GPS and navigation

Oxford botanic gardens

I have been annoyed recently by full-page ads in which RIM is advertising the navigational capabilities of their new BlackBerries. They suggest that people can throw away maps and compasses and wholeheartedly embrace the combination of GPS and electronic maps.

I know firsthand how useful GPS can be. As an altimeter or a way of locating yourself in a featureless landscape, it cannot be beaten. Likewise, it is very helpful for quickly figuring out where you are when you are out on the water in a canoe or kayak. All the same, I think there is a fundamental value in being able to read a map, locate yourself on it, and work out a course to where you want to be. It isn’t enough to take a course in these things and forget about it. As with any complex skill, practice is important.

Some common sense is also a necessity, no matter how you are navigating. If your GPS-based automobile navigation system tells you to drive along train tracks, you should be aware that machines are fallible, and highly stupid as well. They have no common sense by which to evaluate whether, for instance, a bridge has been washed out or whether a linear course between A and B includes a series of lethal cliffs. There is also the small matter that some dead batteries a splash of water or a dropped piece of gear could knock out both your map and compass equivalent, if you are relying on a GPS system.

Related posts:

From Hubble to Webb

NASA has announced some more details on the James Webb telescope, slated to replace Hubble as the most important such instrument in orbit. Hubble is located in an elliptical low Earth orbit, with an orbital height of 589km and an orbital velocity of 7,500 m/s. The Webb will be located at Lagrange Point 2. This is an area where gravity will keep the telescope in a sun-earth line. As a result, the telescope will always be in the shadow of the Earth. NASA has a report on the transition.

Hubble has been one of NASAs great successes over the last 17 years, both in terms of the quality scientific information generated and in terms of the way the project reflects upon the organization. By finally offering an astronomical vantage point not affected by the Earth’s atmosphere, Hubble has been able to make unprecedented observations and discoveries. For example, consider the various exoplanets discovered in recent years, either because of how they obscure stars by passing in front of them or cause stars to wobble with their gravitational pull. Hubble was also ideally placed to observe the impact of Comet Shoemaker-Levy 9 into Jupiter. I remember watching the video feed from that at the Vancouver Planetarium, back in 1994. Some pretty stunning images of the universe have also been generated.

Just yesterday, Hubble may have observed a ring of dark matter. Given the disjoint between how galaxies behave gravitationally and the number and mass of stars we can observe, scientists have speculated that most of the material composition of the universe consists of dark matter and dark energy. The former has gravitational effects but does not interact with electromagnetic radiation. The latter is hypothetically involved in universal expansion: serving as one possible explanation for why the universe is expanding at an expanding rate, as observed through the Doppler shift. Data from the remainder of Hubble’s operational life and the full span of the Webb telescope’s operation may help with the refinement or rejection of both of these ideas, with coincidental improvement in our understanding about the contents and evolution of the universe.

Hubble has been discussed here before. A song about the Doppler shift has also been linked.

Spam egg sausage and spam

Radcliffe Infirmary

As time goes by and Google indexes more and more of my content, I get more spam of every variety. I get spam emails, spam comments on the blog, and spam added to the wiki. Of the three, the email spam is the most common, but also the most easily dealt with. It has existed for so long that good systems exist for dealing with it: whether based on Bayesian reasoning or on group filtering processes. The former are largely centered around word usage. If an email contains the word ‘Viagra’ the chances of it being spam are high. If it includes the string of characters ‘V1agr4!!!’ it is virtually certain to be spam. The latter are based on user reporting. Most spam isn’t very original. As such, if GMail has 1000 people report that a particular message is spam, it can pretty reliably block it for everybody else.

I cannot get too far into how this blog’s anti-spam system works. This is because automated systems seem to have become capable of determining which system or combination of systems a site is using and then launching an appropriate attack. Suffice it to say that the blog uses a variant of both approaches above, plus one more special thing. Since the system was implemented, it has dealt with spam from 9188 different IP addresses. Security through obscurity may not be intelligent or rubust in many circumstances, but it works well enough when you are somewhat better defended than most sites, not of much value to attack, and surrounded by sites with much worse systems.

The wiki is the most vulnerable, precisely because the intended purposes of a wiki requires easy editing. Given that so few users contribute to mine, the best solution might be to lock it down so that only those with approved accounts can access it.

One possible lesson to be drawn from this is that technology eventually evolves the ability to deal with abuse. The older the system being attacked is, the more likely a sensible and effective set of countermeasures will be developed. Alternatively, it is possible that the more open approaches used by blogs and wikis are fundamentally more vulnerable to abuse.

Only time will tell.

Obviousness and patents

This week, the US Supreme Court issued a ruling related to the ‘obviousness’ test in patent filing. The case – KSR Int’l Co. v. Teleflex Inc. (PDF) – hinged on whether an automatic adjustment device for an accelerator pedal created by KSR infringed upon the patents of Teleflex. KSR argued that the combination of technologies was obvious, and that Teleflex could not claim royalties.

In order to maintain a fair and beneficial system, the condition that patents cover non-obvious innovations is highly important. The whole reason for granting patents is to foster innovation by granting temporary monopolies to innovators. Patents are meant to include enough information to allow a skilled practitioner to actually make the thing being patented. Under this system, inventors are meant to be willing to disclose the nature of what they have accomplished so that it might serve to aid the investigations of others. In exchange, they get legal rights over their invention for a defined period of time. This trade-off hardly makes sense when companies are permitted to patent trivial innovations, such as the much ridiculed patent awarded to Amazon.com for ‘one click shopping.’

Recently, there have been a good number of cases where the patent system is accomplishing something quite unlike this ideal. ‘Patent trolls‘ acquire patents of a broad and obvious kind, then wait for another company to release a successful product that arguably infringes on them. More often than not, the objective is simply to receive some kind of payment in return for ending the legal hassle. Of course, this interferes with the processes of innovation, as well as undermining the general credibility of the patent system. RIM and Vonage have both recently been targeted by such suits.

It seems sensible that patent offices should be more aggressive in their interpretations of what it means for an invention to be ‘novel’ and ‘non-obvious.’ As such, they would reduce the occurrences in which someone is unfairly granted rights over an idea that many other people have likely come up with, but not bothered to go through the process of trying to patent. It would also reduce the danger of patent trolling, particularly if the courts recognize that such behaviour can be predatory, and that the patent system ultimately exists to serve the public good.

PS. Slashdot has commented on the Supreme Court ruling. Most of these entries are also relevant.

The Human Microbiome Project

Port Meadow horse

The average human being is a collection of about ten trillion eukaryotic cells: each with a nucleus, 23 chromosomes of nucleic DNA, and a collection of membrane-bound organelles including mitochondria with genetic material of their own. Less obviously, each person is also carrying around one hundred trillion prokaryotic cells, belonging to thousands of different species of bacteria. The implications of that are pretty staggering. Many of those bacteria play critical roles in biological processes that sustain human life, such as digestion. Others may be the benign residents of niches where more harmful microorganisms might otherwise live.

Following up on the Human Genome Project – which sought to decode the three billion nucleotides in the human genome – the Human Microbiome Project seeks to map the genetic sequences of those legions of bacteria. Already, it has been theorized that these bacteria play important roles in maintaining human health, and that their composition and relationship with human cells has an impact on diseases including diabetes, autism, cancer, and cardiovascular disease. Collectively, these bacterial species are thought to have 100 times more genetic material than the colony of human cells they inhabit.

The project is not unrelated to the Global Ocean Sampling Expedition, discussed here earlier, in that it is delving into the complexities of microscopic ecosystems. In so doing, it might serve both the practical function of helping to better understand and treat human disease and the more esoteric one of refining our understanding of what it means to be a human being, biochemically at least.

PS. The DVDs for the BBC’s Planet Earth series, discussed earlier, are now available in North American format. I will definitely buy a copy when I return to Canada. For those who haven’t seen any of the footage, it is absolutely awe inspiring.

Browser considerations

This post, which was linked to on Tony’s blog, got me thinking about web browser choice. All I want is something that displays pages properly without eating too much RAM. Good RSS handling is an advantage. I am likely to stick with Firefox for now, but it is good to assess the state of competition every once in a while.

Continue reading “Browser considerations”

Red light

Canal boat

With people banning incandescent lightbulbs and the days finally approaching appropriate summer length, it seems as good a time as any to be thinking about light. On the human retina, there are two major kinds of photoreceptive cells: cones (which identify colour) and rods (which are only sensitive to the overall brightness of light). Because rods are the more sensitive of the two, people actually see in black and white, when it is properly dark.

Like photographic paper, rods are not sensitive to long wavelengths of visible light, over on the red side of the spectrum. This is because the shorter the wavelength of a particular photon, the more energetic it is. Further to that, only light of a sufficiently narrow wavelength can accomplish certain tasks. For instance, only light of a sufficiently narrow wavelength can excite metals so as to produce the photovoltaic effect used in solar cells. Brian Greene has a rather good explanation of this in his book The Elegant Universe: the first half of which is a highly comprehensible primer on twentieth century physics.

The upside of red light not being able to affect rods is that one can be immersed in red light without losing the ability to see in the dark subsequently. This is why submarines are sometimes illuminated with red light – allowing the crew to see more than would otherwise be possible in the event of a power failure – and one reason I am hoping my replacement headlamp will be especially useful. The last one vanished curiously before the Devon trip, earning me a very nasty knock on the head caused by a thick low beam outside. The lost headlamp served admirably during the 2003 New York City blackout, as well as in a great many places besides, The new one, which has a mode in which it produces only red light, will probably be useful during stays in future hostels. It may also provide some interesting lighting possibilities for future photographs; high contrast red and black compositions can be quite compelling.

Helvetica

Flowers and bricks

With my first printed and bound work sitting on the desk beside me, I might be forgiven for having delved a bit into typography and printing. Most people will be familiar with Helvetica, one of the most commonly used sans serif fonts in history. Fewer will know as much about it as is provided by this article. Quoted therein is Eric Gill, the British sculptor who designed the font I ultimately chose for my thesis. More on Helvetica can be found on Metafilter.

Typefaces have an interesting effect on the presentation of data. Usually, the differences between them are subtle enough to evade perception. Nevertheless, the shape they give to individual words or whole pages of text immediately conveys a great deal of information about the source: in terms of elegance, audience, and approach.

Important OS X update

Mac users, make sure you get the latest security patch from Apple. It covers some distinct vulnerabilities in terms of wireless networking, as well as patching several dozen general system and application vulnerabilities. You can read more about it here.

To get it, just click the Apple icon in the upper-left corner of the screen and then choose ‘Software Update’ from the menu that comes down. While being on a Mac does make you safer, it certainly does not make you invulnerable.