I got up yesterday morning at what for me is quite an early hour – 6.30ish. So with no CSI on the box at that time, I chose the healthy option and went for a walk in the park. Where I took this picture:
Spider web with water droplets (Photo: Tim Jones)
That’s only kind of true. What I actually took was this picture:
Zoom out. Spider web with water droplets (Photo: Tim Jones)
and only later discovered the fine structure of water droplets clinging to the spider’s thread when I got home and fired up the computer.
A beautiful and fascinating sight. But, as per usual, the deeper beauty is in the science behind WHY droplets deposit in such regular patterns.
One Google later, I’d found this relevant study described in a Nature News piece (full research paper doi:10.1038/nature08729 behind pay-wall; also as per usual…).
The News piece describes work by Lei Jiang from the Beijing National Laboratory for Molecular Sciences on the hackled orbweaver spider Uloborus walckenaerius. The authors found that if you get in close enough, spiders’ silk appears not as a simple thread but is covered in puffs of minute nanoscale fibres. When the puffs get wet they contract into tight beads or knots connected by thinner pieces of silk, necklace fashion. Additional water migrates and accumulates on the rough surface of the knots in preference to the smoother connecting silk, forming the uniform droplets we see. The research also inspired thoughts around practical offshoots, like the possibility of a man-made equivalent for the manufacture of highly water absorbent materials.
I didn’t see any ‘puffs’, but I’m pretty pleased with the resolution I achieved with a good but relatively straightforward camera. That said, I’m feeling the need to get some of that spider silk under the microscope.
Here’s one more picture taken on the same day, of a single strand of web stretching between two trees; would you believe a distance of over 20ft?
The water is clearing from one portion, and the dry filament is just visible in the close-up view. In the technical jargon, we can say the ratio of droplet size to silk diameter is ‘amazing’.
And if you’re wondering where the spider/s were all this time? Me too. For the arachnophiles, here’s one I took earlier.
Bakelite coffin at the Plasticity exhibition, London Science Museum (Photo:Tim Jones)
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….
This picture of a Sinclair Scientific is the latest recovered image from the 30 year archive of negatives I’m dutifully working through.
The reflections in this post are also prompted by this recent post on Andrew Maynard’s blog, (2020science), describing the sophisticated graphing calculator his children are required to have for school.
A pass-me-down from my brother, the Sinclair Scientific was my first electronic calculator. Built from a kit in 1975, I used it to prep for the UK O-Levels when I was 14 or 15; in the O-Level exams themselves we only had log tables :-P. By the A-Levels (16-18), I’d upgraded to a Casio fx-39.
John Napier, father of logarithms (Image: Wikicommons)
As it turns out, the calculator my nephews require for today’s GCSE syllabus is a Casio; but costing around £5, against the £75 or so for Andrew’s Texas Instruments machine.
An interesting feature of the Sinclair Scientific was its use of Reverse Polish Notation (RPN): an unusual but logical way to express calculations. Under RPN, the operator (+,- x, / etc) comes after the operands (the numbers); so the more well known Infix representation of 7+8 , in RPN becomes 7 8 +. RPN is more memory efficient for computers – a bigger deal once than it is now. Today, modern computers just translate into RPN without us seeing it.
You might think getting to grips with RPN was an awkward distraction for a 15 year old, but it proved handy background when it came to writing programs for this:
Stantec Zebra (Photo from the Stantec Zebra manual)
I guess this was our graphing calculator. Not exactly pocket size.
If memory serves, my school, named the ‘The Gateway’, acquired the 1958 Stantec Zebra from the local university; before that it was with the Post Office.
Punch card
A small team of students operated and maintained the machine which, filled with hot valves, would frequently catch fire and give the occasional electric shock. This could never happen today of course, on safety grounds alone. But at the time, the teachers and students took it all in their stride, seizing the opportunity to build a short extra-curricular programming course into the timetable.
Programming lessons involved: writing code on cards with pencil and paper, encryption onto punched cards that the Stantec Zebra could read optically, then receiving line-printer output of the results. Looking back, it’s amazing any of this happened – a great opportunistic use of a rare resource.
Powertran Comp 80 (Photo:Tim Jones)
Pupils who later built their own computers, like the Science of Cambridge MK14, a basic kit machine launched in 1977 with about 2k of memory, or the Sinclair ZX-80, were doubtless inspired by the presence on site of their valve-driven (but still significantly more powerful) ancestor.
An interest in computers in this era meant just that: an interest in the information structure, solution algorithms, programming and hardware. High level programming languages, like BASIC even, were too memory inefficient to exist, and ‘games’ typically comprised simple models around the laws of motion; moon lander simulations were popular.
Our household variously hosted a home-built Powertran Comp 80, a Sharp MZ-80A (including some early green dot graphical capability), a Sinclair Spectrum and Sinclair QL. I’ve put pics of these and various other devices I’ve owned in the gallery at the end of the post – minus the obvious PCs that started with a Viglen P90 in 1995. Also our Creed 75 teleprinter – the only one I’ve seen outside the London Science Museum, this true electro-mechanical wonder was brought to good working order save for the chassis occasionally running live with mains voltage.
The Science Museum’s Creed 75
Are there any world-changing messages to be drawn from all this nostalgia? Possibly not. But I’m reminded how very hands on we were in just about everything. And that’s relevant given the buzz today about how kids might not be getting enough practical science and engineering experience in schools (I’m thinking of comments most recently made by Martin Rees in the Reith Lectures).
No one is arguing kids need a nuts and bolts knowledge of all modern gadgetry, but I do think off-syllabus projects like the Stantec Zebra (but perhaps less dangerous) are a good thing in schools. They show how diverse academic subjects come together in an application, making the theory real. This is pretty much my mantra in this earlier post about the Young Scientists of the Year competition. I would have thought such projects give a school a sense of identity and foster a bit of team spirit?
But it’s really an area I’m out of touch with. Does this type of stuff happen in lunchtime science clubs? Is there time in the curriculum? Do teachers have the time and/or skills? Or has our health & safety culture, however worthy, killed off anything interesting?
Question to any crow experts out there. I recently spotted these two standing together, and noticed that they seemed never to blink at the same time – as if consciously taking it in turns. It’s easy to tell when a crow blinks by the opaque whiteness of the inner eyelid. This went on for a minute or two.
Nudge, nudge...Wink, wink...
Say no more...
So, is this some kind of coordinated look-out tactic crows and/or other birds follow to maximise safety? They were long leisurely blinks, so that might make sense. Or was this a one off behaviour – and I’m making up my own stories?
The things that preoccupy one on these warm summer evenings…..
Update September 2010
I found this pic going through my archives; taken in Windsor, UK. Look at the eyes. Still a small sample of two.
Recipes Formulas and Processes by G.D. Hiscox (1907 edition)
I’m lucky enough to own a 1907 first edition of Hiscox’s classic work, and love the way my copy is dis-colored and bleached by chemical splashes. Not by me, I hasten to add. But this book has for sure been used for its intended purpose! Whether the former owner, a James McQueen Jr. according to the bookplate, lived long and prospered because of its secrets, or in spite of them, is a different matter.
Secrets intended for all; the preface:
In compiling this book of formulas, recipes and processes, the Editor has endeavoured to meet primarily the practical requirements of the mechanic, the manufacturer, the artisan, and the housewife.
Some of the information is innocuous enough. You can learn how your great grandmother made blackberry jam. And Celery Clam Punch or Cherry Phosphate (with real phosphoric acid, maybe the origin of cherry coke?) sound refreshing for a summer evening.
But some of the medical cures are distinctly dodgy. We worry enough today about tanning products, but Hiscox’s cure for a tan, made from bichloride of mercury, sounds lethal. Helpfully, he shares with us that:
This is not strong enough to blister and skin the face in average cases.
Phew, good job most folk are average. Responsibly, he adds:
Do not forget that this last ingredient [the mercury compound] is a powerful poison and should be kept out of the reach of children and ignorant persons.
Folk would have taken Hiscox’s Cannabis indica based cure for corns in their stride (ouch!). And concern over the pinch of cinnabar in his nail polish would be just another case of health and safety gone mad.
But surely, even by the standards of the time, Hiscox’s idea of a light-hearted party trick must have raised some eyebrows (or literally blown them off): like ‘To take boiling lead in the mouth’, ‘Biting off red hot iron’, ‘Sparks from the finger tips’. And ‘The burning banana’ doesn’t bear thinking about.
Recipes, Formulas and Processes (1907 edition)
Some recipes were probably safe, but just sound a little icky. Like a nice pomade for sir’s hair, made from vaseline oil and beef marrow. Blue hosiery dye called for some ingredients I’ve never heard of: like 4 pounds of Guatamala and 3 pounds of Beugal Indigo; and others I have heard of: like 1 pail of urine. Hiscox also contains lots of paint and ink recipes but, disappointingly, there’s no mention of the infamous Mummy Brown.
‘Solid Alcohol’ sounds quite useful, maybe as a firelighter. I made something similar as a schoolboy, by dissolving soap in methylated spirit.
There’s nothing in Hiscox to separate the domestic from the industrial. Content is alphabetically indexed, but otherwise all mixed up. The section on glass includes industrial formulas for making different glass types and colourings in the furnace, but also includes instructions for a home-made glass grinding device.
Interestingly, Recipes, Formulas And Processes was republished through many revisions and editions into at least the 1930s. But I’m sure today there is nothing quite like it – unless we include the internet as a whole.
On another tack, it’s worth remembering that when Hiscox was published, the welfare and commercial infrastructure we take for granted today (some of us) was much less developed or non-existent. No popping down to the mall for a ready-made solution to every task. Folk just did more of their own stuff.
And should you decide to do more of your own stuff, don’t do it from Hiscox! He’s academically interesting to browse, but clearly some of his recipes and ideas are best left well alone.
Having unaccountably failed to spot comet McNaught on its recent visit, I was compensated last week by a meeting with this artificial comet created at the Griffith Observatory .
Demonstrator Grace holds the artificial comet (Photo:Tim Jones)
Demonstrator Grace is holding the tangible product of last Friday’s ‘Let’s Make A Comet’ event, held in the Griffith’s Leonard Nimoy Event Horizon Theatre. And I have to say, it was one of the best half hour’s worth of science communication I’ve seen.
I think the shear fun value had a lot to do with it. And although the show was geared to a young audience, there was no dumbing down of the science or talking down to the kids. Presentation style and jokes were witty rather than silly, patronising, or childish; and references to popular culture, like Harry Potter and the Transformers movie, were entertaining but topic-related. The professionalism of the two demonstrators / presenters really made the show, and it’s taking nothing away from the scientific knowledge and skills these guys have, to say they were genuine entertainers.
The comet was made by mixing together common substances containing the elements found in real comets. So that meant shaking up water, sand, carbon, and cleaning fluid (ammonia) together with dry-ice, or frozen CO2, in a plastic bag; the details are here on Griffith’s Teacher Resources page.
Griffith Observatory (Photo:Tim Jones)
I liked the hidden plan to pull an audience in on the promise of seeing a comet being made, then to educate them on broader themes and related topics; the practical demonstration happening only at the end of the session. There was nothing sinister in that though, and it all went down well with the bulk of the show taken up with a mix of talk, slides, videos and Q&A breaks. A lot of ground was covered, ranging from the chemical and physical requirements for life, to how the solar system is thought to have formed, and a pretty good introduction to astrobiology – including a discussion of extremophile life-forms.
Lecture theatre events are inevitably going to be a little one-way, but there was good engagement through the Q&As and frequent questions back to the audience. And it’s not like this was a public consultation on the risks of nanotechnology, the material being relatively uncontroversial.
Having the finished item available for inspection after the show was a big plus, and I’m sure the memory of it will for many people be a lasting anchor for the science they picked up.
Here are the three pictures I got early this morning before cloud set in.
The last in the series was taken at 10:35 UTC, about an hour before greatest eclipse at 11:38 UTC – when more than 50% of the moon was in eclipse. Location – Los Angeles. I suspect the colour fringing in the last shot is a camera artifact, rather than an atmospheric refraction effect, as the frame is exposure enhanced (to counter a rapidly misting sky). :
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:
Cricket sound slowed down to x0.19 original
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).
Oak Galls, Andricus kollari (I believe this particular tree is a Californian coastal scrub oak, Quercus dumosa.)(photo:Tim Jones)
A good few Zoonomian posts are based on things or events I just happen to stumble onto. And that’s certainly the case with these oak galls I snapped on a trail walk this week.
These hard woody growths, about 1.5 inches across, are induced by insects interfering with the oak plant’s bio-chemistry.
Typically a wasp, like Neuroterus albipes in the photo, lays an egg on an oak twig, along with chemicals that react with the plant’s hormones to trigger growth of the gall, making both a home and ready meal for the wasp grub. On occasion, secondary parasites of other species may join the ‘host’ grub after the gall has formed. It looks from the multiple holes like that’s what’s happened here.
Gall Wasp (Wikicommons)
Historically, oak galls have been useful to humans as a main ingredient of Iron Gall Ink, in common use from before the middle ages to Victorian times. I made iron gall ink as a kid, which probably explains why I got so excited when I saw these. And while I’ll concede the skill is probably not a 21st century essential, making the stuff is quite satisfying.
So if you’re up for a little kitchen science, you will need: a handful of oak galls, some ferrous sulphate and, optionally if you want the ink to have a good consistency, some Gum Arabic.
The chemistry begins when the crushed galls are mixed with water, causing the tannin, or gallo-tannic acid COOH.C6H2(OH)2O.COC6H2(OH)3 in them to form gallic acid C6(COOH)H(OH)3H. Adding hydrated ferrous sulphate FeSO4, 7 H2O to this forms the ink, a soluble ferrous tannate complex.
As regards procedure, you should get a workable product by smashing up 5 or 6 oak galls and boiling them down to about a 1/4 pint in water and filtering the liquid through a cloth or handkerchief; then dissolve about a teaspoon of ferrous sulphate in a shot-glass sized measure, and mix the two together. Instant medieval ink. For a much more thorough and professional approach, see this article from the Conservation Division of the Library of Congress. BTW – ferrous sulphate can be bought in art shops, garden supply stores, and some health stores – you want iron(II)sulphate, FeSO4 – not anything else.
Ferrous Sulphate (Wikicommons)
The advantage iron gall ink brought over previous inks was its permanence. Because ferrous tannate is water soluble, the ink soaks into the paper, where the ferrous tannate oxidises to insoluble – and darker – ferric tannate, which is now trapped in the fabric of the paper. Various refinements are seen in recipes, such as the addition of extra acid, maybe as vinegar, to keep the ink from oxidising in the pot, as it were. A drawback of iron gall inks is their corrosive action, sometimes only apparent over a long period, and in extreme cases resulting in writing literally dropping out of the paper.
Despite the corrosion issues, many famous documents were written in iron gall ink, including the dead sea scrolls (the black ink that is; the red ink is cinnabar, or mercuric sulphide HgS), and the Constitution of the United States.
The Dead Sea Scrolls are written in iron gall ink (Wikicommons)
Latest News: The video of Exquisite Corpse of Science won Imagine Science Films‘ ‘Film of the Week’ Competition. Cool huh?
Update March 2024: The Exquisite Corpse project is closed to further entries.
It’s just over a week since I invited the world to take part in the Exquisite Corpse of Science project. It’s very simple: you send me a picture that represents what you think is important about science, and as an option you can add a short audio file describing what you’ve drawn.
One way to launch your artistic views….. (Mosaic software credit AndreasMosaic)
I’ll then combine these into a single artwork in the manner of the Surrealists’ Exquisite Corpse – and further present the project in ‘fly-around’ 3D in Second Life. A couple of high profile events have shown interest in relaying this project – so no promises – but watch this space.
So how’s it going? Well the original post has had over a thousand hits, and the enthusiasm for the idea from individuals and organisations involved in science and science communication is encouraging.
Twitter seems to be the main vehicle by which word is getting around. Many thanks to those who have blogged on the project, and Twitter friends who are promoting it via the infamous ‘Re-Tweet’; especially: Andrew Maynard & family @2020science, @frogst, @imperialspark,@garethm (BBC Digital Planet),@vye, and the organisations @seedmag (SEED Magazine), @naturenews (via Matt Brown/@maxine_clarke), @sciandthecity (NY Academy of Sciences), and @the_leonardo in Utah. Also, thanks to Dave Taylor (@nanodave) at Imperial College – who is working with me on the Second Life virtual incarnation of Exquisite Corpse.
I want to doubly stress that the Exquisite Corpse Of Science is most definitely not just for scientists and engineers; it’s for literally everybody. And it’s absolutely not about producing a Leonardo or Rembrandt……So get your Gran’ma on the case.
I’ve so far received 11pictures (+ 7 more I know are in the pipeline), and 4 audio accompaniments. So keep the pics coming in to make the definitive ‘WALL OF SCIENCE’ big and beautiful. Come on guys, how can I inspire you ! I know, the pictures so far….
Clare Dudman
Joerg Heber
Andrew Maynard
Evren Kiefer
Bill Weedmark
Alex Maynard
Andreia Azevedo Soares
Andrew Maynard (abstract)
Edmund Harriss
Richard Lanzara
Kathryn
Exquisite Corpse in Second Life (building the 3D ‘fly around’ wall)
This website uses cookies to improve your experience while you navigate through the website. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may affect your browsing experience.
Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website.
