Archives for the 'physics' Category
Zero G without a spacecraft
Published on 7 Jan 2009 at 9:46 pm.
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Filed under NASA, aeronautics, microgravity flight, physics.
Everyone is familiar with images sent back to Earth of astronauts frolicking in the weightless environment of a spacecraft. When John Glenn was in orbit around Earth, he radioed back to mission controllers on the ground that he was experiencing “Zero G and I feel fine.” But, do you really have to go […]
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Hadrons
Published on 10 Sep 2008 at 1:23 pm.
4 Comments.
Filed under physics.
Despite what some of the doomsayers had been predicting, the world did not end this morning. Sometimes I wonder about people who seem to always believe that the world is coming to an end soon due to some catastrophe that only they and their friends know about. If I had a dollar for every time […]
Escape Velocity
Published on 3 Mar 2008 at 5:41 pm.
2 Comments.
Filed under physics.
Every now and then, you hear physicists, astronomers, or rocket scientists talking about “escape velocity.” So, what is escape velocity?
To put it very simply, escape velocity is the speed needed to pull away from an object’s gravitational reach. Now, let me explain this. You can imagine throwing an object upwards. From […]
Happy Mole Day!
Published on 23 Oct 2007 at 11:58 am.
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Filed under physics.
My chemistry friends tell me that this is National Mole Day. A mole is the amount of a subestance equal to one Avogadro’s number of molecules or atoms of that substance. Avogadro’s number is about 6.0221418×1023. Almost universally in textbooks this is truncated to three significant figures for solving homework problems, so students learn Avogadro’s […]
Einstein was right
Published on 15 Apr 2007 at 12:46 am.
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Filed under physics.
Well, it looks like Einstein was right. The initial results of the Gravity Probe B mission have been released, and the geodetic precession predicted under Einstein’s general theory of relativity has been measured to better than 1% accuracy. The gyroscopes precessed just as predicted. This is the first non-electromagnetic test of general relativity, and it […]
Testing Relativity
Published on 7 Apr 2007 at 11:17 pm.
1 Comment.
Filed under physics.
In 1915, Albert Einstein set forth his general theory of relativity. Like the special theory, general relativity shows that time and space are relative rather than absolute quantities. Special theory has been tested many times. General theory, though, is a bit tougher to test in full. Among the predictions of general […]
How YORP Works
Published on 8 Mar 2007 at 11:45 pm.
3 Comments.
Filed under asteroids, physics.
There’s been talk lately about YORP. It even made a major non-science news site. So, what is YORP, and what does it do? Well, YORP is basically an extension of the Yorkovsky Effect that I blogged about back a bit over five months ago. In fact, the “Y” in YORP stands […]
