Wednesday Aug 30, 2006
Someone at Sun noticed that the evince process on a recent Solaris Express build consumes a huge amount of memory when it loaded a particular pdf document from IBM. pmap -x showed that it was definitely heap space and that it grew over time. A big leak! I logged the bug in bugzilla because it didn't seem to be specific to Solaris. I used a couple of malloc dtrace scripts but the libumem technique on Adam Leventhal's blog turned out to be the easiest way to track the source of the leak to libz. This build of Solaris was using zlib 1.1.4. When I built zlib 1.2.3 and ran evince with that library, the problem disappeared and performance improved significantly.
For some reason, Adobe still seem to reluctant to recompile and release acroread on Solaris X86. Maybe if enough people ask nicely here, they will do this. But its reassuring to know that the alternative opensource pdf viewer 'evince' continues to improve. It looks like pdf form support is coming soon, thanks to the google summer of code project.
Monday Aug 28, 2006
In the space of one hundred and seventy-six years the Lower Mississippi has shortened itself two hundred and forty-two miles. That is an average of a trifle over one mile and a third per year. Therefore, any calm person, who is not blind or idiotic, can see that in the Old Oolitic Silurian Period, just a million years ago next November, the Lower Mississippi River was upwards of one million three hundred thousand miles long, and stuck out over the Gulf of Mexico like a fishing-rod. And by the same token any person can see that seven hundred and forty-two years from now the Lower Mississippi will be only a mile and three quarters long... - Mark Twain, Life on the Mississippi
Using the same logic, sometime before autumn in the year 2614, our solar system will be fresh out of planets. But I'm not concerned about the IAU's reclassification of Pluto as a dwarf planet. I'm more concerned that some educational systems are heavily focused on rote learning, and therefore quickly obsoleted. Fortunately, my childhood interest in the "stuff" out there never stopped at the end of the "My Very Easy..." or the articles in my 1959 World Book Encyclopedia claiming that "One day man may travel in space.". ROY.G.BIV doesn't encompass the colours of all rainbows and Renoirs and "Every Good Boy Does Fine" is only a stepping stone to Mozart. Likewise, Pluto was never the last planet (especially between 1979 and 1999). In the age before telescopes it was easy, a planet was a wandering star. The stars in a constellation stayed together, rising a few minutes earlier every night over the course of a year. But planets moved separately from this background and sometimes they moved in the opposite direction. IAU's categorization is useful but for the rest of us, other categories might be more useful:
- SEEUMS:Solar system objects which were known in antiquity and which we can see with our own eyes. That is, the Sun, moon, bright comets, mercury, venus, mars, jupiter and saturn. (though mercury, mars and saturn might not be noticed above the glare of a medium sized city.)
- UHOHS(or OH @$&^#!):The 800+ known solar system objects which could hit the earth one day.
I recently read James Gleik's
Genius: The Life and Science of Richard Feynman from Sun Ireland's book club. This and Richard Feynman's own book: "Surely Your Joking Mr. Feynman" demonstrate that Feynman wasn't just a nobel prize winning quantum physicist, he was also gadfly to the U.S. education system. I love the part in "--Joking" where he sends a blank book through the textbook review process and it is voted "above average!" Feynman inherited his aversion to rote learning from his father:
"You can know the name of a bird in all the languages of the world, but when you're finished, you'll know absolutely nothing whatever about the bird... So let's look at the bird and see what it's doing, that's what counts. I learned very early the difference between knowing the name of something and knowing something." - Richard Feynman
So, rather than focusing on the names and IAU categorizations of the planets, shouldn't we encourage students to look at the night sky and see how it works? My daughter pointed out mars to me when she was two years old. She could recognize the bright reddish untwinking star which hovered over the glare of Pope John Paul school's insecurity lights. For northern hemisphere classrooms, september is ideal for astronomy. The cluttered dusty center of our galaxy is still visible early in the night and beautiful autumn asterisms such as the pleides are moving into the night sky. The angle of the sun is ideal for viewing artificial satellites, zodiacal light and aurora. My homework assignment would be that on the next clear night, turn off the T.V., put away the textbook for an hour before bedtime and find a dark place outside. Look for something you haven't seen before and try to discover as much as you can about it. We have allowed criminals, television and outdoor "security lights" to take away our night sky. Let's take it back.
...There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.
- Mark Twain, Life on the Mississippi
Thursday Aug 24, 2006
OpenSolaris Nevada build 46 contains GNOME 2.14.x, python and pyGTK. The pyGTK tutorial has an example of a program which lets you play with Gtk widgets from the python console. Unfortunately the example is based on an earlier version of pyGTK in GNOME 2.14, this should work:
>>> import pygtk
>>> import gtk
>>> w=gtk.Window()
>>> b=gtk.Button('Hello')
>>> w.add(b)
>>> def hello(b):
... print "Hello, World!"
...
>>> b.connect('clicked',hello)
6
>>> w.show_all()
Python is pretty cool, but some of the bindings aren't necessarily write once, run everywhere yet.
Thursday Aug 17, 2006
Since ballpoint pens are no longer allowed as carry on luggage on flights from the U.K., I don't expect giant knitting needles would be appropriate. Yes, these knitting needles are real. My wife completed the wool rug very quickly. It really keeps our feet warm!
Friday Aug 11, 2006
I was never convinced with the logic behind the fact that nail clippers and walkmen were forbidden but laptops containing 50 watt-hour batteries and high voltage power supplies were allowed onboard aircraft. Now that we're starting from scratch with practically nothing allowed, I wonder if we could come up with sane and safe guidelines for hand luggage?
According to this Ryanair notice,
The only items permitted to be carried onboard are the following items:
Travel Documents (passport), Keys (but no electrical key fobs), baby food, milk, sanitary items and prescribed medicines (except in liquid form unless verified as authentic) essential for the duration of the flight.
O.K. There we are, so the books, magazines, newspapers, mp3 player and (of course) laptops are forbidden. It appears that Sun Ray (ID) cards are still allowed, so Sun employees trying to decide between a 10kg laptop and a 5 gram smart card will have more incentive to leave the laptop behind.
Anyone who has ever travelled knows that a certain level of random inconvenience completely outside their control is to be expected. Airlines interested in reducing the increased level of inconvenience caused by these terrorists, without impacting security, should consider the following:
- Provide soft drinks gratis or for a reasonable price, if those 125ml coke cans are your profit margin, I worry about other corners you might be cutting.
- Don't charge for normal checked baggage. Again, if this is your profit margin...
- Stock diapers, nappy wipes, formula and other baby essentials.
- Stock some toys, dolls, pillows and other distractions for the children on board. If you can screen it properly, stock some handheld games, cards, origami instructions, puzzles.
- If an airline doesn't have enough food, drink or blankets for each of the paying passengers, please send someone back into the terminal to get more. I'd like to think that someone has an accurate count of the number of passengers on board.
- Provide some newspapers, magazines and books.
- Increase the selection of in flight music and programs.
- Stock some basic non-perscription medicines such as children's tylenol, aspirin, antihistamine. Also, emergency supplies (insulin, inhalers...)
- Provide crayons and paper for children (and adults.) Are pens and pencils too dangerous?
- Find some way of distinguishing powered key radio controlled fobs from (unpowered) USB memory sticks.
- Improve hand luggage screening procedures to better detect chemicals and dangerous devices. (Much better technlogy does exist.)
Alternatives?
Yesterday, after noticing that the price of flights to the U.S. might prevent us from travelling there this year, I searched for other transatlantic travel options. (Which may have put a red flag next to my name in some cloak and dagger database.) Here is what I found:
It looks like air travel is still the most convenient option, but sailing across could be quite an experience. I'm still waiting for someone to start a sail or kite assisted passenger ferry service.
update:
The pen is mightier than the palmPilot, or at least it is considered to be more dangerous. As of Wednesday night, ballpoint pens were banned from hand luggage on our flight from the U.K., but laptops, palm tops, phones and some other small electronic devices were allowed. Our airline advised passengers to arrive 3 hours before flight on Saturday, but check-in staff only arrived about 1.5 hours before the flight. They advised two hours before the flight on Wednesday, but this wasn't nearly enough. Queues from the X-ray machine went down the hall and circled the food court.
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