Basically


Published on Aug 8, 2014

Wide shot of a thin film of soapy water that is vertically suspended across a 19 cm diameter plastic ring and illuminated with white light. Gravity pulls down on the film to make it much thinner in the top section of the ring than in the bottom section. Light reflecting from the front surface of the thin film is able to interfere with light reflecting off of the back, resulting in different reflected colors from different film thicknesses. For example, where the film thickness causes destructive interference for blue light but constructive interference for green and red, we perceive the color yellow from the reflection of white light. Eventually the film at the top of the ring becomes so thin that destructive interference occurs for most of the visible wavelengths, resulting in no reflection of visible light—the film is rendered completely transparent and all we see is the black background.

At about 1:20, the colors seen in the upper section of the ring are roughly what we would expect from a linearly increasing film thickness. Meanwhile in the lower section the thickness is changing in a more complicated way, and the colors appear washed out.

The soap film shown here consists of 2/3 cup of Dawn liquid dishwashing soap, 3 tablespoons of glycerol, and 1 gallon of water. We guess that the average index of refraction of the solution is close to that of water (about 1.33). The footage was taken July 16, 2014—the third consecutive day of rain and high humidity in Cambridge, MA. The light source is a portable fluorescent light box with a color temperature of between 4500 and 5000 Kelvin. 

The camera used is a Blackmagic Cinema MFT with an Angenieux 20-80 mm zoom lens. The footage was shot at 800 ASA in CinemaDNG RAW 2.5K and color corrected using DaVinci Resolve 10 Lite.

For further study, see

Physical Science Study Committee, Physics, (D.C. Heath, 1960) Chapt. 19 sect. 9 “Interference in Thin Films.”

Leslie J. Atkins, Richard C. Elliott, Investigating thin film interference with a digital camera. Am. J. Phys. 78, 1248 (2010); http://scitation.aip.org/content/aapt…

http://hyperphysics.phy-astr.gsu.edu/…

http://sciencedemonstrations.fas.harv…

MANTIS SHRIMP SOLVES RUBIK’S CUBE

..In the light-speedy scope of relative time and space, proper….

..In the light-speedy scope of relative time and space, proper….

DO CLICK THRU! "Congo: A Group of Chimpanzees Seem to Have Mastered Fire"
"Ubundu| A group of bonobo apes living in the Salonga National Park, may have mastered the basic practice of creating and using fire. This particular group of almost three hundred specimens from this rare and extremely intelligent race of great apes, have been under close surveillance by a team of primatologist for the last three years, and seem to have recently developed a primitive fire building technique using rocks and twigs."

What will they think up next, I wonder?Ape Atom Bombs or Free Energy Systems 

DO CLICK THRU! 

"Congo: A Group of Chimpanzees Seem to Have Mastered Fire"

"Ubundu| A group of bonobo apes living in the Salonga National Park, may have mastered the basic practice of creating and using fire. This particular group of almost three hundred specimens from this rare and extremely intelligent race of great apes, have been under close surveillance by a team of primatologist for the last three years, and seem to have recently developed a primitive fire building technique using rocks and twigs."

What will they think up next, I wonder?
Ape Atom Bombs or Free Energy Systems 

Life’s best balancing act

Parabolic Mirror Paraboloid Concave Solar Concentrator

VIA greenpowerscience.com

Look at These Horrifying Monster Frogs

http://www.fastcoexist.com/3027894/look-at-these-horrifying-monster-frogs

Do Click Thru

Artist and biologist Brandon Ballengée has strange hobby: collecting deformed baby amphibians.