What's New in Physics

What's New In Physics

  • Negative Mass

    A group of Washington State University researchers made a Bose-Einstein condensate fluid that displays negative mass.  In other words, if a force is applied to it, it moves in the opposite direction than the force.  Michael Forbes (one of the researchers) states,  “Once you push, it accelerates backwards.  It looks like the rubidium hits an invisible wall.”  While negative mass has been observed before, this group was the first to be able to isolate and manipulate the effects of it.  This can help further research into black holes, neutron stars and dark energy. Picture from The Daily Evergreen, April 28,2017.

    Negative mass

    Posted Apr 29, 2017, 4:40 PM by Julie Cassady
  • Using Sonar to Detect Oil Spills under Arctic Ice
    • image of UntitledWith more companies drilling under the Arctic Sea ice, scientists are investigating ways to detect oil spills, since they could spread below the ice unseen.  Since sound waves travel at different speeds in seawater, ice and oil, sonar is being investigated as a way to "see" any spills.  It is a complex problem because there are fingers of ice hanging down and multiple layers.  To try to sort it out, Woods Hole Oceanographic Institution built a tennis court size tank of sea water in the Cold Regions Research and Environmental Lab in New Hampshire.  They made six patches of ice and pumped differing amounts of Alaskan crude oil under each.  They then tried out different frequencies and bandwidths of sound waves to see how good each was at detecting the "spill." Picture: C. Bassett et. al., J. Acoust. Soc. Am. 140, 2274, 2016.
      Summarized from Physics Today, December 201
    Posted Dec 10, 2016, 7:44 PM by Julie Cassady
  • Gravity Waves!
    Figure caption100 years ago, Einstein predicted, in his general theory of relativity, that gravity works by massive objects bending space itself, and that big gravitational events should send out gravitational waves that stretch and compress space itself.  Waves decrease in energy as they get further from their source, so many physicists thought they'd never be observed on earth.  Enter an ingenious experiment: the LIGO observatory.  A beam of light is split into two beams that are in phase but perpendicular to each other.  They travel 4 km then reflect back and reconnect.  If nothing happens, the beams are in phase when they reconnect.  If a gravitational wave happens, only one arm will stretch/compress making its wavelength change.  When the wave recombines it will be out of phase.  The scientists made the out-of-phase light make a noise so it could be heard. The signal heard is consistent with two black holes colliding a billion years ago and the energy from that collision just now reaching earth.  Great video explaining this phenomenon. Image from http://physics.aps.org/articles/v9/17.
    Posted Feb 13, 2016, 12:19 PM by Julie Cassady
  • Pluto!
    Remarkable new details of Pluto’s largest moon Charon are revealed in this image from New Horizons’ Long Range Reconnaissance Imager (LORRI), taken late on July 13, 2015 from a distance of 289,000 miles  (466,000 kilometers).  A swath of cliffs and troughs stretches about 600 miles (1,000 kilometers) from left to right, suggesting widespread fracturing of Charon’s crust, likely a result of internal processes. At upper right, along the moon’s curving edge, is a canyon estimated to be 4 to 6 miles (7 to 9 kilometers) deep.New close-up images of a region near Pluto’s equator reveal a giant surprise: a range of youthful mountains rising as high as 11,000 feet (3,500 meters) above the surface of the icy body.  The mountains likely formed no more than 100 million years ago -- mere youngsters relative to the 4.56-billion-year age of the solar system -- and may still be in the process of building, says Jeff Moore of New Horizons’ Geology, Geophysics and Imaging Team (GGI). That suggests the close-up region, which covers less than one percent of Pluto’s surface, may still be geologically active today. In 2006, my earth science class and I watched New Horizons launch live during class.  Now 9.5 years later we see these incredible photos of Pluto (left) and Charon (right) courtesy of NASA.  So cool!
    Pluto has young 11000 ft mountains and may still be growing.  Charon has a 6 mile deep canyon as well as 600 miles of fractured landscape.

    Posted Jul 15, 2015, 3:33 PM by Julie Cassady
  • The Philae Lander of the Rosetta Space Probe Lands on a Comet!
    The Photo is of Comet 67P/Churyumov-Gerasimenko, taken by the spacecraft about 3 km above the 
    This picture released by the European Space Agency ESA was taken by the ROLIS instrument on Rosetta's Philae lander during its descent from a distance of approximately 3 km from  2.5-mile-wide 67P/Churyumov-Gerasimenko comet.
    comet as it landed today (from the AP).  The European Space Agency launched the Rosetta Space Probe 10 years ago; it has traveled 610 billion kilometers and has landed on a 2.5 mile wide comet hurtling through space at 135,000 km/hr. The descent onto the comet was programmed autonomously prior to launch since radio waves take about 30 minutes to reach it's present location between mars' and jupiter's orbits, meaning it could not be controlled in real time from earth.
    The goal of the mission is for the lander to stay attached to the comet as it orbits the sun and use its vast instrumentation to learn about its composition and perhaps how the earth got its first water.
    Posted Nov 12, 2014, 7:49 PM by Julie Cassady
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Quantum Satellite to Test Secure Communication Encryption

posted Aug 17, 2016, 7:00 AM by Julie Cassady

China launched the first quantum satellite on 8-16-16, which will be used to test quantum encryption for communication.  Quantum encryption uses quantum mechanical properties of photons to create an unbreakable code.  The idea of the test is that a message is carried by a photon, which is then encoded by a key into a photon in China that is  "entangled" with another photon in Austria.  If you know the properties of the China photon, you automatically know the properties of the Austria one, and can read your message if you know the key.  Because quantum mechanics dictates that the act of observation of a photon changes its properties, if you try to hack the communication, the photon "code" will change, and you will not only know you're hacked, but also your information will be unreadable, even with the key.  There is still a long way to go to fully develop this technology, but the launch of this satellite is a big step.  To read more, check out the web sites below.
For summary:  http://www.bbc.com/news/world-asia-china-37091833
For more in-depth article: http://www.nature.com/news/data-teleportation-the-quantum-space-race-1.11958

Using Cars to Gauge Tornado Strength

posted Mar 9, 2016, 6:11 AM by Julie Cassady

A group of climate researchers have studied field surveys of 959 cars that were struck by tornadoes from 1994-2008 and concluded that cars' motion due to being in a tornado can be correlated with the strength of the tornado, and that including cars could make the EF tornado scale more accurate. One of the surprising findings is that 65% of cars were not moved by EF1 and EF2 tornadoes, which can overturn mobile homes and uproot trees, suggesting that being in a car might be safer than being in a mobile home in a tornado.  Physics Today, March 2016

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