I bought one of those pocket lasers a couple of years ago. And shortly after I bought it, I did a little experiment late at night. I took it outside and shined it on various objects to test out its range.
It seemed like there was literally no limit to how far I could get it to go. I could shine it on objects literally blocks away. Then I tried shining it on the clouds. And absolutely nothing happened!
I know my laser isn’t as powerful as the ones NASA probably has. But shouldn’t my beam go, in theory, out into infinity?
even the best lasers diverge which really explsins why you can see the dot "blocks away’ if the dot didnt get bigger with distance it would be to small for you to see. Anyway all light theoretically will continue on unless stopped by something. The clouds would be hard to see anything from becasue a: they can easily be several miles high, and b: they ae not solid objects. They are vapor/fog what little light does reach that high would be scattered so diffusly that you would not be able to see it unless you started with a very powerful light source to begin with.
Both true. There may be yet another reason. The hand held laser is capable of FOCUSING for only so far. The light beam may be detectable at some level by highly sensitive equipment ( “light keeps going forever, etc” ), but it does not stay RESOLVED as a tightly focused beam of light past a certain distance.
I own some of those too. They’re good for shooting across a sports stadium (indoors), and will show a dot at …what would that be?..200 yards? Maybe a bit more? Hand held commercially sold lasers simply don’t have A) the raw illuminative power, and B) the optics to throw a dot up a few miles to a cloud.
Those devices are the purvey of military and scientists, IMHO. I bet Edmund Scientific’s cataloge could prove me wrong, but I can tell you that that hand-held one just doesn’t have the juice.
Cartooniverse
A few months ago at work I got my hands on a co-worker’s pointer and shone it up to a level of clouds level with that of the roof of our hotel tower (Ballys Park Place, Atlantic City).
The best way to see it reflected over long distances is to zap a stop sign or car reflector. Otherwise, the beam diverges too quickly to be seen well. There is a brand of green lasers which are better at scattering off junk in the air, and can be seen as a “light saber” for quite some distance. Amateur astronomers use them to point out stars. They are very impressive.
