I wasn’t going to post anything more about the Phoenix Lander, as the media’s picked it up now, and I don’t have a lot to add.
But then, I saw this photo..
It’s Phoenix decelerating with its parachute in the Martian atmosphere, taken by the Mars Reconnaissance Orbiter. Not a high quality image, but there’s something totally awesome about this. It’s not just telemetry and indirect guesses – that’s a man-made probe, landing on an alien world, and we can actually see it.
If you’re not in awe of that, what exactly does it take?
Just quickly, I wanted to link to this rather awesome animated map of England from 0 -> 1050 CE, drawn by Curzon at Coming Anarchy
Over the weekend, I encountered OECake, a demo application of a 2D physics simulation called the Octave Engine. It models gravity, particle interactions, and momentum, as well as evaporation and condensation of water particles.
So, I made a steam engine.
via Open the Future
3D Animation of the Phoenix Lander, due to land on Mars in about 17 hours.
This expedition promising interesting results. It’ll be our first chance to sample soil beneath the Martian surface as it carries on board a digging arm capable of digging a trench half a metre deep. In addition, it carries a wet chemistry lab, a mass spectrometer, and several other instruments, allowing it to analyze whatever it finds.
Not a lot is known about the soil on Mars. Take, for example, this photo, taken by the Spirit rover. It shows a surprisingly pale soil rich in silica found just beneath the red soil surface. It wasn’t found through any deliberate effort, rather, it was spotted when, at one point, the rover’s camera was brought to bear on the trail left by its wheel in the soil. Hopefully this mission will result in a lot more information about the role and amount of water in Mars’ climate and geology. If we’re lucky, it’ll give much more conclusive evidence of whether or not there’s ever been life on Mars..
For those who are really geeky, there’ll be live footage of the NASA mission during the landing available from NASA TV on Monday from about 10am onwards
Either way, here’s hoping the landing goes well..
Recently, I’ve encountered two ways in which evolutionary principles can be applied to medicine. Rather than using brute force to kill pathogens, these are more subtle, systemic approaches.
Viruses and bacteria evolve, just like all other living creatures. The difference is that they do it really fast. This means we can use evolution as a way of manipulating them. In the first story, we alter the environmental pressures that they live under, forcing them to adapt accordingly. In the second, we apply the rapid evolution of one microbe (viruses) to counter the the rapid evolution of another (superbugs).
Anyway – here’s the two stories:
1. By controlling the environmental conditions in which pathogenic organisms grow, we can, in principle, exert limited control over their evolution.
In order to be transmitted, some pathogens require a live, or even an active host. For these pathogens, there is evolutionary pressure towards non-lethal or lower intensity infections – infections that keep the host mobile and able to spread the pathogen. Others do not rely on host transmission, and in their case, there is evolutionary pressure towards the full exploitation of the host; that is, high intensity infections that take full advantage of the host as an incubator and food source.
Two examples of these pressures exist and have been studied:
This approach does little to prevent disease, but does a lot to reduce its intensity.
2. Use viral evolution to counter bacterial evolution of resistance to antibiotics
A major medical problem facing the world today is increased bacterial resistance to antibiotics. It’s generally accepted that the unnecessary use of antibiotics to counter mild infections, and, more importantly, to promote animal growth in farming has led to the rise of anti-biotic resistant ‘super-bugs’, including MRSA, resistant TB, and more. All sorts of diseases once considered controllable are becoming uncontrollable again, and people are dying from them in their thousands.
The principle behind this is simple – bacteria evolve at a rate many orders of magnitude faster than vertebrates. If we exert pressure on bacterial populations (through, say, a particular form of antibiotic), they’ll tend to evolve resistance. We’re stuck in an evolutionary race – we ‘evolve’ attacks (particular drugs), they evolve resistance. Currently, we’re much worse and much slower than the bacteria are at this, and we’re losing.
However, we’re not the only organisms that want to be able to attack and kill bacteria – there’s a whole class of viruses that prey on bacteria, including the famous T4 virus you’ll all have seen pictures of. These are called bacteriophages, and, like us, they’re in an evolutionary race with bacteria. One difference – they’re a lot better at it than we are.
Bacteriophages have another interesting property – they tend to be very specific in what they attack, most only targeting a small number of bacteria. Human cells are quite different to bacteria in many ways, and are effectively ignored by them. Given this, what is to prevent us from using them to target particular types of bacteria? Infected by medicinally resistant staphylococcus aureus (MRSA)? Try this viral cocktail..
OK – it sounds a bit far-fetched, or at least dangerous. There’s almost certainly drawbacks or risks that need to be addressed, but, as a research direction, it sounds really interesting. Several groups have been working with this therapy for quite some time, and some trials are underway. There’s even a book on the subject – Viruses vs. Superbugs.
I find the idea of this sort of manipulation extremely elegant – the phrase ‘playing god’ seems, to me to apply to this sort of thing even more so than it does to genetic engineering; I think of that as something more akin to hacking than the exertion of any divine powers..
via Open the Future;
A set of photos taken during the recent earthquake in Sichuan province, China, by a wedding photographer who’d just begun taking photos of the bride and groom when the earthquake struck.
Two strike me in particular – one of masonry falling off a church, the other of the bride, resplendent in dress, veil, and dusty debris looking out over the rubble as her new husband is climbing to his feet.
It seems their photos were being taken on some steps outside the church, within which many of their guests remained. You can only imagine the shock – they’ve just experienced an intensely joyful experience, then, having only recently left the church to have photos taken, they experience horror, as the building, filled with friends and family, collapses behind them. 33 are reported missing or dead.
Photos like this, untouched by professional media, give, for me, a much more intense window into events – it was easy to see imagery of rescue workers and devastation on the news and think of it as a distant tragedy, a statistic – this brings it all into so much more focus.
In the post mentioned above, Jamais says ‘With every snapshot, every recording, every blog entry, we’re documenting our world.’ – that’s important – it emphasizes the breadth of documentary that crowd journalism can give – if everyone has a camera and a voice, so much more is captured, and so many more perspectives are presented. That said, I think crowd journalism is similarly important for the personal, immediate nature of it – there’s an increase in perceived honesty and emotional intensity that you get when you’re seeing footage and accounts by people who were actually there, experiencing the event. To some extent, I think this is what makes embedded journalism during wartime so interesting, too..
At the Museum of Modern Art in New York, a rather macabre exhibit has been on display. Entitled ‘Victimless Leather’, it’s a miniature ‘leather’ jacket made from living mouse stem cells growing on a polymer matrix.
As art, one interpretation could be that it shows how artifacts currently made from dead animal bits can instead be grown from tissue cultures; another might be that it illustrates the incredibly weird implications of modern biology.
Unfortunately, given unlimited nutrients and a lack of other constraints, tissue cultures have a tendency to keep on growing, which this one did. After a week or two, it clogged several of its nutrient feeds, making it necessary that it be put down. “I felt cruel when I turned it off,” said Paola Antonelli, the senior curator responsible for killing it.
There’s been a lot of coverage of this; here’s a few articles:
A related issue is ‘test tube meat’ – meat grown from cell cultures in a laboratory. Intriguingly, PETA, a sometimes radical animal rights group, have stumped up a $1,000,000 reward for its development.. Clearly this is because this approach would alleviate the suffering of a great many farm animals. It may well also reduce the environmental burden caused by industrial scale animal husbandry.
I find both of these items really intriguing, as it brings up many interesting questions. If you’re game, please leave a comment with your answers to these questions..
(x-posted to LJ)
For those who like pretty astronomical pictures..
ESO has a press release out with several photos of interesting solar phenomena, including the rare green flash and even rarer blue flash, both caused by the earth’s atmosphere acting as a prism when the sun’s light hits it with a very low grazing angle at sunrise or sunset. More in wikipedia
For those not so fascinated by astronomy, here’s a bunny.