Another 405nm Magic Trick

[lasersbee]

I've tried that before... : and yes... shinning a laser on the Radiometer does make
it spin.... But the laser beam needs to hit the Black side of the vanes.

 

[lasersbee]

Somehow I REALLY doubt that thing is moved by light, though I'm not sure, they did make those UFO-like thingies launched by a laser, somehow. :-/ Still it seems kinda unlikely, I would rather give credit to heat and moving air curents. :-/

There is a vacuum inside the Radiometer...

 

[laserwanabe]

=) i can't seem to find mine.

A wrapper weight basically nothing, so strong enough light from a laser will move/burn it. I still think the light moved it but I wasn't there =p

 

[pullbangdead]

Here's one to try, and it happens with all the laser colors I have..

Shine a laser at something reflective, and look at the reflected light on the wall, or inside a porcelain cup, whatever you are trying.

You will see that the reflected light looks "staticy"- like the static you see on an untuned television set. Thing is, if the laser is not moving(such as on a tripod), the static doesn't move either. It does not seem to matter what type of reflective surface you use, eitther-other than a morror of course.

Speckle. That is why laser light looks "staticy". http://en.wikipedia.org/wiki/Speckle

 

[rog8811]

I had to get my radiometer out and give it a try......even a 5mw 635mn laser moves it...slowly.
Blue ray and red burners spin it nicely, best of all though was my 150mw NIR, When I first pointed it at the vain I got the white flash that you get at the sweet spot so pulled it back a bit... it fair flew around.

Thanks for the tip Laserwanabe and laserbee

Regards rog8811

 

[thesk8nmidget]

im gonna have to buy a radiometer now

 

[scopeguy20]

Steam, (not superheated steam), will ocupy 300X the volume of the water it came from, the moisture on the wrapper interior, or the candy residue c/b vaporized and move the wrapper, the light pressure likely would not at so much less than 1 watt IMHO.

I gotta go buy a Snickers bar!

 

[lasersbee]

Hey... I just got a brainstorm Idea... (I'm always thinking Laser Power Meters ;D ;D)

How about setting up a Radiometer with an optical speed sensor (rpm) and use
that as a relation to laser power  :-? : : :

The higher the laser's power... the faster it spins  : : :

That shouldn't be too expensive to build : : :

Don't forget you heard it here first.... ;D ;D ;D ;D

Jerry

 

[suiraM]

I've noticed that blu-ray causes my floaters to become much more noticeable as well. weird.

Not the least bit weird, really. Hell, some of them may even contain fluorescent proteins. But more to the point, it's pretty intense light, in a part of the spectrum where there is very little ambient light. As a consequence, they end up casting more noticeable and distinct shadows on your retina. Also, when you're doing stuff, you're more apt to move your head and eyes about, which causes the floaters to move about in your field of vision, due to inertia and moving in a fluid medium. Finally, there is a small body of evidence to suggest that short wavelength light can increase the number of floaters formed in the macular field of vision.

As daguin said, everyone has some, but most people's brains will start to filter them out. Some are congenital. Some originate with trauma. Most originate with aging of the eyeball, wherein the fluid medium slowly transitions from one viscosity to another, causing strain on thin fibres attached to the retina, such that these fibers eventually snap. Some of those end up tangled into balls, others remain mostly straight. Solid black ones are blood cells that have leaked into the viscous fluid and have not yet settled to the interior surface (where any free-floating ones of a certain size and composition will be reabsorbed into the bloodstream and eaten by macrophages).

They are normally no cause for concern, unless they cause distress. However, if you have many of them, or a large number of them appear at the same time, or if they appear while accompanied by white flashes, then you should see an eye doc about it. If the white flashes occur, you should see an eye doc in the next 72 hours, on the off chance that it indicates retinal detachment (rare, and the flashes are not a strong indicator, but catching it early is important for a good prognosis, so checking it out quickly is always worth it).

If they cause distress, you're in the same boat as me. I get dizzy from them, sometimes, and my brain does not filter them out at all. That is what got me interested in lasers in the first place, as I have done medical research in the past, and fully intend to develop a safer, more effective procedure for floater removal. I've run the initial concept by docs, and it has been deemed viable, so I hope to realize a prototype. Current treatments either involve draining all of the fluid from the eye, or disintegrating them with pulsed lasers. Both of these approaches have a significant risk of accidental damage to the eye, as well as later complications of the treatment. Most relevantly, perhaps, is the 4% chance of going blind, last time I checked. Those risks were not acceptable to me, but a lot of people are worse off than I am, so a lot of people still elect to have these procedures performed.

Anyway, that's probably all you ever wanted to know about floaters.

 

[Glaserfan]

Speckle.  That is why laser light looks "staticy". http://en.wikipedia.org/wiki/Speckle

Cool! That answers what probably would have been my next question It's actually quite an interesting effect, especially when looking at reflected light from a green.

 

[rocketparrotlet]

I read about the speckles that it is caused because as the coherent light hits a surface, it scatters, and sometimes two photons will synchronize, being seen as light, and sometimes, two photons will be reverse of each other, and cancel each other out. This is what causes the speckle effect.

At least, that's what I read.

-Mark

 

[Switch]

I read about the speckles that it is caused because as the coherent light hits a surface, it scatters, and sometimes two photons will synchronize, being seen as light, and sometimes, two photons will be reverse of each other, and cancel each other out.  This is what causes the speckle effect.

At least, that's what I read.

-Mark

And I'm guessing that a green laser gives a more speckly pattern when scattered because of the smaller beam diameter, smaller surface scattered from and therefore less more chance of photons cancelling.With larger diameter they probably have less chance of cancelling out and more chance of the surface being filled with "uniform light" rather than speckly pattern. :-/

Btw, about the floaters, are they the reason for the expresion "seeing stars" when you get hit to the head, cause they do kinda look like little tiny stars

 

[daguin]

Btw, about the floaters, are they the reason for the expresion "seeing stars" when you get hit to the head, cause they do kinda look like little tiny stars

No. Those "lights" are caused by "misfires" in the visual cortex part of the brain. The impact causes "waves" of pressure to pass through the visual cortex.

If you just want to "see stuff" (without the drugs), try pushing [highlight]gently [/highlight]on the side of your eye for a few seconds. The retina "decodes" the pressure increase as visual stimulation and sends screwed up messages to the brain. [smiley=evil.gif]

Peace,
dave

 

[laserwanabe]

Dave, i used to do that all the time in school when i was bored. Sometimes its like your dreaming, if you imagine things you can actually produce coherent pictures. Usually it looks like im getting closer and closer to something, or going into a tunnel.


I don't press on the sides i just rub and hold my eyes, if you do it for to long it does hurt. And if you get a blink reflex while your eyes are closed you lose the picture.

 

[Montana64]

Good information suiraM, seems you have researched this extensively.


Ted

 

[Montana64]

Another LPF member posted this link before, think it may have been daguin, not sure tho.... however, it explains the "speckles"
[urlhttp://en.wikipedia.org/wiki/Speckle[/url]

Ted