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Author Topic: spectrums  (Read 5732 times)

Offline Quantumcat

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spectrums
« on: 20/01/2004 09:02:27 »
Hey, does anyone know why it is that when you look at lights when it's dark you see all these lines come out, two long ones and a whole lot of short ones, and the long ones look like spectrums? I've never heard anyone talk about it but I'm curious. It's not like when you where those spectrum glasses that make you see a couple different images of the thing, each in another colour, but a line of colours.

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Offline cuso4

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Re: spectrums
« Reply #1 on: 20/01/2004 09:12:11 »
Quantum, I'm not sure I understand what you are trying to say. Are you talking about diffraction patterns? This is where light passes through a narrow slit and it forms a pattern of light and dark lines on the screen.

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Offline Quantumcat

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Re: spectrums
« Reply #2 on: 20/01/2004 12:59:15 »
No no not at all. At night when you look at lights you see lines coming out of them. At least I do. If you squint they grow longer.

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Offline Smeggit

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Re: spectrums
« Reply #3 on: 20/01/2004 17:50:53 »
Just an observation, it may be an effect of the cornea.  I see the lines more exaggerated when I wear my glasses.  It could be a lens effect but it's probably just be my glasses magnifying everything. ;)
 

Offline tweener

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Re: spectrums
« Reply #4 on: 22/01/2004 04:25:38 »
It's a lens effect in your eye.  If you've had Lasik surgery (or similar) it will be worse, I understand.

The lines are caused by small imperfections that refract (bend) light more at some angles that others.  The light entering your eye from the vertical will react a little differently to light coming in at 45 degrees and maybe appear brighter.  This is the same effect used by the "star filters" you can buy for camera lenses.  If you look at them you can see that they have lines etched in the filter.  By rotating the filter you can change the angle at which the lines radiate out from a small light source.


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Offline Quantumcat

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Re: spectrums
« Reply #5 on: 22/01/2004 07:25:11 »
So my eyes are stuffed up? =(

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Offline tweener

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Re: spectrums
« Reply #6 on: 23/01/2004 05:30:51 »
I guess that would be one way of saying it QC.  I think it's a normal thing, so don't worry about it unless it gets worse over time.

BTW, they are not really spectrums as the light is not broken into constituent wavelengths.  It takes a diffraction grating to do that.  They are really cool if you ever get a chance to grab one.  I got a small one when I was in college and spent weeks looking at everything through it to see what the spectrum looked like.  Sodium lights are really cool, and stop lights are interesting.

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« Last Edit: 23/01/2004 05:33:30 by tweener »
 

Offline Quantumcat

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Re: spectrums
« Reply #7 on: 23/01/2004 07:09:43 »
Oh allright. The colours are pretty, though.

In Questacon they had a small exhibition with various different lights and some diffraction glasses to look at them with.

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Offline Smeggit

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Re: spectrums
« Reply #8 on: 31/01/2004 20:16:03 »
How about this explination I found on another forum.  The toipc is actually talking abut how higher dimensions interact with our 3.

 
quote:
Physical points have to arrange themselves in triangles on a TV screen. I thought, "How can physical points arrange themselves in 3D space?" They would arrange themselves in tetrahedrons. Two tetrahedrons base to base have lines going in seven directions. When you look at a star, you can see rays going in six or seven different directions, just like you see light spilling out in three directions on a TV screen due to the arrangement of pixels. Old cameras had two rays, which is called a lensing effect. New cameras have three rays, which is not due to the lens, but due to the arrangement of pixels. Stars have six or seven rays, which is just what I would expect since I realized the arrangement of points in space line up in seven directions. In 3D space, one ray might be pointing straight at you so you would not see it. If you see a star with five rays, which is rare, the rays are very clearly defined, since two rays are more or less pointing at you, and the other five are very flat and evenly spaced to your line of sight. Sometimes, on big lights you see rays and the lensing effect. And the number of rays changes depending on when you look. Space has an absolute structure, and the earth is rotating through it. The way to count the rays is to count all the rays on one half of the star or bright light. A bright light in a TV camera has three rays on one half of the light source, and those three rays continue on the other side in the same direction.
 

Offline Bin Laden

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Re: spectrums
« Reply #9 on: 01/02/2004 13:51:12 »
quote:
Originally posted by Quantumcat

Oh allright. The colours are pretty, though.

In Questacon they had a small exhibition with various different lights and some diffraction glasses to look at them with.

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I had a similar problem with my browneye...

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Offline Donnah

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Re: spectrums
« Reply #10 on: 04/02/2004 17:51:01 »
quote:
Originally posted by Smeggit

How about this explination I found on another forum.  The toipc is actually talking abut how higher dimensions interact with our 3.

 
quote:
Physical points have to arrange themselves in triangles on a TV screen. I thought, "How can physical points arrange themselves in 3D space?" They would arrange themselves in tetrahedrons. Two tetrahedrons base to base have lines going in seven directions. When you look at a star, you can see rays going in six or seven different directions, just like you see light spilling out in three directions on a TV screen due to the arrangement of pixels. Old cameras had two rays, which is called a lensing effect. New cameras have three rays, which is not due to the lens, but due to the arrangement of pixels. Stars have six or seven rays, which is just what I would expect since I realized the arrangement of points in space line up in seven directions. In 3D space, one ray might be pointing straight at you so you would not see it. If you see a star with five rays, which is rare, the rays are very clearly defined, since two rays are more or less pointing at you, and the other five are very flat and evenly spaced to your line of sight. Sometimes, on big lights you see rays and the lensing effect. And the number of rays changes depending on when you look. Space has an absolute structure, and the earth is rotating through it. The way to count the rays is to count all the rays on one half of the star or bright light. A bright light in a TV camera has three rays on one half of the light source, and those three rays continue on the other side in the same direction.



Interesting, since one ancient shape shows seven equally sized circles; one in the centre and six that fit perfectly around it.  Try it with seven coins.
« Last Edit: 04/02/2004 17:51:35 by Donnah »
 

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Re: spectrums
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