Server Migration

[Alorael at Large]

...Except internal links like Strategy Central. Fortunately, the explosion was minor, and a little :%s glued everything back together.

 

—Alorael, who also fixed forum headers and redirected a few outdated links. If anything isn't quite right, let him or any other mod know.

[cfgauss]

Every day I get the feeling something's not quite right. Can you fix that?

[Alorael at Large]

How do you feel about icepicks?

 

—Alorael, who has no better alternatives. His usual prescription is gaining a solid background in advanced physics so you can be sure something's not quite right, but in this case he'll just leap ahead to the acute treatment.

[cfgauss]

I've already tried the first treatment. I don't think my insurance covers the second.

[waterplant]

Originally Posted By: Lilith

Originally Posted By: cfgauss

An alarming number of people also think the Sun moves around the Earth

If you take the Earth as your frame of reference, it does!

'Realize the Sun don't go down, it's just an illusion caused by the world spinning 'round'.
Do You Realize, The Flaming Lips.

Great song...

[Archaeolagent]

Everyone wants to live forever... thinking that it'd be a lot better.

[Student of Trinity]

Uranus didn't have epicycles in Ptolemaic theory. Every planet had one single epicycle. Imagine that all the planets orbit the sun on perfect circles. Then, relative to the earth, the sun orbits on a single circle. All the other planets orbit the sun, so they move on circles (epicycles) whose center orbits the earth on a circle (deferent).

 

If everything were kept to the same scale, there would be huge blank spaces on the page between Jupiter and Saturn, and Saturn and Uranus, compared to the cosier little space between Venus and Mercury. But since the only observable for premodern astronomy is angular position in the sky, all the circle pairs can be rescaled — blown up or shrunk independently, in order to arrange the orbits into a pattern that would be easier to draw. With different shrinking factors for Jupiter and Saturn and so on, the single orbit of the Sun that is really the one and only deferent for everyone gets split up into separate deferents for each planet.

 

It does seem a bit funny for all the planets beyond earth to have epicycles larger than their deferents. It just looks awkward from a mechanical point of view, and again it's kind of hard to draw, with a big epicycle like Jupiter's sweeping way out, while its little deferent has to nest in with the orbits of Mercury and Venus. But there is a neat geometrical identity that lets you swap epicycle and deferent and obtain exactly the same total motion. (If you think of vector addition, the identity is trivial.) So to keep all the epicycles smaller than their deferents, Ptolemy did this swap for all the outer planets, making everyone's epicycles comfortably small. For the sun, Venus, and Mercury, the deferent has a period of one year; for the outer planets, the epicycle period is one year. All the other periods are different. In Ptolemy's system, this common year period is sheer coincidence (or, of course, intelligent design).

 

It's really a pretty simple system. It certainly did not have epicycles stacked on top of epicycles in a desperate attempt to reconcile a prejudice for circles with reality. That was actually Copernicus.

[Student of Trinity]

Originally Posted By: cfgauss

Although calling the epicycles a model, in a modern sense, is a bit of a stretch. It's really more of a very careful observation than a model, since there was no theoretical backing behind it, and strictly speaking, since the orbits of everything is periodic, it wasn't really predictive either.

The biggest benefit of the sun-centered system was that it allowed the Newtonian description to come around and easily provide both a theoretical description and to genuinely predict new things--like the existence of new plants through their gravitational effects! That's the real reason this viewpoint is "correct."

If Ptolemy could've predicted the existence of Neptune by looking at Uranus's epicycles.... well, I'd be impressed!

I find this an interesting issue, because I'm interested in what the basic changes of outlook were in the transition from pre-science to science — if indeed there were any. I'm also generally interested in what makes a theory good, in any field or context.

Ptolemaic astronomy could predict the apparent motions of planets many years in advance, and from a remarkably simple set of assumptions. It certainly could not predict a new planet, or any connection between the motion of the moon and ocean tides.

But is prediction of novel phenomena, as opposed to merely encapsulating rich patterns in simple schemes, really the essence of science? What is good about predicting surprises, anyway?

Predicting something previously unsuspected generally means extending the scope of theory, to cover new ground. This is good. Predicting something really crazy that turns out to be true also carries a lot of epistemological weight. It's about as close as empiricism can come to proof. It greatly strengthens one's confidence in a theory. And this is good.

But one can in principle have any given amount of confidence, in a theory of any given scope, regardless of whether it has earned those things through surprising predictions, or through gradual accumulation of many confirmatory details. The spectacular guess that proves right is a more exciting story, but I don't think it ultimately makes the theory any better, other things being equal.

Dirac predicted the existence of the positron, before anyone else had suspected such a thing; positrons were soon detected. This was certainly a high point of human intellectual achievement. But suppose that someone else had predicted the positron before Dirac, based on some cockamamie notion about duality and opposition, say, instead of on a proper understanding of the finite dimensional representations of the Lorentz group. Suppose Dirac had presented his spinor equation only after positrons were discovered, as a way of neatly reconciling the existence of positrons with relativity.

We would still be using Dirac's theory of relativistic electrons and positrons, though it would have no radical predictions to its credit. Dirac's personal story would be less exciting. He might have had to share his Nobel prize with a third person besides Schrödinger. But his theory would be just as good as it is in fact.

From this point of view it seems to me that Ptolemy's astronomy is a good theory in pretty much the same way that the current Standard Model of particle physics is a good theory. They take a certain amount of empirical input, which is not predicted; from this, they generate large volumes of quantitative predictions, which are impressively accurate. And they relate it all pleasingly to some elegantly simple mathematical structures — gauge theories for the Standard Model, circles for Ptolemy.

The total volume of stuff that modern theories describe is enormously greater, of course. But we've been going longer, building on the work of people like Ptolemy, standing on the shoulders of giants. The basic nature of our success seems to me to be very similar. We simply have more of it.

[cfgauss]

Well, as a theorist, what I would say makes a "good" theory is, well, theory...

 

The problem is, from a statistical point of view, just making observations, and then generalizing from those other observations to new observations is, by itself, actually a terrible idea. Basically every statistical bias comes from doing exactly this.

 

This method is essentially Greek philosophy. They noticed things, generalized them into generic ideas, and then applied those ideas to other things. Generally speaking, from a scientific point of view, this is a total failure. When you don't know any better, it's the best you can do, and that's great. And it's a necessary requirement to develop science to do this first, but it's still a failure.

 

The transition between collections of observations to "mechanistic" models is really the transition between science and pre-science.

 

What distinguishes modern science (well, at least physics and some others, all sciences won't be modern by this definition!) is not only the mechanistic description, but an "axiomatic" mechanistic description. That is, one that starts with a few basic assumptions and builds exclusively on the logical consequences of those assumptions.

 

Pre-modern science, by this point of view, was not an axiomatic system, but a collection of equations, describing a collection of facts! (read c. 1800s physics and you will definitely get this feeling!!) A necessary step, a big step up, but not the best one can do.

 

From a more formal point of view, one can think of this in terms of Bayesian probabilities:

 

- Pre-science is concerned with basically, choosing prior probability distributions based on what you know.

 

- Pre-modern science is calculating the conditional probability that your model is correct given the measurements you've made and the assumptions your model makes, using (first) the naive priors of pre-science, and then, the revised priors from other experiments and tested theories.

 

- Modern science is concerned with radically reducing the "dimension" of the probability space by excluding to a high degree of confidence (using Bayesian reasoning), areas of the "theory space" not logically spanned by the axioms. That is, pre-science calculates P(result|experiment|theory|observation|model|experiment|...) for each result completely independently. Modern science calculates P(axiom|all experiments) for all axioms, and then any logical consequence of the axioms is guaranteed to be correct within the margins of error given by (basically) error propagation. [edit: And this means that measurements of things implied by the axioms is really increasing the probability that the axioms are correct, making the entire framework more sound, instead of just a single result.]

 

The modern point of view is why theorists put so much importance into symmetries and conservation laws. They're easy to test, they greatly simplify dynamics, they're mathematically well-defined and exist rather generally (the subject of generalized symmetries to ODEs and PDEs is a whole subject in math) and so make the perfect axiomatic building blocks for science!

 

This is why, e.g., Ptolemy's theory (as it stood before Newtonian mechanics) is not such a good theory. The probability of it being right is significantly less than the probability of Newton's theory. In fact, the probability distribution only has support (in the function sense) on 'points' where measurements have been made, and nowhere else (in other words, it can't predict anything you didn't already mostly know) where, e.g., Newton's theory has support on the set of all possible measurements! Meaning, formally, Ptolemy is wrong "almost everywhere" (in the measure theory sense)!

[Balladeer]

On the original topic: TrueSite has been updated.

[Dantius]

The scientists in this thread do not explain things as clearly as Dr. Sagan. I will also hazard the guess that their turtlenecks and sports jackets are nowhere near as cool, either.

[Student of Trinity]

The great virtue of Bayesian statistics is that it's really just logic and common sense. That's also its limitation. It's not a magic wand. It's not really worth mentioning in any context where you're not trying to spit out a specific number as a probability, because in qualitative argument, there's nothing you can say with Bayes that you can't say every bit as well without mentioning him. I say this as a great fan of Bayes.

 

It's certainly not true that Ptolemaic astronomy said nothing about what wasn't already known. It could predict the future, accurately. To say that the periodic orbits of the planets counted as already known facts is to take far too much for granted, even today.

 

It's true, there's something that distinguishes a 'real' theory from a mere catolog of facts. Chagrined at winning the Nobel prize in chemistry, Rutherford declared that all science was either physics or stamp collecting. There's more to a good theory than having a nice scheme for laying out the stamps in your album.

 

But it's really not so easy to explain what that more is. Picking Ptolemaic astronomy as an example of what a good theory is not seems to me to be a mistake; I think we learn more by classing it as a good theory, and seeing how it is more than stamp collecting.

[Dikiyoba]

Quote:

—Alorael, who also fixed forum headers and redirected a few outdated links. If anything isn't quite right, let him or any other mod know.

You did miss the BoA reviews, but the rest of the board looks so pretty and updated that Dikiyoba can hardly fault you for that.

[cfgauss]

Originally Posted By: Student of Trinity

The great virtue of Bayesian statistics is that it's really just logic and common sense. That's also its limitation.

Well, it's logic with uncertain truth values. All of the most powerful reasoning with uncertain data and AI models are Bayesian for a good reason. It's not just powerful, it's everything. It's literally the most general possible framework for talking about inference (by definition, really). So you can't really ask for a better explanation than that . Although I can provide one in terms of category theory if pressed (well if the forums implemented latex I would).

Quote:

It's not really worth mentioning in any context where you're not trying to spit out a specific number as a probability, because in qualitative argument, there's nothing you can say with Bayes that you can't say every bit as well without mentioning him. I say this as a great fan of Bayes.

This seems to be what most physicists think, since we're influenced heavily by frequency based interpretations, since they're literally the kinds of experiments we do. And although in some sense the two formulations are "equivalent" they aren't identical (technically, the predictions you can make with both agree, and the ones one doesn't make one typically defines to match the other; but Bayesian is more general and there are no frequentest results which are not contained in Bayesian, but the converse is not true).

But the examples you can find in terms of fancy AI algorithms, (or image processing algorithms for a far simpler case that's not too different) show that they're fantastic when you need that combination of quantitative and qualitative statements you just can't get any other way.

This is exactly why I think they're the most natural way to think about theories, since you have the combination of exact results (we measure "x") and qualitative (this is a good theory).

And really some of the Bayesian results just don't make sense in terms of any other interpretation. How do you even talk about the probability of a theory being correct otherwise? It's either right, or it's not. The naive probability is either 100% or 0%, but the Bayesian interpretation naturally not only makes this any number, reflecting something about the "distribution of theories" but includes the fact that a theory can be good in some regions of parameter space and not others.

Of course, the full-blown measure theory formulation is just Bayesian stuff; that's really what the measure is specifying.

Quote:

It's certainly not true that Ptolemaic astronomy said nothing about what wasn't already known. It could predict the future, accurately. To say that the periodic orbits of the planets counted as already known facts is to take far too much for granted, even today.

But they did know each planet individually moved through periodic paths in the sky. Knowing that they all move together isn't important since the model did not essentially mix any observations of one thing with observations of anything else.

This is why the model couldn't predict, e.g., the orbits of comets reliably.

Quote:

But it's really not so easy to explain what that more is. Picking Ptolemaic astronomy as an example of what a good theory is not seems to me to be a mistake; I think we learn more by classing it as a good theory, and seeing how it is more than stamp collecting.

Well, the specific model is stamp collecting followed by interpolation, but the problem is that the interpolation only works because the system was periodic. So it's better than, e.g., early biology, but not as good as real science.

[Kelandon]

In my last semester in college, I finally came upon some reasonable explanations to a question that is tangentially related to the science in this thread: why didn't the Ancient Greeks invent science, when they had all these astronomers looking at exactly the same things that Copernicus, Tycho Brahe, Kepler, Galileo, and Newton were looking at? Why did the Scientific Revolution happen in the 16th and 17th centuries, and not in the 1st and 2nd centuries?

 

At first I thought that it was something to do with culture. So many ancient writers cared primarily about authority and not data that it was hard to get anybody to care about what was actually going on in reality. The way that Ancient Greeks conducted research was to think about things. They sat down and thought, and they came up with ideas that seemed sensible. They were not terribly empirical. However, this was not universally so. Hipparchus, for one, was emphatic about his models matching the reality of the sky better than other lame natural philosophers who didn't really know what they were talking about. There were empiricists back in the day, just as there were in the Enlightenment.

 

The real answer seems to be that Ptolemy's model was too good. Ptolemy's model was a massive synthesis of virtually everything that anybody knew about the positions of stars in the sky and how they changed over time, and, as SoT points out, it's startlingly accurate as an empirical model. The theoretical explanation had to do with perfection of spheres and such, which isn't scientific theory in the way that we recognize it, but it's at least some sort of stand-in. Ptolemy's model worked for fifteen hundred years before deviations from the predictions started becoming so bad that people really cared. Seasons were a couple of weeks off after a millennium and a half. At that point, people became frustrated with the model, which was infuriatingly complex, and decided to trash the system of equants, epicycles, and so forth, and start over. It was only the advantage of a distance of one and a half thousand years, at which point the model was beginning to fail, that people were able to say, "Okay, let's start over."

 

And it was this "starting over" idea, this sense of tossing out the bad model that didn't make sense anymore and looking to see what was really going on, that led to Tycho Brahe's ridiculously precise naked eye measurements. It was this sort of feeling that made people want to invent the telescope, and then, once it was made, look into it. This focus on true empiricism, testing hypotheses against reality instead of just thinking about them, was what made science happen when it did.

 

At least, that's what I put together as my own narrative once I read enough on the borders of this question. I'm sure I'm glossing over some important points or mis-representing some details here or there. But it was an interesting thought, anyway.

[Upon Mars.]

I wouldn't like to sound nasty, but seems, not that don't approve of your highly intellectual debates, but we are currently changing course from one topic to an other, that is from moving the trash to an other campsite, to basic astronomy...

I suggest we move on or continue this discussion else where.

 

Or i shall parody this thread and stun you with my awful writing!

[Student of Trinity]

Heliocentrism was already a controversial proposition in the late 16th century, before Brahe, Kepler, Galileo or Newton got into the game at all. It was argued mostly on philosophical grounds that today seem rather nebulous. Perhaps the strongest ground as far as I can understand was just a feeling that the sun was bigger and more impressive than the earth, and thus made more sense as the planetary boss. That represents at least a sort of proto-axiom that a true cause should be proprtionate to its effects, and that at least a crude kind of causality ought to be relevant to planetary motions.

 

I've spent quite a while now googling madly, and have found innumerable online accounts of the work of Brahe and Kepler and Galileo. And none of these idiotic little notes, which are probably all cribbed from each other, even mentions the one obviously critical point.

 

When did people get any idea of the actual distances of the planets from earth? This is what really shoots Ptolemy down, by showing that either the deferent or epicycle of every planet is in fact the orbit of the earth around the sun. Once you have this fact, you are effectively heliocentric. Or rather, this fact is the only real content to heliocentrism. But the distances have to be known, or it's really hard to justify doing anything more than tweaking Ptolemy.

 

Two of Kepler's three laws are essentially meaningless without knowledge of planetary distances. His first and second laws together do imply a particular way for the direction of a planet from earth to change over time. But this remains little more than a fudged empirical formula, unless one can independently measure the planetary distances, and not just their directions. And Kepler's Third Law explicitly relates distances to orbital periods, so unless there is an independent way to measure those distances, it's sheer fantasy.

 

What I want to see is a statement that Tycho Brahe measured the distance from earth to Mars by parallax. He knew and used parallax; he used it to measure the distances to the sun and the moon, and to a comet. He tried and failed to observe stellar parallax, and failed also to draw the correct conclusion that the stars are incredibly far away from earth. And he dedicated his life to making a tenfold improvement in the accuracy of measurements of planetary directions over time. He was keenly interested in revising the Ptolemaic model. And Kepler used his data to discover his three laws.

 

That much I could find fairly easily. After a lot of searching I did also find one rather indirect mention of how Brahe used parallax: apparently, he simply made two measurements of the angle between an object and a bright star, with a carefully measured timespan of several hours between the angle measurements. The distance through which his observatory had moved in between, by the rotation of the earth, provided the base of his triangle. As long has he could measure angles and times accurately, and his own geographic latitude, he could determine the distances to celestial objects with trigonometry, in terms of the radius of the earth.

 

But nowhere have I been able to find a clear statement of what I think must be a crux of science: that Tycho Brahe made heroic and expensive efforts to measure planetary angles precisely, in order to provide the very first measurements of the distances between earth and other planets. Was this really true? I can't find anyone who has seen fit to mention it. But I think it must be true, because otherwise Brahe was simply a maniac for useless directional precision, and Kepler produced his laws of planetary motion with distance as a purely hypothetical factor. Whereas if measuring distances was what Brahe was really all about, then his career makes obvious sense, and so does Kepler's.

 

I think the ancients might have had a much harder time measuring distances to planets. They did understand enough trigonometry, and the principle of parallax. But I'm not sure their clocks were good enough for Brahe's technique. I wonder, too, if they had a clear enough concept of the rotation of the earth, to be able to see that waiting between measurements would be as good as making simultaneous measurements from two points far apart.

[Khoth]

Originally Posted By: Kelandon

In my last semester in college, I finally came upon some reasonable explanations to a question that is tangentially related to the science in this thread: why didn't the Ancient Greeks invent science, when they had all these astronomers looking at exactly the same things that Copernicus, Tycho Brahe, Kepler, Galileo, and Newton were looking at? Why did the Scientific Revolution happen in the 16th and 17th centuries, and not in the 1st and 2nd centuries?
....

The real answer seems to be that Ptolemy's model was too good.

I don't think it can be just that. There's a lot more to science than planetary motion. There was plenty of optics and dynamics and anatomy and chemistry and whatnot that the Greeks could have used to start doing proper science to.

[cfgauss]

Originally Posted By: Student of Trinity

It was argued mostly on philosophical grounds that today seem rather nebulous. Perhaps the strongest ground as far as I can understand was just a feeling that the sun was bigger and more impressive than the earth, and thus made more sense as the planetary boss. That represents at least a sort of proto-axiom that a true cause should be proprtionate to its effects, and that at least a crude kind of causality ought to be relevant to planetary motions.

Yeah, that's pretty much the impression I'd gotten, too. I believe this was related to the same philosophical grounds that they used to support the Newtonian idea of impulse, which a lot of early pre-Newtonian and Newtonian mechanics was based off of.

Quote:

When did people get any idea of the actual distances of the planets from earth?

I believe the ancient Greeks calculated not only the size of the Earth, but the distance to the moon within a few (1-10%?) percent. They also calculated the distance to the Sun using similar methods, but got an answer that was much too close (although still very far away). I do not know if these results were known to Renaissance scientists, but I don't see why it wouldn't be.

So I would imagine, early on, the distances were based off of rough guesses based on those known scales.

My recollection from intro astronomy classes a long time ago, was that they did indeed use parallax to find distances when they started systematically going at things. Although I don't know the exact timeline, and I've long since given my intro books to nieces and nephews! I have a degree in astronomy, but most of my focus was not on teaching intro classes or history so I've forgotten most of these details!

Quote:

What I want to see is a statement that Tycho Brahe measured the distance from earth to Mars by parallax. He knew and used parallax; he used it to measure the distances to the sun and the moon, and to a comet. He tried and failed to observe stellar parallax, and failed also to draw the correct conclusion that the stars are incredibly far away from earth.

I'm not sure why he would not make this conclusion. It may've been due to the poor sensitivity of their observations at the time, which they knew pretty well. A lot of their measurements were easily ~100% level errors, so I could imagine it being written off to just being more difficult to measure, e.g., due to starlight twinkling and appearing to move around more than planet-light.

Quote:

But nowhere have I been able to find a clear statement of what I think must be a crux of science: that Tycho Brahe made heroic and expensive efforts to measure planetary angles precisely, in order to provide the very first measurements of the distances between earth and other planets. Was this really true?

Yes, I believe this is true.

Quote:

I think the ancients might have had a much harder time measuring distances to planets. They did understand enough trigonometry, and the principle of parallax. But I'm not sure their clocks were good enough for Brahe's technique. I wonder, too, if they had a clear enough concept of the rotation of the earth, to be able to see that waiting between measurements would be as good as making simultaneous measurements from two points far apart.

The ancients did not really have clocks, which is a big negative . I believe they also lacked the experimental skills to do measurements like that, just due to their lack of experience doing things like this.

[Archaeolagent]

Originally Posted By: upon mars

Or i shall parody this thread and stun you with my awful writing!

Please, stun us!

[cfgauss]

Originally Posted By: Kelandon

In my last semester in college, I finally came upon some reasonable explanations to a question that is tangentially related to the science in this thread: why didn't the Ancient Greeks invent science, when they had all these astronomers looking at exactly the same things that Copernicus, Tycho Brahe, Kepler, Galileo, and Newton were looking at? Why did the Scientific Revolution happen in the 16th and 17th centuries, and not in the 1st and 2nd centuries?

At first I thought that it was something to do with culture. So many ancient writers cared primarily about authority and not data that it was hard to get anybody to care about what was actually going on in reality. The way that Ancient Greeks conducted research was to think about things. They sat down and thought, and they came up with ideas that seemed sensible. They were not terribly empirical. However, this was not universally so. Hipparchus, for one, was emphatic about his models matching the reality of the sky better than other lame natural philosophers who didn't really know what they were talking about. There were empiricists back in the day, just as there were in the Enlightenment.

This is a big part of it, I think. There wasn't a real notion of what science was or what it should be. At the time, it was far from clear if one even could describe nature, or if it was somehow indescribable.

But I think a lot of the reason they did not invent science was that their notions of math were very primitive. You have to realize that they did not have any concept of algebra at all. Algebra wasn't developed until the ~1000s AD. Things like Cartesian geometry weren't developed until the 1600s.

The Greeks didn't even have a sensible notion of numbers. They used Roman numerals, and did not even have a sensible conception of real numbers.

They did not even have a sensible system of notation. You can't write something like X+I = XI, because symbols like + and = didn't really exist until algebra. You had to write out things in words, which made even simple expressions incredibly complicated.

I think this is also probably why they put so much stock in geometry as opposed to arithmetic. In fact, their notions of arithmetic really were geometry--it makes much more sense to think of 2+1 as a line -- next to a line - than to think of it in terms of a sentence!

But I think if the Greeks had a reasonable number system and a reasonable system of notation, they'd have easily developed basic mechanics and calculus.

The problem is that to develop a system like that would have required a change in the way they think, from a linguistic describing in words way, to an abstract symbolic way, which is a big step.

[Celtic Minstrel]

Originally Posted By: cfgauss

The Greeks didn't even have a sensible notion of numbers. They used Roman numerals, and did not even have a sensible conception of real numbers.

I'm pretty sure they actually used an even cruder system by overloading all the letters of their alphabet. I suppose they might've adopted Roman numerals after they were conquered by them, but wasn't that after the time of most of the great philosophers?

Originally Posted By: cfgauss

But I think if the Greeks had a reasonable number system and a reasonable system of notation, they'd have easily developed basic mechanics and calculus.

Well, the Arabs and the Indians had a reasonable number system much earlier than the Greeks... not sure about notation though.

[Monroe]

Originally Posted By: CRISIS on INFINITE SLARTIES

Originally Posted By: upon mars

Or i shall parody this thread and stun you with my awful writing!

Please, stun us!

Come on now, you two. The sciency types are allowed to have their fun, too.

[Triumph]

Originally Posted By: Monroe

Come on now, you two. The sciency types are allowed to have their fun, too.

Are you sure there's nothing in the Code of Conduct banning fun for scientist-type board users? If not, maybe it should be amended...

[Archaeolagent]

If you thought watching the Celts wield Crystal Wands against the Romans was cool, wait until you see Nethergate ][, when the Celts lob Crystal Spheres at the Scientists...

[Monroe]

Pretty sure we'd lose half our mod staff if that were the case.

[inni]

no, science posts are against the rules:

Quote:

"We appreciate posts that are easy to read""be family friendly,"Do not post""irrelevant" [science].

 

there, science is obviously against the rule,

any one who has posted science should be banned.

[Celtic Minstrel]

By that argument, posting in General is not allowed.

[Triumph]

You should know better than to expect logical or consistent applications of arbitrary standards.

[Alorael at Large]

Originally Posted By: cfgauss

The ancients did not really have clocks, which is a big negative . I believe they also lacked the experimental skills to do measurements like that, just due to their lack of experience doing things like this.

They did have pulses, though, and even some modern scientists used that rather imprecise gauge of time to determine how long things took. Obviously that's not going to get you far for short measurements, but for anything long enough but not too long to mess up your count it's reasonable.

—Alorael, who suspects that the science question probably connects to the Antikythera mechanism question. If the Greeks had most of the materials necessary to invent science, why didn't they? Because they were busy inventing and then largely ignoring intricate clockwork?

[cfgauss]

Pulses aren't terribly accurate for long observations .

 

And, you're also forgetting, that you need more than clocks to measure time... You really need a standard of time to make sense of things. Otherwise no one can really compare one measurement to another. And the ancients standards of time were based off of the calendar, which doesn't work so well for reasonable measurements.

 

And, I believe the antikythera mechanism was a calendar, not a clock. The actual mechanism behind a clock that makes it run at a predictable rate is actually very complex and wasn't good enough to do science with for quite a while. So it's a big step up from this to a clock.

 

They did have water (and probably sand) clocks, though, but without something to calibrate against, they're more of a qualitative time-keeping device.

[Alorael at Large]

I did point out that pulses have their downsides, didn't I?

 

The Antikythera mechanism isn't interesting as a timepiece. It's interesting as an example of technology that was possible but not, largely, used. Science, similarly, was possible. The Greeks could have made more progress without the second or the independent variable, but they didn't.

 

—Alorael, who is also certain that someone trisected the day using only a compass and a straightedge. Greeks were pretty intense like that.

[Enraged Slith]

You scientists need to stop hijacking every topic and go invent flying cars. I've been sitting here for a while and I'm not flying yet, so this is a problem. Meanwhile, I want to talk about ice cream. This forum doesn't have nearly enough discussion about ice cream.

[cfgauss]

We'll invent flying cars when everyone learns to drive regular cars.

 

And home-made Kahlua ice cream is the best kind of ice cream in the world.

[Khoth]

Originally Posted By: Enraged Slith

You scientists need to stop hijacking every topic and go invent flying cars. I've been sitting here for a while and I'm not flying yet, so this is a problem.

Scientists have invented flying cars. They're flying around now, but they also invented cloaking devices, since avoiding traffic jams works better the fewer people there are who have them.

[Student of Trinity]

Now we have to kill you. Sorry. If it's any consolation, we'll make the bot that replaces you as laconically erudite as possible.

[Dikiyoba]

Forget flying cars. You scientists should be working on a global teleportation system. Let's avoid the hours of sitting at an airport as well as the traffic jams.

 

Dikiyoba.

[waterplant]

Originally Posted By: Enraged Slith

You scientists need to stop hijacking every topic and go invent flying cars. I've been sitting here for a while and I'm not flying yet, so this is a problem. Meanwhile, I want to talk about ice cream. This forum doesn't have nearly enough discussion about ice cream.

Don't worry about scientists, Slith, - they don't know anything . As you say the link on your signature is everything you'll ever want to know. In fact, I looked at it and it was far more than I ever want to know.


Now where's this ice cream...

[Dintiradan]

Originally Posted By: Dikiyoba

Forget flying cars. You scientists should be working on a global teleportation system. Let's avoid the hours of sitting at an airport as well as the traffic jams.

It's not the future until we have magtubes and psi gates?

[Student of Trinity]

The internet is a series of tubes. And a lot of gates.

[Randomizer]

Originally Posted By: Dikiyoba

Forget flying cars. You scientists should be working on a global teleportation system. Let's avoid the hours of sitting at an airport as well as the traffic jams.

Dikiyoba.

The teleportation part was easy, its when two objects teleport to the same spot at the same time. The resultant explosion of two objects occupying the same space has been a major delay. Also the cleaning crew is on strike demanding more pay for removing the mess of all those bloody parts when they run live subject tests.

[Celtic Minstrel]

If only...

[Triumph]

So now this thread has transitioned elegantly from science to mad science.

[Student of Trinity]

Fools. We'll destroy them all!

[Celtic Minstrel]

*blows up the forums*

 

 

 

FOR SCIENCE!!!

[Goldengirl]

Originally Posted By: Triumph

So now this thread has transitioned elegantly from science to mad science.

There is no transition to make there, silly. All science is mad science!

[Archaeolagent]

Originally Posted By: Goldenking

There is no transition to make there, silly.

You're cute!

[Ephesos]

Originally Posted By: Dintiradan

It's not the future until we have magtubes and psi gates?

Nah, Orbital Power Transmitters are really all you need.

[Dantius]

Originally Posted By: Ephesos

Nah, Orbital Power Transmitters are really all you need.

Can those be modified to orbital death lasers at all?

[Randomizer]

Originally Posted By: Dantius

Originally Posted By: Ephesos

Nah, Orbital Power Transmitters are really all you need.

Can those be modified to orbital death lasers at all?

At that power level you don't need lasers. It's all about targeting them from energy collection sites to where you want to eliminate something.

Originally Posted By: Triumph

So now this thread has transitioned elegantly from science to mad science.

If it's not mad, then you aren't doing it right.