Point Laser
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 CST XLP34PKG Mini Line Point Laser Level NEW  US $600.00
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 CST XLP34 Mini Line Point Laser Level NEW US $450.00
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 PLS5 Point to Point Self Leveling Layout Laser w Detector New in Box US $449.99
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 LEICA Lino P5 5 point laser Regular $420 US $342.57
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 Spectra Laser 52XL Multi Purpose 5 Point CrossLine US $345.00
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 Spectra Precision 52XL Point and Cross Line Laser US $339.00
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 Used PLS5 System With Detector Self Leveling 5 Point Laser Level US $260.00
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 New Leica Lino P5 5 Beam Point Red Dot Laser Self Leveling US $259.00
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 Leica Lino P5 5 Beam Point Laser Dot Laser US $259.00
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 10 7x250 LASER WELDED Tuck Point Concrete Blade US $236.95
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 10 7x250 LASER Tuck Point Concrete Blade US $236.95
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 10 7x250 LASER WELDED Tuck Point Blades 4 Concrete US $236.95
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 10 7x250 LASER Tuck Point Blade for Concrete Masonry US $236.95
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 10 7x250 LASER WELDED Tuck Point Concrete Blades US $236.95
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 Stabila Laser Type 80 LMX P Point Laser Level Kit W Case US $225.00
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 Pacific Laser Systems PLS3 PLS 60523 3 Point Level US $205.00
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 Bosch GPL4 4 Point Self Leveling Alignment Laser US $199.99
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 Leica LINO P3 3 Beam Point Dot Laser 777067 PLS3 US $199.00
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 NEW Leica 777067 Lino P3 3 Point Laser US $189.00
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 New Leica Lino P3 3 Beam Point Red Dot Laser Self Leveling US $189.00
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 Leica Lino P3 3 Beam Point Laser Dot Laser US $189.00
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 Bosch 5 Point Self Leveling Alignment Laser GPL5 NEW US $186.98
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 Bosch 4 Point Self Leveling Alignment Laser GPL4 NEW US $176.98
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 Bosch GPL3 3 Point Self Leveling Alignment Laser NEW US $175.00
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 Bosch GPL5 New 5 Point Self Leveling Alignment Laser Valid Bosch Warranty New US $154.95
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 CST Berger XP5S 5 Point Laser Level US $149.99
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 Bosch GPL5 5 Point Alignment Laser US $149.95
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 BOSCH GPL5 5 Point Self Leveling Alignment Laser NEW US $129.99
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 5 7x250 LASER WELDED Tuck Point Concrete Blades US $129.95
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 5 7x250 LASER Tuck Point Concrete Masonry Blades US $129.95
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 5 7x250 LASER WELDED Tuck Point Blade 4 Concrete US $129.95
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 5 7x250 LASER Tuck Point Blade for Concrete Masonry US $129.95
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 5 7x250 LASER Welded Tuck Point Conrete Masonry Blade US $129.95
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 Bosch 3 Point Torpedo Laser Alignment Kit GPL3T NEW US $106.99
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 BOSCH GPL3 Alignment Laser 3 point self level NEW FREE SHIPPING US $105.00
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 Hilti PMP 34 Point Laser in Case US $103.50
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 Bosch GPL5 5 Point Self Leveling Alignment Laser US $100.00
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 Bosch GPL5 5 Point Alignment Self leveling Laser Brand New FREE SHIPPING US $125.00
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 NEW CST Berger 5 Point Laser Level XP5s US $100.00
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 BOSCH GPL3 3 Point Self Level Alignment Laser US $99.99
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 Bosch GPL3T 3 Point Torpedo Laser Alignment Kit US $99.99
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 7 Laser Welded Tuck Point Diamond Blade 3 8 thick Best on Ebay US $99.00
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 BOSCH GPL5 5 Point Alignment Self Leveling Laser NEW US $90.00
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 NEW BOSCH 3 POINT SELF LEVELING ALIGNMENT LASER GPL3 W SOFT CASE US $89.00
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 CST Berger XP5S 5 Point Laser Level US $120.00
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 Bosch 2 Point Self Leveling Laser GPL2 NEW US $86.98
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 Bosch 3 Point Alignment Laser US $95.00
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 7 Laser Welded Tuck Point Diamond Blade 1 4 thick Best on Ebay US $79.00
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 Bosch 3 Point Self Leveling Alignment Laser GPL3 RT US $76.98
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 Bosch GPL3 3 Point Laser Level GPL 3 US $76.95
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 BOSCH 2 Point Self Leveling Laser Model GPL2 NEW US $75.00
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 BOSCH GPL3T TORPEDO 3 POINT ALIGNMENT LASER BRAND NEW US $69.00
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 4 Laser Welded Tuck Point Blade 250 thick US $69.00
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 45 Laser Welded Tuck Point Diamond Blade 250 thick Best on Ebay US $69.00
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 5 Laser Welded Tuck Point Blade 1 4 thick US $65.00
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 4 Laser Welded Tuck Point Diamond Blade 3 8 thick Best on Ebay US $65.00
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When I point a laser into the night sky, how far is it getting?
Just a regular red laser you buy your local convenience store. If I stood it upwards on a table on a clear day and kept it there for awhile how far would it get. Does it get weaker as it travels or is my little light already past the moon?
Thanks, Candice. Essentially though, will the diffused rays travel forever? Even if you can't see them?
JACK is right -- but with a caveat. Yes, it will go forever, but not like anybody could see it, after a short time-of-flight.
What makes a good laser better than a flashlight (for this sort of thing, that is), is what is known as its collimation. What that means is that when you shine the beam, you want to get all the individual rays in that beam lined up and going in as close to the same direction as you can. A laser can do this really well. But not all of them do, and the convenience-store laser probably isn't going to be very good at this.
So the beam will spread out as it goes. Even if it's really good for a convenience-store laser, it might spread out by an angle of, say 0.05º (that's probably very optimistic), which would mean it widens to about 1/1000 of the distance it has traveled. Which would make it about 250 miles wide at the distance of the Moon (after only 1 1/3 seconds!), or about 4,000,000 miles by the time it leaves the solar system (after about 6 hours). The photons are almost all there (a tiny percentage will get absorbed along the way), they're just spread way out.
But the same is true of an ordinary flashlight, only it spreads out a lot more quickly.
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