## Tuesday, April 17, 2012

### Oracle v. Google...

Reading this brought back lots of memories, of the Stac v. Microsoft case in the early '90s, in which I was a participant...

### Dragon Cleared for Launch...

The SpaceX Dragon space craft has been cleared for launch, tentatively scheduled for April 30th.  This is a private space venture (which I support), but publicly funded as a resupply mission to the ISS (space station) – which I do not support.  What I'd really like to see is open commercial competition for NASA's robotic explorers.  Several private space companies are clamoring for exactly that, but the NASA bureaucracy is furiously resisting, of course.

We're doomed to the government we elect...

### Engaging the Mathematical Mind...

I've posted before about the way in which doing math by slide rule forces one to estimate the answer before “reading” it from the slide rule.  You can't get an answer from the slide rule without actually understanding the math in the problem you're trying to solve.  Calculators eliminate that requirement, to my regret – and, I think, to the detriment of our young folks learning how to apply math to the real world.

Here's a calculator that changes that, in an interesting way: it won't give you the answer until you've supplied an acceptable estimate.  That is exactly how it works with a slide rule.  As I read the description of the QAMA calculators, it occurred to me that there's an even simpler way to make a calculator that “behaves” like a slide rule: simply disable the decimal point display!  Such a calculator, if you were to (say) divide 1 by 7, might display 142857143 – and it would be up to you to figure out where the decimal point belonged.  When I divide 1 by 7 on the slide rule at my desk, I read off the answer as 143 – the same answer as the decimal-less calculator, but to less precision.  In both cases, I'd have to estimate the answer in my head to figure out that the decimal place was before the first “1” (the correct answer is 0.143, to three decimal places).

I don't suppose I'd actually be able to talk people into disabling the decimal display :-)

### Explosion on the Sun...

 Solar Explosion
Yesterday there was a huge explosion on the sun, visible from Earth along the rim of the solar disk.  The image at right (of 304 angstrom luminosity) was captured by the Goddard Space Flight Center on a solar telescope (I'm not sure which one).  There's a movie of it here.  The SpaceWeather site has a little more on it, including links to other imagery, and another movie in ultraviolet wavelengths.