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Glass viscosity calculations debunk the myth of flow in medieval windows (2017)

ceramics.org

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Re: Glass viscosity calculations debunk the myth of flow in medieval windows (2017)

#101
While this was specifically about glass from the middle ages, is there certain window glass more recently that does flow measurably? The soda lime glass referenced?

Or when you see waves in window glass in 1930s buildings, is that too from the original imperfections in the glass fabrication itself?

Re: Glass viscosity calculations debunk the myth of flow in medieval windows (2017)

#102
I wonder if the craftsmen also knew that the windows were a little wedge shaped from manufacture and put the thick bit at the bottom. That's what I'd do at least, makes sense structurally.

Then later, random people made guesses as to the 'flow' of glass because all the windows are thick on the bottom...

If anyone can confirm this theory, you and I will feel eternally smug. Best of luck!

Re: Glass viscosity calculations debunk the myth of flow in medieval windows (2017)

#103
post #63

Earlier quoted context omitted.

He must not have been the top of his class if he had ended up a HS teacher. Which is actually kinda sad. Pay and working conditions for teachers shouldn't be so that being a teacher is regarded as a failure.

You are the one regarding them as failures. I had a variety of teachers in school, some were very educated (PhDs), and simply found a calling in teaching. Not everything is about money, you shouldn’t look down on teachers.

I think the public perception of teachers varies a lot between societies. In breaking bad it was clear that Americans don't think much of a guy who ends up teaching chemistry. If you go to other countries it's very different, eg in Switzerland it seemed totally legit to aspire to teaching. Salary was 120k according to the kid who told me.

Re: Glass viscosity calculations debunk the myth of flow in medieval windows (2017)

#104
post #19
post #5

Earlier quoted context omitted.

I'm not the original poster, but I was shocked by how many of the otherwise super smart friends I had in college were taught common falsehoods in high school. For example: the idea that your veins look blue through your skin because the deoxygenated blood in them is blue, and that it only turns red outside your body because it's exposed to oxygen.

Or how reentry heating is apparently caused mostly by friction. (Compression of air is the main cause in actuality)

Technically it's not "friction" because "friction" has to be between two solids. But arguably that's just being pedantic. The air gets in the way of the object moving through it and slows it down, but energy is conserved, as always, so the energy ends up as heat. Knowing that the correct term is "air resistance" rather than "friction" doesn't seem to provide any insight into what's happening, so I don't understand the obsession with correcting people online who call it "friction".

I've been told you can bring water to the boil with a food mixer and a bit of patience. That's not friction either. It's water getting in the way of and slowing down the blades.

Re: Glass viscosity calculations debunk the myth of flow in medieval windows (2017)

#105
post #98

Finally! I always knew my 7th grade science teacher was full of shit on that one, she was so adamant about some things that turned out to be wrong. This one was maybe more excusable because it was common to teach at the time. Maybe it ended up making us better students in the end because we learned to fact-check our teachers, and not to be adamant about things we only think are true (though I'm still guilty of that m…

The problem is that it's obviously wrong with a simple experiment - just look at a few really old windows. I live about 1/4 mile from a church that was built 1300 years ago ( https://en.wikipedia.org/wiki/St_Peter%27s_Church,_Monkwearm... ). There's not much of the original glass left but where there is the thicker part is occasionally at the top of the pane because that's how it was originally mounted. Teachers (and…

I would not disagree that your teachers failed you or vice-versa. But making grand pronouncements about people ("everyone else") and their problems as you see them ("without doing any critical thinking or experimentation of their own") and teachers too - and apparently based solely upon your personal experience in school and your thoughts on one church that just happens to be physically nearby you - isn't gonna convince anyone. Your comment is ignorant and offensive to teachers.

Re: Glass viscosity calculations debunk the myth of flow in medieval windows (2017)

#106
post #42

Finally! I always knew my 7th grade science teacher was full of shit on that one, she was so adamant about some things that turned out to be wrong. This one was maybe more excusable because it was common to teach at the time. Maybe it ended up making us better students in the end because we learned to fact-check our teachers, and not to be adamant about things we only think are true (though I'm still guilty of that m…

Most school teachers are full of it, but they don’t mean to. They are simply low level clerics in the church of truth. They recite a very lossy account of what they were ordained with at a likely low level institution. It’s not really their fault - people need jobs, the ministry needs repeaters, and the pay is bad. Your teachers weren’t the disease - they were just a symptom.

This is a great analogy. The teachers in school are not there to teach you the most detailed model of the world, they are mostly there to make you exercise your model critiquing ability on some toy models that are simple to deal with. Your math teacher might draw a blank when you tell him he taught you an inconsistent notion of limits in calculus, and your physics teacher will certainly admit that there are holes in the high school version of gravity.

But the point wasn't to tell you the exact version of what we know, it was to make you think about how models work.

Re: Glass viscosity calculations debunk the myth of flow in medieval windows (2017)

#107
post #63

Earlier quoted context omitted.

You are the one regarding them as failures. I had a variety of teachers in school, some were very educated (PhDs), and simply found a calling in teaching. Not everything is about money, you shouldn’t look down on teachers.

I think the public perception of teachers varies a lot between societies. In breaking bad it was clear that Americans don't think much of a guy who ends up teaching chemistry. If you go to other countries it's very different, eg in Switzerland it seemed totally legit to aspire to teaching. Salary was 120k according to the kid who told me.

> according to the kid who told me

Come on, you can do better than this and actually invest the minute to type this into your search engine of choice and verify:

https://www.swissinfo.ch/eng/society/swiss-salaries-teachers...

So according to this, Swiss teachers make between CHF 95,590 and CHF 110,590 annually. Cost of living is also higher in Switzerland, so it's a bit less than "120k" would suggest, but still a solid salary. Refer to the link for details.

Re: Glass viscosity calculations debunk the myth of flow in medieval windows (2017)

#108

Earlier quoted context omitted.

I think the public perception of teachers varies a lot between societies. In breaking bad it was clear that Americans don't think much of a guy who ends up teaching chemistry. If you go to other countries it's very different, eg in Switzerland it seemed totally legit to aspire to teaching. Salary was 120k according to the kid who told me.

> according to the kid who told me Come on, you can do better than this and actually invest the minute to type this into your search engine of choice and verify: https://www.swissinfo.ch/eng/society/swiss-salaries-teachers... So according to this, Swiss teachers make between CHF 95,590 and CHF 110,590 annually. Cost of living is also higher in Switzerland, so it's a bit less than "120k" would suggest, but still a sol…

It's in the ballpark, and will certainly get to 120K once you have some seniority.

The point was more that a person thinking about what to do could admit to saying he wanted to be a teacher in Switzerland, whereas in the US it seems like making Walter White a teacher was the perfect way to say he'd somehow failed.

Re: Glass viscosity calculations debunk the myth of flow in medieval windows (2017)

#109
post #98

Earlier quoted context omitted.

The problem is that it's obviously wrong with a simple experiment - just look at a few really old windows. I live about 1/4 mile from a church that was built 1300 years ago ( https://en.wikipedia.org/wiki/St_Peter%27s_Church,_Monkwearm... ). There's not much of the original glass left but where there is the thicker part is occasionally at the top of the pane because that's how it was originally mounted. Teachers (and…

I would not disagree that your teachers failed you or vice-versa. But making grand pronouncements about people ("everyone else") and their problems as you see them ("without doing any critical thinking or experimentation of their own") and teachers too - and apparently based solely upon your personal experience in school and your thoughts on one church that just happens to be physically nearby you - isn't gonna convi…

I didn't suggest they're always wrong, or that all of them are wrong, or that some of them won't have done any checks on what they're teaching. I said that teachers will be wrong about things. That only means they're fallible and don't get things right all the time.

If any teacher, or literally anyone else, is offended by the suggestion that they're human and could be wrong sometimes then I think I'm OK with offending them. If you think you're perfect and will never be wrong then frankly you deserve to be offended as often as possible.

Re: Glass viscosity calculations debunk the myth of flow in medieval windows (2017)

#110

Finally! I always knew my 7th grade science teacher was full of shit on that one, she was so adamant about some things that turned out to be wrong. This one was maybe more excusable because it was common to teach at the time. Maybe it ended up making us better students in the end because we learned to fact-check our teachers, and not to be adamant about things we only think are true (though I'm still guilty of that m…

I seem to remember research has found some windows were placed upside down so these would now support the story that glass flows up.
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