Topic: Science Blunders

[♫♪ FX ♪♫]

      Pedantic man to the rescue.

[vociferous]

It was a hemispherical neutron reflector that slipped, not the core itself, despite what the guys on Caustic Soda said.

Actually, it was the screwdriver that slipped, if you want to be pedantic.

Marie Curie died of aplastic anemia caused by her work with radioactive material; she did not die of radiation poisoning.

Radiation caused her aplastic anemia, hence she died of radiation poisoning.  If someone gets shot, the shooting is listed as the primary cause of death, not blood loss or cardiac arrest, because it is what caused the injury. 

Ptolemy's epicycles were useable but they were hardly good, even in his day. An error of a few degrees after a few years made nobody happy.

Ptolemy's epicycles actually made very good predictions given the instrumentation of Galileo's day, which were just beginning to incorporate optical magnification.  It had several problems, but so did Galileo's theory of orbital motion, the failure to observe parallax being one of the most obvious. 

I was not aware Galileo had his own theory of planetary motion. Please elaborate?

You need to familiarize yourself with Galileo's published works.  He lays out several theories on mechanics which he then later incorporates into his final two works on Copernican motion of the planets around a heliocentric solar system. 

[Chew]

It was a hemispherical neutron reflector that slipped, not the core itself, despite what the guys on Caustic Soda said.

Actually, it was the screwdriver that slipped, if you want to be pedantic.

Marie Curie died of aplastic anemia caused by her work with radioactive material; she did not die of radiation poisoning.

Radiation caused her aplastic anemia, hence she died of radiation poisoning.  If someone gets shot, the shooting is listed as the primary cause of death, not blood loss or cardiac arrest, because it is what caused the injury. 

I see your point. Radiation poisoning nowadays has a specific medical meaning but this was in her day before there was even such a cause of death.
 

Ptolemy's epicycles were useable but they were hardly good, even in his day. An error of a few degrees after a few years made nobody happy.

Ptolemy's epicycles actually made very good predictions given the instrumentation of Galileo's day, which were just beginning to incorporate optical magnification.  It had several problems, but so did Galileo's theory of orbital motion, the failure to observe parallax being one of the most obvious. 

I was not aware Galileo had his own theory of planetary motion. Please elaborate?

You need to familiarize yourself with Galileo's published works.  He lays out several theories on mechanics which he then later incorporates into his final two works on Copernican motion of the planets around a heliocentric solar system.

I must bow to your superior knowledge of Galilean orbital mechanics. May I ask what the parallax problem was all about?

[Johnny Slick]

I know! I know!

Basically, parallax is the idea that if you're standing in one place with a building a mile away from you and a tree half a mile away, and then you walk 100 feet over to your left, that building and that tree are going to be in a slightly different position within your field of view, and their relative position to each other will change as well. Think about this from the perspective of the Earth-centered universe people: if everything didn't revolve around the Earth, why is it that when you walk from Paris to Rome the stars are in the exact same places relative to each other? We know now that the answer is basically "because the stars are really, really far away"; nonetheless, the early astronomers had no real way of knowing this and in fact IIRC their instruments weren't sophisticated enough to observe stellar parallax until the 19th century.

[Chew]

I know! I know!

Basically, parallax is the idea that if you're standing in one place with a building a mile away from you and a tree half a mile away, and then you walk 100 feet over to your left, that building and that tree are going to be in a slightly different position within your field of view, and their relative position to each other will change as well. Think about this from the perspective of the Earth-centered universe people: if everything didn't revolve around the Earth, why is it that when you walk from Paris to Rome the stars are in the exact same places relative to each other? We know now that the answer is basically "because the stars are really, really far away"; nonetheless, the early astronomers had no real way of knowing this and in fact IIRC their instruments weren't sophisticated enough to observe stellar parallax until the 19th century.

Not that parallax problem, doofus. The parallax problem with Galileo's theory of planetary motion.

[vociferous]

I see your point. Radiation poisoning nowadays has a specific medical meaning but this was in her day before there was even such a cause of death.
 

Well, I am not medical expert, but I believe that radiation poisoning can refer, even today, to any of the acute or chronic diseases, injuries, and maladies caused by acute or chronic radiation exposure.  I suppose people usually use it today to refer to the acute effects since we know enough about bionuclear medicine to prevent chronic exposure from being a problem. 



 

I must bow to your superior knowledge of Galilean orbital mechanics. May I ask what the parallax problem was all about?

Well, essentially there were two competing systems, neither of which made perfect predictions.  One was Ptolemy's system of orbital mechanics, which was pretty good, but was occasionally having to have new epicycles added to it to make it more accurate in line with better observations.  The Copernican model that Galileo embraced and helped perfect, while also imperfect had the virtue of being simpler.  However, simply being simpler does not necessarily make it more correct, and during his trials, the inquisition essentially found that while Galileo's system of orbital mechanics was a better system in terms of predicting planetary motion, it had no better empirical evidence than Ptolemy's system and should not be taken literally.

In modern times, we have the virtue of knowing what the "right" answer was, but at the time of the trial, the evidence for Galileo's theory was only marginally better than the accepted theory, so let us look at the evidence.

 
 

• Both were roughly equal at predicting the motion of the planets.  Both were imperfect.  It was later scientists who helped provide the essential evidence modifying Galileo's mechanics to make it better able to predict the motions of the planets. 
• Galileo's theory was simpler and had less ad hoc revisions, but still had to have had revisions to better refine it.
• Galileo's observation of the phases of Venus and the apparent circular motions of Jupiter's four Galilean moons seemed to support the notion that smaller objects moved in circles around larger objects.  However, as the telescope's use in astronomy was fairly new, not many people had seen this evidence themselves. 
• According to Galileo's theory, the earth would move once orbital radius away from its present position every six months.  Between those time periods, if the stars were not equal distances away, stellar parallax should be observed (the foreground stars moving relative to the background stars [if you need a primer on this, look for a video or illustration of stellar parallax] Despite numerous attempts, Galileo failed to observe any stellar parallax.  This was a huge failure of his theory.  What few realized was just how far away the closest stars were.  Even today, we cannot measure the parallax of distant stars.  The first parallax as measured in the mid 1800s.
• Another problem with Galileo's theory was that, despite the work of Kepler, Galileo insisted that orbits were circular.  If he had recomputed the orbits assuming they were elliptical, he probably could have made better predictions. 

[Chew]

Thanks for the primer. But I wouldn't consider the failure to detect stellar parallax as a failure of his theory since detecting it was beyond everybody's capability at the time.

[vociferous]

Thanks for the primer. But I wouldn't consider the failure to detect stellar parallax as a failure of his theory since detecting it was beyond everybody's capability at the time.

You have to put yourself back in time.  At the time, nobody knew what stars were.  They had no idea that most stars' distances were on the order of millions or billions of times the distance between the earth and the other planets (which looked like stars to astronomers, being called planetai, or wandering stars).

I am not even sure Galileo really had any idea why his theory failed so spectacularly.  It predicted stellar parallax, yet no matter how hard anyone tried, the could not observe it.   Trying to argue that the great stellar distances were the cause would sound like special pleading in order to preserve his theory, if anyone even made that argument. 

[Johnny Slick]

Thanks for the primer. But I wouldn't consider the failure to detect stellar parallax as a failure of his theory since detecting it was beyond everybody's capability at the time.

YEAH MY EXPLANATION IS RIGHT DOOFUS PUT THAT IN YOUR DOOFUS PIPE AND SMOKE IT LIKE A DOOFUS DOOFUS

[Chew]

Thanks for the primer. But I wouldn't consider the failure to detect stellar parallax as a failure of his theory since detecting it was beyond everybody's capability at the time.

YEAH MY EXPLANATION IS RIGHT DOOFUS PUT THAT IN YOUR DOOFUS PIPE AND SMOKE IT LIKE A DOOFUS DOOFUS

Even a broken clock is right twice a day.

[Morvis13]

Thanks for the primer. But I wouldn't consider the failure to detect stellar parallax as a failure of his theory since detecting it was beyond everybody's capability at the time.

YEAH MY EXPLANATION IS RIGHT DOOFUS PUT THAT IN YOUR DOOFUS PIPE AND SMOKE IT LIKE A DOOFUS DOOFUS

Even a broken clock is right twice a day.

Unless its digital then I'm sure it is 18:88 somewhere.

[Chew]

Famous moments in astrometry: 61 Cygni was the second star to have its distance measured. It was measured in 1838.

[Johnny Slick]

Thanks for the primer. But I wouldn't consider the failure to detect stellar parallax as a failure of his theory since detecting it was beyond everybody's capability at the time.

YEAH MY EXPLANATION IS RIGHT DOOFUS PUT THAT IN YOUR DOOFUS PIPE AND SMOKE IT LIKE A DOOFUS DOOFUS

Even a broken clock is right twice a day.

Unless its digital then I'm sure it is 18:88 somewhere.

YEAH CHEWFUS YOU SHOULD PUT THAT INTO YOUR DOOFUS CHEWFUS PIPE ALONG WITH STELLAR PARALLAX

[Chew]

Thanks for the primer. But I wouldn't consider the failure to detect stellar parallax as a failure of his theory since detecting it was beyond everybody's capability at the time.

YEAH MY EXPLANATION IS RIGHT DOOFUS PUT THAT IN YOUR DOOFUS PIPE AND SMOKE IT LIKE A DOOFUS DOOFUS

Even a broken clock is right twice a day.

Unless its digital then I'm sure it is 18:88 somewhere.

YEAH CHEWFUS YOU SHOULD PUT THAT INTO YOUR DOOFUS CHEWFUS PIPE ALONG WITH STELLAR PARALLAX

[peristaltor]

Just now reading Carl Zimmer's Soul Made Flesh.  I am amazed at how long people in Europe taught Aristotle's medical meanderings and Galen's anatomy based on the four humors without actually cutting open a human corpse to see for themselves.  (In their defense, it was forbidden in most places.)

Count the number of people bled to death as treatment and other unproven, untested quackery, and this might be the largest blunder of all when gauged by human suffering.