Sunday, June 28, 2015

Regal cat...

Regal cat...  This is Jahar, our Savannah Cat.  We're pretty sure that he believes himself to be a panther, notwithstanding the abundant evidence to the contrary.  He is Debbie's constant companion while she's bedridden.  From his point of view, that's the best thing that could possibly have happened.  He will be very disappointed when Debbie is mobile again!

Falcon 9 failed...


Falcon 9 failed...  Dang it!  Elon Musk is already tweeting about the cause – an “overpressure event” in the second stage liquid oxygen tank.  Commenters were speculating that almost in real time; apparently quite a few observers are familiar with the internal details of the Falcon 9.  Probably the biggest consequence to this is that they lost the payload, which included the docking adapter needed by SpaceX's Dragon crew capsule and other competing launch vehicles.  Hope they have a spare somewhere!

Progress in Paradise...

Progress in Paradise...  Today is “paperwork” day – time for me to catch up on almost two weeks of accumulated paper.  The pile is getting too tall :)

On our dog walk last night, I spotted a flock of birds I don't know.  There were about a dozen of them, poking around in the sopping soil underneath a sprinkler in an alfalfa field.  When I got back, I searched through our Sibley, and the closest thing I can find is a white-faced ibis (at right, not my photo).  The birds were backlit, and in that lighting they appeared to be completely black.  But color quibbles aside, everything else matches – and nothing else in the book did.  There's another ibis (the glossy ibis) that it might possibly have been, but they're supposedly rare here (and the white-faced ibis is common).  It was interesting watching them poke those long curved beaks deeply into the soil.  Presumably they're looking for either worms or bugs.  Imagine how disconcerting that would be for the victim – one second they're “safely” ensconced in their dirt fortress, the next second they're on their way down a monster's gullet!

I moved sprinklers for my friend and neighbor Tim D. again this morning.  His grand-daughter Taylor came over to help when I was about halfway through.  I was sopping wet by the time I got done, as the pipes I had to move were in waist-high (and very wet!) alfalfa.  In some places the field was so muddy that it threatened to suck the boots right off my feet!  I also set up sprinklers around our house – sixteen sprinkler heads are currently going all around us.

On this morning's dog walk, we left well before sunrise and I caught the sprinklers backlit by the dawn (at right).  The dogs were thrilled by the cold (48°) wet air.  The humidity was high in general, but even more so downwind of the sprinklers.

When we're walking uphill, Miki and Racer are straining at the leash to go faster, and Mo'i (the old man) is straining at the leash to go slower.  I'm stuck in the middle, looking like the dogs had collaborated to try to pull me apart.  Going downhill it's a whole different story: Mo'i is now the one straining at the leash (he's got the green leash in the photo at left).  That photo was taken just before dawn, as we were headed back home this morning, marching down the steepest hill on our path.  From observation, it appears that Mo'i's walking speed can be computed by a constant added to the inverse of the tangent of the slope, adjusted linearly by the inverse of the temperature.  I can guess our pace pretty easily :)  The other two dogs, though, are almost constant speed walkers.  There is perhaps a little derating for temperature, but the slope doesn't seem to affect their pace at all!

It's paperwork time!

Slowly but surely...

Slowly but surely ... I'm weening my immediate family off of the festering sore of an operating system known as Windows.  My mom is the latest to make the leap: she's taken delivery of her new Apple iMac, and I'll be setting it up for her when I visit in August.

All three of my siblings, unfortunately, are still serial victims of the Microsoft empire.  The tech version of the Stockholm syndrome seems to have afflicted them – none of them are inclined to see the light.  I'm afraid that may not change until Chinese hackers hold their data for ransom...

New Horizons faces an unusual challenge...

New Horizons faces an unusual challenge...  The New Horizons spacecraft is on its final approach to the Pluto/Charon system, which it will fly by on July 14th.  The unusual challenge derives from a simple fact: NASA doesn't actually know exactly where Pluto and Charon are!  The margin of error from Earthbound measurements is greater than the accuracy needed to aim New Horizons – so they're depending on frantic last-minute measurements from New Horizons itself (such as the imagery at right) to pin down the exact location of Pluto and Charon.

This is the first interplanetary mission where the aiming wasn't done entirely with Earth-bound metrics.  Unmentioned in the article is another interesting fact: none of this would have been possible until about 7 or 8 years ago, when the computing power required to model complex gravitational systems became routinely available...

Solar spectrum...

Solar spectrum...  This is the best image I've ever seen of the solar spectrum in visible light.  Each of the black bands represents absorption lines for molecules that lie between the sun and the spectrometer.  There are so many of them!  If you expand this spectrum, you'll see that some of the absorption lines look “fuzzy” – these are the absorption lines of molecules at a wide range of temperatures.  I first ran into these absorption lines when reading about the discovery of helium, and I've read much more since then.  Still there was a big surprise for me in here: some of the absorption lines are still unidentified – they're being caused by a molecule (possibly an element) that we don't yet know about.  Via APOD, of course.  Full resolution version here.

Good luck, Falcon 9!

Good luck, Falcon 9!  Everything is looking good for a 10:21 EST launch.  Here's hoping for a successful soft landing on the recovery barge this morning!!

Heinlein would be loving this – a private company leading the way to space...