No, it is reasonably normal. Bitumen is one of those peculiar materials which is both a liquid and a solid. Hit it hard and it will shatter, but will flow under its own weight.
No, it is reasonably normal. Bitumen is one of those peculiar materials which is both a liquid and a solid. Hit it hard and it will shatter, but will flow under its own weight.
Indeed. Glass is, I believe (per the ongoing demo in the Science Museum), the same, except that it flows very very slowly (and it certainly shatters if hit!)
Indeed. Glass is, I believe (per the ongoing demo in the Science Museum), the same, except that it flows very very slowly (and it certainly shatters if hit!)
I thought this had been disproven, the glass in old shop windows is thicker at the bottom because the proudction process was far from perfect in those days and the panes often varied in thickness, and it was always the bottom that was thicker because that was the sensible way to install the imperfect glass, no one would ever suggest putting the heavy bit at the top
I thought this had been disproven, the glass in old shop windows is thicker at the bottom because the proudction process was far from perfect in those days and the panes often varied in thickness, and it was always the bottom that was thicker because that was the sensible way to install the imperfect glass, no one would ever suggest putting the heavy bit at the top
What I remember, was as above, except that yes glass does move under gravity - though extremely slowly, not nearly enough account for old glass being thicker at the bottom.
I thought this had been disproven, the glass in old shop windows is thicker at the bottom because the proudction process was far from perfect in those days and the panes often varied in thickness, and it was always the bottom that was thicker because that was the sensible way to install the imperfect glass, no one would ever suggest putting the heavy bit at the top
I think you will find that the (qualitative) concept of 'glass flowing' has not been 'disproved'. What has been discredited is the once common belief (which you allude to) that such flowing was the reason why very old glass windows, particularly church/cathedral windows, and the lower parts of antique glassware, are often thicker at the bottom (the true explanation probably being as you suggest)
My understanding is that glass is an 'amorphous solid' and, as such will flow - but, as I said, very very slowly, probably such that it would probably take many millions of years, or longer, for it to result (at normal ambient temperature) in a detectable different between the thickness at the top and bottom of the window. Of course, that would change dramatically if ambient temperature got much higher, when the 'flowing' would eventually become quite rapid.
I think that even the various 'pitch flowing' experiments which have been running in various museums and institutions around the world for a century or so only see flow at the rate of something like "1 drip per decade", and pitch flows very much more rapidly than glass.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local