Green laser fun, Part II

fracman

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You can easily trace the laser trail at night, but in the smoke of a campfire it looks absolutely "light saber"

As the fire drifts down, you can aim the laser up through the air and see the location of the smoke amazingly well as it rises and stretches out.

What a fine toy.
 

Graham

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Steam works pretty well too. It looks pretty cool flashing around the bathroom after the shower has been used...although you can't get the same cool long range effect that you can get outdoors.

If you have a pool, shining it into the water at night is fun too (as long as you don't drop it in!)

Graham
 

The_LED_Museum

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I just picked up a big Meade astronomical telescope at a flea market today, and that should make a *great* collimator for those really long shots. I don't yet know the power of the instrument, but I believe it's strong enough to enable me to see to the edge of our star system. Probably Neptune and Uranus, but probably not Pluto. Should also be good enough to view several galaxies and other NGC- & Messier objects too.

If I had a ruby laser out of an old Hughes rangefinder and then fired it through this telescope, I should be able to put a visible flash on the moon with it.
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Though I doubt any of our green laser pointers would be strong enough to leave a spot visible from Earth regardless of what kind of collimator they were fired through.
 

007

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Yep, there isn't any doubt about it, what else can you buy that's fairly unique as a Green Laser????

I certainly have fun with mine!

James
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PS - I sit outdoors at night and smoke a cigar, then aim the green laser at the rising smoke. Ah, the things I do to entertain myself! My wife thinks I'm just an overgrown kid. If that's the case, then so be it.
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PhilAlex

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Stupid Question:

A pal of mine insists we didn't land on the moon.

All I have to do is point a telescope at the moon and show the "stuff" left, right?

And... Isn't there a mirror on the moon to reflect a laser beam so we can calculate how far it is away?

--Phil
 

Darell

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Going somewhere seriously humid (oh, like Kauai, for example) is a blast with the green laser. Doesn't have much reach in thick air like that, but it sure sparkles! We had about 5" of rain in four minutes at one point, and I was creating my own stars out over the lawn. It was quite a blast. The margaritas helped too, I'm sure...
 

The_LED_Museum

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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by PhilAlex:
Stupid Question:

A pal of mine insists we didn't land on the moon.

All I have to do is point a telescope at the moon and show the "stuff" left, right?

And... Isn't there a mirror on the moon to reflect a laser beam so we can calculate how far it is away?
<HR></BLOCKQUOTE>

The stuff we left behind (such as dead space probes, spent rocket boosters, a car, golf clubs, golf balls, a toilet, a few plaques, a few US flags, and some seismometers) are probably too small and far away to be resolved with any readily available earth-based telescope, but there is a retroreflective mirror that was dumped off way back when. With a seriously powerful pulsed laser and a seriously good telescope, it should be possible to fire the laser at the moon through the telescope, then knock the laser out of the way and look through the eyepiece in time to see a faint little sparkle of laser light returning to earth. This would probably only work on a night with a new moon and someplace away from high levels of atmospheric pollutants and those obnoxious sodium vapor lights.
Because the assembly left behind is retroreflective, it will work through a wide range of incident angles so positioning is not a factor.

If instruments can pick up the flash most of the time, the human eye should be able to pick up the flash at least part of the time. Not looking directly at the area where the flash is expected will increase your chances of seeing it. A high-powered green YAG laser would be the way to go.
 

PhilAlex

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Craig: How 'bout this:

You figger out how to WRITE on the moon's surface. with a laser. (Any colour)

We'll sell advertising! I'll place it and write it, you transmit it.

We split the profits.


I'm sure Surefire and Arcflashlight have Ad Budgets...
 

Darell

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Well, here was my first attempt at writing my name on Mars.

greendarell.jpg


(10 seconds of red laser through a frosted patio table, and the green [obviously] writing some idiot's name - on the rafters of our porch at the rental in Kauai)
 

Harrkev

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Does somebody remember this:

A couple of months ago, sombody was trying to get everybody i the USA with a laser pointer to point them at the moon simultaneously for five minutes. He was trying to paint a red dot on the moon. It was, as I recall, and as expected, a spectacular failure.
 

Darell

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I hadn't heard about that. It would surprise me if nobody on this board mentioned it when it was in full swing. Would have been fun to make fun if the project, I'm sure....

Did somebody REALLY think that little red pointers could somehow penetrate the atmosphere?
 

Harrkev

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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by darell:
REALLY think that little red pointers could somehow penetrate the atmosphere?<HR></BLOCKQUOTE>

They could. The problem is that they would be spread out across a sizable portion of the moon. On the return trip, they would be following the 1/(r^2) law, which means that the light would be incredibly feeble by the time that it got there, and even feebler still on the return trip. When the moon is lit, it has full sunlight illuminating it. How can 1000 laser pointers compete with the sun?
 
D

**DONOTDELETE**

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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by darell:
Yeah Dugg. What IS that thing?<HR></BLOCKQUOTE>

Worked fine for me! Certainly didn't crash my computer! It's a RealMedia file. I think you need RealPlayer to listen to it.

It's about the Apollo 11 astronauts putting the first retroreflector on the moon.
 
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