What is Digg?33 Comments
- LemurHorde, on 10/12/2007, -2/+25Short attention span version:
A material appears transparent when it doesn't strongly absorb or diffract light. Stuff that mucks with this are electrons absorbing the light and radiating it in other directions and diffraction caused by gaps between the microcrystal substructure (grain boundaries) that are larger than the wavelength of light. - sockpuppets, on 10/12/2007, -4/+24Its proximity to Britney Spears.
- pastasauce, on 10/12/2007, -0/+5No, because then almost everything will be transparent.
- pollardito, on 10/12/2007, -1/+4water by itself is a poor conductor. water with stuff dissolved in it is a good conductor:
http://www.physlink.com/Education/AskExperts/ae61.cfm - plarp, on 10/12/2007, -1/+4Read QED by Richard Feynman
http://www.amazon.com/QED-Strange-Theory-Light-Matter/dp/0691024170
k thanx - CornStarch, on 10/12/2007, -1/+4You have no idea how Ironic that comment is.
- NikoKun, on 10/12/2007, -0/+3hmmm Transparent Aluminium? XD (star trek... XD)
- crilen007, on 10/12/2007, -0/+2Not sure why... but the caption made me think of the Monty Python Witch skit...
- CornStarch, on 10/12/2007, -1/+3The ability of light to pass through it unreflected or minimally reflected.
- somon90, on 10/12/2007, -0/+2 Well researchers at Penn State University have cracked one of the mysteries on the way to transparent metals. The researchers set out to accomplish a task never before completed...make uniform pores in the size range between 10 and 100 nanometers. In the past, researchers have been able to create pores larger than 100 nanometers using polymer spheres as templates. They could also produce pores less than 10 nanometers by using molecules as templates, but the 10-100 nanometers range alluded them as no suitable template was available.
The Penn State researchers had come across an article printed in 1990 describing a method of producing identical silica spheres of only 35 nanometers in diameter. The researchers wanted to try using this "high tech" sand as a template for new materials. By adding an organic monomer to a pellet of the pressed sand and then processing the monomer to a polymer, the researchers were able to chemically dissolve the silica spheres. The result is 75% empty space surrounded by polymers.
Potential uses for these porous materials are nearly unlimited. They could be used to separate chiral compounds in the pharmaceutical industry. Also, since the length scales of the pores are well below the wavelength of light, any material made with the pores will be transparent....even metals! - KniteWulf, on 10/12/2007, -0/+2Make your tank see-through. The enemy won't know what hit them!
- x00x, on 10/12/2007, -1/+2If anyone remembers Star Trek IV where they had to return to the past to save the whales Scotty gives this manufacturing company a couple of hundred years head start on "transparent aluminum". Until transparent aluminum I had the whole transparent chemistry thing all wrapped up.like Reynolds Wrap aluminum the opaque-shiny silvery metallic kind.
- Onychophora, on 10/12/2007, -0/+1Al2O3 (aluminum oxide) actually is transparent, if that counts. It's clear sapphire, used for expensive watch faces. (Iron and/or titanium impurities make sapphires blue.)
- gerryk, on 10/12/2007, -2/+3That's a result of transparency, not a condition of it.
- Phatt138, on 10/12/2007, -1/+2Well royall, technically what you said was something along the lines of, "a substance is transparent when it's made of transparent stuff;" whether you meant it to be or not, that's the way it read. In the end, that's not really saying anything at all.
Meanwhile, Lemur addressed the physical properties that allow light to pass through a substance made up of what, in their natural arrangements, are opaque components. That's an actual explanation.
edit: dougless - not only is this digestible, it's actually understandable by the average person - not just physicists. If you're interested, there are plenty of good explanations of the way that light and matter interact both on the web and elsewhere. - somon90, on 10/12/2007, -0/+1N00bs they don't even explain the quantum interference mechanism between the light and matter interactions!
- somon90, on 10/12/2007, -0/+1Such as aluminum
- slothlovechunk, on 10/12/2007, -0/+1you're dumb.
- W00DR0W, on 10/12/2007, -1/+2What are you talking about sloth? The eye only sees light that is reflected, so what Corn says is true; if light passes through something with minimal reflection it's transparent!
Your response doesn't even make sense. And your mislead berating of Corn makes you look like an ass. - slothlovechunk, on 10/12/2007, -2/+3This is what I'm talking about. If you don't know anything quit trying to teach people what you don't know.
Light, at an interface, where the index of refraction changes, is both reflected and refracted as can be described by the fresnel reflectance equations, which can be derived from maxwell's equations. If the index of refraction of the material is high enough (light travels slow enough in it), most light is reflected, still, some light is refracted.
The part you are missing in your simplification is that things can be opaque, simply from absorbing light in the visible spectrum. You are missing absorption. Differentiating between these two effects is quite important.
Think about milk. Milk is mostly water with maybe little fat particles or whatever, inside. When the index of refraction changes within the medium, light scatters around, but very little is absorbed, look how white that milk is.
On the other hand, what about water with food coloring? The food coloring disolves and there are none of these interfaces, like in the milk. The water now absorbs some of the light that passes through it, but you might still be able to see through it clearly.
"if light passes through something with minimal reflection it's transparent"
So back to my original comment, you both ended up proving my point. You continued to spout your ignorance and try to sound like you know what you're talking about. If something passes through something with minimal reflection, it is not necessarily transparent. (if you actually read the article you would see many examples)
If you don't have anything productive to add to this well-written article, stfu. - mb3581, on 10/12/2007, -2/+2umm... when you can see through it??? :-o
- HappyScrappy, on 10/12/2007, -2/+2Article propagates myth that glass isn't a solid, but really a slowly-flowing liquid.
dugg down. - Llanowar, on 10/12/2007, -3/+2Well, duh... because it is glass of course! Everyone knows glass is transparant and sand isn't!
- CornStarch, on 10/12/2007, -2/+1You cannot see absorbed light you retard, if it doesn't get back to your eye you can't see it. You're trying to go into a bunch of physics and ***** because you're a self righteous ***** know it all, but if you were looking at if from the perspective of how the human eye sees you would know that you cannot see something if light is not reflected back to the eye. That is why when it is dark you cannot see, it doesn't matter wtf is absorbing the light, because if it doesn't make it to your eye you can't see it.
You're trying to get into Spectroscopy and physics when there is no need for it. You're not looking at glass through some apparatus that detects were every ray of light goes, you're talking about what the human eye can see. - slothlovechunk, on 10/12/2007, -3/+2Really? what about the light that isn't reflected?
Seriously, if you're going to post a comment here and attempt to sound smart, please, at least know something. Because people who aren't as dumb as you will read what you wrote, and feel obliged to comment. The problem is, that a majority of people on digg can't tell the difference between someone who knows his *****, and someone who sounds like he knows his *****, so your lame comment doesn't get buried, and their correction may. - DBrez8, on 10/12/2007, -4/+3ummmm....you mean like water???
- YeahOK, on 10/12/2007, -1/+0Uhhhh what?
- matrixbandit, on 10/12/2007, -2/+0Actually, most sand probably is transparent. Consider if you had sugar cube size pieces of glass, but about a billion of them all dropped randomly in a giant pile. Effectively the light going in one side would be scattered so efficiently you'd never see it coming out the other side. I guess you could consider it to be a form of subsurface scattering, though different than the subsurface scattering you see with human skin, I think the general principle is vaguely similar.
- sockpuppets, on 10/12/2007, -10/+5Smart girls rock. You're my new bff, I just wanted you to know that.
- inactive, on 10/12/2007, -10/+3Sure, say the exact same thing as I do and get dugg up.
- extremophile, on 10/12/2007, -7/+0if it passes through Homeland Security screening.
- inactive, on 10/12/2007, -30/+6If something is transparent light passes through it. An element is transparent when all it's forms are transparent.
Digg is coming to a city (and computer) near you! Check out all the details on our 
© Digg Inc. 2009
— Content created and posted by Digg users is