[ul]
[li]Mexicans are slow because they have thick blood (from my sister’s fifth grade teacher).[/li][li]The Civil War had nothing to do with slavery.[/li][li]Only Jesus can help you give up drugs. (Our Jr High had mandatory anti-drug lectures where an expert (usually a preacher) would tell us about the evils of drugs, and how only Jesus can help you.[/li][li]If you put a candle in a small tub of water (so the top of the candle is outside), light the candle, and then cover it with glass. The candle goes out and water enters the glass because the candle uses up the air.[/li][li]There’s a place in France where the women wear no pants. (Technically, I didn’t learn this from a teacher, but it was at school.)[/li][/ul]
Is it possible you mean that it’s impossible to make a baseball rise? It’s definitely possible to make a baseball curve. Baseball lore includes a fastball thrown so hard it appears to be rising, which is impossible. Some fastballs don’t fall as fast as other pitches but they still fall.
You could, at least in principle, put a spin on a baseball such that it does indeed curve upwards. I have no idea whether any real pitcher can actually achieve this, but it certainly doesn’t violate any laws of physics.
Baseball is my favorite sport, and I’ve read a bit on the pitching. The curve of a classic curveball is a bit of an optical illusion. I used to have a book that showed strobe photography of an NCAA Division 1 pitcher’s curveball in flight. It curved close to a constant angle, of course accentuated the more it dropped, as it was helped by gravity. Of course, it wasn’t breaking any laws of physics. The pitcher learns to throw the curve slightly higher than the fastball, allowing for the future drop.
The ball rises slightly out of the hand, crests, then falls to the original perspective point. During this time it’s been traveling at perhaps 70 mph toward a target only 55 feet away. The batter sees the ball as traveling essentially on a straight line. Then the ball really starts dropping, and the expected arrival point of the ball changes dramatically. Even top batters in the world’s best paid league have trouble hitting, or even laying off this pitch when thrown by the best practitioners. It seems to have been traveling in a straight line, and then it “drops off the table”.
There are coaches who advise recognizing the spin of the ball when thrown this way, as the axis tends to be visible to the batter, but this skill seems to rest with only the very best. Sometimes of course the arm motion or the attitude of the pitcher may give away the pitch, but the competent or best learn to hide this.
As for the rising fastball, the explanation that makes sense to me is that when the ball is thrown at an appreciable faster speed than the batter is used to, he misses under the ball. Anyone in MLB has hit hundreds of thousands if not millions of pitches, and has adjusted naturally to the fall of the ball under earth’s gravity. When the ball is thrown hard enough, the ball falls (I’m guessing) .5 inches less than the batter expects, meaning he either misses or pops up. In his experience, it’s as if the ball is “rising.”
I don’t know what of a scientific analysis, but I’ve heard people give anecdotal evidence of a riser. There is the optical illusion, not the one I talked about before, but the effect of lace motion when there is slow spin. But that would not be the conditions for getting the ball to rise. I believe reports of risers come from balls thrown with an initial upward direction.
Maybe Chronos can address this question though. Is it likely that anything in the universe, that is affected by gravity, travels in a euclidean straight line?
Well, if we’re going to use slotted balls, arm-extenders, or lightened plastic balls, yes, I suppose the ball may actually rise. I’ve not heard any reliable reports of hand-thrown baseballs rising, though.
The view of the Great Depression put forward by some is that by 1932 the market had undergone a traumatic and severe correction but left alone would have rebounded. The claim is that the New Deal policies, along with measures such as tariff acts by the US and Britain that hurt world trade, essentially institutionalized the Depression, prolonging it over what it would otherwise have been. And that indeed only the advent of World War Two broke the economic gridlock.
OK, quickly: The Crash was a discernable event, so used to mark the beginning. There is no definitive end, except WWII, changed the economic situation so greatly that whether the GD was over or not, a new phase was entered. I know the alternate claims about the effect of the New Deal they were started before I was born, and I’ve never seen evidence to support them, have seen evidence to deny them, but haven’t examined that closely either. I would agree that the original statement ‘ended the GD’ is inaccurate. Just wondered about which alternative the poster meant.
That may have been a plausible argument when the Depression started in 1929. But by 1932 most people could see that the market was not rebounding by itself. I’m not saying the New Deal was perfect but it was better than doing nothing - the Hoover administration tried that for three years and it hadn’t work.
It’s more like half a second, but your point is valid. Batters who aren’t really good at watching the ball closely along its entire path tend to have short baseball careers. That illusion is not likely to be relevant.
The effect of gravity falls off fairly rapidly with distance to the point of being negligible (i.e. undetectable to the naked eye). How precise an answer do you want?
DesertDog said:
Agreed. That illusion only works when you don’t look directly at the ball.
An interesting point of view, and useful to hear expressed. The view from here is rather different: a reasonable position, which I agree is largely valid, stated with too many dogmatic assertions, often over-broad for the purpose, and often misleading.
I’ll put the bottom line at the top, and then trim the rest of this posting for space.
I disagree with the inverse great-man theory of “Galileo did it” that pervades this discusison of the origins of the trouble; I also disagree with the confident, seemingly authoritative, attacks on Galileo’s scientific stance as of 1616. For the first part the argument is not hard; the science, I’ll get to later.
1610 wasn’t crucial because of Galileo, but because of the telescope.
Though Galileo was the best observer with the earliest decent telescope, or something like that, he was not the only one active. Since people were not stupid in those days, can it be doubted that others would soon have been making those observations? Not being stupid, some would inevitably have been noticing the destructive effect of the new data on the classic systems. The controversy was definitely a creature of its times; but it’s hardly conceivable that the data would not have been in place by 1612, not a very different time from 1610.
But perhaps the problem was all in the way that Galileo presented heliocentrism and dabbled in theology?
No, it doesn’t look that way. Galileo published the Messenger in April of 1610 with no arguments for Copernicus (Kepler didn’t like his leaving Copernicus out) and no theology at all. By the end of that year, at least two philosophers were putting out responses to the Messenger, and specifically introducing literalist Scriptural arguments. One was Sizzi; the other was delle Colombe, more famous as one of the sources of Simplicio. Both of them and many other die-hards would have lived long enough to apply the same to somewhat later discoveries.
As to the nitpicking business: One man’s omission of unnecessary distractions is another’s denial of any kind of doubt or amibiguity or reasoned objections to a position.
As to irrelevant details, there is a problem basic to controversy. To use a trivial example, though surely if a matter is not worth getting right, it’s hardly worth making in the first place: It is easy to make a quick assertion A, as it might be “There is no contemporary basis for this story, and its first appearance is 150 years after the alleged event.” It is easy, and can be even more terse, to assert not-A, as it might be “There is so!” From this, the reader can conclude that one guy says one thing, and another says something else. I think it is a courtesy to the reader to show why the second position is taken, rather than merely demonstrating that there is one person in the world who disagrees with A. It might even be seen as a courtesy to the person asserting A, as offering the possibility of rebuttal. But however briefly this is done, it will take more words than assertion A.
Mutual accusations of disingenuousness noted.
Not something that I ever asserted, or ever would assert concerning this Catholic heretic. To anticipate confidently that I would do so shows, I guess, that I have produced an attitude bordering on paranoia, which is regrettable.
Which, of course, I never claimed.
It does appear in favorable form at Rostock in 1600,
and skip back to page 242, though this is not an official University postion by any means. And the matter is, as you say, not important, but merely an aside.
Kepler BTW seems to have known of a couple of early pro-Copernicans, judging from what he said about the Starry Messenger; and Galileo notes one, though he gives the wrong first name in the Dialogue to Christopher Wursteisen, whom he also says to be from Rostock. A small point, but it’s not clear that Copernicans were utterly rare.
Or rather, that in the strong disagreement in 1616 on whether it could be taught at all, Bellarmine won against the Dominicans and the Inquisition. I note this only because the view that the Church was somehow monolithic is widespread on both sides of the controveries about Galileo, and is wrong. Quite possibly you didn’t mean to imply this, but just don’t think the error is any importance. I disagree. Nor is it irrelevant to later developments what position the boss of the Inquisition took in 1616.
Well, the text to which I was responding was “The evidence that had been offered in support of heliocentrism by 1616 was extremely weak, and there was a good deal of seemingly strong evidence against it…” which is not, in the first part, true. In using the word “conclusively”, though, I committed the sin that annoys me in others, going further than necessary for the argument, so let’s leave that out for a moment.
To start at the end of the objectionable statement, in what way is it relevant that there could be valid objections to the Copernican position? It would be important if he has been trying get the Church to make his position dogma. It has no importance to what he was trying to do: persuade the authorities to allow him and others to continue discussing the theory as a factual matter in the observable world.
How powerful a case is required to get a license to treat a question of nature seriously? Perhaps we disagree on this. It would be anachronistic to apply the radical standard that was raised 50 years later, which was that I don’t need no stinkin license from any government to discuss what I bleedin well please. (I do not actually think the authorities should have been smart enough to predict that after barely 150 years some Enlightement republic would enshrine the principle in its written constitution; this will, I hope, allay any fears of Whiggery in my position.) But does permission to debate require prior proof beyond reasonable cdoubt? Or this something more akin to a search warrant than to a criminal conviction?
There seem to be three contentions here as to the facts: that the motives of Galileo and Kepler were wrong; that no parallax had been observed (revived later in the post); that there reasonable objections to the telescope. Let’s take the last one now, the one relevant to the intemperate “conclusively”.
“Kepler’s student Horky” first. Whether he dismissed Galileo’s telescope “reluctantly” or “gleefully” seems to depend on which expert you read. Not having seen his letter, I can’t judge that. His behavior in his brief time on stage, however, does not support him in the position of a neutral or fair-minded observer. To avoid long digressions, I’ll merely note Kepler’s opinion of Horky’s book as expressed in a letter to Galileo: it was, he said, adolescent and petulant. Note that all of this was in 1610.
Horky is brought in to support the point that “… many people, for reasons that seemed perfectly reasonable and scientific at the time, did not” accept the telescope as valid.
Really? in 1616? This sounds like something even worse than Whig interpretations of history: simple ignorance of the chronology.
In 1610 there were lots of objections to telescopic evidence, many of them reasonable by any standards. This was a bunch of strange new claims; they contradicted much that philosophers and astronomers knew, or thought they knew; they were based on a new-fangled device that no one really understood; and there were only one or two people in the world claiming to have good enough instruments, which made it impossible to check their results. The Jesuits at Rome, for instance – who are important not for any religious reasons but because they included a bunch of fine astronomers including Clavius, the preminent living astrnomer of the previous generation.
Gradually, though, the evidence started accumulating as other people got telescopes. Clavius himself later informed Galileo that they now had telescopes that confirmed the satellites of Jupiter. And how long did that take? Clavius wrote to him, plainly not having any objections to the telescope itself, in December of 1610. A few months Galileo visited Rome and was treated with honor by the Jesuits as to his discoveries if not his philosophy. In 1611, Clavius did a last revision of his Commentarium in Sphaerum, remaining staunchly against Copernicus but crediting Galileo’s observations and saying the astronomers would have to account for them.
Not everyone was required to believe Clavius, to be sure. But might we get some better examples of reasoned opposition to evidence from the telescope from
somewhere close to 1616? That there were ill-informed and unreasonable objections goes without saying – and of course I mean, by the knowledge and reasoning of the time.
Omitting a good deal of stuff about the reasonableness of not accepting the Copernican system, which I’d sort of like to answer, but heck, I never did remotely claim that that system (unlike Galileo’s data) was fully proved…
Well, now we know your opinions on all the reasonable people of 1616. I definitely would not say the reverse, that any such person would have found Copernican ideas better.
No, that’s silly. State your own idea of their true motives as unequivocal truth; tell us that these views blinded them to contrary evidence and made them present bad evidence; and wow, they look unreasonable. Allow any uncertainty about the absolute truth as the motives, and observe the actual science and whether it’s bad enough to require base motives as a reason: not so much.
By way, on that parallax business: there is a considerably better basis for questioning Galileo on this than the purely negative one you present. To avoid irrelevant digressions, and because I still don’t find the case very compelling, I’ll not state it for you here.
Already noted and answered.
Yeah, disingenuous if we merely assume that other people were raising that argument in 1616 and Galileo never responded. Otherwise, not so much.
Am I belaboring a point by repeatedly mentioning that I never denied such a thing? Sorry; but perhaps the fault is not all mine.
Good. Not how I read it, from the context, so thanks for clearing up the point.
Apart from the evident falsity of the old views in light of then-current information, and what seemed to many people then as well as now to be the dynamic absurdities of Tycho’s system. Which is to say, in oversimplification, that the huge Sun circling daily around the much smaller Earth seemed as worthy of skepticism as it apparently did to Aristarchus.
Well, the censors were convinced of it. That’s not really commanding evidence, I know, but there are also Foscarini’s strong arguments against Ptolemy and his answer to Clavius’ challenge to find a way of accounting for the telescopic discoveries: “But what other system could one find better than that of Copernicus?”
Foscarini was an example of the increase of people taking Copernicanism seriously. Must we consider only Famous People and ignore upstarts like Wedderburn (who wrote the rebuttal to Horky that Galileo didn’t bother to write)?
My point is that there are not many scientific opinion polls concerning scientists in 1615-1616; hence we judge opinion on the basis of more or less famous publications. These respsected established people are, as a popular and not badly wrong modern principle holds, the ones who need to die off in order for a new idea to be accepted. But no matter; it’s unclear to me anyway why we need a head count here at all, for an idea that had come to be of interest only a few years before.
For the central point you could do worse than read Galileo’s final presentation in the Dialogue. In short, it involves the first description of we now call a seiche, and the more general perception that tides in the real world are strongly dependent on the size and shape of tidal basins. His analysis of tides in the Adriatic Sea are well reasoned, and it would be incredible to attribute their actual correctness to some kind of luck.
Perhaps his original ideas do seem to have been such as you say. Perhaps not. Perhaps the seeming is not a very strong argument for a strong conclusion about his science.
Heavens no. I assumed, perhaps wrongly, that you or someone else who might read it had encountered the masses of garbage in the Mob Wisdom of the Internet concerning history of science, of which this thread has been pleasantly free and would recognize what I was saying. If not, I congratulate you on your good fortune.
But of course it’s not just the internet. I was responding to the scorn with which the tidal theory is treated, sad to say, even by people who publish on dead trees.
Meanwhile the “circular inertia” remains a matter of controversy. My example is, as I said, one corner of the matter that illustrates the non-simplicity of the question. One can, of course, simplify the presentation by never mentioning that one is basing arguments on one side of a controversy; or one can simplify further by not making that argument.
I agree with this. I disagree with the inverse great-man theory of “Galileo did it”.
Reading this thread, I was feeling pretty pleased with my (100% public from kindergarten to grad school) education because some of y’all have had some bad teachers. But one just occurred to me: the story about how Rosa Parks didn’t want to give up her seat because she was tired and her feet hurt. It was only in the last few years did I learn that she was a longtime civil rights activist and her refusal to give up her seat was planned.
I think the true story is more powerful than the imagined one and I don’t know why it’s been whitewashed, so to speak.