Category: Geek stuff

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

Attacking encrypted bitmaps

Just because your photos are encrypted, it doesn’t seem that you can count on them to be totally unreadable to someone without the key. The attack only seems to work against bitmap images, so those secret JPGs, PNGs, and GIFs should be safe for now. This is because most types of files contain significantly more entropy than bitmaps. That is to say, there is a lot more redundant information in a BMP file than there is in something compressed. Even in the case of the vulnerable images, the technique can only produce “the outline of a high-contrast image.”

Once again, it proves the statement that ‘you can’t hide secrets from the future with math.’ Cryptographic attacks – and the resources available to attackers – will only keep increasing over time.

Re-jacketed

I once again have cause to praise the excellence of Mountain Equipment Co-Op as well as W. L. Gore & Associates. Two years ago, I got one of their excellent but now discontinued Aegis rain jackets. Recently, I noticed that a patch on the back near my right shoulder was starting to de-laminate: the Gore-Tex was coming apart from the nylon.

I took the jacket into MEC today to ask if there was any way to stop the patch from spreading. They told me that Gore-Tex has a lifetime guarantee that their jackets will not delaminate and that they would refund me the original purchase price. I used it towards a new MEC Synergy Jacket. It is dramatically lighter than the Aegis and has waterproof zippers instead of flap-covered ones. The only obvious downside is that there are fewer and somewhat less capacious pockets. The new jacket is less cumbersome and takes up less space in a pack. It is also made from Gore-Tex Pro Shell, which is supposedly more waterproof and breathable than the Gore-Tex XCR the Aegis was made from. I hope I get the chance to climb some rainy mountains in the new garment – ideally back in British Columbia.

An idea for reducing problems with dead links

As mentioned before, one of the most frustrating things about the internet is the likelihood that following a link will lead to a page that has moved, changed, or vanished since the link was posted. Given the massive increases in bandwidth and storage space that have taken place, I had an idea for combating this. Basically, it would be an automated system that saves a cached copy of any linked page, then allows anyone viewing the linking page to view the saved version of the linked page, in the event the latter became unavailable. That means a blog post linking to a news story or other blog entry would be able to provide access to either of the latter, even at a point in time when they are no longer available in their initial contexts.

It would work a lot like Google’s cache: saving text and formatting, with links to any images and video in their original locations. As such, the maximum amount of content would be retained without using too much disk space. To begin with, the system could be integrated into content management systems like WordPress. Eventually, it may be sensible for every link created to express this behaviour by default – at least on websites that choose to enable it.

Like so many useful things, the system would but up against copyright restrictions. That being said, Google has thus far been successful in defending the legality of their own caching practices. Perhaps the courts would be willing to consider the kind of enhanced links I described as a fair use of potentially copyrighted material.

Geoengineering with lasers

This Economist article on geoengineering takes the same basic stance I have: that it is worth developing as a backup strategy, but that it is too dangerous to rely upon as an alternative to mitigation. That being said, they treat some of the options more generously than I would. On the basis of what I have read so far, ocean fertilization seems unlikely to work, and the secondary side-effects of sulfate injection seem too severe – not to mention how any geoengineering strategy that does not actually reduce carbon dioxide concentrations dooms to oceans to becoming ever-more-acidic for as long as we keep burning fossil fuels.

The strangest idea discussed in the article sounds like the kind of approach a Bond-villain would dream up:

Perhaps the most intriguing idea—which was published last year, though not discussed by the Royal Society—is to eject carbon dioxide from the atmosphere at the Earth’s poles, using the planet’s magnetic field. This may sound absurd, but oxygen already leaks out this way (the phenomenon is the subject of a paper just published by Hans Nilsson of Swedish Institute of Space Physics). Alfred Wong, a researcher at the University of California, Los Angeles, proposes that a system involving powerful lasers and finely tuned radio waves could encourage carbon dioxide to take the same route. His calculations suggested that using lasers to ionise molecules of carbon dioxide, and radio waves to get them to spin at the correct rate, would cause those molecules to spiral away from Earth along the lines of magnetic force until they were lost for ever in space.

I have no idea whether this could actually work. Furthermore, implementing it meaningfully would require ejecting about 35 billion tonnes of carbon dioxide per year into space. That seems likely to have some weird consequences.

Spore tip: getting to the galactic core

To get to the core of the galaxy, you need to fly through a very large number of hostile Grox-held systems. Before attempting it, I recommend having the best possible interstellar drive, energy capacity, and health capacity. You will also need about 25 full repair kits and 25 full energy recharge kits. The tool that allows you to fly through black holes is also highly useful.

Some specific suggestions:

  1. Plan a general route through the most densely-starred corridor you can see. As you get close to the centre of the galaxy, the distance you can travel per jump falls off sharply.
  2. Don’t waste time attacking any Grox ships or cities. Just fly
  3. Use a repair pack whenever you are down to 1/3 health. It is a bit wasteful, but makes it less likely you will get blown up and need to start over.
  4. Black holes are very useful. Once you have ten or so Grox ships attacking you, being able to fly through one and lose them all is quite helpful.
  5. Keep an eye on the 3D nature of the starfield. Finding a route will be tricky at times.
  6. Once you have finished your business at the core, the easiest way to get back to your own space is to let yourself get blown up. It is a lot less costly and frustrating than flying back through the whole Grox mass.

Bon chance.

Medical treatment using internal robots

Magnetic resonance imaging (MRI) is a medical technology that uses powerful magnetic fields to visualize structures within the body. One innovative expansion of the technique presently being investigated is using the magnetic fields to guide small magnetic objects:

Sylvain Martel and his colleagues at the NanoRobotics Laboratory at Ecole Polytechnique de Montréal in Canada are also using magnetic fields, but in a different way. They are using fields generated by a magnetic-resonance imaging (MRI) machine to ferry small beads through the bloodstream with the goal of delivering therapeutics close to tumours. This has several advantages, says Dr Martel. For one thing, most hospitals already have an MRI machine, so there is no need to construct or buy additional equipment. Furthermore, as well as propelling a magnetic device through the body, an MRI machine can also locate it.

The whole article is well worth a look, as it describes several other novel medical technologies and approaches. My other favorite is the ARES ( Assembling Reconfigurable Endoluminal Surgical system) Project, which seeks to create robotic operating tools that are swallowed as a set of small pieces that then assemble together inside the patient’s stomach.

A few Apple complaints

Last night, after the Bluetooth connection failed for the hundredth unexplained time, I switched back from my Apple wireless Mighty Mouse to my old Microsoft optical scrollmouse. I must say, the change is for the best. The old mouse is lighter, smaller, and more comfortable. It is possible to press both buttons at once, and press the middle button without accidentally scrolling. Most importantly, the scroll wheel itself is much less finicky – it may not be able to scroll horizontally, and it lacks the Might’s Mouse’s useless ‘squeeze’ buttons – but it seems the superior device overall, despite the need for it to be tethered to my computer.

In general, I think Apple does a magnificent job of making computer gear and software. If I had to make two complaints, the first would be about the way they sometimes privilege form over functionality. Alongside the Mighty Mouse (and the infamous prior hockey puck mouse), there is the interface of Time Machine, which is pretty but probably less useful than it could be. My other complaint is their willingness to change things after the fact in ways that cannot be reversed and that people might not like. For example, there was when they locked iTunes so that only three people per boot session could access your library over the network (a real pain in university residence), or when they limited the volume on my iPod Shuffle through a software update.

A Wikipedia paradox

The site is most useful when you know either absolutely nothing about something, or a great deal about it. It permits those utterly unaware of a topic to get some essential facts – probably true – very quickly and easily. It also allows real experts to track down something they once knew, can remember, but had forgotten very quickly.

Wikipedia is least useful for those in the middle zone. These are people who know more than the minimum, but not enough to really judge the credibility of complex arguments in the subject area.

Nonetheless, it is a wonderful resource. I use it at least twenty times a day.

Spore tip: species for terraforming

There is no quicker way to make money than to develop a bunch of T3 planets that are close to one another and which produce valuable forms of spice. Getting planets to T3 can be a pain, however. This is largely because you will need three species of small, medium, and large plants; six species of herbivores; and three carnivores or omnivores.

The easiest way to get them all – and avoid repeats – is to dump all the species you are carrying, visit an existing T3 planet (like your homeworld) and collect a dozen or so of each species present. You will then have a hold full of terraforming goodness.