Archive for the ‘science’ Category
The BBC TV show Top Gear has recently come in for some major criticism over a new “special”: a trip to the North Pole. The criticism has revolved around the environmental impact of driving three cars to the North Pole, especially if they leave their customary trail of parts behind them. If you haven’t seen the show, and don’t want to know what happened before you do, stop reading now: there are spoilers coming.
I’m prepared to overlook the environmental concerns, for the simple reason that the show is unlikely to inspire many more such jaunts: it was expensive, complex, and hardly easy on anyone involved, even those in the three cars. I came away with a general impression of “we did this, so you don’t have to, and we even got it on HD Video”.
After many scrapes, including one that required several parts and left a pool of diesel on the ice, the car with Clarkson and May got to the North Pole first, before Hammond’s dog sled (which he wasn’t driving). The truck needed a backup team of Icelanders to help them, who pulled off tricks such as re-inflating a tyre with a bottle of butane and a lighter. That’s alright, then isn’t it? It’s just TV, right? Not so fast.
I’m hardly a Geographic geek, but the shot of the truck arriving at the North Pole raised more questions. They showed the truck’s GPS screen hitting the mark: N78˚35’7” W104˚11’9”. The North Pole is at N90 latitude, of course, and all the Longitudes at once. What’s the difference? According to the Great Circle Mapper, the difference is 792 miles, or 1275 kilometers. You can see the positions on a map, here.
A-ha, I hear you saying: they must have gone to Magnetic North, then? Yes, I thought of that, but it still doesn’t add up: throughout the program, they always referred to the North Pole: no mention of the word “magnetic” that I can recall, though I could be wrong about that. There’s another problem: they didn’t actually go the North Magnetic Pole.
The latest coordinates I can find for the location of the North Magnetic Pole are those from 2005, which were estimated at 82.7°’N 114°4’W. This is quite a long way from the show’s “North Pole” location: 307 miles, to be exact, according to another Great Circle Map. To be fair, however, the North Magnetic Pole has been near the location they used in the show: in 1994, according to the this map and other historical figures I looked up.
How does that compare to how far they actually went? They started at Resolute, in Nunavut, which is at 74°41’40.27″N 94°50’23.64″W. I know they didn’t go in a straight line, but if they had, another Great Circle Map tells me how far the crow flew: 308 miles.
In other words: their trip to the North Pole took them almost exactly halfway to the North Magnetic Pole. Come on, Jeremy: care to talk your way out of this one? If you were following the 2007 Polar Race route, you didn’t say anything about that… 🙄
At the beginning of 2006 I speculated that I would be doing less travelling. That suited me, simply out of general consideration for the environment. I didn’t need news headlines , or the European Union, to tell me that air travel is not good for it. So, I imagined, 2006 would be a quieter year for me, with fewer flights.
The reality turned out to be very different:
- April = 4 flights: Dublin <-> London, Dublin <-> Lisbon
- May = 1 flight: Dublin -> Copenhagen
- June = 5 flights: Copenhagen -> Dublin, Dublin <-> Amsterdam <-> Lyon
- July = 2 flights: Dublin <-> London
- November = 2 flights: Dublin <-> London
- December = 4 flights: Dublin <-> Dubai <-> Bangalore
That makes eighteen (18) flights in one year; eight of those for work-related reasons, the other ten for no good reason. By way of comparison, I calculate that I took nine (9) flights, half this year’s tally, in my first 25 years. Must do better this year – the environment needs me to cut back on the flying!
Besides, the romance has gone: RyanAir is working hard to make flying as exciting as taking a bus, and even though I didn’t fly with them last year, Aer Lingus are not that far behind, out of competitive pressures. I think I’ll take the ferry next time I visit the UK.
I didn’t want to do it, honest, but I have really had enough of the “plane on a conveyor belt” myth, so I’m posting my take on the problem here. I’m using the kind of title that search engines will like, and I can point other people, on other forums, to this response.
The basic question goes something like this: if you could put a plane, of any size, on a conveyor belt, will it take off? The conveyor belt speeds up to match the plane’s exact speed, keeping it stationary, so it can’t move forward, right?
The question is framed badly – a bit like an “irresistible force vs. immovable object”. The first key point, which most people get, is that the engines are pushing against the air, not driving the wheels, which spin freely with a small amount of friction. This should make the answer easy, if you think in terms of Forces: the plane is trying to move forward, what would hold it back? Not friction – far too small a force. The plane moves forward, and eventually takes off, regardless of whatever the belt is doing.
Not enough? Well, what can the belt do, anyway? Another fundamental problem lies in the idea of the conveyor matching the plane’s speed. How would such a control system work?
- measure the plane’s speed
- speed up the belt to match the speed of the plane
- GOTO 1
Steps 1 and 2 both take time.
- All forms of speed measurement mechanism have an inherent time delay. If you doubt this, go back to the fundamental definition of what speed is: distance over time. This is even true of high-frequency speed measurement systems such as Doppler Radar or Lidar, as used by law enforcement.
Another way of looking at it: if you could take a zero-time snapshot of any object at any speed, it would always appear to be standing still (velocity=0), making that useless for velocity measurement: you need time to measure the distance travelled.
- If the conveyor has any mass, it can not change speed instantaneously. That would require infinite acceleration of its mass, meaning an infinite force would be needed (since force = mass x acceleration). Anything less, there’s a time delay. Don’t believe me? Try putting the figures in to the basic Newtonian acceleration formula, A = ΔV / T , where A = acceleration, ΔV = the change in velocity, and T = time = 0. Oh, and before you invoke Einstein, be aware that his Relativity formulae do not contradict Newton’s at these non-relativistic velocities.
- With these inherent time delays in the control system: by the time the conveyor reaches its intended speed, the plane has accelerated to a new speed, so the conveyor is slower than the plane, which is thus moving forward! Repeat until V0, V1, and Vr (takeoff).
Can I go now? 8)
For years I’ve been a little worried about a demographic trend that has the potential to stop “positive evolution” in its tracks. By “positive evolution” I mean the idea that evolution leads to better, smarter people. Perhaps it’s considered elitist to wish for such a thing, and I know that assuming it would be a fallacy, but one may hope, may one not? After all, we don’t have another life to look forward to, so it’s natural for me to wish for more from this one.
I’m hardly the first to wonder where the human race is heading – as any Devo fan will know – but the trend that worries me is the falling birth rate in the developed countries in general, and among the most intelligent and educated sections of society in particular.
Unfortunately, in the absence of education and intelligence, it’s back to “survival of the fittest”, in my estimation. Today that seems to mean “breed like bunnies”. In poor countries this seems to imply “have many children, because some will die, and who will look after you in your old age?”. In the lower demographic strata of Western societies, especially Europe, this is read as “have many children, because the government will pay you and do what you can’t do for them”. I won’t get in to the politics, but this is compounded by poor education and awareness of family planning, which religion sometimes plays a part in. The Catholic ban on contraception is the obvious example here.
I keep in touch with various people I’ve met over the years: many of them are not married, and those who are have families of one or two children. One friend has a third on the way, which is very much the exception. I’m not exactly “high class”, whatever that is, but my acquaintances are all professional, working people, the “salt of the earth”.
Compare and contrast that with the poorer countries of the world, and the less-educated parts of the developed countries: Africa, Central America, the US South. I was shocked to see the 2005 statistics for Afghanistan, which had a birth rate of 46.6 per 1000 per year, and a 20 per 1000 death rate, that still leaves them which a 2.67% growth rate. I have all the stats in a spreadsheet, so I can sort them by the different factors, and they make sobering reading. The poorest countries – nearly all in Africa – are growing the fastest, thwarting any attempts to improve their living standards.
In the USA, this trend has not gone unnoticed by Mike Judge, creator of Beavis and Butthead and Office Space, whose new film Idiocracy was belatedly “dumped” in US cinemas and has not made it to Europe yet, if it ever does. It imagines an ordinary man who spends 500 years in stasis, and emerges in to a world that has gone downhill, intellectually, leaving him the smartest person in it by far.
In my view, even if things don’t go all the way down that road, we are still facing a “cap” on the intelligence of the human race: with the smartest people the best at reading the signs all around them and having small families, while the lumpenproletariat* think only of their short-term needs and desires, and not about how their world will be affected by their profligacy.
I am well aware that talk of “improving the human race” carries all sort of negative connotations, from elitism to eugenics, and I’m not suggesting any kind of direct intervention in what I perceive as a negative trend. However, what strikes me as most relevant to this forum is the way organized religion prevents individual people from realizing their potential in many different ways. Wilful ignorance of leaders, obstructions to family planning initiatives, education sabotaged by religious beliefs… those are the areas where I hope Prof. Dawkins’ book can make a difference, perhaps eventually proving me wrong!
* I’m kidding! Please stop hitting me with copies of Das Kapital!
Much as I enjoy and appreciate Anousheh Ansari’s groundbreaking (?) blog from the International Space Station the title of one entry distracted a little from the contents: Thank God for Velcro. Velcro®, after all is purely man-made, with nothing religious about it. Sure, it was inspired by nature, but nature is hardly a spiritual place, except when viewed from perspectives particular to some members of the human race. Of course I know what she meant, but it’s a little odd.
It’s only a tiny distraction; Ms. Ansari’s writing gives me that “wish you were here” feeling, and I really wish I was, despite some of the privations she describes. I would be tempted to spend hours staring out the window at the Earth turning beneath me. I had imagined it would be “all go” up there, with the cosmonauts taking as little sleep as they could get away with, but that’s not sustainable over an extended stay up there, so it makes sense for them to pace themselves.
Sadly, my eyesight alone will ensure that I never see space in this lifetime. Even if I have laser surgery to correct my vision, the shape of my eyes means that I will remain vulnerable to a detached retina if I am ever subjected to high G-forces. Never mind: I can live vicariously through blogs such as Ms. Ansari’s.
Finally: some scientists are looking beyond ways of slowing down or stopping global warming, and are starting to address the questions of how humanity will cope. I’ve asked, in these pages, why people continue to build their homes in low-lying areas that are subject to flooding, when a little geographic knowledge will let them understand just how dangerous it is.
In most cases, of course, people do not have much of a choice: they need to be somewhere, within the borders of their country, and when their country is e.g. Bangladesh – most of the country less than 10 metres above sea level – they can assume they will be affected by floods even before global warming kicks in. A sea level rise of just one metre will submerge an estimated 10% of Bangladesh – already one of the most densely-populated countries in the world.
Once again, we come back to the question of population: people producing more children than their country can support. It doesn’t make sense even at this time, far less if you are to look at the known problems facing any particular country in the future. Once again I find myself saying: if people don’t take care of themselves and their futures, by planning their families, Mother Nature will take care of them.
I just took two quick tests on colorvisiontesting.com, along with a colleague; while I have doubts about such tests, because of the variability of computer monitors, these ones gave a clear result, confirming that I’m colour-blind relative to “normal” people.
I would never have known I was severely colour-blind if not for the Ishihara tests, which I took under medical supervision years ago. One translation of Ishihara (石原) might be “stony wilderness”, which (I suppose) describes where the Cones should be in my retinas; I hope that means more Rods, since I do think I have good night vision. Apart from that, the only effect visible to me, outside the tests, is difficulty distinguishing between similar colours in poor light – which I thought everyone had problems with.
I took a more thorough test, a few years ago, in the research department of the Royal Victoria Eye Hospital here in Dublin. (An Irish institution named after an English Queen, with the Royal prefix? Hey, if it ain’t broke…) It involved laying little pots of colour in order, e.g. from blue to red. Didn’t do too well there either, if the tut-tutting of the researcher was any clue. (I admit to being slightly distracted by the researcher, who was named Hilary, and was rather beautiful in a slightly Lilith Sternin Crane fashion.)
So, if I’m colour-blind… what am I doing learning photography? Or should I stick to black-and-white film? I find some software colour correction of digital images to be overactive, but I think I have to trust it, at least on pictures aimed at this site.
No, it’s not spelled “color”. I don’t mind using some American spellings, particularly those where a “s” is replaced with a “z” (e.g. “realize”), since I think the change aids in correct pronunciation, but this one is a little beyond the pale (pun intended)…