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(YouTube) Video Coolest use of a 5-watt laser pointer you'll see today   (youtube.com) divider line 36
    More: Video, Subaru Telescope, galactic center, laser pointers, adaptive optics, Mauna Kea, lasers  
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12310 clicks; posted to Video » on 05 Aug 2012 at 12:55 PM (2 years ago)   |  Favorite    |   share:  Share on Twitter share via Email Share on Facebook   more»



36 Comments   (+0 »)
   
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2012-08-05 01:04:54 PM  
Oh great, why not just announce where we are so they can find a new source of nutrition.
 
2012-08-05 01:05:36 PM  
PEEEEEEEEEEEEEEEEEEEWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWW WWWWWW......
 
2012-08-05 01:06:18 PM  
First the commercial pilots, then the Navy pilots. Now the Sagittarius Armada pilots.

This will not end well.
 
2012-08-05 01:07:05 PM  
Not the coolest use of a 5-watt laser pointer you'll see today ever. FTFY
 
2012-08-05 01:08:25 PM  
I wonder when the alien counterattack will begin?
 
2012-08-05 01:11:06 PM  
Needs more ghetto bird.
 
2012-08-05 01:31:21 PM  
Will 5 watts even make it out of the atmosphere? How many watts to reach the moon?
 
2012-08-05 01:42:47 PM  
i.crackedcdn.com

Another great 'Welcome to Fark' pic.
 
2012-08-05 01:52:56 PM  

OlderGuy: How many watts to reach the moon?


2.3 watts of average power is enough to reach the moon and return a measurable signal from a retro-reflector.
 
2012-08-05 02:08:41 PM  
In other news the entire constellation Leo was spotted chasing something towards the edge of the visible universe.
 
2012-08-05 02:13:00 PM  
FYI:
120 milliwatts will ignite newsprint at about 6 inches. Five full watts is, actually, A LOT.
(Start your grill, harm small woodland creatures, etc.)

But, it takes quite the farkload of electricity to generate 5 watts of laserness -- at least, it did in the '80's -- tech is likely more efficient now.
Electricity watts not same as laser watts.
Off the lawn, lest I PEWWWW thee . . .
 
2012-08-05 02:15:18 PM  
In before someone says NASA could never have built retro reflectors with 1960's technology.
 
2012-08-05 02:21:44 PM  

BumpInTheNight: In other news the entire constellation Leo was spotted chasing something towards the edge of the visible universe.


Nice....
 
2012-08-05 03:15:17 PM  

BumpInTheNight: In other news the entire constellation Leo was spotted chasing something towards the edge of the visible universe.


+1 I LOLed.

I'm building a 3 axis laser spirograph projector this afternoon so I'm getting a kick...
 
2012-08-05 04:04:22 PM  
BumpInTheNight

In other news the entire constellation Leo was spotted chasing something towards the edge of the visible universe.

Aaaaaand we're done.
 
2012-08-05 04:05:41 PM  
I was looking for something more in the 40 watt range.
 
2012-08-05 04:11:17 PM  
Popcorn? It's popcorn, isn't it?
 
2012-08-05 04:14:11 PM  
KarmicDisaster: I was looking for something more in the 40 watt range.

You can get 40W tubes on ebay for like 600 bucks. Its kinda hard to find ones larger than that on there outside of a surplus place. You can end up spending 4 or 5k on a commercial one designed for etching steel or burning warts.

I wanna build one
 
2012-08-05 04:34:50 PM  
KarmicDisaster: I was looking for something more in the 40 watt range.

Hey, only what you see, buddy.
 
2012-08-05 05:07:20 PM  
OlderGuy: Will 5 watts even make it out of the atmosphere? How many watts to reach the moon?

I'm guessing the end of the visible beam in that video is the end of the atmosphere and it just keeps going without anything to scatter it.

10^32 watt laser:
3.bp.blogspot.com
/still insignificant next to the power of the Force.
 
2012-08-05 05:13:03 PM  
5W is not a laser pointer, it's a laser pistol...
 
2012-08-05 05:56:08 PM  

Snargi: I wonder when the alien counterattack will begin?


I think we are safe considering that it takes 27,000 years until the laser gets there, but we are trolling our future descendants real good.
 
2012-08-05 06:02:40 PM  

BumpInTheNight: In other news the entire constellation Leo was spotted chasing something towards the edge of the visible universe.


+1 internets reward for you
 
2012-08-05 06:05:03 PM  

OlderGuy: Will 5 watts even make it out of the atmosphere?


It doesn't have to. The function of an observatory laser is to provide a known reference in the upper atmosphere, which the adaptive optics then calculate against in order to correct for atmospheric distortion.

How many watts to reach the moon?

This isn't as simple to answer as you might imagine. Most people have what I'd term a 'linear' concept of laser power: x Watts delivers y Power/yield/whatever. In reality, the functional yield power (radiant light) of a given laser is a function of its peak level (steady) output power against the duration of a given pulse. I don't know the math for this, but as a very general rule, a modest-powered laser gets a higher yield with shorter pulses. I don't know a lot about lasers, unfortunately, so everything you're reading here is based on what I believe I understand from what I've read about it. Hopefully, someone who knows more will correct or clarify this mess.

In the case of sending a laser to the Moon, we can use the example of the lunar ranging laser at the Apache Point observatory, used to track the distance and motion of the Moon relative to Earth, by firing lasers at reflectors left there for this purpose by Apollo astronauts. The level output of Apache's ranging laser is a very modest 2.3 Watts -- not much more than most laser pointers. However, the pulses delivered to the Moon for reference are less than 100 picoseconds (100 x 10−12 sec.), for a calculated yield of 1.15 gigawatts -- more than 650 million times the laser's peak level output.

Because of atmospheric effects and interplanetary dust scatter, the overall loss of these pulses is substantial. Only about 1/30th of the original light pulse reaches the reflector on the Moon, and only about 1/30th of that returns to Apache Point: Only about one thousandth of the original pulse light makes it back.
 
2012-08-05 06:50:10 PM  

Sylvia_Bandersnatch: OlderGuy: Will 5 watts even make it out of the atmosphere?

It doesn't have to. The function of an observatory laser is to provide a known reference in the upper atmosphere, which the adaptive optics then calculate against in order to correct for atmospheric distortion.

How many watts to reach the moon?

This isn't as simple to answer as you might imagine. Most people have what I'd term a 'linear' concept of laser power: x Watts delivers y Power/yield/whatever. In reality, the functional yield power (radiant light) of a given laser is a function of its peak level (steady) output power against the duration of a given pulse. I don't know the math for this, but as a very general rule, a modest-powered laser gets a higher yield with shorter pulses. I don't know a lot about lasers, unfortunately, so everything you're reading here is based on what I believe I understand from what I've read about it. Hopefully, someone who knows more will correct or clarify this mess.

In the case of sending a laser to the Moon, we can use the example of the lunar ranging laser at the Apache Point observatory, used to track the distance and motion of the Moon relative to Earth, by firing lasers at reflectors left there for this purpose by Apollo astronauts. The level output of Apache's ranging laser is a very modest 2.3 Watts -- not much more than most laser pointers. However, the pulses delivered to the Moon for reference are less than 100 picoseconds (100 x 10−12 sec.), for a calculated yield of 1.15 gigawatts -- more than 650 million times the laser's peak level output.

Because of atmospheric effects and interplanetary dust scatter, the overall loss of these pulses is substantial. Only about 1/30th of the original light pulse reaches the reflector on the Moon, and only about 1/30th of that returns to Apache Point: Only about one thousandth of the original pulse light makes it back.


most laser pointers are around 5mW, nowhere near 2.3W. Unless you're referring to more advanced machines that utilize lasers, but those aren't really laser pointers, so...
 
2012-08-05 07:15:46 PM  

mason4300: most laser pointers are around 5mW, nowhere near 2.3W. Unless you're referring to more advanced machines that utilize lasers, but those aren't really laser pointers, so...


Thanks for the clarification! That's an embarrassing oversight on my part.
 
2012-08-05 08:40:15 PM  
My take-different perspective, different night:
lh6.googleusercontent.com
 
2012-08-05 08:55:13 PM  

Ianman: Not the coolest use of a 5-watt laser ever.


Oh, absolutely not. I've seen lasers going up into the sky on many occasions - though to be fair, most of those were more in the 8-12 watt range. I've seen multiple beams converging on a single target. I've watched c-beams glitter in the dark near Tannhäuser Gate. I've seen what happens when these lasers actually hit things. I've seen the back-end gear that produces them.

But truth be told, this was the only 5-watt laser I saw today.
 
2012-08-05 09:06:55 PM  

dbirchall: Ianman: Not the coolest use of a 5-watt laser ever.

Oh, absolutely not. I've seen lasers going up into the sky on many occasions - though to be fair, most of those were more in the 8-12 watt range. I've seen multiple beams converging on a single target. I've watched c-beams glitter in the dark near Tannhäuser Gate. I've seen what happens when these lasers actually hit things. I've seen the back-end gear that produces them.

But truth be told, this was the only 5-watt laser I saw today.


Here's my candidate for ever
 
2012-08-05 09:22:23 PM  

ScreamingHangover: Here's my candidate for ever


Ooh, I remember that one... can't find how many watts it is, though. Kinda doubtful that it'd be as high as 5.
 
2012-08-05 09:30:59 PM  

dbirchall: ScreamingHangover: Here's my candidate for ever

Ooh, I remember that one... can't find how many watts it is, though. Kinda doubtful that it'd be as high as 5.


Probably not. but still... coolest use of a laser I've ever seen.
 
2012-08-06 12:14:46 AM  
Good job. I give it an A*.
 
2012-08-06 01:44:03 AM  
We tried to burn down water hyacinths with a skiff-mounted CO2 laser in the multi-kW range, but you couldn't see it.

Lasers are NOT a good method of water hyacinth control. You can burn them to the water line, but they don't die. OTOH, water ripples will occasionally smoke the guys on the boat. And a big CO2 laser will definitely break windows quite some distance away.

/car windshield...locked. Firing. (psssh!) Target shattered. You have earned the thanks of a grateful nation. Mission accomplished.
 
2012-08-06 09:55:02 AM  
Wake me when they are cutting a girl's clothes off with it.
 
2012-08-06 10:42:16 PM  
MrBonestripper

Wake me when they are cutting a girl's clothes off with it.

Oh, you'll know.

/Nighty-night :)
 
2012-08-07 12:16:34 AM  

ScreamingHangover: dbirchall: Ianman: Not the coolest use of a 5-watt laser ever.

Oh, absolutely not. I've seen lasers going up into the sky on many occasions - though to be fair, most of those were more in the 8-12 watt range. I've seen multiple beams converging on a single target. I've watched c-beams glitter in the dark near Tannhäuser Gate. I've seen what happens when these lasers actually hit things. I've seen the back-end gear that produces them.

But truth be told, this was the only 5-watt laser I saw today.

Here's my candidate for ever


WANT
 
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