• Skip to primary navigation
  • Skip to main content
  • Skip to footer

Oh Well

  • About This Blog

Radio Waves, Infra Red and Sound

22 January 2007 by Tim 13 Comments

On a number of occasions, I have tried to explain to Big about things like radio waves, radiant heat and so on.

Me: “It is like light but you can’t see it.”

Big (blank, puzzled, Daddy is taking the **** again look): “?”

We have talked about rainbows and splitting light up into different colours, that is fine, you can kind of see that and I think she has caught on to the idea that light can be bent.

Anyway, although I have had wondered about doing some digiscoping with our telescope, I had never considered whether digital cameras were any good at infra red. Well, it turns out that they are, in fact so good that the manufacturers have to go to great lengths to filter it out.

So if you want to prove the point, that there is light (emr) that you can’t see, try pointing a tv remote at a digital camera, or take a photo of the front of a Thinkpad like this one here (sorry, blurry, no tripod, no cable release, must buy myself a Gorillapod).

Filed Under: General

« How Big?
A little history »

Reader Interactions

Comments

  1. Lin says

    22 January 2007 at 20:36

    Not sure if its just me or not but I get nothing when clicking on the digiscoping link, a sham,e ‘cos I have no idea what it is! ๐Ÿ˜‰
    (May be me, we are having major bb probs here at the moment.)

    Reply
  2. Tim says

    22 January 2007 at 20:43

    Sorry, should work now.

    Reply
  3. DaddyBean says

    22 January 2007 at 22:26

    so what you gonna do about the rest of the Electromagnetic spectrum ?:-)
    It’s quite a difficult one really, it’s one of those things were really you just have to accept that that’s the way the world is – kids at school much much older can struggle with it .
    however, never thought of the digital camera thing, will ahev to have a play.

    Reply
  4. Tim says

    22 January 2007 at 23:11

    Dunno, but I think it got across the idea that there might really be something beyond what you can see. I think she has already wondered how the tv remote worked, now she nows it is something ‘like’ light that does it, so it is not such a leap that it might be something ‘like’ light that accounts for the tv signal too. Maybe.

    Reply
  5. Jax says

    22 January 2007 at 23:23

    You know, if you’d said it was like light you couldn’t see to me, you’d have got a blank look. Light is not dark, it’s what you see by. (Is it morning, is it light yet?) How can you have light you can’t see? If you’d said it was a colour you can’t make out you might have got further…we’ve already done things around rainbows – prisms breaking up light into different colours (though whether she remembers that) and colours recombining to make white on a little spinny thing, so colours might well have got you further.
    Still think your experiment with the camera is rather fun though, I wouldn’t have ever thought of that.

    Reply
  6. DaddyBean says

    23 January 2007 at 03:13

    Whereas i’d see talking about colours you can’t see just weird ๐Ÿ™‚
    SB seemed happy enough when we talked about UV ‘light’ the other day, in the context of vision and how cats see better in the dark, which wandered into things like some insects which can see UV light.
    don’t know what she made of it though.

    Reply
  7. Tim says

    23 January 2007 at 07:31

    I think the colours explanation makes sense, I wish I had thought of it, we will have to try it. ๐Ÿ™‚

    Reply
  8. Raymond says

    23 January 2007 at 11:45

    In the photo: is that the IrDA port you can see glowing (it’s not clear)? That’s neat-o! Must try it …

    Reply
  9. Raymond says

    23 January 2007 at 12:00

    That’s brilliant! No.1 son has been asking about light and why things are different colours recently. I’ll show him this little demo later [I used my pocket digital cam and PDA].

    Reply
  10. Bob says

    23 January 2007 at 12:41

    There was a documentary on BBC 4/2 last year (I think – might have been the year before) called Light Story. The DVD might be available – I seem to remember it was good and went on about the colours next to the visible spectrum as well as the visible stuff. (Plus some yuck stuff about Newton jabbing his eye with a pencil on purpose. Raving mad.)

    Reply
  11. Tim says

    23 January 2007 at 12:52

    Raymond, sounds you have worked it out for yourself, yes, that is the IrDa port.

    Reply
  12. Tim says

    23 January 2007 at 13:10

    Just crossed my mind, you could have a lot of fun with an IrDa hat and a CCTV camera.
    Also, I am thinking of fitting my car number plates with IrDa. ๐Ÿ™‚

    Reply
  13. Tim says

    23 January 2007 at 13:18

    Just found this:
    How to make a webcam work in infra red

    Reply

Leave a Reply to DaddyBean Cancel reply

Your email address will not be published. Required fields are marked *

Footer

Archives

Categories

Search

Copyright © 2025 ยท Tim Marchant ยท Cookie Policy ยท Privacy Policy ยท Log in