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Powerlines disturb animal habitats by appearing as disturbing flashes of UV light

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  • Powerlines disturb animal habitats by appearing as disturbing flashes of UV light

    Powerlines disturb animal habitats by appearing as disturbing flashes of UV light invisible to the human eye


    STEVE CONNOR Author Biography SCIENCE EDITOR Wednesday 12 March 2014

    Wild animals see overhead power cables in remote regions of the countryside as disturbing lines of flashing lights, which could explain why many species avoid electricity pylons to the point where their natural territories become seriously fragmented, scientists said.

    A study of wild reindeer in Norway has shown that they can see overhead power lines in the dark because their eyes are sensitive to the flashes of ultraviolet light which are invisible to the human eye but are constantly being emitted by high-voltage electrical transmission, the researchers said.

    Many other species, from birds in the Arctic to elephants in Africa, can also see ultraviolet radiation which may explain why different kinds of animals in widely varying habitats all tend to avoid overhead power lines even though they are considered to be inert and invisible to wildlife, they said.

    The adult human eye can only see wavelengths of light down to the blue-violet end of the visible spectrum but other animals are able to see well into the ultraviolet range. Reindeer for instance have reflective surfaces at the back of the eye that help them to see UV light on dark winter days, said Professor Glen Jeffery of University College London.

    “Reindeer see deep into the UV range because the Arctic is especially rich in UV light. Insulators on power lines give off flashes of UV light,” Professor Jeffery said.

    “The animals potentially see not just a few flashes but a line of flashes extending right across the horizon. This is the first bit of evidence that explains why we think they are avoiding power lines,” he said.

    High-voltage power cables cause a build-up of ionised gas at certain points on the overhead lines which results in an overall UV glow with occasional, random flashes of UV light as the ionised gases or corona suddenly dissipate. Power companies try to minimise the phenomenon because it causes power leakage, but not to the extent of eliminating them altogether, Professor Jeffery said.

    Scientists also know that many animals avoid power lines to the point that it sometimes causes their populations to fragment into separate habitats. But until now the observation could not be easily explained, especially as the avoidance goes on for many decades after the power lines were first erected.

    “Animals avoid man-made structures and, in the case of high voltage power lines, this can be by several kilometres. This is perplexing because the suspended cables are neither a physical barrier nor are they associated with human activity,” Professor Jeffery said.
    Interesting! I learned last year that humans see better at night than most animals. Most people don't know this or see it for themselves because it takes 30 minutes for human eyes to become dark-adapted (exactly the average time of dusk in most places).

    I installed Flux on my computers to eliminate blue light gradually at local dusk.

    There's always more 'stuff' out there than we think.

    Independent
    "Alexa, slaughter the fatted calf."

  • #2
    One of the most informational pieces of training I received in basic training was night vision.

    The whole battalion was on bivouac and one of the exercises involved having close to 1,000 trainees in a large open area just prior to sunset with no moon at all.

    We were in platoon groups with our respective DI's pointing out what we could see as the sun set, how the colors changed and how things turned to shadows then nothing.

    Eventually, fully dark in Feb, no moon, we covered one eye and a white flare was sent up. It was amazing to comprehend how long it took the uncovered eye to recover and actually make out shapes with only star light.

    Next... someone lit a single paper match 1/4 mile away.... amazing.... looked like a bonfire

    We also got to use a starlight scope... the fore runner of today's night vision devices...
    Nothing at all ... seriously pitch black... look through the starlight scope and you could make out figures moving 200 yards away.
    The starlight scope took the ambient light and ran it through some seriously advanced analog amplifiers... everything was shades of gray and green.
    Last edited by Gramps; Wednesday, March 12, 2014, 7:58 PM.
    Robert Francis O'Rourke, Democrat, White guy, spent ~78 million to defeat, Ted Cruz, Republican immigrant Dark guy …
    and lost …
    But the Republicans are racist.

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    • #3
      Originally posted by Gramps View Post
      One of the most informational pieces of training I received in basic training was night vision.

      The whole battalion was on bivouac and one of the exercises involved having close to 1,000 trainees in a large open area just prior to sunset with no moon at all.

      We were in platoon groups with our respective DI's pointing out what we could see as the sun set, how the colors changed and how things turned to shadows then nothing.

      Eventually, fully dark in Feb, no moon, we covered one eye and a white flare was sent up. It was amazing to comprehend how long it took the uncovered eye to recover and actually make out shapes with only star light.
      People in our society are largely unaware of their own abilities in this area. Not only are human beings pretty excellent in outdoor night vision but we are also pretty excellent in dim indoor settings. We no longer know this because of technology but it's true.

      People who constantly flick on lights forget that much great literature was written in the middle of the night using nothing more than firelight. When people followed a more natural body clock it was common for most healthy people to have both a first and second sleep. The period in between was used for writing (among the literate) and for conversation, sex, eating, and amusement by everybody. Most of the activity was done by firelight since lighting a candle at that time was seen as wasteful by most people.

      Makes you think.
      "Alexa, slaughter the fatted calf."

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      • #4
        Very interesting. It's indeed rare for most of us to be in complete darkness with only natural light from the moon or stars. I generally only have this experience while camping or boating and it is indeed amazing how much you can see without artificial light if you allow yourself to adjust to it.
        Not where I breathe, but where I love, I live...
        Robert Southwell, S.J.

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        • #5
          Originally posted by phillygirl View Post
          Very interesting. It's indeed rare for most of us to be in complete darkness with only natural light from the moon or stars. I generally only have this experience while camping or boating and it is indeed amazing how much you can see without artificial light if you allow yourself to adjust to it.
          I think this is largely what accounts for the camping phenomena of "seeing the Milky Way". Light pollution absolutely dims a lot of stars but simply not being out long enough to get adapted is also part of the reason contemporary urban people can't see common constellations.

          In the summer I often sit or lay out as dusk passes into night and I can see a lot. Of course, I'm not by a fire, not looking at my phone or notebook, and not running in and out of the house.
          "Alexa, slaughter the fatted calf."

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          • #6
            Originally posted by Gingersnap View Post
            I think this is largely what accounts for the camping phenomena of "seeing the Milky Way". Light pollution absolutely dims a lot of stars but simply not being out long enough to get adapted is also part of the reason contemporary urban people can't see common constellations.

            In the summer I often sit or lay out as dusk passes into night and I can see a lot. Of course, I'm not by a fire, not looking at my phone or notebook, and not running in and out of the house.
            Yeah but it's really really hard to align the telescope without some light, and then I trip over the power cords.


            Actually, I think it's sad how few people have actually seen the Milky Way. My kids were mesmerized when we went to the top of a mountain in Virginia, away from almost all light pollution.

            "Faith is nothing but a firm assent of the mind : which, if it be regulated, as is our duty, cannot be afforded to anything but upon good reason, and so cannot be opposite to it."
            -John Locke

            "It's all been melded together into one giant, authoritarian, leftist scream."
            -Newman

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            • #7
              I had hoped to find myself alone in the dark when driving across country. Unfortunately it never happened. Wherever you drive there are street lights, towns, other vehicles, etc... There are some palces that are darker than others, but no true untouched view from a roadway. I guess you have to go down some dirt road into the desert to get close to that experience. Even so, it's pretty neat what you can see. Even here in Florida, the sky is so different from Washington DC or the Atlantic beaches.
              The year's at the spring
              And day's at the morn;
              Morning's at seven;
              The hill-side's dew-pearled;
              The lark's on the wing;
              The snail's on the thorn:
              God's in his heaven—
              All's right with the world!

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              • #8
                Originally posted by scott View Post
                Yeah but it's really really hard to align the telescope without some light, and then I trip over the power cords.
                LOL! Try just laying outside from dusk to nightfall on a night when there is no moon. No cellphone, no lighters, no fire, and no yard lights (cover the solar ones if you've got some).

                The entire canopy will open up! While it's true that I live very high compared to sea level, you ought to be able to see a lot more with the naked eye than you thought you could.

                I'm shocked at the number of adults who can't locate the Polar Star. Even with ambient light I can easily see this and my eyes aren't excellent. They just have lost or never had the ability to see constellations.
                "Alexa, slaughter the fatted calf."

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                • #9
                  Originally posted by Gingersnap View Post
                  LOL! Try just laying outside from dusk to nightfall on a night when there is no moon. No cellphone, no lighters, no fire, and no yard lights (cover the solar ones if you've got some).

                  The entire canopy will open up! While it's true that I live very high compared to sea level, you ought to be able to see a lot more with the naked eye than you thought you could.

                  I'm shocked at the number of adults who can't locate the Polar Star. Even with ambient light I can easily see this and my eyes aren't excellent. They just have lost or never had the ability to see constellations.
                  It's one of my favorite parts of camping.

                  Nothing is ever going to compare to doing blackout operations on a ship in the Indian Ocean though. That was truly incredible. I really wish I knew more about what I was looking at and/or could do that again. ZERO man made light anywhere on a completely clear and moonless night. It was amazing. I could read my LCD watch by the starlight.
                  "Faith is nothing but a firm assent of the mind : which, if it be regulated, as is our duty, cannot be afforded to anything but upon good reason, and so cannot be opposite to it."
                  -John Locke

                  "It's all been melded together into one giant, authoritarian, leftist scream."
                  -Newman

                  Comment


                  • #10
                    Originally posted by Gingersnap View Post
                    LOL! Try just laying outside from dusk to nightfall on a night when there is no moon. No cellphone, no lighters, no fire, and no yard lights (cover the solar ones if you've got some).

                    The entire canopy will open up! While it's true that I live very high compared to sea level, you ought to be able to see a lot more with the naked eye than you thought you could.

                    I'm shocked at the number of adults who can't locate the Polar Star. Even with ambient light I can easily see this and my eyes aren't excellent. They just have lost or never had the ability to see constellations.
                    Or have no idea what to look for *raises hand sheepishly*
                    Not where I breathe, but where I love, I live...
                    Robert Southwell, S.J.

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                    • #11
                      Originally posted by phillygirl View Post
                      Or have no idea what to look for *raises hand sheepishly*
                      I still love you.

                      Look to the North and identify the Big Dipper. If you can see a ladle shape, the outside edge of the ladle will line up with the pole star. That star is brighter than the surrounding stars.



                      Your orientation will be different (usually). My view of this star is flipped from the image. The Big Dipper is on my right and the pole star on my left. Since all the constellations appear to rotate around the North star, timing is an issue.
                      "Alexa, slaughter the fatted calf."

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                      • #12
                        Originally posted by Gingersnap View Post
                        I still love you.

                        Look to the North and identify the Big Dipper. If you can see a ladle shape, the outside edge of the ladle will line up with the pole star. That star is brighter than the surrounding stars.



                        Your orientation will be different (usually). My view of this star is flipped from the image. The Big Dipper is on my right and the pole star on my left. Since all the constellations appear to rotate around the North star, timing is an issue.

                        Oh..the North Star. Why didn't you just say so?
                        Not where I breathe, but where I love, I live...
                        Robert Southwell, S.J.

                        Comment


                        • #13
                          Originally posted by phillygirl View Post
                          Very interesting. It's indeed rare for most of us to be in complete darkness with only natural light from the moon or stars. I generally only have this experience while camping or boating and it is indeed amazing how much you can see without artificial light if you allow yourself to adjust to it.
                          There always seems to be meteor showers the last few days of July and the first few of August. We all take our sleeping bags and blankets outside and just lay there watching the sky. My husband is an avid night sky watcher. He built a telescope when he was a high school freshman and he's been hooked ever since. When you come to CO, I'll drag the lounge chair down to the lower forty so you can watch the sky in comfort.
                          May we raise children who love the unloved things - the dandelion, the worm, the spiderlings.
                          Children who sense the rose needs the thorn and run into rainswept days the same way they turn towards the sun...
                          And when they're grown and someone has to speak for those who have no voice,
                          may they draw upon that wilder bond, those days of tending tender things and be the one.

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