Loading ...
Sorry, an error occurred while loading the content.

Re: [UVB_Meter_Owners] Re: Those black polar bears...

Expand Messages
  • spinytail@zonnet.nl
    ... I just looked because that sounded fantastic, but there are a few articles debunking that story. Measurements have shown that the hairs do not transmit
    Message 1 of 5 , Dec 1, 2005
    • 0 Attachment
      > LOL! Wonderful stuff, Richard.
      >
      > That was too good to miss, so I just had a dig around on Google and
      > can add that I found a bit more. The translucent hairs transmit
      > infra-red through to the black skin, which presumably absorbs it;
      > whereas they reflect visible light, so the bear appears white. How
      > neat is that? "Dichroic" bears!

      I just looked because that sounded fantastic, but there are a few
      articles debunking that story. Measurements have shown that the
      hairs do not transmit light, less than 0.001 of red light traveled the
      length of a 1 inch hair, even less for UV. The whole transmission
      thing is a myth. It seems that polar bear hair absorbs UV really well
      due to the keratin in there and therefore they look black on UV
      pictures.
      Here's a nice article with all the hairy facts:
      http://www.azadocents.org/polarbear.pdf


      > I also found that some researchers tried to track polar bears using
      > infra-red cameras to detect their body heat. They failed; the bears
      > didn't emit infra-red.
      in fact they do emit infra red, but only the face! Here's a nice floating
      face pic:
      http://www.coe.berkeley.edu/engnews/spring03/3S/polarbear.html
      They are insulated so well, that they can overheat when chasing a
      seal. In the arctic!
      Wonderful animals.
      Well, back to coldblooded UV lovers.
      Ron

      > Thanks for the great diversion!
      >
      > Frances
      >
      >
      > --- In UVB_Meter_Owners@yahoogroups.com, "richardlunsford"
      > <drrich2@C...> wrote: > > I hope this will be accepted in the spirit
      > of good fun, & my nit- > picking need to find a use for a piece of
      > trivia stuck in my head. > > Polar bears are in fact black. It's a
      > fact. Technically, in a way. > They have black skin & 2 types of fur
      > (one clear, one white). Here's > a link. >
      > http://www.enchantedlearning.com/subjects/mammals/bear/Polarbearcolori
      > ng.shtml
      >
      >
      > > Richard.
      >
      >
      >
      >
      > [Non-text portions of this message have been removed]
      >
      >
      >
      > ------------------------ Yahoo! Groups Sponsor
      > --------------------~--> 1.2 million kids a year are victims of human
      > trafficking. Stop slavery.
      > http://us.click.yahoo.com/WpTY2A/izNLAA/yQLSAA/APOolB/TM
      > --------------------------------------------------------------------~-
      > >
      >
      >
      > Yahoo! Groups Links
      >
      >
      >
      >
      >
      >
      >
    • lilacdawndragon
      Even better! What fun... Thanks Ron! Isn t it fascinating how just one article can get a theory so widely accepted? Most of the articles I read were on
      Message 2 of 5 , Dec 1, 2005
      • 0 Attachment
        Even better! What fun... Thanks Ron!

        Isn't it fascinating how just one article can get a theory so widely
        accepted? Most of the articles I read were on children's education
        websites.

        In the second article it says:
        <<<Preciado took advantage of the advanced light-source technology at
        LBNL (one of the few in the country) to take a closer look at polar
        bear hair procured from the San Francisco Zoo. "Not many people have
        access to the technology they need to measure something this small, I
        was lucky to have the advanced light-source telescope so close," she
        adds. >>>

        I wonder if this lady would be interested in measuring the "radiative
        properties" of shed reptile skin with the "advanced light-source
        technology"??

        Frances

        --- In UVB_Meter_Owners@yahoogroups.com, spinytail@z... wrote:
        >
        > I just looked because that sounded fantastic, but there are a few
        > articles debunking that story. Measurements have shown that the
        > hairs do not transmit light, less than 0.001 of red light traveled
        the
        > length of a 1 inch hair, even less for UV. The whole transmission
        > thing is a myth. It seems that polar bear hair absorbs UV really
        well
        > due to the keratin in there and therefore they look black on UV
        > pictures.
        > Here's a nice article with all the hairy facts:

        http://www.azadocents.org/polarbear.pdf

        > I also found that some researchers tried to track polar bears using
        > > infra-red cameras to detect their body heat. They failed; the
        bears
        > > didn't emit infra-red.
        > in fact they do emit infra red, but only the face! Here's a nice
        floating
        > face pic:
        >
        http://www.coe.berkeley.edu/engnews/spring03/3S/polarbear.html

        > They are insulated so well, that they can overheat when chasing a
        > seal. In the arctic!
        > Wonderful animals.
        > Well, back to coldblooded UV lovers.
        > Ron
      Your message has been successfully submitted and would be delivered to recipients shortly.