Galileo, Open Science, and History

I'm a big believer in open science -- see this great polemic over at Mendeley for a good read -- but it's always interesting to think about how such things as "data release" can be perverted by clever scientists. I'm currently in France working on some ascidians with Billie Swalla -- more on that later -- and we've been talking about what data we plan to release, and how. During these talks (leisurely conducted over cafe au lait and chausson pomme, of course!) Billie brought up an interesting historical parallel.

The story, as I understand it, is this: when Galileo Galilei first looked through a good quality telescope and discovered Jupiter's moons, nobody believed him. Since he was the only person able to make such good telescopes, he actually made and distributed them to other scientists -- not just as a profitable sideline, but so that the other scientists could confirm his observations!

One could see this a first step towards "open science": in order to reproduce Galileo's observations, astronomers had to have a telescope that only Galileo could make. So Galileo had to make telescopes and send them out, thus allowing others to both reproduce his observations and build upon them.

The story takes on a different aura, however, when you realize that Galileo could have just given out the actual manufacturing instructions for the telescopes, but didn't. Two possible reasons are money (he made money selling the telescopes to others) and scientific miserliness: he didn't want others to get credit for building on his results. As long as he withheld the details necessary to reproduce his instruments, he ensured that no one could build on his results, and that he would have preeminence in astronomy. (The parables between this and source code are uncanny, no?)

It was quite a balancing act. To quote from Dr. Biagioli's "Replication or Monopoly" (pdf here),

"His primary worry was not that some people might reject his claims, but rather that those able to replicate them could too easily proceed to make further discoveries on their own and deprive him of future credit (Galilei 1989, 17). Consequently, he tried to slow down potential replicators to prevent them from becoming competitors. He did so by not providing other practitioners access to high-power telescopes and by withholding detailed information about how to build them.

But as important as it was for Galileo to keep his fellow astronomers in the dark, such negative tactics alone would not have allowed him to gain credit from his discoveries and move from his post at the university of Padua to a position at the Medici court in Florence as mathematician and philosopher of the grand duke - goals clearly on his mind in 1610.He needed proactive tactics as well. First, he did his best to make sure the grand duke saw the satellites of Jupiter (which Galileo had named "Medicean Stars") by sending detailed instructions to Florence on how to conduct these observations, and then by going to court himself at Easter time (Galilei 1890- 1909, X:281, 304). Second, through the prompt publication of the Sidereus nuncius in March of 1610 he tried to establish priority and international visibility - resources he needed to impress his prospective patron, not just the republic of letters.

The Nuncius was carefully crafted to maximize the credit Galileo could expect from readers while minimizing the information given out to potential competitors."

Here you can see calculation as fine as any modern professor, trying to decide if they should release all their data, or only some of it; all of their source code, or only a crippled version.

Billie also observes that one potential irony in this story is that Galileo, by so strongly taking sole credit for his discoveries, made himself a clear target for the Catholic Church...

An even more pernicious approach, seeking priority while avoiding embarrassment by publishing hashes (well, anagrams ;) of formulae or observations, was common in the 17th century. In The Newton Handbook, by Derek Gjertsen, Gjertsen writes:

"It was not uncommon for seventeenth-century scientists to record their more valued results in the form of anagrams. Thus, Galileo published his discovery in 1610 of the phases of Venus in a thirty-five letter anagram, Huygens announced his 1656 observation that Saturn was surrounded by a ring in a sixty-three letter anagram, while, in England, Robert Hooke and Christopher Wren resorted to similar stratagems. The advantages of the ploy are obious. Priority was established, yet nothing was given away to potential rivals. If, by chance, the work failed to stand up to further analysis it could be quietly forgotten without the embarrassment public failures tended to incur."

One can only wonder how many one-shot awesome Science and Nature papers, using software that was and remains unavailable, are entirely unreplicable or otherwise uninteresting -- for example, I like to pick on one of Eran Segal's publications, because it's so neat and yet very very difficult to replicate without source code. (A colleague is trying.)

Compare this to the recent discussion of the (leaked) P != NP proof, now shown to be erroneous - see, e.g., Greg Baker's blog post, P != NP. Now this is the way science is supposed to work! Quick, thoughtful commentary by experts, highlighting potential problems with your work -- and allowing or enabling others to build off of it.

It's clear to see that by withholding the manufacturing instructions, Galileo may well have held back astronomy as a whole. And by publishing their equations in anagram form, it's likely that Newton and the others did damage to science as a whole.

Today, intellectual reputations like that are in some ways less important (at least in my bottom-feeding scientific world). Publications and citations are more important, since they're measurable by Promotion & Tenure committees. I (and probably many other scientists) are continually worrying about the line between publishing good stuff that enables citations, and giving away all of our future research directions. It takes a real act of faith to throw yourself off the cliff and offer up your latest & greatest source code and data to the world, in the hopes that somehow the resulting "usefulness" will provide lift to your career. We'll see how that goes: road kill? Or tenure?

Back to Galileo -- I think the Galileo example is why, as wonderful as the Panton Principles are for data, for truly open science it's critical to provide not only the raw data, but the source code used to do the analysis. And not only the source code, but useful source code: documented and tested source code [1]. To do anything else would be the equivalent of selling telescopes while withholding the manufacturing instructions that would let others build on your own ideas.

Interesting stuff to think about! Now, back to science...


[1] Yeah, I realize that most scientific source code probably isn't documented or tested. Draw your own conclusions there ;).

Legacy Comments

Posted by Shanti on 2010-08-26 at 18:17.

Three cheers for open science. The telescope was invented by
Lippersley (and independently by Jacob Metius) in the Netherlands in
1608. Lippersley published and widely distributed the manufacturing
instructions. Galileo improved it with better optical tolerancing in
1609 and looked up at the planets. Galileo published his observations,
Kepler heard about them, and made an even better telescope.
Development of optics in Europe moved exceedingly fast after Galileo's
discovery. The early telescopes were made by guess and check -- you
move the lenses around until you get an image. It was only 8 years
later that the Europeans were designing telescopes using ray tracing,
which got smart folks like Newton involved. Until Newton came along,
there wasn't much language for communicating about optical design.
Snell didn't even figure out refraction until 1621.

Posted by Erich Schwarz on 2010-08-27 at 19:00.

First of all, genuinely good ideas just don't get stolen.  Because
they look <i>weird</i> and people can barely stand them at first.  For
some months after he invented it, Kary Mullis could barely get anybody
to pay attention to PCR.    My own experiences with innovation are
microscopic, but I can nevertheless attest that it has been a pain in
the neck, in the last few months, to come up with something creative
and have to pitch it even to a coauthor or to labmates in group
meeting.  I sure don't worry about being scooped after getting the
comments I've gotten; I worry that my stuff'll come out in print and
then be quietly forgotten for years, unless I myself follow it up!
"Not Invented Here" is very real, and scientists are generally as
susceptible to it as Detroit.    Second, people who are trying to
scoop you in your own area of expertise are likely to have a miserable
time.  You're doing what you do because you actually care about it and
enjoy it.  They're doing it because they're scared epigones.  That's
not a formula for winnitude.    Third, I've seen a lot of people stay
closed-source or outright not-available-source in genomics.  I have
never seen it end well.  Generally, the field treats them as damage
and works around them.  Because it has to!  Irreproducible science may
get a Nature article if the authors are from the Coolkids Institute of
Technocruft, but it's still irreproducible, which leaves everybody
else in the field having to redo the whole thing to reproduce it.  The
second person who has to do that is likely to not want to deal with
that nonsense again later.    Finally, there are people who will use
your code and do cool things.  But they'll generally do things you
weren't going to think of anyway.  Seeing your work used to do things
better than you'd have thought of yourself is quite humiliating.  But
it's also one of the main points of science.

Posted by Titus Brown on 2010-08-28 at 14:29.

@Shanti, I guess the question is, would they have moved faster or not
if Galileo had communicated better?    @Erich, well, yes, we agree. I
don't find it humiliating on the (rare) occasions that other people
use my code to do more clever things than me, though; I find it

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