Foldscoping snow

What a way to start 2019 – it was snowing all morning; and I tried to foldscope snow. Here is a quick tutorial. It’s beautiful how the snow flakes melt!

More soon. Enjoy the video.

Now, here is a puzzle. Why does the snow flake melt as soon as we start imaging them. Leave comments with ideas and control experiments below.



12 Comments Add yours

  1. GujuRocks says:

    Might be due to radiation of the cell phone
    Heat convection iside slide or foldscope

    1. Manu Prakash says:

      That’s a good idea! How should we tests this?

      1. GujuRocks says:

        I think puting phone in airplane mode will work .
        If not then putting something cooler thank ice
        Like a cooled metal in foldsvope would work?

  2. I don’t know the answer to your puzzle but I’m more curious about Water Memory…
    Can we prove this with foldscope..??

  3. GujuRocks says:

    I think puting phone in airplane mode will work .
    If not then putting something cooler thank ice
    Like a cooled metal in foldsvope would work?

  4. manalinayak13 says:

    Could it be because the lens focuses the light into a point? Like the experiment in which a biconvex lens concentrates sunlight at its focus and burns paper?

    But I thought the lens in Foldscope is a sphere, in which case I’m not sure if the same idea works here.

  5. Akib says:

    The reason maybe pressure exerted by magnetic couplers and weight of mobile phone on the snow as water gets melted due to application of pressure. Try imaging them with ordinary compound microscope.

  6. Akib says:

    Sorry its ice, not water!

  7. Akib says:

    Try searching regelation.

    1. Manu Prakash says:

      That’s an excellent idea. It would imply that when we do keep the foldscope on pack of snow – the snow flake being imaged is being pressed down. It’s possible since all the snow is kind of forming a continuous network. Will have to try to see by imaging an isolated flake – in which case it would not be in contact.

      Great idea to test! We should now show is it heat or pressure?

      Here is a link on regelation – specially for ice.


  8. laksiyer says:

    @Manu. We need to try that trick of putting snow flakes in elmer’s glue and solidifying it to make permanent slides.

  9. Akib says:

    Let me explain the thing:
    Although looping a fine wire around a block of ice with a heavy weight attached to it is a good demonsteation of regelation, you can melt a whole block of it by applying enough pressure on it in subzero temperatures (not by hands or legs!).
    Secondly, pressure can rise high in the setup above and can be enough to melt it for two reasons:
    1) The area is very small. Suppose the weight of mobile is 1N and the area is 4mm2. Then the pressure is more than two atm! (Not counthig the pressure of magnets and 1atm by atmosphere!). The reason for being the area so small can be that the flakes are irregularly shaped and only a small portion of its whole area touch the coverslip like apex of hills have small area. The magnetic couplers also don’t cover the whole slide but only a small portion of it. The flakes have gaps in between them. If the area is smaller and a little bit more force is applied on it, the pressure will rise super high!
    2) The latent heat of fusion (heat energy required to melt) of such small amount of ice is very small. 5mg ice reguires only 1.67 joule to melt. The energy is mostly supplied by the pressure (force to be exact). Small amount of energy can be got from other sources ( like the led).

    You can try imaging them by keeping the phone upside down on the table and the foldscope on top of it. The coverslip will cover all the flakes so you can not just isolate one and expect different result from the same setup.

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