What inaccurate or flawed history, science, etc. lessons was I taught in school as a kid?

Skeletons. A skeleton can tell us a lot about a person’s health and diet.

It could, probably did. But it’s hard to see how it would affect longevity on any way at all.

The San are tricky because most of them were agriculturalists. Only relatively small numbers lived as HGs, and most of *them *spent the off season working as farm labourers. Intermarriage between the two groups was ubiquitous. As a result anything we learn from the San will tell us more about “primitive” agriculturalists than about HGs.

As far as I can tell, there really is no very substantial difference in our views on the Galileo affair, which only serves to make the more irritating the way that you insist on nitpicking at every post I have made on this topic, and obscuring the basic, and thread-relevant point I have been trying to make (that popular understanding of the Galileo affair as a primarily religious, or grand ideological conflict is at odds with the historical facts) under masses of irrelevant details, trivial corrections, and subtle misrepresentations of my words. You seem determined to keep implying that I have got something wrong, when in fact I am not wrong (even according to the facts you cite), but have simply refrained from going into unnecessary, distracting details and misleading hyper-qualifications of every point.

I didn’t much bother before, but this time I am going to go through your entire post in detail myself, and point out just how irrelevant and or misleading much of what you say is (even though I accept that it is mostly, technically speaking, true). I expect you will still find things you want to nitpick at and obfuscate. Have at it. I am not going to waste any more time on you after this.

The point you make in the quote above is a case in point. I was replying to **SlowMindThinking[\B], who appeared to believe, or think it might be reasonable to believe, that the Protestant churches, or a significant number of Protestant leaders, had “adopted” Copernicanism before 1616, and that the Catholic Church then came to reject it as part of their ongoing conflict with Protestantism. Nothing like that happened, and I think you know it. It is disingenuous to say “it’s hard to find a trend” when in fact it is about as clear as any such historical matter could be that there was no such trend, and no such ideological use of the controversy (inasmuch as it even was a controversy at that time).

I can think of just five people who had clearly expressed some commitment to the physical reality of heliocentrism by 1616 (and it is definitely the physical reality, not the mathematical elegance or utility of Copernicus’ system, that is the point at issue here). Copernicus himself, Giordano Bruno, Thomas Digges, Kepler, and Galileo. By my count, that is three Catholics and two Protestants. Descartes, another Catholic, may have already become a convinced heliocentrist by 1616, although I think it is much more likely that he came to the view a bit later. (To anticipate your nitpick, Bruno was a Catholic apostate, but he was certainly no Protestant, and I am only about 95% certain that Digges was a Protestant.) Perhaps you know a handful more names, and perhaps (though I doubt it) they are all Protestants. Perhaps, at a generous estimate, there were a couple of dozen others neither of us know about who were convinced heliocentrists (given the very small numbers of people who knew or cared anything about astronomy at the time, I think this is a very generous estimate). Perhaps (highly unlikely though it would be) all of them were Protestants. That still would not have amounted to Protestantism having “adopted” Copernicanism.

Your raising of the example of Rostock is merely further obfuscation of this point. Are you suggesting that the Rostock faculty were teaching the physical reality of heliocentrism by or before 1632? If not, it is irrelevant to the point at issue, and fully consistent with what I said about the situation in the wake of Galileo’s trial. If so (which I doubt), it simply means that there are one or two more names to add to the ledger on the Protestant side. It is still not a trend or an “adoption” by Protestantism.

If you are talking about teaching the mathematical apparatus of Copernicus’ system, as opposed to its physical reality, then I wonder whether Rostock was the first. You don’t give a date, but Kepler was certainly taught about Copernicanism by Maestlin at Tübingen, in or before 1594. Of course, there is no reason to believe that Maestlin advocated the physical reality of heliocentrism. From soon after its publication, many people recognized Copernicus’ system as a mathematically more tractable, and slightly more accurate predictive tool than Ptolemy’s system, without for a moment dreaming that the Earth really moves. Even when the Catholic authorities declared heliocentrism “formally heretical” in 1616, it was clear from how they ordered only quite light amendments to De Revolutionibus that they had no objection to Copernicus’ system being used in this instrumental way.

It was “conclusively refuted” only if you accepted that Galileo’s telescopic observations were accurate, which many people, for reasons that seemed perfectly reasonable and scientific at the time, did not. Even Kepler’s student, Martin Horky, who had an opportunity to use Galileo’s telescope, had to report regretfully back to his master that he could not see the things Galileo claimed to see. Of course, we know now, in hindsight, that Galileo was right, but to imply that this was, or even should have been, obvious to everyone at the time is the worst sort of Whig history. Optical devices were well known, at the time, to cause all sorts of distortions and stray spots of light, and telescopic observation of the heavens is a difficult skill that (we now know) Galileo had trained himself in well, but that very few others, at the time, had had any chance to develop.

Well of course Galileo and Kepler rejected it, they were convinced heliocentrists. Clavius may not have liked the Tychonic model, but he remained a staunch geocentrist, even though he accepted most of Galileo’s telescopic findings. Anyway, that is just three people.

And, once again, the way you raise these examples simply serves to obfuscate the much more significant fact that very many astronomers, at the time, took Tycho’s system very seriously. He was, after all, the greatest observational astronomer of the age (arguably, of any age). Furthermore, when compared the systems of both Ptolemy and Copernicus, riddled, as both of them were, with epicycles and eccentrics, Tycho’s system was not all that weird or absurd. Although we know in hindsight that it was Kepler who was on the right track, at the time his system was very new, still incomplete, and, to astronomers who had been raised on Ptolemy (as they all had) those ellipses, and vectors sweeping out equal areas in equal times, undoubtedly looked a damn sight weirder and more absurd than either Tycho’s or Copernicus’ systems (and that is quite apart from being expected to accept that the firm Earth beneath their feet was actually spinning rapidly and whizzing through space - a huge concern that did not really even get addressed until Galileo’s Dialog appeared, in 1632). Even Galileo never accepted Kepler’s system! I would go so far to say that, in 1616, to any reasonable, open-minded, well informed, and unbiased astronomer who accepted Galileo’s claims about Venus, Tycho’s theory would have seemed by far the most plausible of those on offer.

It is Galileo and Kepler who were acting like irrational cranks at the time, not their scientific opponents (though I would concede that some of Galileo’s religious opponents acted pretty irrationally). It just so happens that they were cranks who were both brilliant and right, but we only know that through 20/20 hindsight.

Again, the point is not whether it looks like strong evidence to us now, but whether it seemed, and reasonably should have seemed, like strong evidence to open-minded people at the time. There was absolutely no reason to believe that the stars were vastly further away than anyone had previously imagined (OK, maybe Archimedes had, but so what?), except that the assumption was needed as a fudge factor to reconcile the observed facts with a new-fangled theory for which there was very little positive supporting evidence, and which was inconsistent with other incontrovertible facts, such as the manifest immobility of the Earth beneath our feet. The latest, best measurements (those of Tycho Brahe), hugely more accurate than any available before, had still utterly failed to find any hint of stellar parallax. That meant that, if the Earth was in orbit round the Sun, the stars must be much, much further away than even Copernicus had dared to imagine. Why should da rational scientist accept such an absurd and ad hoc assumption?

Anyway, bringing up the arguments of the Dialog is again disingenuous. I was explicitly talking about the period before the Dialog appeared. I accept, and, indeed, I said that with the appearance of the Dialog, the weight of argument and evidence began to shift decisively towards heliocentrism. The Dialog effectively demolished the strongest arguments against heliocentrism (of course, it took a genius of Galileo’s caliber to pull this off), while, at around the same time, it was becoming apparent that the predictive and retrodictive accuracy of Kepler’s Rudolphine Tables was providing the first really strong positive evidence in favor of heliocentrism. Even so, although these developments made heliocentrism much more attractive and defensible than it had been, until the appearance and assimilation of Newton’s Principia, it was still perfectly possible for a rational, informed, and open-minded person to remain a geocentrist (and many did).

I do not believe, nor did I assert, that Kepler’s idea of the Platonic solids led him to heliocentrism. As you say, it seems much more likely that he found that pattern when already looking at the solar system from a heliocentric point of view. However, it does not follow that he was committed to heliocentrism before he came up with the Platonic solids theory of the Mysterium Cosmographicum. It seems to me that it was much more likely that he was initially toying with heliocentric ideas, but that it was the Platonic solids theory (and it is a very beautiful theory, though sadly false) that convinced him that heliocentrism was actually true, to the extent of leading him to devote the rest of his life to the development of it (often under difficult conditions) and to persuading others of its truth. At that time, there was precious little other reason why anyone should have been convinced. Even Copernicus was never fired up about heliocentrism the way that Kepler was. But Kepler, apart from being very public about his views, devoted enormous time and effort into trying to get Tycho’s data to fit a heliocentric model. To the best of my knowledge, he never even tried to see if it could be fitted to a geocentric one, he was totally convinced.

I am pretty sure he did not abandon the Platonic solids theory when he came up with the elliptical orbits. In later writings he refers to it as a discovery, not as something like “a silly idea I had in my youth,” and there is certainly a lot of even weirder “Platonic stuff” - music of the spheres, etc. - in later works such as the Harmonice Mundi.

Well, they never played much role in the wider scientific debate, since few others believed them, but I think the evidence that they motivated Kepler throughout his career, and certainly at the beginning, is strong. Anyway, it is history that we are talking about here, and nothing you say is actually inconsistent with the historical point I was originally making: that both Kepler and Galileo were motivated to take up the cause of heliocentrism largely by theories that we now know to be quite wrong, and this is historically important (as well as philosophically interesting), because when they first committed to heliocentrism, there was almost nothing in the way of what, from a modern perspective, we would consider as good evidence to support it.

I take it that this is a reference to Foscarini. Do you have any evidence that he actually believed in the physical reality of heliocentrism, as opposed to arguing, as he did, that it was not a theory that should be ruled out purely on the basis of what he thought to be a very questionable interpretation of scripture.

Anyway, even if Foscarini was a committed heliocentrist, that is one name to add to the five given above. It is by no means evidence that heliocentrists were “far from rare”.

I am not sure what you mean by the “central part” of his theory. Anyway, to point out, true as it might be, that he got some aspects of the explanation of tidal motions right, is once again, beside the point, and a distraction from what is the point (what was my point, anyway, and of at least some relevance to the OP) which was that he got the motive force wrong, and that his incorrect ideas about this motive force seem to have been a large part of what led him to embrace heliocentrism.

Also, what is with the reference to “Internet stuff”? Do you think you are the only person who has read books and journal articles about this Galileo?

Well, “circular inertia” played a crucial role in the arguments of the Dialog, through which, toward the end of his career, he demolished the most important objection to heliocentrism (that if the Earth is moving, we should feel it, and falling objects should fall to the west). It, or something very like it, can also be found in the De Motu near the very beginning of his career. I think that implies he was pretty committed to it, and such a commitment does seem to me plausibly factor in to the explanation of how he came to be committed to heliocentrism. That can only be speculation, but I think it is reasonable speculation. Otherwise, I find Galileo’s motivation to believe pretty mysterious. He does not seem to have been touched by the Hermetic solar mysticism that motivated Bruno, and to a lesser extent Kepler and even Copernicus. Neither does he seem to have cared about the mathematical elegance of the detailed astronomical system, which was important to the latter two

I don’t know how he would have reconciled his views on circular inertia with his work on parabolic trajectories, but I do not see why it should have been a deal breaker for him. Perhaps he was content to live with any inconsistency, or perhaps (more likely, I think) he actually considered the rectilinear component of projectile motion to be strictly speaking a circular arc, but an arc of a circle so large (the circumference of the Earth) that for all practical purposes it closely approximates a straight line. This seems consistent with the ideas about circular inertia in the Dialog.

I am not sure I understand what you are getting at here, but it looks as though you are agreeing with the point that I have been repeatedly making (and that you sometimes seem to be denying), that before Galileo got involved in the issue, very few people knew or cared about these arcane astronomical issues. I really doubt whether very many people knew or cared even after 1610, but after the publication of Siderius Nuncius (although it was far from being a decisive refutation of the “the old system”) Galileo was a very famous man, and there were people in high places who came to care, if not about the issues as such, about Sr Galileo as a potential threat to their power.

That is quite consistent with what I said.

Darn! I wasted so much time writing all that, I seem to have quite forgotten how this poem I was working on is supposed to continue. :mad:

That the New Deal ended the Great Depression.

That hot water freezes faster the cold water.

You should never end a sentence with a preposition.

It’s physically impossible to make a baseball curve.

Indians taught the pilgrims how to survive in the New World.

The next ice age is right around the corner.

Lack of definition. Do you think something else ended the Great Depression? Do you think the New Deal didn’t help?

More definition problems. Hot water can freeze faster then cold in some unlikely situations. But it was stupid the way I first heard it too, referring to an ice cube tray, the hot/cold taps from the kitchen sink, and a household freezer.

Well, I was given that as rule a teacher’s rule, and one I always adhere to.

Saw that in a book when I was pretty young and pretty dumb. Still didn’t believe it though. The optical illusion theory sounded really far fetched.

Definition again. The Plymouth colony was not thriving initially. They did learn how to grow corn from the Indians. And how not to get killed by Indians in some cases. Sounds reasonable.

[/QUOTE]

How do you know its not?

I think the problem here is that some folks have a mistaken notion of just what a curveball is. Some folks think that a curveball is supposed to go straight for a while and then suddenly swerve to the side, and that is indeed impossible. But there’s nothing wrong with one continually curving.

Well, not exactly straight to start with, but baseballs have laces. Proper orientation of the laces along with grip and release can change the path of the ball along the way as the laces change orientation from interaction with the air. I was given the optical illusion explanation, the laces cause air movement that results in a distorted perception. I recall some unknown source claiming to have calculated the result of such effects, and concluding the optical effect would be insubstantial. I had already seen recorded images of a pitcher curving a ball around a post, so I started out skeptical of the illusion claim. I don’t recall hearing the exact claim from as stated in the post, about the impossiblility, but I’m sure its been said.

Wait, an optical illusion resulting from the movement of the air? That’s just completely, utterly absurd. When you said “optical illusion theory”, I thought you were just referring to projection effects from the batter’s point of view.

I don’t recall who said that, it was probably 45 years ago. I don’t recall who claimed to have investigated the effect either, that was also in the previous century. What do viewers project? I’ve never heard that term, unless it was a long time ago also? Also, did I give the impression I believed those things?

I am NOT suggesting it is the same thing, but the break of the curveball. The ball actually curves, but is exacerbated by an illusion. This is from 2009.

He may be referring to an idea that’s become common in some circles. The idea is that you fix the standard to where the economy was before October 1929 and declare that to be before the Depression. Then you say that the Depression didn’t end until the economy got back above those levels.

There is a partisan reason for doing this. The economy declained from 1929 to 1932 and then rose from 1932 to 1945. These periods coincide with the Hoover and Roosevelt adminstrations. Conservatives don’t like to talk about how the economy went down under Hoover and went up under Roosevelt. So they ignore the direction and look at only the level.

Exactly. Blake, the version you heard makes no sense.

Consider the situation in which you drop three balls of the same size and shape: one made of lead, one made of balsa wood, and one made of styrofoam. All three balls will experience the same force due to air resistance, but this force will have a greater effect on the less massive balls. This is why the less dense balls fall at a slower rate.

What makes more sense is to drop a 5-lb lead ball and a 10-lb lead ball. Both balls are sufficiently dense that air resistance will not be a significant factor. Aristotelian theory would predict that the 10-lb lead ball would fall twice as fast as the 5-lb ball, but this is demonstrably not the case. The balls will hit the ground near simultaneously.

In any event, as mentioned previously, Galileo’s actual experiment actually involved inclined planes, not dropping balls off of a tower.

Exactly.
Downward force F=ma, or the force is dependent on mass (weight).
Air resistance upward counterforce for equal-sized objects is equal - proportional to cross-sectional area, roughly.

So 3 objects, with wildly different mass, weight, downward force. Subtract an equal force from each of them, and the net downward force (result vector) is much less on the lighter objects.

The version I heard was a big and small lead ball. The big ball should hit sooner than the small one according to contemporary theory, but the effective difference, including air resistance, is small enough to be negligible.

Trouble with rolling balls down a ramp may involve the momement of inertia in rotation.

Exactly. (What Gary said.)

RickJay, I don’t know why you keep going on about sails being in the way and unobstructed views. For one thing, the crow’s nest does not always have an unobstructed view because of the presence of other masts. The real reason you put your lookout in a crow’s nest is to get the lookout higher above the surface of the water, which increases his line of sight to the horizon because of the curvature of the Earth.

See here:

If the observer is relatively close to the surface of the earth, where h is the height (in feet) above ground or sea level of the eye of the observer, the straight line of sight distance d (in miles) to the true horizon on earth is approximately:

d = (1.50 * h)[sup]1/2[/sup]

Submarines have a conning tower (today referred to as a sail) which acts as a place to retract masts and antennas. There is a clear view from the top of the sail. However, we also extend the periscope, even when the submarine is surfaced, because the periscope extends higher than the personnel in the sail, which increases the distance to the horizon for the observer using the periscope.

In my time in the Navy, I have seen many ships whose hull is below the horizon due to the curvature of the earth.

I was trying to get clarification. I don’t think the New Deal necessarily ‘ended’ the Depression. But revisionists have (probably since then) been trying to say it didn’t do anything. Just wondered which part of the statement he considered false, and why.

Indeed, it’s a daily - often hourly - commonplace. About as controversial as the contention that fish sometimes jump out of the water.

No, just that someone believed them. It was that mysterious someone who did believe it that I was laughing at, not you.

Not a problem. I wonder myself where patently, and often obviously, false factoids come from. Are there really people who could be described as ‘scientists’ that ever say these things (at least in the last hundred years or so)? As for people who believe something written on a soft drink container or paper placemat at a restaurant, well they get what they deserve, knowledge-wise.

That was category (2).

I never heard of The New Deal ending the depression. WWII gets credit for that.

I was taught that rockets fly by pushing back against the air.
Yes, it sounds silly as it gets, but I swear I was taught that.
DeKalb County Georgia, mid 20th century, public school system.

Oh and for what it is worth, the old canard about waiting a period of time after eating before swimming apparently has a real origin.
If I remember correctly, it was published back in the early 1900s in a Ladies’ Home Journal or something like that. I can’t find the reference right now (stupid Internet!) but I am fairly sure that this is not just a WAG.