Cientific Minds Needed Single Quiz.

BigBossLucas

BigBossLucas
I was wondering,

When you miss your shot using Lasers, does that shot keeps flying through the space forever?

Does the intensity of the Light Beam, vanishes while it travels? (to become a harmless light) or it stays strong and dangerous for ever?



Just asking for leisure and knowledge;)
 

Koen

Koen
Inverse-square law

Intensity is inversely proportional to the square of the distance from the source.

Edit: For non isotropic radiators such as parabolic antennas, headlights, and lasers, the effective origin is located far behind the beam aperture. If you are close to the origin, you don't have to go far to double the radius, so the signal drops quickly. When you are far from the origin and still have a strong new signal, like with a laser, you have to travel very far to double the radius and reduce the signal. This means you have a stronger signal or have antenna gain in the direction of the narrow beam relative to a wide beam in all directions of an isotropic antenna.

Source: http://en.wikipedia.org/wiki/Inverse-square_law
 
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Googol

Googol
The beam will attenuate through a combination of absorbtion and dispersion until it is effectively extinguished. That's not to say that theoretically photons from it could keep going indefinitely, but in the real world "dirty" universe something will get in their way eventually.

Edit: read "dispersion" to include inverse square effects (thanks Koen) as well as scatter :rolleyes:
 
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Spectre Alpha

Banned
Spectre Alpha
A laser beam will continue until acted upon by outside influences, ie gravity will bend it, matter will absorb / deflect it. Lasers are a coherent light and do not degrade like a flashlight.
And you mis-spelled Scientific btw.
 

BigBossLucas

BigBossLucas
Spectre Alpha said:
A laser beam will continue until acted upon by outside influences, ie gravity will bend it, matter will absorb / deflect it. Lasers are a coherent light and do not degrade like a flashlight.
And you mis-spelled Scientific btw.
Click to expand...

Oh, you're right in Spansih we say "Científico" I got confused, thanks for the correction.:eek:
 

Clifford

C
Alot of bad information being thrown around here....

Edit: better article:

There's a good article here, correct to answer the OP's question:
https://van.physics.illinois.edu/qa/listing.php?id=21368

In empty space, the wave does not dissipate (grow smaller) no matter how far it travels, because the wave is not interacting with anything else. This is why light from distant stars can travel through space for billions of light-years and still reach us on earth.
Click to expand...
Of course space is not _exactly_ empty, as already mentioned above.
 
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Spectre Alpha

Banned
Spectre Alpha

Spectre Alpha

Banned
Spectre Alpha
Cody said:
If you're picking typos, then that should start with an upper case I.
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I was continuing a former idea, the ... was implied, I will add it for you though. But if it was a new sentence, then yes, it would have been.

And just for your information 'upper case' is no longer used as it is an archaic form used to relate to the California Job Case that was used to set type by hand when lead type was still in use, today it is called a capital letter, not upper case.
 
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Clifford

C
Unknown Terror said:
I'm no scientist but with all that space dust floating around, it's not likely to go forever, or very far at all.
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Light from Rho Cassiopeia star travels 8200 LY , and still enough of its light reaches earth to be visible by the un-aided eye. (But it is a very bright star to being with.)
Rho Cassiopeiae ..... is a yellow hypergiant star in the constellation Cassiopeia. It is about 8,200 light-years (2,500 pc) away from Earth, yet can still be seen by the naked eye (in the Northern Hemisphere only), as it is 500,000 times more luminous than the Sun.
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http://en.m.wikipedia.org/wiki/Rho_Cassiopeiae
 

DaveB

DaveB
Spectre Alpha said:
I was continuing a former idea, the ... was implied, I will add it for you though. But if it was a new sentence, then yes, it would have been.

And just for your information 'upper case' is no longer used as it is an archaic form used to relate to the California Job Case that was used to set type by hand when lead type was still in use, today it is called a capital letter, not upper case.
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Now you're just being silly. Your nitpick is incorrect, however. FYI typographically speaking "upper case" is still perfectly valid usage. "Upper case" is only synonymous with "Capital letter" where you don't have a SMALL CAP FONT to deal with.

As it happens I have a few cases of type next to my press in the basement here and while most job case layouts, not just the California, have the capital letters along the top I think you'll find that "upper case" actually derives from the even older practice of having two separate cases in a rack above the compositors workstation.
 

Spectre Alpha

Banned
Spectre Alpha
DaveB said:
Now you're just being silly. Your nitpick is incorrect, however. FYI typographically speaking "upper case" is still perfectly valid usage. "Upper case" is only synonymous with "Capital letter" where you don't have a SMALL CAP FONT to deal with.

As it happens I have a few cases of type next to my press in the basement here and while most job case layouts, not just the California, have the capital letters along the top I think you'll find that "upper case" actually derives from the even older practice of having two separate cases in a rack above the compositors workstation.
Click to expand...

The schools (in America) are teaching 'Capital letter' as the correct form, that is what I was referring to. I know all about the upper case in typesetting (from the days of wood type), I did hand set (lead and wood) type in high school for a platen press, now I am a retired digital press tech that used to work in a shop with 28 iGen Diamonds and 36 HP Indigos, (12 of which were web). There are no cases of type in modern (digital, variable data) printing.

And of course I was being silly, life without silly is boring.
 

DaveB

DaveB
Spectre Alpha said:
The schools (in America) are teaching 'Capital letter' as the correct form, that is what I was referring to. I know all about the upper case in typesetting (from the days of wood type), I did hand set (lead and wood) type in high school for a platen press, now I am a retired digital press tech that used to work in a shop with 28 iGen Diamonds and 36 HP Indigos, (12 of which were web). There are no cases of type in modern (digital, variable data) printing.

And of course I was being silly, life without silly is boring.
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You'd be surprised how many print shops keep a letterpress and a guy who knows how to run it still. Yes you can get specialized machines for foiling, scoring and die-cutting and you can do the fancy embossed ink without a letterpress.. but only a letterpress can do ALL of those things. :)
 

Calaban

Calaban
:rolleyes: dont know what the above discussion is about....

OP: by way of example, a laser pointer shot to the moon would be a "dot" 50km wide by the time it gets there. As such it will be a much weaker beam in any given point, and would need a special photon detector, or a big telescope pointing exactly in the correct direction, to even see it shining from the earth.

That is what lasers do when they go extra far. The go farther than regular EM signals, but not forever as a tight beam.


A more interesting thing to talk about for your Curiosity and Leisure is:

If my Cobra found itself in the void between galaxys [terrifying mis-jump], and shot its cannons at the nearest galaxy. It. Would. Never. Reach. it! A gun's bullet- which will continue on until it hits something "forever", is going "only" 450 m/s or so. The expansion of the universe has galaxies pulling away at over 3,000 m/s, so in effect, and for all practical purposes, the bullet never really goes anywhere, and remains near the gun... forever. :)
 
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