From Physics Research Features

PhysicsCentral: Fiddle Physics

Mon, 16 Nov 2009 00:00:00 EST

These patterns, known as Chladni patterns, show modes of vibration on a guitar faceplate and a metal plate. The motion of the plates shakes sand into lines where the surface is still--these lines are called nodes. Read more about Chladni patterns here, and see the larger image for more Chladni patterns on a guitar. Check out PhysicsCentral: Fiddle Physics to see how a fiddle works and how Chladni patterns form on a violin faceplate. You can watch Chladni patterns form in this YouTube video, Chladni Patterns on a Square Plate.

Nuclear Power

Sun, 01 Nov 2009 00:00:00 EST

Nuclear reactors create heat through nuclear fission instead of burning fossil fuels. Learn about fission and how nuclear reactors work at Nuclear Power. Why does the water in a nuclear reactor glow blue? When particles enter water moving faster than the speed of light in water, blue light is produced, like in the picture above. Read more about the mechanism here.

APOD: X-Ray Moon

Fri, 16 Oct 2009 00:00:00 EST

What you see above is two images of the moon in x-ray light as it moves in front of an x-ray binary star system. The binary is visible as a yellow dot in the first image before being obscured by the moon in the second. Learn more about this image here. To see another image of the moon in x-ray light, see APOD: X-Ray Moon.

Through a lens, darkly

Thu, 01 Oct 2009 00:00:00 EST

This image shows a prediction of how a "metamaterial" prism bends light. The prism is the white wedge in the middle, and the white light shines on the prism from below. To learn about metamaterials, see Through a lens, darkly and this Discover Magazine article. Compare the position of the red light in this spectrum to what you see in Physics in Your World.

Granular Materials

Wed, 16 Sep 2009 00:00:00 EST

Is this the maze from Labryinth or the back of a kid’s cereal box? It’s actually fingers of air winding through a fluid and grain mixture as it drains. You can see more pictures here. Find out about granular materials and research going on in the field from this University of California, Santa Barbara research page.

Research Helps Protect Against Lightning Damage

Tue, 01 Sep 2009 00:00:00 EST

Researchers at Georgia Tech hurl artificial lightning at electrical equipment as part of their work to better protect utilities against lightning strikes. Read more about their research here.

From Quasicrystals to Kleenex

Sun, 16 Aug 2009 00:00:00 EST

These tiles might appear to follow a simple design, but look closer and you’ll see that the pattern never repeats. Read From Quasicrystals to Kleenex to learn the history and rules behind these tiles, as well as how they relate to quasicrystals.

Io's Alien Volcanoes

Sat, 01 Aug 2009 00:00:00 EST

Do you see the two volcanoes on Io’s turbulent surface? Check out this NASA Image of the Day for an analysis of the picture. - Io’s volcanoes are caused by tidal forces from Jupiter. Learn more about the volcanoes at Io's Alien Volcanoes, and be sure to see this following article with additional information from the Galileo probe. - Io’s volcanoes have caused some trouble for passing spacecraft. Find out why at Beware: Io Dust. - Other moons in the solar system may have volcanoes as well. Read about possible cryovolcanoes on Titan here.

Earth Observatory: The Intertropical Convergence Zone

Thu, 16 Jul 2009 00:00:00 EST

The band of storm clouds you see near the equator is caused by converging trade winds. This region is called the Intertropical Convergence Zone (ITCZ, a.k.a. “itch”). - The trade winds are pushed westward by the Coriolis effect. In the Northern hemisphere, large wind patterns curve toward the right; in the Southern hemisphere, they curve left. You can watch this happen in an animation of NOAA satellite images here. - Learn more about trade winds with this MIT OpenCourseWare simulation.

Why isn't the Martian sky blue like the Earth's?

Wed, 01 Jul 2009 00:00:00 EST

The Martian sky is butterscotch, not blue like our own. On Mars, scattering by dust particles predominates, as described in Why isn't the Martian sky blue like the Earth's?.

Crab Nebula and Pulsar

Tue, 16 Jun 2009 00:00:00 EST

This visible light image of the Crab Nebula from the Hubble telescope captures the violence of a supernova event. - The intricate filaments are rapidly expanding strands of gas left over from the progenitor star. - The nebula is lit up by the rotating neutron star, or pulsar, at its center. - Learn more about Type II supernovae and pulsars through the Crab Nebula at Crab Nebula and Pulsar. This feature was updated on 6/22/09.

The Blue Marble from Apollo 17

Mon, 01 Jun 2009 00:00:00 EST

This view of the "Big Blue Marble" was captured by the crew of Apollo 17. -- Note how bright the clouds appear from space. -- The fraction of sunlight an astronomical object reflects is called its albedo, about 0.3 for Earth. -- To find out how its albedo affects Earth's climate, visit The Blue Marble from Apollo 17.

Spinning Carbon Nanotubes

Sat, 16 May 2009 00:00:00 EST

The photo shows a bundle of nanotubes grown by University of Cincinnati engineers. To see how these nanotubes are spun into thread, and used as a cell phone antenna, see the second video in Spinning Carbon Nanotubes. For more on how the nanotubes were grown, see this National Science Foundation press release.

Astronomy Picture of the Day: Ion Drive for Deep Space 1

Fri, 01 May 2009 00:00:00 EST

This Astronomy Picture of the Day shows a laboratory test of the ion drive engine that propelled the probe Deep Space 1 to the outer reaches of the solar system. -- The little solar-powered engine, only about 40 cm on a side, ionized xenon atoms and expelled them at about 100,000 km/s, exerting a small reaction force on the spacecraft over a long period of time. -- The engine's thrust was small, as was the corresponding acceleration, but since the engine ran for weeks at a time, the final speed was substantial. To find out more about this probe and its unusual engine, visit Astronomy Picture of the Day: Ion Drive for Deep Space 1 and Deep Space 1.

Earthquake Summary Poster: L'Aquila, Italy

Thu, 16 Apr 2009 00:00:00 EST

This is portion of a poster from the US geological survey on the earthquake in Italy on April 6, 2009. -- Click on the image for the larger version to see the boundary between the Eurasian and African plates. -- The poster text says this earthquake occurred "primarily a response to the Tyrrhenian basin [this basin is west of Italy and east of the islands of Sardinia and Corsica] opening faster than the compression between the Eurasian and African plates." -- For more from USGS, see Natural Hazards--Earthquakes.

A Soapy Solution

Wed, 01 Apr 2009 00:00:00 EST

In this experiment, observations of soap films helped explain mixing in turbulent fluids. The colors, produced by interference, reveal the thickness of each part of the film. -- To learn more about this experiment, visit A Soapy Solution. -- For more on interference, see this Hyperphysics page.

Spotless Sun: Blankest Year of the Space Age

Mon, 16 Mar 2009 00:00:00 EST

The image above shows the sun on March 11, 2009--nary a sunspot to be seen. But click on the image to see the sun at the last solar maximum, in March of 2001. To learn more, visit Spotless Sun: Blankest Year of the Space Age and the Exploratorium's Sunspots.

Light Bends Glass

Sun, 01 Mar 2009 00:00:00 EST

A long-standing issue in physics has been what happens to the momentum of a photon as it passes from a transparent material into the air. -- Weilong She investigated this question by firing laser light through fine glass fibers, including the ones shown in the photo, which are only 0.5 µm wide and 1.5 mm long (a human hair is about 100 µm wide). -- The change in the photon's momentum determines, according to Newton's third law, whether the fiber recoils backwards or stretches forwards. -- As the photo shows, this experiment indicates the fiber recoils backwards, but the issue persists; to learn about it, see the American Physical Society's Physical Review Focus article Light Bends Glass.

Astronomy Picture of the Day: The Milky Way in Stars and Dust

Mon, 16 Feb 2009 00:00:00 EST

This image of the Milky Way shows how interstellar dust in the plane of the galaxy obscures the view, particularly of the galactic center. -- The galactic center looks somewhat reddish because the shorter wavelength blue light is scattered preferentially by the dust; with shorter wavelengths removed, the remaining light is reddend. -- To find out more about this image, visit Astronomy Picture of the Day: The Milky Way in Stars and Dust. -- Click for a remarkable view of both the Zodiacal Light and Milky Way.

Shear Forms Force Chains

Sun, 01 Feb 2009 00:00:00 EST

-- These plastic discs, all on the same level surface, are squeezed top-to-bottom and allowed to expand right-to-left. They are backlit, and the light passes through two linear polarizers, one behind the discs and one in front, so the colors indicate the stresses inside the discs. -- To learn more about this experiment, see the American Physical Society's Physical Review Focus article Shear Forms Force Chains. See this video to watch the experiment in action.

Roundup At the Optical Corral

Fri, 16 Jan 2009 00:00:00 EST

Although this image looks like electron waves in an "atom corral," it's actually a theoretical optical corral--a prediction--with the waves representing quantum states of light. To learn more, see the American Physical Society's Physical Review Focus Roundup At the Optical Corral.

STM at Sljus

Thu, 01 Jan 2009 00:00:00 EST

The bright spots in this scanning tunneling microscope (STM) image are silicon atoms. They are sitting on top of a silicon crystal, which includes some gold atoms have displaced silicon atoms. -- Silicon atoms have formed a thin layer at the upper right, and have assumed the structure of the underlying crystal (note the ordered arrangement). Also, excess silicon atoms have accumulated at the steps of the crystal. --To see a different STM image of the steps in a silicon crystal, and for more on the STM itself, visit STM at Sljus. This feature was updated on 3/17/09.

Pale Blue Orb

Tue, 16 Dec 2008 00:00:00 EST

For a different perspective on Earth and the moon, here is the view from Saturn as seen by the Cassini spacecraft. -- Earth is the blue speck on the right side of the image above the center, and is shown with greater magnification in the inset. -- To learn more about this image, see Pale Blue Orb.

The Large Hadron Collider

Mon, 01 Dec 2008 00:00:00 EST

This image shows the profile of one of the two colliding beams in the Large Hadron Collider during its startup in September, 2008. When the machine is operational, the beam will be thinner than a human hair. For more information on the "first beam," see CERN press release. To find out how the LHC absorbs the beam energy, visit "Protecting the LHC from itself." And for more about the LHC itself, go to The Large Hadron Collider.

X-Ray Fluorescence Recovers Ancient Text

Sun, 16 Nov 2008 00:00:00 EST

This image shows how a Cornell University collaboration used x-ray fluorescence to restore the inscription on a 2000-year-old weathered stone. Some of the atoms producing this fluorescence were residues from the stoneworkers' chisels and from paint applied to the stone. To learn more about this investigation, see X-Ray Fluorescent Recovers Ancient Text.