Collaborating with Aliens

UFO behind Delphi
UFO behind Delphi

The Treasury of the Athenians at Delphi. Nothing to see here.

I’ve been kick­ing around an idea for a paper for a couple of years. Every so often Stephen Hawking will announce that con­tact with an extra-terrestrial civil­isa­tion would be a Very Bad Thing. Therefore silence, or as close to it as pos­sible is a good idea. It’s not just Stephen Hawking, many other people agree. Hawking makes the point that con­tact from Europe to other regions hasn’t gone well for the nat­ives since 1492. I think this is a bet­ter argu­ment than “Aliens are scary”, but I think he’s using the wrong ana­logy. There is room for a paper that takes another view. There’s a couple of reas­ons I haven’t pushed on with it.

The main reason is that I’ve not been clear about where the paper could be pub­lished. Ok, Hawking hasn’t pub­lished his belief as a paper either, but he’s a fam­ous phys­i­cist. Famous phys­i­cists are pre­sumed not only to be experts on Physics, but all sci­ences, pseudos­ciences, etc. I can’t claim this expert­ise. If I’m going to say any­thing mean­ing­ful I should at least have it scru­tin­ised. This is the second prob­lem. It would be weird if my pos­i­tion were unequi­voc­ally cor­rect, par­tic­u­larly as we have no data at all on extra-terrestrial con­tact — unless you con­sider the Mars nano-bacteria that were announced and then dis­missed as a trial run. I could rely on review­ers to pick up obvi­ous errors or blind spots, but there’s surely a bet­ter way to fix prob­lems before sub­mit­ting to a journal with some collaboration.

I am part of a group of people who were apply­ing to have a blog hos­ted some­where. I think that’s very likely to not hap­pen. I’ve been quiet here, partly because of a broken arm and partly with a pile up of work that I need to sort through because it’s been delayed by my arm. It’s a shame because the site has a big audi­ence, but maybe not too big a shame as this site has a qual­ity audi­ence. What I’m inter­ested in now is if a col­lab­or­at­ive or even massively col­lab­or­at­ive paper could be writ­ten and how could it work.

Before even dis­cuss­ing tools there’s an issue over dir­ec­tion. As I said at the start, I think Stephen Hawking is wrong. You might think he’s right. He may even be right even if the method he got there was wrong. One of the inspir­a­tions for this approach is Timothy Gowers’ col­lab­or­at­ive approach to solv­ing math­em­at­ical prob­lems. He pulled together a group of people to tackle a prob­lem for a couple of years that he alone could not solve. The prob­lem was solved in seven weeks by a method that came as a sur­prise to him. I can see how that can demon­strably work. In the case of this paper, the sample is zero, and the res­ult is (expec­ted to be) a counter-opinion. Without a real­ity check is it pos­sible to write such a paper with open collaboration?

Alan Cann has used another method. He put up a paper for open peer review. I think it was a clever idea and I could do the same. My worry here is that some of the ana­lo­gies will be out­side my period and I think there could be very good and insight­ful com­ments from people who say, “No, you’ve got this wrong. You should be look­ing at…” In my opin­ion this makes the paper bet­ter and it’s worth author credit. If you give the per­son credit then to an extent you tor­pedo the claim that the paper is pre-reviewed because to some extent it’s self-reviewed.

I’m try­ing to think of a work­able solu­tion, and you’re wel­come to tell me I’m wrong about this too.

I think I should put up the first draft of the paper, prob­ably on Google Docs. I prefer DokuWiki, but leav­ing it open for com­ments and edit­ing could leave it wrecked. For the people who leave sub­stan­tial com­ments which can be pos­it­ive or neg­at­ive, but also indic­ate a dir­ec­tion to go for­ward with the paper, I offer co-authorship. I close the paper from pub­lic view and we write and re-write until it’s ready to go to a journal that’s either OA or happy to have an arXiv pre-print up. The gamble here is that enough people will see the call to review the first draft that it gen­er­ates a sens­ible amount of feed­back to improve it.

Ideally, I’d like to have a sys­tem that can re-used so that I can use it for gen­eral his­tory or archae­ology papers as well as odd ones like this. The reason for choos­ing this topic as the test sub­ject is that it’s doesn’t mat­ter that much to me if it gets massively delayed and it will very neatly high­light some areas where I am emphat­ic­ally not an expert and that col­lab­or­a­tion could be useful.

Thony Christie on Hevelius

Scutum constellation in the Uranographia

If you have any interest in the his­tory of astro­nomy you should be fol­low­ing The Renaissance Mathematicus blog and this post, The last great naked eye astro­nomer, is a per­fect example of why. This is a post about Johannes Hevelius who has to be one of the most fam­ous unheard of astro­nomers ever.

That doesn’t make sense I know. There are a lot of people who haven’t heard of Hevelius, but if you have heard of Hevelius, then the idea that people haven’t heard of him seems non­sense because his work is every­where in astronomy.

Scutum constellation in the Uranographia

Scutum in the Uranographia by Hevelius. Source: Wikipedia.

Everyone’s happy that most con­stel­la­tions are ancient, but what is less well-known is that not every star was in a con­stel­la­tion. There were gaps between con­stel­la­tions filled with faint and bor­ing stars. These were called αμορφοι amorphoi or unformed stars by the Greeks. This is no good if you want to do sci­ence, because things like comets don’t stick to the inter­est­ing parts of the sky. That’s why map­ping was so import­ant in the Renaissance. In the case of Hevelius, his maps were so use­ful that he formed seven con­stel­la­tions that stay with us to this day.

I’ll admit con­stel­la­tions like Lacerta or Vulpecula aren’t fam­ous con­stel­la­tions, but he was work­ing with the haps between con­stel­la­tions. The fact that his charts were made of con­stel­la­tions vis­ible in Europe shows he was work­ing in a highly com­pet­it­ive space.

It’s easy to take this kind of work for gran­ted. The out­put can be seen as an uncon­tested fact, but Thony’s post put’s Hevelius’s work into the con­text of its time includ­ing the often intense sci­entific rivalry between astro­nomer defend­ing per­sonal and national status.

The also shows that while with hind­sight it seems obvi­ous that tele­scopes would bring more accur­ate meas­ure­ments, at any given time in his­tory it’s not always obvi­ous that new tech­no­logy is The Next Big Thing, it could be a dis­trac­tion or Expensive Dead End.

Would Copernicus have been more convincing if he’d been more accurate?


As a follow-up to yesterday’s post, I was won­der­ing if Copernicus would have been more con­vin­cing if he’d used ellipses in his model instead of circles. By using circles Copernicus had to use epi­cycles like Ptolemy, though not so many. Still, it gave the impres­sion that epi­cycles were neces­sary. If that’s the case then why not have a sta­tion­ary Earth as well? The dis­cov­ery that plan­et­ary motion would be bet­ter described by ellipses didn’t come about till Kepler’s work almost a cen­tury later. As far as the post title goes, I think Dr* T’s Theory #1 applies here: Any tabloid head­ing that starts ‘Is this.…’, ‘Could this be…’ etc. can be safely answered ‘No’

So my post title is a bit of a cliché, but the reason I’ve used it is that if the answer is no, then some­thing strange is hap­pen­ing. More accur­ate is less convincing?

The reason I think that is that Copernicus’ model wasn’t isol­ated from the rest of thought for that period. It used and built on a num­ber of assump­tions of the time. One of those ideas was the cre­ation of the uni­verse by a per­fect being. Another was the idea that a circle was a per­fect shape, derived from clas­sical geo­metry. By telling people the Sun was at the centre of the uni­verse and not the Earth, Copernicus was ask­ing people to make a big shift in their think­ing. A lot of people thought it non­sense. If he’d made the orbits ellipt­ical as well then many people who would have been will­ing to listen to Copernicus’ ideas would have balked at that, redu­cing his poten­tial audi­ence fur­ther. In terms of num­bers, the pop­u­la­tion of math­em­at­ic­ally minded people who could exam­ine his work was small enough already.

If he’d reduced the num­ber of ini­tial read­ers fur­ther, would his ideas have spread enough for oth­ers to pick them 50 years later? It’s impossible to say, but if Copernicus hadn’t given Kepler the idea of a put­ting the Sun at the centre of uni­verse, could Kepler have dis­covered it inde­pend­ently? It’s hard to say but, given how Kepler struggled with let­ting go of circles and using ellipses, I think it’s unlikely.

This is why I’m wary of his­tor­ies of sci­ence that are purely about who got it right and who got it wrong. Copernicus’ use of circles isn’t ‘right’, but it was neces­sary at the time.

I’ve «cough» bor­rowed the por­trait of Copernicus from Prof Reike’s page on Copernicus. It’s well worth vis­it­ing if you want to find out more about the astronomer.

You can read more about Kepler’s dis­cov­ery of the ellipt­ical path of plan­ets at:
Boccaletti 2001. From the epi­cycles of the Greeks to Keplerʼs ellipse — The break­down of the circle paradigm

Copernicus and the Star that was bigger than the Universe

The constellation Delphinus

I’ve been try­ing to watch Cosmos by Carl Sagan. I’ve never seen it and it’s prov­ing to be a bit of a struggle. He def­in­itely can write. Some of the sequences are fant­astic, but some of it is badly dated. The thing that really grates to me is his dis­missal of Ptolemy and his geo­centric uni­verse. For Sagan at best Ptolemy’s sys­tem held back astro­nomy by 1,500 years. At worst he’s only worth men­tion­ing to say he’s dead wrong, like in the first episode.

It’s not really fair to lay into Sagan for his atti­tude to Ptolemy. His work is a product of its time and it was writ­ten over thirty years ago. But the idea that Ptolemy was clearly wrong seems to the pop­u­lar under­stand­ing of Renaissance astro­nomy. The ques­tion here is Why did some people oppose the helio­centric the­ory of the uni­verse? not Who in their right mind would accept it? It over­looks the power of the Ptolemaic sys­tem. If you fol­lowed Ptolemy’s work you could pre­dict where the plan­ets would be with enough accur­acy for naked-eye astro­nomy. If Copernicus had only used simple circles, then his model might have seemed bet­ter, but he too needed to add epi­cycles and fudges to make his sys­tem match the observ­able sky. It needed fewer epi­cycles, but it was hardly perfect.

Popular belief is that the prob­lem was solved when Galileo picked up his tele­scope and proved the helio­centric the­ory. In fact a recently pub­lished paper by Christopher Graney, The Telescope Against Copernicus: Star Observations by Riccioli Supporting a Geocentric Universe in the Journal for the History of Astronomy shows that the tele­scope could have dealt a ser­i­ous blow to the Copernican model of the uni­verse.
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Astronomy in Metal Heaven


Astrolabes at the Museum for the History of Science at Oxford.

If you ever want to embar­rass me, try to get me to enthuse about a dis­play of astro­labes. They’re the kind of thing I should love. They’re devices for show­ing what is vis­ible in the sky at any given time. They’re very sim­ilar to the plan­i­spheres that people use today. The math­em­at­ics behind them is eleg­ant. The best also tend to have extraordin­ar­ily ornate metal­work to com­ple­ment the soph­ist­ic­a­tion of the devices. Yet, when they’re hanging up like this, they leave me cold.

I think the reason is that an astro­labe on dis­play is a dead astro­labe. There are bet­ter ways to show a static night sky. What you need is an astro­labe in motion to appre­ci­ate them. That’s what makes this talk by Tom Wujec so good. He demon­strates how you could use an astro­labe to tell the time. In his hands, an astro­labe becomes a lot more interesting.

Tom Wujec demos the 13th-century astro­labe video from TED.

It’s easy to under­es­tim­ate how much you can do if you’re will­ing to observe intently. What I also like about this talk is that Tom Wujec emphas­ises the import­ance of con­nect­ing with the night sky. You could claim accur­ate clocks have broken this con­nec­tion, but I’m not sure that’s the case. Where I live light pol­lu­tion is often so bad that I could not use an astro­labe. He’s right to point out that you can lose things with pro­gress. Ironically Global Astronomy Month with try to show how immense the uni­verse is, while arte­facts like this show that on a day-to-day basis for urban dwell­ers the vis­ible world is much smal­ler than the cos­mos of the past.

You can see many astro­labes like the one below at the Museum of the History of Science, Oxford.

A Persian Astrolabe at the Museum for the History of Science at Oxford.

A Persian Astrolabe at the Museum for the History of Science at Oxford.

Re-thinking the archaeology of Mars


I’ve been rum­ma­ging through the depths of my hard-drive and found a few things I’d for­got­ten about. Here’s one of them, from 2006 I see, a present­a­tion on the con­tem­por­ary archae­ology of Mars.

The reason I’ve pulled it up is I might want to go back and think this over again. I’m not happy with it, which is why it was left on the drive, but it might have potential.

The slide on the 1980s probes is inten­tion­ally blank, because there were hardly any probes sent in the 1980s to Mars. The reason is that the com­pet­i­tion between the major powers has moved to Earth Orbit, with the USA build­ing the Shuttle and the USSR build­ing long-term space sta­tions. Recent events have high­lighted a couple of reas­ons why it’s worth look­ing at this again. One is the regis­tra­tion of lunar her­it­age by California, which is grabbing head­lines for some­thing that Alice Gorman and Beth O’Leary have been say­ing for a while. The other is Obama’s can­cel­la­tion of the return to the Moon.

It could be a sci­entific re-prioritisation, but like the Mars gap in the 1980s, it could also be due to polit­ics. The Nobel laur­eate already has wars in Iraq and Afghanistan to man­age, and he wants to keep his options open for a war with Iran. That could turn very nasty as Iran is next door to his two other prob­lems. It’s pos­sible that there simply isn’t a threat on the Moon, but there is in the Middle East. Unless China devel­ops lunar ambi­tions, the dis­cov­ery of water on the Moon could be a sci­entific curi­os­ity rather than a step­ping stone to colonisation.

There’s a few reas­ons why I don’t like this present­a­tion as it stands. I think the biggest prob­lem is that one of the big factors for mak­ing it was that I needed a present­a­tion. It wasn’t an idea that was ready, and to some extent the prob­lem was “there’s some­thing archae­ology could say about this, but what?” Now I’m think­ing about the social, polit­ical and eco­nomic effects of Mars explor­a­tion. This time around I see archae­ology as a tool to find­ing out about these factors, rather than ‘being archae­olo­gical’ as the pur­pose of project.

The Antikythera Mechanism: Art or Science?

The Antikythera Mechanism. Photo (cc) Tilemahos Efthimiadis.

The Antikythera Mechanism. Photo (cc) Tilemahos Efthimiadis.

This post was chosen as an Editor's Selection for ResearchBlogging.orgSome posts take quite a while to write. This is a response to Candy Minx and Martin Rundkvist who were dis­cuss­ing the Antikythera Mechanism back in 2006 (Antikythera, Time, A Reply to the Minx). Candy Minx thought that the Antikythera Mechanism was an expres­sion of what was already known and embed­ded in a soci­ety through things like myth and ritual. Martin thought that the mech­an­ism was far more com­plex, indeed need­lessly com­plex, for an ancient soci­ety and so was some­thing quite dif­fer­ent to the folk astro­nomy of the time. Originally I planned to write a fence-sitting com­prom­ise. I thought that Candy Minx was right to an extent, there was no need for a device like this because rituals and folk obser­va­tion could allow people to time the year as well as they needed. At the same time I thought that Martin was right to point out that the mech­an­ism gave res­ults with far more accur­acy than folk astro­nomy needed, or would even recog­nise. A dif­fer­ent sort of astro­nomy is vis­ible in the Antikythera Mechanism. I didn’t blog too much about the 2006 paper because I atten­ded a few of Mike Edmunds’ talks on the topic and heard that more would be pub­lished, which happened in 2008. Anyhow in my own fluffy and fence-sitting way I’ll now offer my compromise.

Someone with an extraordin­ary ima­gin­a­tion built the Antikythera Mechanism and, if he were alive today, we wouldn’t hes­it­ate to call him a sci­ent­ist. I don’t know if the designer was in the same league as Newton or Galileo, but he was cer­tainly the equal of Kepler, Copernicus or Brahe. It’s hard to over­state how extraordin­ary the device described in the 2006 paper is, but I’m going to give it a go.

If you’re the one per­son who hasn’t heard of the Antikythera Mechanism then Nature have a handy video introduction.

All that remains now is a col­lec­tion of cor­roded lumps found off the island of Antikythera. The 2006 paper described what the team dis­covered after x-raying the lumps to read the hid­den inscrip­tions without priz­ing apart the device and dam­aging it. Prior to this paper it was thought that the device could keep track of the Sun and the Moon. This is no small feat.

Epicycle et deferent. Image by Dhenry @ Wikimedia Commons.
Epicycle et defer­ent. Image by

The Sun would be mov­ing slowly against the back­ground stars, so over the course of a year it would pass through all the signs of the zodiac. The Moon how­ever is more com­plex. The Moon also moves in front of the back­ground stars, but it only takes about 27 days to do this. It’s called the sider­eal period. So you need a couple of gears to drive those two motions. But you wouldn’t really think of the sider­eal period as a month. For most people the syn­odic period, the time between one New Moon and the next or the time between one Full Moon and the next, is a month. This is around 29½ days. Throw in extra gears for driv­ing other dis­plays show­ing eclipse cycles and it’s clearly a com­plex device. The ori­ginal stud­ies found evid­ence of epi­cycles, gears moun­ted on other gears. Add other fea­tures like dis­plays for eclipse and lunar cycles on the back and it’s obvi­ous you have a com­plic­ated device. The 2006 research showed that in fact it was all a bit more com­plic­ated than that.

The Moon’s move­ment isn’t con­stant. It speeds up and slows down. This is because its orbit isn’t exactly cir­cu­lar. Instead it’s slightly egg-shaped. The point fur­thest from the earth is the apo­gee and the point closest to the Earth is the peri­gee. When it’s near the apo­gee it travels slowly, but when it moves closer to the Earth it picks up speed until it passes peri­gee and then it slows down again. This is called the first lunar anom­aly. The dif­fer­ence is notice­able by the naked eye, if you’re will­ing to make sys­tem­atic obser­va­tions. This is all simply explained by Kepler’s Laws of Planetary Motion. There’s small prob­lem. Kepler used ellipses.

You can’t use ellipt­ical gears. The point of gears is that they must have inter­mesh­ing teeth. An ellipt­ical gear would lose con­tact with the driv­ing gear as its axis changed. Instead it seems that the mech­an­ism used two gears, one slightly off-axis from the other. The rota­tion was con­nec­ted by a pin-and-slot arrange­ment, so that the one gear wouldn’t turn at quite the same rate as the other gear. The on-axis gear can then be turned reli­ably by the drive gears, while the motion of the moon can driven by the off-axis gear. So you have a device that can track the sider­eal, syn­odic and anom­al­istic months, all while the Earth is spin­ning round the Sun. If that’s caus­ing your head to spin you might want to skip the next paragraph.

There’s another prob­lem. The lunar anom­aly describes the Moon’s travel from one apo­gee to the next. This apo­gee is also rotat­ing around the earth. If the apo­gee is in Aries then two and a bit years later it will be in Cancer, and another two and a bit years to move into Libra until it too has trav­elled through the zodiac over about nine years. So now we have a device which tracks the Moon around the Earth, and its phases and it’s vari­able speed and vari­ations in that vari­ab­il­ity, while also keep­ing track of the Sun’s pos­i­tion, poten­tial lunar and solar eclipses and inter­cal­a­tion cycles so you know when to stick an extra month in to keep the lunar months in step with the solar year round gears, some moun­ted slightly off axis to cre­ate a pseudo-sinusoidal vari­ation using cir­cu­lar gears to replace ellipses. If you have funny feel­ing near the back of your head right now, that’s prob­ably your brain try­ing to crawl out of your ears. The Antikythera Mechanism is insanely com­plex. Still just because it’s insanely com­plex, that doesn’t make it sci­entific.

In fact you can argue about whether or not Science exis­ted in the ancient world. Certainly a lot of ele­ments like test­ing ideas with exper­i­ments didn’t really become pop­u­lar till after Galileo. On the other hand some nat­ural philo­sophy of the time was based on obser­va­tion. There was cer­tainly tech­no­logy which was the res­ult of applied know­ledge. With those kind of pro­visos a lot of ancient his­tor­i­ans would be happy with the idea of ancient sci­ence, albeit a sci­ence dif­fer­ent to post-Renaissance sci­ence. In this case, the sheer intense obser­va­tion and cal­cu­la­tion involved in mak­ing the Antikythera Mechanism marks it out as a work of ancient sci­ence. There’s also another factor which might make it more sci­entific than artistic.

To some extent the Antikythera Mechanism Research Project have been inter­ested in hanging a name on the device. It was thought to have ori­gin­ated in Rhodes and sunk on its way to Rome, which would have con­nec­ted it to the home city of Hipparchus, one of the great astro­nomers of antiquity. The 2008 paper has examined the parapegma on the mech­an­ism and dis­covered it may be con­nec­ted to Syracuse, home of Archimedes.

A parapegma is a cal­en­dar, usu­ally with holes for stick­ing a peg into for mark­ing the days. In the case of ancient Greece they’re inter­est­ing when they tell you what day of the month it is, because each Greek city had its own set of months. The months were usu­ally named after reli­gious fest­ivals, and this was tied into local polit­ics. That meant hav­ing your own cal­en­dar was a good way of show­ing your inde­pend­ence. The best match for the months men­tioned on the mech­an­ism is Tauromenion, mod­ern Taormina, in Sicily. This is likely to have shared some months with Syracuse as it was re-settled from there in the fourth-century BC, so Syracuse is a strong pos­sib­il­ity for the home of this device. Archimedes is said to have inven­ted a plan­et­arium accord­ing to Cicero and is thought to have writ­ten a lost book on astro­nom­ical devices. However he could not have made this device. Archimedes died in 212 BC. The Antikythera Mechanism is cur­rently thought to date to the second half of the second cen­tury BC, but that might change. But it was very likely to have been made after Archimedes death and that’s what makes it scientific.

Art can be col­lab­or­at­ive, or it can be per­sonal. Science in con­trast is built on cumu­lat­ive know­ledge. The per­son who inven­ted the gear­ing did not have to be the per­son who made the astro­nom­ical obser­va­tions. He didn’t even need to live in the same cen­tury as the astro­nomer. In fact the maker of this device might not have done either. He could have fol­lowed a kit and added his own per­sonal touches on the cas­ing. There’s a core to this device which, once expressed, is inde­pend­ent of per­sonal vis­ion. Archimedes didn’t have his own per­sonal Moon which moved in a dif­fer­ent way to every­one else’s, while an artist can have a per­sonal inter­pret­a­tion of the Moon.

A reason people might think the Antikythera Mechanism is a work of art is that it’s clearly the res­ult of a lot of ima­gin­a­tion. Great art requires ima­gin­a­tion, but so too does great sci­ence. It requires the kind of ima­gin­a­tion that can look at a tool­box full of circles and see ellipses. The kind of ima­gin­a­tion that can watch wheels turn within wheels as bod­ies waltz to the music of the celes­tial spheres. Another com­mon factor between art and sci­ence is that great art can show a new way of look­ing at the world, and great sci­ence does this too. That’s why I dis­agree with Candy Minx when she says “Science is always play­ing catch up with the poets.” Science can reveal beauty too, as a visit to the Antikythera Mechanism Research Group’s homepage would show.

Freeth, T., Bitsakis, Y., Moussas, X., Seiradakis, J., Tselikas, A., Mangou, H., Zafeiropoulou, M., Hadland, R., Bate, D., Ramsey, A., Allen, M., Crawley, A., Hockley, P., Malzbender, T., Gelb, D., Ambrisco, W., & Edmunds, M. (2006). Decoding the ancient Greek astro­nom­ical cal­cu­lator known as the Antikythera Mechanism Nature, 444 (7119), 587–591 DOI: 10.1038/nature05357

Freeth, T., Jones, A., Steele, J., & Bitsakis, Y. (2008). Calendars with Olympiad dis­play and eclipse pre­dic­tion on the Antikythera Mechanism Nature, 454 (7204), 614–617 DOI: 10.1038/nature07130