[Seany (OP)]

My friend bought this Green Laser off ebay...
Apparently it goes like 50 miles...!
And like you can see the beam, and it's amazing!!
We shone it on like a castle like 1km away and like the spot was as big as like a bed!

Would it really go 50 miles?

[Karen W.]

One of my husbands friends son just did that only he shined it at a police helicopter in Sacramento... and boy did they come down on him... It went on his record and There were police and other officials all over him.. With 911 thing.. it was crazy.... Guns the whole bit!

[Seany (OP)]

Wow... He has a criminal record for that???
What did the helicopter land in front of him?? []

[Karen W.]

Nope it was flying and they thought they were being targeted by a snipper with a laser or some such silliness.. Its probably somewhere in the Sacramento news.. I guess they made a bigger deal of it then they needed to but they wanted him to learn a lesson!

[Seany (OP)]

How did they catch him?

[Karen W.]

They called in back ups I guess I heard they arrested him in his dorm room or something like that... I will ask me daughter later for more details.. she knows more then me.. I may be off as to where they snagged him!

[Seany (OP)]

Wow.. That was really mean of them!!
LOL Christiano Ronaldo had a laser shone at his face when he was about to shoot (soccer).. The team or something got fined like $5000

[Karen W.]

WowI bet that person won't do that again!

[Seany (OP)]

LOL, I think they will [] Because it wasn't them who got fined, but the people who hosted the match I think lol!

[Karen W.]

LOL.. I never thought about that.. How far can the human eye see.. is it approximately 11 miles so even if the laser did shine 50 could we see it that far away!

Seems like we see further then that, but for some reason I am thinking 11. some odd miles!

[Bored chemist]

"Would it really go 50 miles?"
Yes, in clear air there's really not a lot to stop the beam traveling "forever". Strictly speaking scattering would weaken the beam but, with the right equipment, you would still be able to detect the beam at much greater distances. The same would be true for other colours.

How far it can go and still make a visible bright green spot on a wall is another question.

[DoctorBeaver]

Taking the curvature of the Earth into account, you'd be hard pressed to shine it on anything 50 miles away except an aeroplane.

I wonder if any of our maths genii can calculate the height it would shine at over a range of 50 miles. I feel a new thread coming on!  []

[Seany (OP)]

LOL.. I never thought about that.. How far can the human eye see.. is it approximately 11 miles so even if the laser did shine 50 could we see it that far away!

Seems like we see further then that, but for some reason I am thinking 11. some odd miles!

I think we could see about 100 miles? If it was like dark.. and the laser is green.. If you shone it on like a moutain 100 miles away...

[Seany (OP)]

Taking the curvature of the Earth into account, you'd be hard pressed to shine it on anything 50 miles away except an aeroplane.

I wonder if any of our maths genii can calculate the height it would shine at over a range of 50 miles. I feel a new thread coming on!  []

LOL LOL

[Karen W.]

LOL.. I never thought about that.. How far can the human eye see.. is it approximately 11 miles so even if the laser did shine 50 could we see it that far away!

Seems like we see further then that, but for some reason I am thinking 11. some odd miles!

I think we could see about 100 miles? If it was like dark.. and the laser is green.. If you shone it on like a moutain 100 miles away...

Hummmmm. I wonder..

[Seany (OP)]

Not sure, now thinking about it lol []

[ukmicky]

Taking the curvature of the Earth into account, you'd be hard pressed to shine it on anything 50 miles away except an aeroplane.

I wonder if any of our maths genii can calculate the height it would shine at over a range of 50 miles. I feel a new thread coming on!  []

To save you the energy of typing out a new thread, (ive heard how tiring things can be once you reach 60  [] []

http://newton.ex.ac.uk/research/qsystems/people/sque/physics/horizon/

[danielpower]

Laser beam is harmful to your eyes,you should wear a pair of laser safety goggles.
[spam removed]

[JulioMarco]

I will complement what danialpower said: green lasers should be handled with extreme caution.

If you aim it at a reflecting surface, depending on the level of reflection, you may end up with serious, sometimes permanent damage to your eyes... or someone else's, which is worst for another person would be taking damage from your actions.

Green lasers are, prioritarily, a tool for astronomy. Amateur astronomers point them upward, in the direction of a desired spot in the sky, so they can more accurately target it with a telescope (the laser is called a "designator" in such context).

Green lasers are not toys and should not be used unless by someone who needs them for a specific reason and takes all the necessary precautions.

I hope I have been of assistence.

Cheers!

Julio

[FuzzyUK]

One of my husbands friends son just did that only he shined it at a police helicopter in Sacramento... and boy did they come down on him... It went on his record and There were police and other officials all over him.. With 911 thing.. it was crazy.... Guns the whole bit!

Only a few days ago two men were arrested in my hometown for doing the same thing.

http://www.cambridge-news.co.uk/Cambridge/Two-arrests-after-laser-beam-pointed-at-police-helicopter.htm