Category: Geek stuff

If it involves physics, math, computer science, electronics or has general geek cachet, this is the place for it.

WPA cracked in 60 seconds

WPA is a more secure encryption system for wireless networks than the older WEP system, which was notoriously vulnerable. Now, Japanese researchers have devised an attack that cracks WPA networks using the Temporal Key Integrity Protocol (TKIP) algorithm quickly and easily. So far, WPA2 and WPA using AES are not vulnerable to the attack. On past form, it seems likely that those will eventually become vulnerable to rapid compromise, as well.

The broader point this demonstrates is how attacks always get better and never get worse. As such, the longer any particular system has been deployed, the less likely it is to be secure. Threat analysis needs to be ongoing, and accompanied by the patching and replacement of vulnerable systems. Both because of improving computer power and new mathematical developments, this is especially true when it comes to cryptography. As MC Frontalot explains (in a song that references rainbow tables), “you can’t hide secrets from the future with math.”

Built-in antivirus for OS X

Rumours are circulating that Apple’s Snow Leopard OS will include antivirus capabilities. This is a welcome development. While OS X rightly has a good reputation for security, there is no commercial operating system that is immune from malware. In addition to malware that targets OS X itself, there are also exploits based around flash, Adobe PDFs, and even specific pieces of hardware.

Adding antivirus protection might be a bit of a public relations blow to Apple, which has cultivated a false sense that there is no malware that affects Macs. Nevertheless, it is a good security move. Indeed, the server version of OS X has included such capabilities for some time.

Building a camera system

Woman with flowers in her hair

I often get asked about what sort of photographic gear serious amateurs should buy. Normally, I direct them towards this excellent primer on building a digital SLR system, written by Philip Greenspun. It is, however, a bit on the long side. Here is a briefer encapsulation.

Brand

I would go with Canon or Nikon. This is mainly due to compatibility, both across a wide range of accessories (lenses, flashes, etc) and across long spans of time. Both companies make excellent gear that will be usable for decades. I happened to go with Canon and have always been happy with them.

There are other brands that have advantages (both in terms of price and features), but the market for Canon and Nikon related gear is broad and deep.

Sequence

This really depends on what sort of photography interests you most. Someone seriously into nature photography would skew their purchases towards telephoto gear, while someone looking to take informal shots in casual settings might go for fast primes. The basic sequence, however, looks something like this:

  1. Get a crop-sensor dSLR. These cost about $600-700 and are very capable cameras. One thing to remember, though, is that they will multiply the effective focal length of all your lenses by 1.6. As such, a 50mm lens on a crop sensor is akin to an 80mm lens on a film body or full-frame dSLR.
  2. Get a memory card, but don’t worry about filters and things unless you are going to be working in very wet or dusty places.
  3. Get a couple of batteries. You don’t want to find yourself in the middle of an excellent and unexpected photo session, but unable to snap any more shots.
  4. Buy the kit lens. It won’t be of great quality, but they are usually very cheap when bought with the camera body. They are also often the only way to get cheap wide angle capability for a dSLR.
  5. Buy a 50mm f/1.8 lens. These have great optical quality, can allow fast shutter speeds in dark circumstances, and can often be purchased for about $100. A 28mm or 35mm lens would more closely approximate a 50mm ‘normal’ lens on a film camera, but these tend to cost a lot more.
  6. Get a tripod. It’s not necessary for absolutely every kind of photography, but it is useful for most. It is also a good way to keep your camera stored in an accessible and highly visible place (which prompts me, at least, to go out shooting more often).
  7. Get a camera bag that works for you. This is a tricky process that usually takes some experimentation. You want something big enough to carry what you need, but not so big you can never take it anywhere. You also need to decide whether you prefer a shoulder bag (much more accessible), a backpack (more comfortable), or something else. When carrying around just one camera and lens, don’t bother with a camera bag. Just bring a plastic bag in case of rain. Having your camera stuffed a way in a bag when walking around will make you miss photos. Bags are for carrying extra gear, and providing protection in transit.

Beyond this, the sequence really depends on what you plan to shoot. Some people might start with flash(es), some people might save their pennies for professional grade zoom lenses. Others might improve on their kit lens with consumer grade zooms (such as the reasonably high quality lenses that zoom from around 30mm to around 100mm and are available for under $500). Some people might assemble a collection of primes. Some people might save up to go straight to a full-frame body.

As someone who has tried a fair sampling of different kinds of photography, I would suggest that the following is a reasonable sequence:

  1. Consumer grade zoom (about 30mm to 100mm)
  2. Portable reflector (for portraits in sun)
  3. External flash and method for triggering it off-camera (either a cable or radio triggers)
  4. Light stand for flash and umbrella
  5. Second flash with triggering system
  6. Light stand for flash and umbrella
  7. Professional grade telephoto zoom (i.e 70-200mm)
  8. Professional grade wide angle zoom (i.e. 24-70mm)
  9. Wide angle prime lens (28mm or 35mm)
  10. Macro lens (85mm or 100mm)
  11. Full-frame dSLR body

You may want to sell the consumer zoom once you have professional grade ones, though it can be useful in situations where you need a wide range of focal lengths but can only bring one lens. If you never plan to get a full-frame dSLR, a professional grade wide angle zoom specific to crop sensor bodies might be a good idea.

Other options beyond this:

  • More flashes
  • Flash accessories (grids, snoots, softboxes, beauty dishes, gobos, etc)
  • Crazy nature lenses (i.e. 100-400mm)
  • Teleconverters (make any lens act like a longer one)
  • Fisheye lenses
  • A second body, so you can use two lenses without having to swap.

If you’ve worked your way through all of that, probably know a lot more about photography than I do. If you are in need of more distant horizons, there are two words to consider: medium format.

Ethics and autonomous robots in war

The increasing use of autonomous robots in warfare raises questions about how they can be used ethically and in concordance with international law on armed conflict. While unarmed robots like those used by bomb squads are ethically unproblematic, those with both weapons and an independent capability to make decisions about their use are quite different. This is especially true if they will be used in environments where civilians could be injured or killed.

The BBC has an article about some of the concerns that have been raised and issues that have been considered. In some ways, the trade-offs are similar to those with existing technologies. For instance, there is often a trade-off between how much risk an army exposes its own personnel to, and how effectively it can avoid causing civilian casualties.

How Americans spend their time

The New York Times has cooked up a neat interactive graphic on how Americans spend their time. It is broken up by hour of the day and by characteristics like employment status, race, and level of education.

Everyone devotes a surpising amount of time to TV and movies, especially compared to socializing. It is also interesting to see that those with advanced degrees seem to spend the largest share of their time traveling, though the graphic doesn’t make clear whether this is intra-city commuting, vacation travel, or both.

I found the graphic via Sightline Daily. There are some interesting observations there, such as: ” Just so, only five percent of men over 15 say they spend any time walking on a given day. Yet for most of human existence, walking was the only form of transportation available to the large bulk of humanity.”

A notebook to track organizational bugs

As someone who has come under three different major bureaucracies in the past eight years (and many different sub-elements of each one), I find a suggestion from Dame Julia Cleverdon, the chair of trustees for the UK’s Teach First program, to be an interesting one. She suggests that people joining new organizations should:

“keep a notebook and write down everything that strikes them as crazy in the first few months—because a year in, those things will seem normal. And two years in, when they have gained in experience and confidence, they should get that notebook out and start changing those things.”

It’s an approach that neatly balances the fact that people new to organizations probably think about them most creatively, while recognizing that experience is necessary to be influential and to be able to anticipate the full consequences of reforms.

High-speed stock trading

I had no idea stock markets operated so quickly now:

High-frequency traders may execute 1,000 trades per second; exchanges can process trades in less than 500 microseconds (or millionths of a second).

In addition to showing off just how blazingly fast financial transactions have become, this also demonstrates just how much more precise and reliable some networking hardware is, when compared to consumer stuff.

For the sake of comparison, I sent four packets from my home computer to the server that runs this site. It took them an average of 92 milliseconds to make the journey: 184 times longer than the rate at which exchanges can apparently process trades. Indeed, the difference between the quickest and the slowest packet to return was itself six times longer than the total processing time.

Clearly, those on dial-up connections need not apply.

Preliminary review: smartphones and the Nokia E71

Kitchen hooks

Since the E71 is my first smartphone, I am inevitably responding to both the general medium and the specific device. So far, my experience has been mixed. The phone doesn’t do anything as well as a real computer does – obviously – nor as well as I was hoping when I purchased it. While usable, the keyboard is awkward. The OS is a bit finicky and annoying. The web browser lacks capability and fluidity of use, and even voice calls seem to be of a worse quality than on my cheap old Nokia 6275i.

All that being said, the E71 has the considerable advantage that it puts the internet into a form that fits in a pocket and can be accessed from anywhere. The email and messaging features are those I use and appreciate most, with web browsing and maps following next. The media features are very basic, and I never use them. Coupled with a bluetooth keyboard, the phone is extremely capable for email, texting, and instant messaging. Even without, you can maintain one conversation at a reasonable pace, without needing to strain yourself excessively. Another feature that is surprisingly good is the speakerphone, which can be used quite effectively while cooking or sitting at a desk. The battery life is also good: enough to cover about eight hours of very active internet use. The built-in email app is ok, but limited. Annoyingly, the installable GMail application is only a bit more capable. It cannot, for instance, apply labels to messages. As such, they clutter up my inbox instead of being slotted away into appropriate places. Managing multiple streams of emails is far less intuitive with this interface than with GMail’s excellent online version (not fully usable with the E71 browser). Thankfully, Microsoft’s Mail for Exchange application allows perfect syncing of contacts and calendar items between GMail and the native Nokia apps. Never mind the oddity of using Microsoft software to help Nokia hardware and Google software work well together.

My specific complaints about the E71 include:

  • Annoyingly often, you need to tell the phone to connect to the internet, then using what protocol. For me, the answer is always ‘yes’ and the network is WiFi if available, GPRS otherwise. I dearly wish I could just lock those choices into the whole OS, rather than being forced to enter them literally every five minutes of use.
  • The keyboard is annoyingly small, though that comes part and parcel with a device smaller than an iPhone.
  • Copying and pasting requires an acrobatic manoeuvre: pressing three keys simultaneously, releasing, and then pressing three more.
  • The web browser doesn’t work with a lot of the menus at the back end of WordPress and can be very finicky about posting comments. It also has a viewpoint that lurches around violently as new portions of pages get loaded: super annoying if you are filling in a number of fields.
  • Even with a WordPress-specific app, the phone is not adequate for posting to the blog. For instance, it cannot interact with the WordPress media library, so as to include images in posts.
  • The device won’t download the full content of even small text-only emails. Each time you open one, it goes to a ‘retrieving’ screen that lasts 5-20 seconds.
  • Unlocking the keypad requires pressing two small keys in order. A dedicated lock switch would be better.
  • The camera is rotten, and the video recording is even worse.
  • Bluetooth connections go idle after an absurdly short period of time: maybe 60 seconds. There is no option to alter this.
  • There is no way to use the built-in read LED as a flashlight, as you can on the 6275i.
  • It lacks the super-useful automatic calling card dialler from the 6275i.
  • The voice quality isn’t great. If often sounds a bit like a VoIP phone without enough bandwidth.
  • Both applications and the whole OS crash pretty often, even when you are running programs one at a time. Sometimes, the only way to resolve it is to turn off the device and turn it back on.
  • For some reason, my unlocked E71 can only find a handful of applications in Nokia’s ‘Download!’ area.

Given how well reviewed the E71 is among smartphones, I can only guess that others have even bigger problems. I will admit to wondering whether the iPhone would have been a better choice. For web browsing and media, I would say ‘certainly yes’ since the demo iPhones I have tried are enormously better than the Nokia in both regards. In terms of messaging – which is my number one use – I still think that even a cramped physical keyboard is better than no keyboard at all.

At this stage, about two weeks in, I am less impressed than I expected to be with both smartphones and the E71. That said, it is a useful thing to have when computers are not readily available, and I may grow more accustomed to it as more time passes. One thing I mean to try but haven’t yet is tethering it with my G4 iBook.

Latent heat

Graffiti on brick, Ottawa

This blog’s focus on matters of energy and climate frequently leads to discussions of thermodynamics. One aspect of that not yet mentioned is latent heat: the energy involved in phase changes of matter. While it takes 1 calorie (not one kilocalorie, as what people call food ‘calories’ are) to heat 1 ml (1 gram, 1 cubic centimetre – don’t you love metric) one degree Celsius, it takes a lot of energy to change that 1 mL of 100˚C water into 101˚C water vapour. Indeed, it takes 540 calories to induce the phase change (turning 1 g of ice into 1 g of water takes 80 calories).

An entertaining way to see this demonstrated is to watch Julius Sumner Miller (mentioned before) talk about temperature. Another is to watch an episode of James Burke’s The Day the Universe Changed: Credit Where It’s Due. As a bonus, it explains how religious dissenters helped to kick off the coal-fired Industrial Revolution in England, eventually generating the climate change problems that confront us so dauntingly now. There is also a fair bit of talk about banking, and the role it played in industrial development.