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Green Laser Stuff


MolecularMan14

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have you ever seen a red one?

If I was less of a nice person' date=' I would say something sarcastic (let us all be thankful that im so damned nice) :) yes

 

asking to see if you are saying it is bright compared to a red laser... or compared to what you thought it'd be like.

Oh, its a lot brigher than a normal red laser. I figured that the beam would be almost a solid green line, but its close. Not quite up to my expectations, but then, few things are. And still, though the beam is not as extreme as it appears in some of the ebay pics, its easily visible in the dark, and the brightness of the dot is almost unbelieveable at such incredible distance. Im very much impressed with both the brightness, and the distance.

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Oh, its a lot brigher than a normal red laser. I figured that the beam would be almost a solid green line, but its close.

 

 

It's brighter because your eye is more sensitive - 550 nm is 4x more sensitive than a HeNe, and about 250x more sensitive than a laser at 700 nm.

 

By solid line do you mean the beam as it extends through the room, or when it hits the wall? You can only see the beam if there's something to scatter it, so it's not a function of the laser quality.

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Read my post again, IM NOT TALKING ABOUT GRAVITY. I'm talking about weight, is that really that hard to understand, I've said this once.

 

How is gravity not related to weight? W = mg

 

Percieved weight is really the normal force exerted on you. Is that really hard to understand?

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i spose if you were at the poles/equator that'd be the same thing with being different distances from the center of the earth...?

 

Two effects: You get an r change from the oblateness of the earth, plus the change in the normal force owing to the circular motion.

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By solid line do you mean the beam as it extends through the room' date=' or when it hits the wall?

[/quote']

 

what I mean by the beam is the light that extends across the room.

 

You can only see the beam if there's something to scatter it

 

Acually, I can see the beam in one of our rooms, (We have one of those air-purifier things, to eliminate dust), so there would be little to scatter it, but it's still rather bright

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It's brighter because your eye is more sensitive - 550 nm is 4x more sensitive than a HeNe' date=' and about 250x more sensitive than a laser at 700 nm.

[/quote']

 

Upon further review, this isn't the whole story. Those numbers are for photopic (daylight) vision. The peak is actually at 555 nm.

 

For scotopic vision (dark-adjusted), the peak sensitivity is close to 500 nm. But even comparing to 555 nm, that appears ~120 times brighter than a HeNe, and 22,000 times brighter than 700 nm, for the same power.

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  • 2 weeks later...

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