Interaction between light and matter – no room for the photon
One of the fundamental aspects of physics is the study of light and how that interacts with matter. I have been putting off this post - mainly because I am not a quantum mechanic (I am a classical...
View ArticleWhy are sparks blue?
why are sparks blue? My first gut response was that this is the blackbody color. Wrong for several reasons. The short answer is that sparks are blue because o the colors given off from nitrogen and...
View ArticleA demo for the color black
What do you see when you are in a completely dark room with no lights?
View ArticleSpectroscopy and Collimated light
"A simple question for which I can't find an answer: Why do you have to collimate light spectroscopy? What would happen if you didn't collimate it?"
View ArticleHow much of yourself can you see in a mirror
How much of yourself could you see in a small mirror?
View ArticleHow do color filters work?
When you look through a red filter, everything looks red. What do they do to the light? I am not going to tell you the answer. However, I will show you some examples so that you can ...
View ArticleBlue laser awesomeness
First, they don't look too bright. This is probably because our eyes are not too sensitive to this wavelength. The blue 10 mW does not look anywhere near as bright as the 5 mW green that I used ...
View ArticleNotes on the Physical Science Final Exam
The simplest answer is that the gravitational field on the moon is smaller than on Earth (I would accept that answer). Why is this? It is because the moon as a much smaller mass even though it also ...
View ArticleKids like demos
Sometimes I get asked to do some demos for kids. I like this, it is fun. This week, I was asked to do just such a demo. Kind of as a historical record, I am going to ...
View ArticleKindle vs. iPad in the Sun
There is this commercial that has been coming on lately showing some people reading the Kindle at the beach. Why is this a selling point? It has to do with the way the Kindle works compared to...
View ArticleLaser Light Can Lift Tiny Objects
Light has been put to work generating the same force that makes airplanes fly, a study appearing online December 5 in Nature Photonics shows. With the right design, a uniform stream of light has pushed...
View ArticleClik here to view.
Invisibility Crystals Make Small Objects Disappear
Professor Snape beware — invisibility cloaks aren’t just for the microscopic anymore. Using natural crystals, two independent research teams have designed “carpet cloaks” that can abracadabra 3-D...
View ArticleClik here to view.
Laser-Powered Tractor Beam Could Move Tiny Particles
Solenoid Tractor Beam Solenoid beams in proposed tractor-beam devices contain a bright spiral of energy woven into their light. Credit: David Grier/New York University =
View ArticleClik here to view.
Physicists Build Big Bang in a Box
Sitting on a bench at the University of Maryland is the first-ever desktop model of the Big Bang. Don’t worry, the 20-micrometer&endash;wide device simulates how light behaved and time flowed at...
View ArticleClik here to view.
New Materials May Allow One-Way Light
Normally, a glass window doesn’t care where a ray of light came from. But special kinds of glass or plastic could be a bit pickier. Nonlinear materials could distinguish between two rays of light...
View ArticleClik here to view.
Desktop Big Bang Shows Time Travel May Be Possible After All
The first desktop model of the Big Bang reportedly showed why time travel doesn’t work. But a new look suggests time travel may be possible after all, at least on the lab bench. Electrical engineers...
View ArticleClik here to view.
Could Tractor Beams Be Made From Light?
A physicist has proposed and intriguing new possibility for a tractor beam: one that uses nothing but light.
View ArticleClik here to view.
New Lights to Help ISS Astronauts Stay Alert
A neuroscientist is working with NASA to develop special lamps that could help restore the circadian rhythm of exhausted astronauts working aboard the International Space Station.
View Article
