http://physics.about.com/ Get the latest headlines from the About.com http://clk.about.com/?zi=1/1hh http://www.about.com/ 118 20 en-us 2013-04-29T21:26:03Z Mon, 29 Apr 2013 21:26:03 +0000 hourly 1 2000-01-01T12:00+00:00 http://physics.about.com/b/2013/05/01/bananalev.htm <p>I came across <a href="http://clk.about.com/?zi=1/1hc&#038;zu=http://boingboing.net/2013/04/30/just-look-at-this-whirling-mag.html">this intriguing video</a> of a banana being levitated in the air. This isn't the first time I've discussed this strange new technology of <a href="http://clk.about.com/?zi=1/1hc&#038;zu=http://physics.about.com/od/quantumphysics/f/QuantumLevitation.htm">quantum levitation</a>, but it's been a while. The last time I brought it up was back in November 2011, when talk show host and comedian <a href="http://clk.about.com/?zi=1/1hc&#038;zu=http://physics.about.com/b/2011/11/18/colbertquantumlev.htm">Stephen Colbert levitated his ice cream flavor on his show</a>.</p>...<p><a href="http://clk.about.com/?zi=1/1hc&#038;zu=http://physics.about.com/b/2013/05/01/bananalev.htm">Read Full Post</a></p> http://physics.about.com/b/2013/05/01/bananalev.htm Wed, 01 May 2013 22:50:10 +0000 2013-05-01T22:50:10Z http://physics.about.com/b/2013/04/29/collisions.htm <p><img class="alignright" src="http://0.tqn.com/h/physics/1/3/i/4/-/-/87993823.jpg" alt="Newton's Cradle" />Physicists like it when things crash together. Okay, not so much when they do so unexpectedly. Just like anyone else, physicists prefer to keep their cars out of the body shop.</p>...<p><a href="http://clk.about.com/?zi=1/1hc&#038;zu=http://physics.about.com/b/2013/04/29/collisions.htm">Read Full Post</a></p> http://physics.about.com/b/2013/04/29/collisions.htm Mon, 29 Apr 2013 21:26:03 +0000 2013-04-29T21:26:03Z http://physics.about.com/b/2013/04/21/timereborn.htm <p><img class="alignright" src="http://0.tqn.com/h/physics/1/3/j/4/-/-/images.jpeg" alt="Cover of Time Reborn by Lee Smolin" />One of the deepest questions in physics is the attempt to provide an answer to the seemingly simple questions: <a href="http://clk.about.com/?zi=1/1hc&#038;zu=http://physics.about.com/od/timetravel/f/doestimeexist.htm">Does time really exist?</a></p> <p>Though we all experience time moving in one direction (the "arrow of time" as it is called), the curious thing about the laws of physics don't actually require this. If you tried to apply the equations with time moving the opposite direction, they would actually still make sense. Why, then, do we experience such an unrelenting forward motion in time?</p>...<p><a href="http://clk.about.com/?zi=1/1hc&#038;zu=http://physics.about.com/b/2013/04/21/timereborn.htm">Read Full Post</a></p> http://physics.about.com/b/2013/04/21/timereborn.htm Sun, 21 Apr 2013 22:38:29 +0000 2013-04-21T22:38:29Z http://physics.about.com/b/2013/04/13/darkstuff.htm <p><img class="alignright" src="http://0.tqn.com/h/physics/1/H/R/2/-/-/080998_Universe_ContentM.jpg" alt="Pie Chart of the universe's contents" />If you've been paying any attention at all to astrophysics or cosmology over the last couple of decades, you'll be aware that one of the major mysteries science has been exploring is the composition of matter in the universe.</p>...<p><a href="http://clk.about.com/?zi=1/1hc&#038;zu=http://physics.about.com/b/2013/04/13/darkstuff.htm">Read Full Post</a></p> http://physics.about.com/b/2013/04/13/darkstuff.htm Sat, 13 Apr 2013 15:01:45 +0000 2013-04-13T15:01:45Z http://physics.about.com/b/2013/04/03/cosmicraydetector.htm <p><img class="alignright" src="http://0.tqn.com/h/physics/1/9/F/1/-/-/GammaRay.jpg" alt="" />Did you know that every moment, your body is being bombarded by particles with their origin in distant galaxies? These <a href="http://clk.about.com/?zi=1/1hc&#038;zu=http://physics.about.com/od/physicsatod/g/CosmicRay.htm">cosmic rays</a>, as they're called, come from supernovas in distant star systems. Upon reaching the Earth's atmosphere, these particles from the "primary cosmic ray" collide with the molecules there and emit other particles that are part of a "secondary cosmic ray." It's these secondary particles that actually reach us on the surface of the Earth.</p>...<p><a href="http://clk.about.com/?zi=1/1hc&#038;zu=http://physics.about.com/b/2013/04/03/cosmicraydetector.htm">Read Full Post</a></p> http://physics.about.com/b/2013/04/03/cosmicraydetector.htm Wed, 03 Apr 2013 21:00:46 +0000 2013-04-03T21:00:46Z http://physics.about.com/b/2013/04/01/rightquestions.htm <p><img class="alignright" src="http://0.tqn.com/h/physics/1/9/S/2/-/-/473058main_globaldisruption.jpg" alt="NASA picture of the sun, from Aug. 1, 2010" />Okay, not really. April Fool's Day! Sort of. Actually, the exaggerated title comes from a very real exchange with my son which showed me that I seem to be doing something right, at least if one of my parenting goals is raising a child who asks the right questions.</p>...<p><a href="http://clk.about.com/?zi=1/1hc&#038;zu=http://physics.about.com/b/2013/04/01/rightquestions.htm">Read Full Post</a></p> http://physics.about.com/b/2013/04/01/rightquestions.htm Mon, 01 Apr 2013 04:00:41 +0000 2013-04-01T04:00:41Z http://physics.about.com/b/2013/03/23/momentum.htm <p><img class="alignright" src="http://0.tqn.com/h/physics/1/3/i/4/-/-/87993823.jpg" alt="Newton's Cradle" /></p> <p>The popular desk toy Newton's Cradle show off the conservation of momentum in a fun way. What are the equations that govern momentum? How is it useful in physics?</p> <p>Momentum is a calculated quantity, derived from multiplying the mass of an object times its velocity. Momentum is a conserved quantity, which means that it is transferred between objects during collisions. (You can actually derive this fact from <a href="http://clk.about.com/?zi=1/1hc&#038;zu=http://physics.about.com/od/classicalmechanics/a/lawsofmotion.htm">Newton's laws of motion</a>.) This means that momentum can be calculated based on information before or after objects interact and can give us information that is useful in determining what happened either before or after the collision.</p>...<p><a href="http://clk.about.com/?zi=1/1hc&#038;zu=http://physics.about.com/b/2013/03/23/momentum.htm">Read Full Post</a></p> http://physics.about.com/b/2013/03/23/momentum.htm Sat, 23 Mar 2013 11:23:18 +0000 2013-03-23T11:23:18Z http://physics.about.com/b/2013/03/22/evidenceproof.htm <p><img class="alignright" src="http://0.tqn.com/h/physics/1/3/h/4/-/-/WarWorldviews.jpg" alt="War of the Worldviews cover" />Can science prove anything with absolute certainty? The short answer is no ... but the virtue of science is the degree to which it tries to contain and even quantify its level of uncertainty, while recognizing that it cannot be truly eliminated. I would argue that one of the greatest shortcomings in our world is the inability to recognize the difference between good evidence and bad evidence, and that this is precisely why scientific thinking is so crucial!</p>...<p><a href="http://clk.about.com/?zi=1/1hc&#038;zu=http://physics.about.com/b/2013/03/22/evidenceproof.htm">Read Full Post</a></p> http://physics.about.com/b/2013/03/22/evidenceproof.htm Fri, 22 Mar 2013 11:17:44 +0000 2013-03-22T11:17:44Z http://physics.about.com/b/2013/03/16/higgsfollowup.htm <p><img class="alignright" src="http://0.tqn.com/h/physics/1/9/t/2/-/-/elemparticles.jpg" alt="" />Getting straight information about the Higgs boson can be hard work. When <em>Time</em> magazine nominated the Higgs boson their "Person of the Year," each sentence in the nomination paragraph <a href="http://clk.about.com/?zi=1/1hc&#038;zu=http://blogs.scientificamerican.com/observations/2012/11/29/person-of-the-year-nomination-for-higgs-boson-riddled-with-errors/">contained serious factual errors</a>. (Some of these are errors I've been guilty of, as well, such as calling physicist <a href="http://clk.about.com/?zi=1/1hc&#038;zu=http://physics.about.com/od/famousphysicists/p/PeterHiggsBio.htm">Peter Higgs</a> a Scottish physicist, even though he was born in England, not Scotland. Sorry for that slip, Dr. Higgs.)</p>...<p><a href="http://clk.about.com/?zi=1/1hc&#038;zu=http://physics.about.com/b/2013/03/16/higgsfollowup.htm">Read Full Post</a></p> http://physics.about.com/b/2013/03/16/higgsfollowup.htm Sat, 16 Mar 2013 16:14:33 +0000 2013-03-16T16:14:33Z http://physics.about.com/b/2013/03/01/popscifair.htm <p>The magazine&#160;<strong><em>Popular Science</em></strong> has announced a virtual science fair. The <a href="http://www.popsci.com/sciencefair"><em><strong>Popular Science</strong></em> science fair</a> allows students from Kindergarten through college to sign up. Don't worry, though ... the college students won't be stealing prizes from the Kindergartners. Here are the categories, along with what the applicants need to submit (along with their registration form):</p>...<p><a href="http://clk.about.com/?zi=1/1hc&#038;zu=http://physics.about.com/b/2013/03/01/popscifair.htm">Read Full Post</a></p> http://physics.about.com/b/2013/03/01/popscifair.htm Fri, 01 Mar 2013 10:30:15 +0000 2013-03-01T10:30:15Z