Your article on the Mars canals says that canali is Italian for “channels”, but the English-speaking translators change it to “canals”. Actually, canali (plural of canale, can mean either, and can also mean “ducts” or “conduits”. I double-checked this in my Italian dictionary (Harper Collins Italian College Dictionary, reprinted 2002). So it’s hard to determine what Schiaparelli had in mind.
Damn. All this time I’ve been hoping there were cannoli on Mars.
Madame de Farge: when you start a thread, it’s helpful to other posters if you provide a link to the column you’re commenting on. Saves search time, and helps keep us on the same page. In this case: Whatever happened to the canals of Mars? - The Straight Dope
No biggie, you’ll know for next time.
Percival Lowell may have been viewing his own blood vessels. Apparently, the way he set up his telescope resembles the sort of optical system used today to detect cataracts. This explanation was discussed in Sky and Telescope back in 2003, 18 years after the original treatment by Cecil.
What’s the earliest photo we have of Mars? It always occurred to me that most claims pre-dated telescopic photography. If so, it is entirely possible that canals (or something that looked like them) existed, but were gone by the time the first good photo was made.
Not that that’s the best explanation, but I wonder if it can be eliminated.
It’s more complicated than that. Because of the wibbly-wobbliness of Earth’s atmosphere, until very recently (well into the space age), human eyes could perceive surface details of the planets better than earth-bound cameras could. However, eyes have problems of their own.
J-Dub–may I call you J-Dub?–can you explain that a little further? How is it that human eyes were affected less by atmospheric jiggle than cameras, until recently? Or am I not understanding you?
When looking at fine detail through a telescope, the atmosphere makes everything “swim about”. In trying to take a photograph of such detail, the exposure time means that this movement blurs it out. Furthermore, you get moments when the view is suddenly particularly good. A good and patient observer can watch until one of these happens and use the brief better glimpse to memorise and hence capture the finer detail. For photographs, even if your exposure time is shorter than these better glimpses, you can’t anticipate when one is going to happen.
I’m not sure when the first non-trivial photos of Mars were taken, but photographs did play a part in the debate. Lowell’s assistant Carl Lampland took ones that Lowell believed were evidence of the reality of the canals. But it seems to have been the case that, when published, those who were inclined to believe thought they bolstered Lowell’s case, those who weren’t couldn’t see much sign of canals in them.
The photos can be seen here and it’s indeed difficult to see how Lowell thought they were evidence of anything. See this article for some discussion of later Lowell Observatory photos allegedly showing the canals.
And, just to fill it out, modern computerized telescopes can correct much of the problem by refocusing on the fly. Of course, space telescopes can do even better, because they don’t shoot through the atmosphere to begin with – but they have their own problems, too (cost and fragility). Direct probes are best of all, but they also have drawbacks.
Well, we can look to Schiaparelli’s words themselves:
He seemed inclined to think them natural features, but straight lines not curving paths, so didn’t rule out artificial constructs.
“Canals” has the implication of artificial constructs, so it seems that the ambiguity of the Italian is captured better in “channels”.
bonzer, John, thank you for explaining. However, the question I really wanted answered was, of course, whether I could call John W. Kennedy “J-Dub.”
I’d say yes.
Which doesn’t mean he’ll answer to it. 
Here is an example of eyes better than cameras.
A modern planetary observer, rather famous in astronomy circles (though his name escapes me at the moment) kept seeing “spokes” in Saturns rings. Now, the interesting thing is I am sure this guy (like nearly everbody else as the time) would have bet good money that having “spokes” in the ring system just wasnt possible.
Yet, he kept seeing them, and drawing them. Well, sure enough, they were eventually detected by space probes and space bases telescopes.
And, IIRC they still might not have been imaged by ground based cameras.
Depends. Will he be good in the regular season but choke in the payoffs? I guess only time will tell.
Right - the words themselves *canale/canali *in Italian (like their cognates canal/canales in Spanish) do not intrinsecally distinguish natural v. artificial, as opposed to the English usage of “canal” which implies something engineered.
If you throw out enough predictions, some might come true. How many other claims did he make that didn’t?
Why would you assume he made any? Did you read the posts (bonzer’s is the most detailed) explaining why things can sometimes be seen by eye that cannot be picked up in a photograph? I would add that the human retina is a very sensitive light detector, capable of responding to a single photon.
And the human mind is quite capable of making up shit that isn’t there.
He wasn’t some astrologer who throws things out hoping something will stick just do to volume and chance. He was a well renowned observational astronomer.
And again, I suspect he knew enough basic physics and astronomy to “know” what everybody else "knew"at the time. That you “couldn’t” have spokes in a ring system.
He wasnt some crank with a pet theory or a mission. He just saw something most others weren’t seeing and didnt expect to see (and wasn’t really believed at the time). And reported it.
Yeah, its possible he was just lucky. But it wasnt luck due to volume or a pet theory that influenced what he saw and he happened to be right about it.
IMO he was just a damn good and persistant observer.
Oh, I remember the name now. Stephen O’Meara.
Many folks who arent serious visual astronomers don’t realize the work it takes to be a good observer. They think you just look in telescope and there it is. Doesn’t work that way. I was a way better observer at 100 hours in than I was at 10. And by a thousand hours I could easily see things that were quite hard for me at 100 and impossible when I first started.
Furthermore, when it comes to visual planetary observing, you spend hours staring through a telescope just waiting for usually very brief (often split second brief) moment when everything become perfect. And its pretty damn amazing when it happens.