ChristopherWhite.info

The online version of a piece by Martin Rees for the Guardian’s science course series:

“We are each made up of between 1028 and 1029 atoms. […] More than 1078 atoms lie within range of our telescope.”

So there’s only about 1.05 people in the visible universe, and bugger all else.

(In a recent post, which I’ve since misplaced, I criticised Madeleine Bunting for writing C02 rather than CO2, and took some flak myself for not being entirely accurate either, and not writing CO₂. In that case the lack of a subscript doesn’t obscure understading — not much anyway; it’s reasonably obvious we’re talking about a molecule made of one carbon atom and two oxygen. But in Rees’s article, having lost the superscript on 10²⁸ and so on makes it a complete nonsense.)

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Current methods of producing biofuels release so much carbon that it could take hundreds of years for them to make any greenhouse gas savings, a recent study has found.

Research led by David Tilman from the University of Minnesota has shown that whether biofuels offer carbon savings depends on how they are produced. Converting heavily vegetated land such as rainforest, savannah or grassland in Brazil, the US and southeast Asia can release between 17 and 420 times more CO₂ than the annual reduction in emissions provided by using biofuels in place of fossil fuels.

Growing demand for alternatives to petroleum is increasing the production of biofuels from food crops such as corn, sugarcane and soybean, with both agricultural land and native ecosystems being converted to biofuel production. The soils and plant matter on this land are large stores of carbon, and together they contain almost three times as much carbon as is found in the atmosphere. Converting the land to grow crops for biofuel manufacture releases this as CO₂ via burning or decomposition.

After these initial emissions, there is a prolonged release of greenhouse gases as roots and branches decay. The amount of CO₂ released over the first 50 years of this process is the ‘carbon debt’ of land conversion. Biofuels made from crops grown on converted land can repay this carbon debt if the net greenhouse gas emissions generated by their production and combustion are less than those of the fossil fuels they replace, but in many cases this may take centuries.

Tilman and his colleagues estimated the time taken to repay the carbon debt of biofuels produced from various crops and habitats. They found that only two would pay off their greenhouse gas emissions in under 50 years – sugarcane ethanol and soybean biodiesel, both grown on converted Brazilian Cerrado savannah, have repayment periods of 17 and 37 years respectively.

Most repayment periods are far longer, rising to an estimated 420 years for palm biodiesel grown on converted tropical peatland rainforest, as the required drainage causes additional emissions due to peat decomposition. There is also a 48-year repayment even when converting farmland that has been under the US Conservation Reserve Program for 15 years, as such systems gradually recover their carbon store.

In fact these figures may be an underestimate, since the researchers assumed cleared land to be in a fixed state, whereas it could still be accumulating carbon. In this case, the debt would be increased by loss of future carbon storage.

The production of biofuels must release as little stored carbon as possible if they are to successfully mitigate climate change. Biofuels made from plant waste, or native perennial plants grown on abandoned agricultural land, create little carbon emissions and offer immediate reductions in greenhouse gas generation, as well as reducing the displacement of food crops that causes the price of food to rise.

However landowners may prefer land clearance that results in greenhouse gas emission if they can make a profit producing biofuels but do not receive payments for carbon management.

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The best tribute would be to crack on with this.

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A Japanese astronaut is planning to release some paper planes in orbit later this year:

Should one of the fleet miraculously make it to Earth, its journey will have been about 300 miles, no doubt the longest flight for a paper plane.

The planes are statistically most likely to land in the sea. But if one floats down to solid ground, the lucky finder will be able to unfold it and discover the return address at the Japan Space Agency.

“It’s going to be the space version of a message in a bottle,” Professor Suzuki said. “It will be great if someone picks one up, We are thinking of writing messages on the planes saying, ‘If found, please contact us’, in a couple of languages.”

Contact them? I’d try eBay first.

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Oh dear. As if pillocks like Loose Change director Tim Sparke weren’t bad enough, take a look at this:

I have spent over 13 years trying to show the scientific community what I have found, but they refuse to listen. During this same time, everyone who has no emotional or financial ties to the idea that Einstein’s theory of relativity is wrong, have all turned into healthy skeptics after being exposed to what I have discovered. This film’s goal is to do the same on a global scale.

But wait:

Are you interested in becoming Executive Producer of a documentary film that already has two distributors with Oscar-winning documentaries interested in a rough cut? Then go to our investment wepage for details.

Ah. It’s that kind of scam.

(Via.)

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Well, not quite. But…

My screensaver does clever things — it downloads data and analyses it to contribute to a couple of science projects, almost justifying not bothering to turn my computer off ever. I imagine it’s doing it now. I don’t know.

One of the projects is a climate change model, from which the following are two screenshots. Spot the bullshit:

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Today’s Guardian response column sees berk extrodinaire Tim Sparke replying to George Monbiot’s demolition (pun not intended) of his 9-11 conspiracy film, Loose Change. It, like the film itself, is the most tremendous balls.

Sparke writes:

“…in accepting that the towers collapsed at virtually free-fall speed (”the weight of the collapsing top storeys generated a momentum the rest of the building could not arrest”), Monbiot shows no awareness that this explanation violates the law of conservation of momentum.”

That explanation doesn’t even remotely violate conservation of momentum, as most GCSE physics kids could tell you. Nor does Monbiot’s piece accept that the towers collapsed at free-fall speed. Just as well: they didn’t.

WTC1 was 417m high; WTC2, 415m. Using another GCSE physics favorite, the equations of linear motion [1] a free-fall collapse would take 9.22 seconds and 9.19 seconds respectively.

Each collapse actually took approximately 12 seconds. (Loose Change claims that free-fall and the actual collapse is ~10 seconds.)

Three seconds is quite a difference. I emailed Tim Sparke to question this. He said:

“Your [sic] right its [sic] not quite ‘free-fall’ speed, but it is still so fast as to be
near free-fall.”

No. It isn’t. Three seconds is sufficient to pancake.

Then we have:

“Monbiot also appears oblivious to NIST’s failure to explain that, although fire could not have melted any steel, there were pools of molten metal under the rubble, and these pools remained molten for weeks after the collapse”

A vastly more sensible Tim points out that the molten metal isn’t necessarily steel, and suggests a convincing alternative.

Then:

“…the clear video evidence of explosions taking place”

The flashes in the building? They could be anything. (Having had the misfortune of seeing Loose Change…)

And Sparke adds:

“It is about whether we should accept unconditionally a story which defeats the laws of physics…”

Which is why Loose Change should be ignored.

Not mentioned in either Monbiot’s original criticism of the film or in Tim Sparke’s response is the part in which the film’s producers attempt to “prove” that an aircraft impact couldn’t, on its own, have brought down a building. They cite the B-25 that crashed into the Empire State Building in 1945 (only in the original version of the film, they refer to a B52, which didn’t enter service until 1954, so high-quality is their research). The Boeing 767s that hit the World Trade Center will have had a kinetic energy over 3000 times higher than the aforementioned B25 [2], which Sparke conveniently disregards.

I wouldn’t like to speculate on what “really” happened that day: I don’t know enough about it. But, clearly, neither does Tim Sparke, and tripe like Loose Change does nobody any favours.

[1] In this case s = ut + ½at² , where u is the initial velocity, zero; s the height of the buildings, as above; a the acceleration due to gravity, 9.81ms^-2; and t the time taken to collapse.
[2] Based on comparing empty weights of 10,000kg and 80,000 kg and cruise speeds of 370km h^-1 and 870 km h-1 respectively, with Kinetic Energy = ½mv²

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From today’s G2:

The Question
Is today the worst day of the year?

It is, according to Dr Cliff Arnall, a psychologist with a taste for self-publicity. His formula, taking in six factors - weather, debt, time since Christmas, time until pay day, low motivation and failure to keep new year resolutions - has been wheeled out for the past few years to calculate the most depressing day of the year. And since today is that day, wipe that smile off your face and remove that spring from your step.

Only “Dr” Cliff Arnall isn’t a doctor. And he is a proper crank, as Mr Mickel pointed out nearly a year ago.

Mark Twain needs to be adapted for a world of information overload. Not “A lie can travel halfway round the world while the truth is putting on its shoes,” but “nobody gives a toss if truth’s evenin the race.”

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More idiocy from the Northern Echo’s letters pages:

“AMONG the list of “vestigial structures” that Chris White cites as “remnants of evolution” is the coccyx (”tail bone”); obviously believing that humans at one time had tails.

Supposing we had had tails: who or what decided we should now not have them; and why did that decision/natural selection/evolutionary process affect all humans, causing all to be without tails?

Surely some humans would have found them very useful and would have wished to retain them. So why has the whole human race evolved with such uniformity? For there is not a single human being living or recorded in history as having a tail.

The theory of evolution is based on tales, not on fact. There is no fossil evidence or any other evidence to support this assumption. - Colin G Farquhar”

Observing that we have a tail bone doesn’t imply that I think that human beings once had tails any more than six-week-old foetuses’ gills suggest that we used to be able to breathe underwater. Our ancestors had tails. This is rather different.

As for why that evolutionary process should affect all humans: it, for whatever reason, confers a survival/mating advantage and increases the probability of No Tail to [survive long enough to] be able to breed and pass down the No Tail gene. That’s the entire basis of Darwin’s theory, which Mr Farquhar evidently doesn’t grasp.

As for no fossil evidence to support evolution - well, maybe not on his planet…

The thing is, this isn’t even the worst misunderstanding of evolution that I’ve heard. That accolade goes to a street preacher (why are they invariably creationists) I was having a chat with a couple of months ago. He couldn’t understand how - particularly given his A-Level in psycology - that humans all across the world came down from the trees at the same time and just happen to think in the same way.

I pointed out that, actually, humans came down from the trees all in Africa and then spread out across the world. He wasn’t listening.

It’s such a beautiful theory if people bother to try to understand it. But they don’t.

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Back when I was studying astrophysics, one of the bits of research the department was involved in was trying to find out the shape of the universe.

The solutions of Einstein’s field equations that describe an expanding universe have three possible solutions, corresponding to universes that are geometrically flat, hyperbolic or elliptic. Which actually applies to the real universe can only be determined observationally.

According to the website for my old supervisor’s book (I had a peek at some of it while it was still being written - it’s a good read), they’ve since discovered that it’s flat. Seems counterintuitive to me - I went through denial for about half an hour - but what do I know?

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