structures like water towers.

If a bunch of straight steel beams can form a curved shape, lasers should be able to pull off the same effect. By employing persistence of vision, [Jack] was able to create his hyperboloid with only 10 small lasers. The lasers are mounted on the rim of a bicycle wheel and carefully aimed. The wheel is spun up with using an electric bicycle motor. [Jack] kept things safe by building a centrifugal switch. The switch powers up all the lasers in when the tire is spinning. This ensures no one can be hit by a static beam.

Once the wheel is spinning, all you need is a bit of smoke or haze in the room. The spinning lasers combine to form the hyperboloid shape. You can see the project in action in the video after the break.

17 thoughts on “Bending the Light

  1. Builds 3x3x3 Led Matrix, runs demo, calls it realtime raytracing engine. Wires WS2812B strip to Arduino, runs FastLED demo library, calls it FiFo algorithm based on quantum decays.

    Forgive me for being a bit skeptical of this dude’s mix of basic maker skills, obvious buzzword vomit, and terrible video editing and music aesthetics. Not to mention the demoscene style credits (for what? at least a demo had some collaborative effort that went into it).

    Just my two cents. I really hope he did pull this off, it would be the height of badassery. Tragically, my heart of hearts has some really serious doubts.

    1. Ok, I have to agree on being surprised to see the text “fifo algorithm” scrolling over the screen… a simple shift is now called an algorithm?!? Why doing so complicated/theatrical over basic stuff.

      But the idea behind this post was the illusion of a deformed tunnel and that was exactly what we’ve seen.
      All the other silly stuff (taking of more then halve of the video) is distracting/anoying and completely takes all the focus of the great idea of making a hyperboloids with lasers. Which simply works and deserves some proper credit. So I would like to say, well done!

      If he only showed the hyperboloid laser contraption and nothing else, I’m sure everybody would agree that this was great. So please people, don’t be to hard on this guy.

      1. I know ohm’s law. Suddenly I’m an electrical engineer ;]
        I’m pretty good with lego. I’m an mechanical engineer or an architect. Whichever I want.
        I can put some butter onto some bread. I’m a 5-star chef.

    2. I see, there is some confusion about the style. Last year we did a small “partyprod” at the demoscene party “Evoke”. The category was “wild animation”. The video is a parody of old eighties demos. It won the 3rd place in this category. We used the video here because it’s already on youtube. The hyperbolid is to be seen after the break in the middle. Unfortunately it’s hard to take a picture or record a video of lasers. You shoud see the real thing. The shape has vibrant colours and looks great. We really recommend trying to build this sculpture. So please don’t be disturbed by the rotocube. This video wasn’t made as a presentation for this project. We just recycled media which was already there.

      1. Hey Jack, I totally got the 80’s/90’s demoscene nod. I was a future crew fan back in the day. Some of the readers may be too young, or weren’t aware of that bit of history. I should have made that clearer in the article.

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