This interesting resource shows what happens when a light bulb is placed in a microwave oven. Click on the source to get a video and Steve Spangler’s explanation of how this works.
MIT Media Lab researchers have created a new imaging system that can acquire visual data at a rate of one trillion frames per second. That’s fast enough to produce a slow-motion video of light traveling through objects. Continue reading
Watch as chlorophyll transforms from an intense green to a bright red colour as UV light is
absorbed and photons are emitted from the solution.
Chlorophyll is the green pigment essential for photosynthesis. It is found in all plants and readily absorbs light in the range of
600–700 nm. Upon excitation by light, an electron in a chlorophyll molecule is moved to a higher energy level, called an excited
state. The exciting source in this demonstration is the UV black light. In fluorescence, when a light source is shined on a material,
a photon is absorbed. From this excited electronic state, the electron naturally wants to relax back down to the ground
state. As it relaxes back down to the ground state, it emits a photon. If the emitted photon’s wavelength is in the visible portion
of the spectrum, we observe a colourful, glowing effect. Emission of this form is termed fluorescence. This process is practically
instantaneous so the fluorescence is observed as soon as the exciting source is present, and it disappears as soon as the exciting
source is removed. The fluorescent glow is brighter than the colour of the solution seen under normal visible light because
light is being emitted from the solution, not just transmitted through it. When a flashlight is shined directly into the solution,
a slight red fluorescence can be observed around the edges of the flask. This is due to a very small amount of light generated by
the flashlight in a range which will excite the chlorophyll molecules.
This video is about the astronomical amount of astronomical evidence for black holes, ranging from x-ray binaries with accretion disks, supermassive infrared-radiating galactic nuclei black holes, orbital characteristics of high mass binaries, and direct gravitational wave detection of inspiraling merging black hole binaries with LIGO. Yes, they’re real. Continue reading
A photon is a purely quantum mechanical object representing the smallest piece of energy (or quanta) for light. Every quantum particle is a packet of energy though, so how do we tell photons apart from electrons, quarks, and neutrinos?
Where do glaciers and icebergs get their beautiful blue color? This unique blue might be nature’s most brilliant, and the color arises in a very special way thanks to some surprising interactions between light and water molecules. Who knew physics could be so breathtaking? Continue reading
You’ve probably noticed something different about both the sunrise and sunset over the past few weeks. Steve Spangler shares the science behind this phenomenon with a simple experiment you can try at home. Continue reading
In this demonstration, students observe what happens to activated glow sticks when they are submerged in water at three different temperatures: cold, room temperature, and hot. Continue reading