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FrozenGate by Avery

Weird thing happened tonight while playing with my laser

connorr93

connorr93

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I was shining my 150mW green laser into the night sky tonight and all of a sudden I hit something that caused the beam to reflect back down and hit the ground about 100 ft from me. I could see the beam reflecting back down just like a beam reflects in a mirror. I could tell that whatever I hit was a few miles away and hundreds of feet in the sky. I turned off the laser and looked carefully into the sky. There were no lights or anything I could see. I was hoping it wasn't a plane so a waited a few minutes (to let any potential plane pass) and shined my laser into the same general location. It took me a while to find the same exact point but I found it again and had the same effect. What could this possibly be? It's like there is something hovering in the sky that just happens to have a reflective surface directing the beam back into my direction.
 
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Well assuming this post is true as you describe and not made up or something, if the object was a 'few' miles away and the object a few hundred feet in the sky(say 500 feet) then you would have to be shining the beam almost at the horizon. Secondly the size of the reflected beam reflected back near you after traveling several miles in both directions would be about 20 feet in diameter, also very faint. Does this describe what you saw? If not you need to rethink your numbers. You could get an accurate estimate of how far away the object was if you know the divergence of the laser beam and how big the dot appeared reflected back.
 
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kaunak said:
Well assuming this post is true as you describe and not made up or something, if the object was a 'few' miles away and the object a few hundred feet in the sky(say 500 feet) then you would have to be shining the beam almost at the horizon. Secondly the size of the reflected beam reflected back near you after traveling several miles in both directions would be about 20 feet in diameter, also very faint. Does this describe what you saw? If not you need to rethink your numbers. You could get an accurate estimate of how far away the object was if you know the divergence of the laser beam and how big the dot appeared reflected back.
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Post is 100% legit. The "spot" in the sky was just slightly above the horizon. I couldn't really examine the beam because it would only flash for a half second when I hit whatever was in the sky. I was it out of the corner of my eye and right in front of me for split seconds. It lit up a tree and my neighbors house so I assume the beam was at least 10 feet wide.
 
Things said:
0d099c06-d98c-4102-8a42-fc843b675987.jpg
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A photograph would be impossible because when I hit whatever was in the sky it only would flash for a split second. There is no way I could hold the laser on something that far away steadily unless it was in a mount.
 
Probably a road sign on a hill. They are designed to reflect on-coming light, back in the direction it came from. :beer:
 
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grainde said:
Probably a road sign on a hill. They are designed to reflect on-coming light, back in the direction it came from. :beer:
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Yea I think that makes the most sense. If something was near the horizon and it reflected a beam back to you from far away it was probably some time of reflective sign. Something like a stop sign will reflect a laser beam brightly even from over a mile away
 
Sounds like someone saw your beam and pointed their own.

grainde said:
Probably a road sign on a hill. They are designed to reflect on-coming light, back in the direction it came from. :beer:
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It's more diffuse than a flashlight. The return light would not be in any "beam," and it wouldn't travel miles.
 
Hmm Ive hit a road sign in the past from over a mile away with a 5 mW (metered) 532. It was by accident, but the reflection was blindingly bright. I really dont think they give a diffuse, but rather a specular reflection.

Other thought maybe there was one of those turning mirrors hung above the street.ie one that is used on a blind corner? :beer:

Edit: Just googled it and road signs use retroreflective coatings which return a large proportion of the on coming light. So its most definitely not diffuse.
 
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I'm using "diffuse" as the dictionary definition of "not concentrated." Road signs do NOT reflect a laser like a mirror would. Try it up close and you'll see.
 
Yeah I understand what you are saying, but a flashlight wouldn't blind you over a couple of miles... Admittedly you loose some of the light, but (depending on the angle) a large proportion of the light is reflected back as a SPECULAR reflection from the sign.

Yes laser light may become diffuse over a distance as a result of beam divergence, but the same would apply to reflected laser light from a road sign, over a distance.

Go try shining a low power laser, pref lower than 5 mW, at a road sign from a distance of a mile or so and try to tell me its diffuse. BTW my laser was a 5 mW with a min divergence of 0.1 mrad;)

Anyway as I mentioned it could well have also been a turning mirror. :beer:
 
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