The fantastic weather in Oxford yesterday meant museum visits took a back seat to a good punting session on the Cherwell (a violation of physics in its own right with me at the helm).
But we did get a half hour in the Museum of the History of Science , where I snapped this papier mache box lid, a great early example of newspapers not letting facts get in the way of a good story. For what they lacked in hacking scandals in 1835, they made up for in hoaxing, in stories like the one to which this exhibit relates: The Great Moon Hoax.
The picture is a satirical sketch of the astronomer Sir John Herschel, in a scene based on a series of reports by Richard Adams Locke for the New York Sun in 1835, supposedly describing observations made by Herschel at his South Africa observatory.
You can read up on the detail at the museum of hoaxes), but in this rendition, which is new to me, I particularly like the weird equipment combo Herschel’s minions are wielding around him: some sort of camera obscura / microscope mash-up by the looks of things. Maybe those instruments were more familiar than telescopes? Or, more likely, the journo just let his imagination get the better of him. Either way, I guess it’s still the little winged moon-men that steal the show.
The exhibit put me in mind of two lectures on a similar tack I enjoyed in the Royal Society’s History of Science series. You might like to check them out:
‘Fleas, lice, and an elephant on the moon’ by Dr Felicity Henderson (Sept 24 2010)
‘The Telescope at 400: a Satirical Journey’ by Richard Dunn (April 24 2009)
(both can be found by tracking down to the correct dates at the Royal Society podcast/vidcast page here).
A couple of months back, I sent away for a free set of genome fridge magnets from the Open University. Problem is, our fridge is a built-in one hiding behind solid Brazilian Rosewood chipboard/oak veneers; and they aren’t magnetic.
Talk about blessing in disguise. Now we have this fantastic genome-inspired central heating radiator. Good eh? (There’s me, then there’s Damien Hirst.)
So, 22 matching pairs of chromosomes, plus an X-Y pair (because I claim to be male; females have an X-X pair), for a total of 46.
When I lived in the Midlands of the UK, away from the bussle of London’s controlled airspace, one of my pleasures on an evening was to hire a light aircraft at my local airfield and tootle off for an hour or so practicing maneoveurs and generally enjoying the sunset – all very peaceful.
Except, one evening when I was out tootling above the Cotswolds; like a flash, an RAF Tornado jet whooshed from under me, matching my track but far exceeding my speed, and all uncomfortably close – a disappearing dot before I could blink.
In fact, he was probably a good 500 ft below me and certainly had on-board radar – so nothing actually dangerous going on. (There’s a popular myth – that may be true – that on such occasions the military use light aircraft for practice interception.)
Anyhow, it made an impression on me, and today the memory returned unbidden with these two photographs snapped at the Rick Pond in Hampton Court Park. They show a Sand Martin in a low-level, high speed pass over a convoy of ducklings – as bemused, no doubt, as I was 4000 feet above the Cotswolds (Figs 1 & 2).
I’d been trying to catch the Martins’ aerobatic fly-catching with no success, and started snapping the ducks more as a gesture of resigned failure. I only spotted the Martin when I downloaded the flash card.
This type of ‘buzzing’ seems to be in the Sand Martin’s nature. People on the bank get similar treatment – the bird coming from behind, passing within inches of heads, as if honing their own targeting systems.
I’d left the camera in rapid fire mode of 8 fps, so the time interval between the two photographs is known. If we also know the length of a duck, we can calculate the Martin’s speed, in ducks per second – or more tedious conventional units. So:
Assuming SML = 0.3m (Standard Mallard Length)
Time between pictures at 8 f.p.s = 0.125 s
Ducks passed between frames = 5.75 (use the grid to measure; one duck = 2 grid squares)
Q – What did the grape say when an elephant stepped on him?
A – Nothing. He just let out a little wine.
The first alcohol I ever drank was home brewed. I was twelve when the evil liquor – orange and raison wine – was served up by my refreshingly enlightened policeman uncle of all people. We’d visit the house and find these wort-filled vessels in the bathroom, glug-glug-glugging as bubbles of carbon dioxide chugged through little glass airlocks.
Not that I was swilling the stuff in quantity you understand, but what better introduction to the practical application of biochemistry and chemical engineering. Who knows what influence these little episodes have on later life decisions?
Six years later, as an impoverished student at Birmingham University, I was brewing my own 40 pints of barely drinkable delicious Mild Ale (pronounced ‘m + oiled’ in the local dialect). And while I never got into the brewing habit big time, I still on occasion reach for the demijohn and yeast – like recently, prompted by the promise of summer blackberries and the pungent whiff of Thames-side hops.
It’s obvious booze is an educational resource we ignore at our peril; but to consolidate, consider what’s going on in that murky ochre, as it sits in my hall, infusing the carpets and curtains with its fruity ambience. I hope it’s this:
The contents of the bottle are yellow because the blackberries haven’t actually appeared yet, so for now I’m using Chardonnay grape concentrate out of a can. And as that contains fructose from the grapes plus added glucose syrup, and I’m adding sucrose on top of that, both reactions should have kicked off immediately – the whole thing enabled by one of my favourite eukaryotic micro-organisms – Saccharomyces cerevisiae: a wine yeast.
There’s nothing to do now until it ferments out, but I managed to kill 20 minutes using the chemistry and bubble rate data to figure out how things are ticking along. I reckon I’ll produce 511g of alcohol and 488g (273 litres) of CO2, which at the current bubble rate means the fermentation will take 6 days (workings in the end-notes for those interested and assuming I’ve remembered my O-level chem.).
We covered production of ethanol from fermentation at school, but I don’t remember doing any distillation (which is illegal without a license in the UK). Certainly nothing to compare with the alcohol education afforded 1960s American youth courtesy of the fabulous Golden Book of Chemistry Experiments (excerpts below), which covers fermentation with yeast plus the distillation/synthesis of ethanol, methanol, and a bunch of other fun compounds from the ethanol ‘Family Tree’:
I love the helpful precautionary note on chloroform:’THEN SNIFF CAREFULLY’. A complete home schooling if ever there was one:
That’s all really. I’ll update with a report on the finished product, assuming the wrong types of bug and oxygen don’t intervene and vinegarate the show.
One last item though. Yeast is of course also used in baking; the carbon dioxide from fermentation causes dough to rise. So here’s a particularly rigorous explanation of the process from Alton Browne. It’s over my head, but I’m sure the trained biochemists out there will relate. (Quality isn’t up to much either – sorry about that.)
Guessing there’s about 300g of glucose in the concentrate, and I know I’ve added 450g sucrose to 5.5 litres of water. As 1 Mole sucrose (242g) yields 2 Moles glucose/fructose (360g), 450g sucrose will make 669g glucose/fructose. With the 300g in the syrup that rounds up to about 1000g total C6H12O6. 1 Mole of C6H12O6 (180g) makes 2 Moles ethanol (92g) plus 2 Moles carbon dioxide (88), so 1000g should make 511g of alcohol and 488g carbon dioxide. That’s roughly half a kilo of alcohol in 5.5kg water, or, ignoring the density difference, about 10% by volume . These kits supposedly deliver 12%, so the 300g estimate was probably low. The volume of gas produced can be calculated given 1 Mole CO2 (44g) has a volume of 22.4 litres at STP (24.6 at current 25deg C room temp), so our 488g equates to 273 litres of gas having to bubble through the airlock. It’s bubbling at about 1 per second with an estimated bubble volume of half a cm3 ; so I figure at that rate it will take 6 days to ferment out. All of which seems to hang together with what it says on the tin.
This piece from last Saturday’s New York Times on food colorings and the influence of color on taste perception takes me back to a Wellcome Trust exhibition I visited in 20031
Hosted by the London Science Museum, the Treat Yourself exhibition included an artwork, ‘Chromatic Diet’, by French artist Sophie Calle, that reproduced the colour-based diet followed by a character in Calle’s book Double Game2.
As I haven’t read it, the appeal of eating a different monochromatic dish each day of the week is beyond me. But Psychologists have for years studied the effect of colour on taste perception, exposing diners to the likes of green french fries, blue steak, and black spaghetti, sometimes under distorting lighting conditions.
And as the NYT piece underlines, for manufacturers of processed foods, colour is a powerful marketing tool.
Yet without any higher scientific motive, I like the idea of inflicting the chromatic diet (or something similar) on an unsuspecting dinner party, just to see what would happen.
O.k., probably lose some friends; but at least it’s mainly natural ingredients and looks quite doable. And having chickened out in 2003, I’m thinking in the age of Heston Blumenthal this might be the moment. Let me know what happens if you get there before me.
Here are the ingredients list for the dishes in the picture2:
Orange: Purée of carrots, Boiled prawns, Cantaloupe melon, Orange juice
Red: Tomatoes, Steak tartare, Roasted red peppers, Lalande de Pomerol, domaine de Viand, 1990, Pomegranite
O.K. – so I was the last person on the planet to see E.T., I still watch TV on a cathode ray tube, and I’m seven years late reading Olivia Judson’s hugely entertaining, accessible, not to say stimulating, guide to evolutionary biology: Dr.Tatiana’s Sex Advice to All Creation, making this an admittedly after-the-event review, but a recommendation all the same.
Throughout the guide, Judson stays in character as sex therapist Dr Tatiana, helping all manner of creatures out with their sex problems – agony aunt style.
And creatures it is. Ranging from a stick insect jaded with the tedium of ten week copulations; to a praying mantis who finds sex so much more satisfying after biting off her lover’s head; to a fruit fly dismayed that he’s run out of sperm; to a queen bee’s concern that her mates leave their genitalia inside her after sex.
Mixed in with these familiar heterosexual and homosexual practices are gang rape, cannibalism, self-sacrifice, and deception – all to a background of hopeless promiscuity.
The entertainment is delivered by a fascinating cast of cads, bints, sluts, and whores, bonking away at romantic locations – including the inside of a rat’s intestines.
That’s the language and tone then: spirited rather than crude I’d say, but probably not first choice for your great gran.
The anthropomorphism is extreme, caricatured, and humorous enough to make any questions around ambiguity and appropriateness non-issues (at least for me). It’s clever too, each section introducing a discussion on an aspect of evolutionary biology with some fun, if not a giggle, then quickly morphing into serious, yet always palatable, science.
The concepts are familiar: sex ratios, altruism, asexual vs sexual reproduction, dangers of recessive genes and such like; so perhaps I’ve not been under a log after all. I kept getting flashbacks to ideas I’d first read about in Richard Dawkins’s Selfish Gene or Matt Ridley’s The Red Queen. By comparison, Judson’s style in the guise of Dr Tatiana is deliberately and overtly entertaining; but not at the cost of scholarly rigor (there are 62 pages of Notes and Bibliography).
Previous reading certainly didn’t stop me picking up a bunch of new facts and figures on the more macabre and icky side of sexual reproduction. Knowledge any schoolboy/girl would be proud to have in his/her armoury.
Insects dominate Dr Tatiana’s surgery hours, but mammals and birds do get a look in. Like the girl hyena concerned over the size of her pseudo-phallus, or the moorhen bemused that his girlfriends are always fighting with each other.
But now I’m giving too much away.
Amazon have the paperback Dr Tatiana on for about £6.50 in the UK, and there’s also a DVD of the TV series based on the book. No brainer – go get it!
In one version of the illusion, an audience member stands in the coffin on a stage, and the rest of the audience watch as he gradually decays into a dancing skeleton before their eyes. In that case, the image of a brightly lit skeleton placed in a pit in front of the stage is reflected by an angled sheet of glass placed between the audience and coffin.
On similar lines, a less elaborate experiment you can try yourself with a sheet of plane glass and two tea-lights is described in this piece from the Naked Scientists.
I’ve had this picture for a while, and only noticed the Pepper’s Ghost effect when I pushed the shadow enhance slider on iPhoto. Quite scary seeing oneself encoffined. Good job I’m not superstitious….
Can you tell the temperature from how fast crickets chirrup in the evening? Neil deGrasse Tyson thinks so, according to this Tweet yesterday evening:
Sounds like a great idea, and as I’m in the foothills of the San Gabriel mountains – cricket central by my standards – I’ve tested tested out the theory.
Dr Tyson is not the first person to suggest you can tell the temperature with a cricket, and he’s only having a bit of fun, so in the worst case he’ll be guilty of spreading, rather than generating, misleading information ;-).
Armed with a digital recorder and a laboratory thermometer, I quickly found a suitable subject. The temperature read 65 degrees Fahrenheit. This is what the chirruping sounded like:
Press the arrow key:
– Cricket at 65F, 20.40hrs
From this sample, using only my ears, I counted 67 chirps in a 15 second period (it’s tricky counting that fast, but I found I could do it by checking off groups of 8 chirps on my fingers). According to Dr Tyson’s formula, that gives a temperature of 67 plus 40 = 107 F; a whole 42 degrees above the actual temperature.
Why the difference?
We’re doing science here, which means there’s a whole load of stuff to check out before rushing to condemn Dr Tyson for inaccurate tweeting.
Was it indeed a cricket I was listening to? Sounded like one, but I didn’t actually see it.
Was Neil referring to a specific type of cricket, but the 140 Twitter limited the detail he could provide? If he’s missed out a division factor of 2 on the cricket count, that would put my number in the right ballpark.
Did I listen to the cricket long enough? Was it in a cricket warm-up or warm-down mode?
Was my thermometer broken? Ideally I’d have two or more to check, calibrated against a standard. But I don’t think it was the problem.
Could the cricket be hiding under someone’s air-conditioning unit outlet? This isn’t so far fetched actually. We have one in the house at the moment living under our fridge because it’s warm.
Was my sample large enough – both in terms of number of recordings and number of crickets? I did make four separate recordings and (for now take my word for it) they were pretty similar. That said, I should really come back over a number of evenings at different times to be sure – right?
Well, in the longer term the sample could get large, as I’ll probably be listening out for these things obsessively for the rest of my life now.
What is a chirp?
Meantime, I wondered if the explanation was down to the definition of a ‘chirp’. I convinced myself the chirps I had recorded might be doubling up; maybe something the cricket was doing with its legs: ‘chirp-chirp’, ‘chirp-chirp’, etc. – each ‘chirp-chirp’ counting as one ‘chirp’. Are these double chirps that Neil counted as single chirps? Was it an issue of resolution and my ears? To find out, I slowed the recording to 0.19 times its normal speed and re-recorded a sample to get this:
Press the arrow key to stream live:
and a waveform looking like this:
Interestingly, what you hear on the playback isn’t ‘chirp-chirp’ at all; but ‘chirp-chirp-chirp’. And it doesn’t help us, because each group of three sub-chirps only makes up a single one of our original chirps. And there is no indication of a slower beat or modulation that would yield a lower chirp count. My original estimate remember was 67, and if you count the groups on the expanded trace above you’ll find there are 13 in 15 seconds on the slowed down trace or, correcting for the factor of 0.19, gives us 68.4. Virtually where I started. The cricket still says it’s 107F when it’s only 65F. (BTW – you can also hear another animal making an even faster noise in the background.)
Conclusion
In conclusion, accepting all the experimental limitations and caveats listed above, this test alone does not inspire confidence in the formula, and hence, the value of the tweet.
But hey, on the bright side we’ve all learned some possibly quite useless information about crickets, plus, more importantly, something of the pitfalls to watch out for in chronological cricket research (or any research for that matter).
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