Physics in Your World Archive - Page 3
Nonlinear Geoscience: Fractals - Aug 2, 2011
Look up at the clouds and look at the patterns you see. It turns out that if you zoom in or out, you still see the same patterns, a property mathematicians call self-similarity.
What is Microgravity? - Jul 1, 2011
The photo shows astronauts training in a NASA plane that flies in a parabolic arc--the same path a projectile follows--so they can experience free fall, just as they will in space. To find out what these flights are like, check out the Reduced Gravity: Vomit Comet Blog from the American Physical Society's Physics Central. To learn about gravity in space, see the first page of Fluids in Space, also from Physics Central, and What is Microgravity? (but don't be fooled by the title--there is plenty of gravity in space around the Earth, and it keeps satellites in their orbits).
Chaotic Pendulum - Jun 8, 2011
The photo above shows a three-way double pendulum at the Exploratorium, and you can see a video about this exhibit at Chaotic Pendulum. (A double pendulum is essentially one pendulum hung underneath of another--see this diagram.) In general, the motion of this pendulum is chaotic.
Fiestaware - May 12, 2011
The distinctive color of orange-red Fiestaware, which was popular in the 1930s and 1940s, is produced by uranium oxide in the glaze. For more information, see Fiestaware, and for a list of similar items, see Radioactive Consumer Products (the two websites referenced here are from Oak Ridge Associated Universities).
image credit: Jim Krider, Physics Instructional Resource Team, Arizona State University; larger image
Flame Tube - Apr 12, 2011
In the classic Ruben's tube demonstration, the tube containing the Bunsen burner gas has a speaker at each end that emits a pure tone. The tones have the same frequency and are in phase. The frequency of the tones is selected to set up a large standing wave inside the tube, and the resulting pressure distribution produces the pattern of flames. Read more on standing waves here.
3C273 - Quasar in Virgo - Feb 1, 2011
In a telescope, object 3C273 will look like an ordinary star to you--it looked like an ordinary star to astronomers until the 1950s, too. In fact it is a quasar, or quasi-stellar radio source. These objects might look like stars, but they emit radio noise and are very distant--in the case of 3C273 above, nearly 2.5 billion light years away.
Image credit: Andrew Davidhazy, Rochester Institute of Technology
Wikipedia: Shadowgraph - Dec 1, 2010
This is a Schlieren image, which reveals differences in the density of air above the candles. To find out more about these images, visit Wikipedia: Shadowgraph, and to learn how to make one, visit Schlieren Photography Principles.
Physics 2000: Lasers - Nov 1, 2010
Lasers don't come only in red: you can buy handheld lasers that produce light in various wavelengths in the visible spectrum. Remember, lasers can be dangerous--so get adult supervision for any laser experiment you try.
image credit: Eurico Zimbres, Wikimedia Commons (taken at the San Diego Natural History Museum); image source; larger image
What Really Killed the Dinosaurs? - Oct 16, 2010
Dig into rocks around the globe at the right depth and you may find a thin layer like the one pictured above, a geological hint about our planet's past. This sedimentary layer contains much more iridium than the surrounding layers, and the element iridium is rarely found on Earth but plentiful in rocks in space. For this reason, some scientists believe that there was an enormous meteorite impact that covered the planet in its dust.
The Geothermal Power Plant - Oct 1, 2010
The above photo shows the Nesjavellir geothermal plant in Iceland, which produces power and hot water for the towns surrounding it. To learn more about how the plant works, see this site from the University of Rochester.