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"Blaise Pascal, Florin Périer, and the Puy de Dôme experiment"

21 Comments -

1 – 21 of 21
Blogger Bee said...

Dear Stefan,

Thanks for this interesting journey! Isn't it funny how the "emptiness" has fascinated scientists over the centuries, and the nature of the vacuum is still today subject of vivid discussion? Best,

B.

1:13 PM, November 21, 2007

Anonymous michael said...

A fun and interesting post.

It amazes me how they can make math and science so boring in school and then you read something like this; how intigueing it is; you realize how bad our [U.S.A.] education system is.

3:21 PM, November 21, 2007

Blogger stefan said...

Dear Bee,

Isn't it funny how the "emptiness" has fascinated scientists over the centuries, and the nature of the vacuum is still today subject of vivid discussion?

that's true, it's really fascinating! But I have to add, it's a funny coincidence that while I was researching this story and preparing the post, you wrote about the Casimir effect and the Cosmological Constant. I'm not sure now anymore what exactly gave me the idea for the post, but while I was thinking about it, I read about the vacuum several times: The Zeit had a discussion about the 10-meter-limit of suction pumps, another magazine featured a 20 year old Scientific American article (in the German translation) about a modern version of Berti's experiments for the use in class.

A thing that struck me about these experiments of the 1640s is that they constituted, I believe, the first big experimental research program in what we now call "Modern Science". Many different scientist at different places in Europe contributed to this program, and within a decade or so of research, with ever more sophisticated experiments and improved equipment, the notion of the vacuum, as it is still valid in the framework of classical physics, had been established.


Best, Stefan

4:22 PM, November 21, 2007

Blogger stefan said...

Dear michael,


thanks for the nice words! I thought that the story has a few nice twists - the puzzled engineers, a clueless Galileo, experiments with long tubes filled with wine and water, the Pascal wunderkind, an errant Descartes, and finally this kind of expedition on the mountaintop - so the posting had to become a bit longer ;-)

That math and science classes are in school can often be quite boring isn't, I think, a specific US problem - unfortuntely, it's the same also in Germany. The problem is, I guess, that it needs good teachers to raise interest in science with the pupils, and that often the curricula are packed with just too much stuff which has to be done and that there is no time to do play around with experiments and the like, and there is no time to tell nice stories...

But, as I told Sabine, by some funny coincidence the November issue of the German edition of the Scientific American sugggests the use of the Berti water barometer for the use in a school project! This article by Jearl Walker in the "Amateur Scientist" column was originally published in the April 1987 issue of the Scientifc American, "Making a barometer that works with water in place of mercury."

I imagine it could be fun to do such an experiment in school!

Best, Stefan

4:49 PM, November 21, 2007

Anonymous krishna said...

I am regular reader (and lurker) on your wonderful blog. This is a really nice writeup. I also liked the discussions of the cosmological constant very much. Thanks.

4:52 PM, November 21, 2007

Anonymous Dr Who said...

If people didn't believe that atmospheric pressure was the explanation, then presumably they didn't believe that atmospheric pressure drops with altitude! It's just that the density of the aether up there on the mountain is different, or something......

8:15 PM, November 21, 2007

Blogger Lex said...

I'm afraid I have to point out one piece of information that I believe to be incorrect. The Torr is still in use -- most high vacuum systems measure the pressure in mTorr. I don't know if that's enough though.

8:16 PM, November 21, 2007

Blogger CapitalistImperialistPig said...

Very nice article.

9:20 PM, November 21, 2007

Anonymous Uncle Al said...

http://arXiv.org/abs/0706.2031
Physics Today 57(7) 40 (2004)
http://physicstoday.org/vol-57/iss-7/p40.shtml
http://cfa-www.harvard.edu/Walsworth/pdf/PT_Romalis0704.pdf
No aether

http://fsweb.berry.edu/academic/mans/clane/
http://physicsweb.org/articles/world/17/3/7
No Lorentz violation

http://www.mazepath.com/uncleal/lajos.htm#a2
Uncle Al seeks a Christmas shoe not a Christmas stocking. Crytals are grown - now cutting and polishing.

9:50 PM, November 21, 2007

Blogger arivero said...

I will put quotes, but I am getting it from heart, so not accurrate:

"The followers of Aristotle tell us that these experiments do indeed show that Nature abhors vacuum, and that it is because of it that the mercury climbs the tube. And I say them: 'Does Nature abhor the vacuum more in Paris than in the Puy de Dome?' "

10:50 AM, November 22, 2007

Blogger arivero said...

About the 10m limit, I run into a personal anecdote in a small rural town one year ago. Someone gave us some old pumps, and asked to go to the local workshop to ask about them. The Master of the workshop came jointly with an apprentice, and told to my friend and me: "this is a suction pump, you can use it in non-clear water, but you can not use it to raise water higher than seven meters". And he did a pause. I answered, "yes, of course". And then a pause. And my friend, then, agreed "Of course".
When we were back in the car, my friend asked me: "Why?". And I feel inclined to guess that really the intention of the master was to provoke the apprentice to ask him "why" after we were out of the workshop. I feel that both the apprentice and my friend got that the master and I were exchanging some secret masonic greeting.

11:01 AM, November 22, 2007

Blogger Plato said...

Wonderful Post.

I like this kind of history being explained in such a way, while it holds us to what is happening today in cosmology, it is also explaining the process and how we got here.

Ideas, about what is emergent. Where our universe came from and what it was before it became the way it is today.

Please allow me to detract Stefan for a moment from your post a bit.

This has always been part of my position that when using Pascal, that probability gives a wide berth to what may come out of that "empty vacuum."

See the marble drop experiment and look at Pascal's triangle.

The statistical sense of Maxwell distribution can be demonstrated with the aid of Galton board which consists of the wood board with many nails as shown in animation. Above the board the funnel is situated in which the particles of the sand or corns can be poured. If we drop one particle into this funnel, then it will fall colliding many nails and will deviate from the center of the board by chaotic way. If we pour the particles continuously, then the most of them will agglomerate in the center of the board and some amount will appear apart the center.

11:40 AM, November 22, 2007

Anonymous Anonymous said...

Nice article. You may want to fix one 1947 to 1647, and I guess the 1867 is supposed to be 1767, or else the 18th century should read the 19th.

3:36 PM, November 22, 2007

Blogger stefan said...

Hi anonymous -


thank you very much for yourappreciation and attentive reading - I have fixed the "1947", it's 1647 now.

The 1867, however, is correct, if we trust the catalogue of the Bibliothèque Nationale de France. The illustration is from a 19th century popular science book, which is actually quite interesting to read, with a lot of applied science and technology.

When I saw the figure, something looked strange to me about it, until I realized that people on real contemporary illustrations of the 1640s and 1650s (such as the first two illustrations of the post) wear quite different clothes, and that the guys on this illustration out of the 19th century popular science book followed the fashion of the French enlightenment, Voltaire, Diderot, etc, mid-18th century or so, thus 100 years later than the actual time of the experiment. Just a rough estimate - I am not a fashion geek ;-)

Sorry if this has created confusion...

Best, Stefan

4:14 PM, November 22, 2007

Blogger stefan said...

Hi Lex,


The Torr is still in use - most high vacuum systems measure the pressure in mTorr.

thank you very much for your remark - that allows me to explain that my focus was on the "official" when I said "now officially out of use", and I wanted to make the point that in contrast to the pascal, the torr is not a SI unit. Moreover, in Gemany, and probably in the whole European Union, usage of the Torr is officially not allowed anymore in technical devices and pressure gauges.

Of course, that's the official regulation, which doesn't hinder the usage of the torr as a convenient unit of pressure. It's the same as for the astrophyscist's erg, the Angström, or the eV, all of which are not SI units, but nevertheless still in use for historical or practical reasons.


Best, Stefan

4:35 PM, November 22, 2007

Blogger stefan said...

Hi dr who,

... it's just that the density of the aether up there on the mountain is different, or something.

Well, that's more the attitude of modern-day crumpy old amateur scientist and Einstein denialists ;-)...

Descartes, for example, had no problem at all to accept the air pressure as the force balancing the weight of the column of the fluid. But that didn't stop him from being convinced that the empty space in the barometer on top of the fluid was not a vacuum, but filled with aether. Of course, he had more philosophic reasons than physical proof for this opinion, but he was convinced that there has to be "something" everywhere, which is responsible for the transmission of forces, something that can happen, in his conviction, only by direct contact. He didn't like the idea of atoms, nor that of action at a distance (no proof for these concepts either at that time), so this was not unreasonable. And it was way ahead already of the older concepts that some vague abhorrence of the void by nature does forbid the vacuum...



Hi Uncle Al,


thanks for the links - but please, do not turn this in a debate about whatever aether.

Moreover, I have to say that I strongly oppose the usage of the denomination "aether" with respect to any Lorentz-symmetry breaking field - that word is burned by way too many and too diverse connotations, and only creates confusion. After all, these fields, if they exist, are not some substance or fluid...


Best, Stefan

4:55 PM, November 22, 2007

Blogger stefan said...

Hi Alejandro,


thanks for sharing that anecdote! But I have to admit, the limit height for pumps is not at all intuitively obvious...

BTW, this quotation, do you remember the author, or the circumstances? I have read it somewhere just when preparing the post, but alas, I do not remember where and cannot find it anymore...


Hi Plato,

true, that Pascal triangle and the binomial coefficients, that's something deep also...


Dear all,

thanks for the nice and encouraging words - I was already afraid of boring away lots of readers ;-)...


Best, Stefan

6:05 PM, November 22, 2007

Anonymous Dr Who said...

stefan said: "Well, that's more the attitude of modern-day crumpy old amateur scientist and Einstein denialists ;-)... "

Yes, exactly. But still I would think that the aetherists in those days would have put up a bit of a fight. I wonder how long it took for people to accept the correct explanation, and whether there were many diehards who cooked up excuses, like the MOND diehards nowadays.

As for Descartes: I have always found his idea a bit hilarious. Yes, aether rushes into the space, and the water at the bottom pushes some aether aside, so it has to sort of loop around and connect at the top somehow....."human beings are excuse-making devices", sorry I forget who said that....

8:23 PM, November 22, 2007

Blogger Arun said...

Dear Stefan,

A marvellous story! I love the way experiment was king! If only we could do quantum field theory experiments so readily!

10:24 PM, November 22, 2007

Blogger arivero said...

Stefan, I think the quote is told to come from Pascal himself, but again I do not remember what treatise or discourse.

5:05 PM, November 23, 2007

Blogger Manechka said...

Thank you very much for a great post. Most of the science books are written in a language that is hard to capture for many students. Your article proves that history and physics can be told in simpler and interesting to read English!

6:49 PM, May 04, 2014

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