TOP 100 SCIENCE SITES
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| Numberplay: How Many Light Bulbs Does It Take ... A set of puzzles involving light bulbs. feeds.nytimes.com |
Spacewatch: Jupiter's extraordinary moons This January brought the 400th anniversary of Galileo's discovery of the four main moons of Jupiter, a finding that helped to demolish the idea that all celestial objects circled the Earth. His crude telescope would be no match for those widely available now, and even decent binoculars are enough to glimpse the Jovian moons. Check for yourself as Jupiter climbs brightly through the E and SE this evening (15 September).Since the first flyby of the planet by Pioneer 10 in 1973, those moons, named Io, Europa, Ganymede and Callisto in order from Jupiter, have become recognised as interesting worlds in their own right. Io is the most hostile: bathed in an intense belt of radiation and tidally squeezed between Jupiter and the other moons, it is the most geologically active body we know. More than 400 volcanoes spew lava and towering sulphurous plumes that paint and repaint the surface in hues that range from yellow and green to white and red.Ganymede surpasses Mercury in diameter, while Callisto comes close: both may harbour oceans of water under their rocky and icy surfaces. It is the likely subsurface ocean of Europa that is usually seen as a possible location for extraterrestrial life, though it may be decades before anyone gets to drill through its icy crust to investigate directly. Meanwhile, Nasa and ESA are considering a joint mission for launch in 2020 to discover whether habitable conditions might exist on Jupiter's moons.Alan Pickupguardian.co.uk © Guardian News & Media Limited 2010 | Use of this content is subject to our Terms & Conditions | More Feeds guardian.co.uk |
Black holes and falling objects | Lily Asquith Lily Asquith from Argonne National Lab in the US on what killed the E687 experiment, and what won't kill youI was driving into Argonne with a colleague yesterday morning and he was telling me about the experiment (E687) that he worked on when he was a graduate student. It caught fire and burnt down. The fire was found to have originated from a very high voltage power supply with no fuse. This alone would not have caused the fire. But the wires in those days were flammable, and they were hanging down a bit where they were fed into the detector so they were separated with (highly flammable) polystyrene wedges. The wires were also of exactly the right length and separation to smoulder and ignite the surrounding material rather than just breaking when the power shorted. The experiment went down for a year.For some reason I am fascinated by this story. I know that there was no such thing as health and safety in those days, as we are reminded by this internal memo from the Fermilab archives stating that people should "watch out for falling objects":The halcyon days of health and safety in particle physics.Anyone who has sat through day after day of excruciating talks on unbelievable topics such as which bin to use (~2 hours) and what to do if you see someone in camouflage climbing over the lab security fence (~3.5 hours) will understand my nostalgia for the good old dangerous days. I like to keep track of how much of my life has been taken from me in the name of safety. If I include airports I think the current total is about 135 hours. And now I'm writing about it ... should this count towards the total?Of course the only danger discussed by normal people (normal = not fascinated by health and safety issues) is the risk of the LHC producing a black hole that will swallow our planet. When this story first came out I chuckled and thought to myself that maybe the Cern press office had pushed it out in order to get publicity for the LHC startup. In fact the Cern press office does not count Max Clifford among its staff, so this is not likely.I stopped chuckling (briefly) when one of the mums at my daughter's school approached me about it at an after-school fencing club at Brixton recreation centre. She was a really smart, sensible, friendly woman. And she was genuinely very worried. Humans like a bit of danger, but The End Of The World is possibly a bit too much for some sensitive types.She wanted to know why it was being reported in the media all around the world that there is a possibility of this happening. I told her that there is a possibility of it happening, because there is a possibility of absolutely anything happening. I could walk into a wall later on this afternoon, head in the clouds, and actually just walk straight through it. These things are allowed to happen within our current understanding of physics. I don't know if anyone has shown that the danger of this happening with the LHC/without the LHC are equal, but I know of no reason why this would not be the case.The problem is that in everyday life when we think of something as possible we only really consider possibilities such as there is a 50:50 chance of rain or a 1 in 14 million chance of winning the lottery. Probability is not a user-friendly branch of maths - it is counterintuitive and weird a lot of the time. See the Monty Hall problem for an example of this weirdness.So the physicist who answered "Yes" to the question, "Is there a chance that the LHC might make a black hole that swallows the Earth?" was right. Unfortunately the interviewer did not follow that question with "Is there a chance I will suddenly just disappear through the floor at half past four this afternoon?" because the answer to that would also have been yes.Jon ButterworthLily Asquithguardian.co.uk © Guardian News & Media Limited 2010 | Use of this content is subject to our Terms & Conditions | More Feeds guardian.co.uk |
The number game Numerologists get a far better press than they deserve, but Matt Parker finds he has an unexpected empathy with themI like patterns. I only ever buy palindromic values of petrol because numbers such as £34.43 not only make me smile but are easy to spot on a bank statement. Humans have an innate love of patterns and our ability to exploit them has led to modern civilisation. People enjoy sudoku for the thrill of completing a puzzle and the same numerical patterns underpin modern information technology.So I was happy to talk to the Daily Mail about yesterday's date – 10/10/10. There is nothing inherently amazing about it; it's just a quirk of the fact that we divide the solar year into 12 months of which we're in the 10th (when we could have any number of months) and that the calendar we use was zeroed 2,010 years ago (which isn't the case in many other cultures). But there is still something satisfying about the time 10:10am and 10 seconds on 10/10/10. Just like I remember stopping at 1:23pm and 45 seconds on 6/7/89. And mark your calendar for later this month when the date will be 20/10/2010.Then I read the Daily Mail article last Friday and saw it also had comments from my nemeses: numerologists.If you want to irritate astronomers, call them astrologers. To see mathematicians get downright emotional, talk to them in earnest about numerology. According to numerologists, the satisfying 10/10/10 date is "not just a once in a 100 years quirk of the calendar", but rather, the numbers have deeper meaning. Just like how the numbers from the date you were born, the position of the letters of your name in the alphabet and even your house number, affect who you are and even predict the future. Which feels like a lot of meaning to attach to arbitrary numbers.As for what the number 10 actually means, the Mail asked Sonia Ducie, author of Numerology: Your Personal Guide For Life, who said: "Ten is the number for wisdom, because it contains the essence of all the numbers of one to nine within it."Firstly, one to nine are just the digits that we happen to use. They are the symbols we use to represent numbers. Any number, such as 36 for example, is the same number when it is written "normally" as 36 or in binary as 100100 or in base-five as 121. We happen to use base-10 numbers because we have 10 fingers to count on (also called digits); if humans had evolved with five fingers we'd probably write 36 as 121.Not only that, but I'm not sure exactly how 10 contains the essence of one to nine within it. It seems to be just because it is bigger than one to nine, which means that every number contains the essence of every number smaller than it. This is the kind of vacuous but sciencey-sounding effluent that gushes from purveyors of pseudoscience.As you can see, I'm now getting a bit emotional. Honestly though, I do have some empathy for numerologists because I'm driven by the same thirst for patterns and causality. As humans, we all are. Our craving for patterns and logic means that we tend to seek patterns where there are none; clutching at random straws. We selectively manipulate things to produce patterns. The date is a perfect example: we use "2010" sometimes and "10" at other times, depending on which looks nicer, we switch between 12- and 24-hour time to get the most aesthetic numbers. We remember the times when seven is lucky and ignore all the occasions when it isn't. It is science and mathematics that allow us to overcome this innate tendency to generalise and separate the spurious from the insightful; coincidence from causal.Our being wired to spot patterns and make connections allowed civilisation to develop, and our ability to rationally manipulate and exploit patterns has provided civilisation with all its life-changing technology. Everything from modern medicine to mobile phones and computers exists because we didn't just decide that 10 is the number for wisdom and call it a day. Without our species' passion for meaning and order being balanced by our capacity for logic we would have nothing. Not even a sudoku to pass the time.Matt Parker is based in the mathematics department at Queen Mary, University of London. His lucky number is 496.Matt blogs at Stand-up MathematicianMathematicsMatt Parkerguardian.co.uk © Guardian News & Media Limited 2010 | Use of this content is subject to our Terms & Conditions | More Feeds guardian.co.uk |
Astronomers say they've found oldest galaxy so far By SETH BORENSTEIN 2010-10-20T21:17:28ZWASHINGTON (AP) -- Astronomers believe they've found the oldest thing they've ever seen in the universe: It's a galaxy far, far away from a time long, long ago.... hosted.ap.org |