Andrea Sella - Glassblowing and Didymium Glasses
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- čas přidán 2. 12. 2012
- UCL Chemist Andrea Sella picks two elements that combine to form the compound didymium. This material is used by glassblowers in the lenses of their safety glasses because it absorbs the light from the sodium flares given off by hot glass.
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My favorite part of a glass demonstration is handing viewers a set of Didymium Glasses. The reaction is always worth it.
Masterful combination of science, video and music!
One of my favorite things in science is the optical distortions and revelations possible. Since the day I removed the filter from my calculator so I could use it in high school in 1989 so the teacher wouldn't know I had it turned on to things like this video I have always been blown away by stuff like this. Also removing the filter from an LCD monitor so you can surf the web privately anywhere unless someone has on a pair of polarized lenses LOL
very sneaky, thanks for the tip..lol
Andrea Sella really does need to do a documentary series on the telly...
As a flame worker myself, having glasses like these is definitely amazing
Too bad he didn't mention the bigger picture: every (practical) chemist is dependent on his glassblowers. Not just because it's often cheaper to repair glassware than to buy it anew but also because sometimes you need an apparatus which can only be custom made.
We had an apparatus for anionic polymerization that spanned two conjoined fumehoods.
Thanks glassmen!
Thank you Magatherium, as a scientific glassblower for over 40 years (now retired), you'd be amazed at the stuff we made, designed, and fixed all without any credit. Think of the number of chemists out there who relied upon their glassblower to make their chemistry happen only to not even get a comment of gratitude in the resulting paper.
Thank you for the information on didymium. I am going to buy some before I use my gas forge.
That's why I'm thinking using that glass with bourkes. Something you could flip down and not have them constantly "on" like they would be with a mask. Or if on a mask a switch to activate them like an auto dimming welders helmet.
Neodymium is also used for lasers. Nd doped glass is used for 1064nm infrared laser (and also green 532nm laser).
Awesome!
Thanks a million, its much appreciated. =)
now that is amazing. What i always wonder is who came across this discovery, and how did they get their hands on the 2 different elements and how did they ever think to combine them into a pair of glasses etc etc gotta love living at a time where so many of these cool discoverys have all ready been discovered
Nobody had to think to combine the two elements! Didymium was actually discovered *before* praesodymium and neodymium - the two are so chemically similar that they pretty much always occur together in nature, and were difficult for chemists to separate or even tell apart at first. When first discovered, didymium was originally thought to be a *single* new element, atomic symbol Di, and was only later determined to actually be a mixture of two new elements.
Nobody had to think to combine the two elements! Didymium was actually discovered *before* praesodymium and neodymium - the two are so chemically similar that they pretty much always occur together in nature, and were difficult for chemists to separate or even tell apart at first. When first discovered, didymium was originally thought to be a *single* new element, atomic symbol Di, and was only later determined to actually be a mixture of two new elements.
SO COOL!
Super cool.
So the didymium glass works in a similar way to a solar filter by taking away the bright glare. Only difference is that solar filters are used in observing the sun safely while these glasses are used in reducing the glare caused by the sodium atoms in the glass so the glassblower can see what he or she is doing.
Science is awesome!
I think that he's allowed a little 'cheat' on this one. A marvellous discovery and an elegant application.
I Really liked this video! What inspires you to do this
How badass is the guy in the back?!?!?!?
3:01
Maybe didymium can be used by photographers in heavy light polluted areas like cities if they want to take pictures of the night skies?
Neil Camara actually it was very useful for astronomers back when sodium street lights were more popular
Imagine wearing these glasses at night - it would block all the artificial sodium lights.
My favorite element is Americium 241...Saving lives.
My favorite element would have to be gold.
Mind you, cobalt glasses were also used for the same purpose (as well as for brazing metals)
Cobalt glasses only decreased the amount of light coming through they do not filter the sodium wavelength. For brazing you want less light reaching your eyes, there is no specific frequency wavelength to be concerned about.
With due respect, have you ever tried cobalt classes? 🤔 (I have)
They do block the 590 nm wavelenght light (yellow) emitted from sodium.
Besides, infrared radiation can cause eye damage on the long term, welding and brazing glasses are specifically made to shield from excessive light and most of IR waves.
@@BartolomeoPestalozzi444 Yes I have. I was a glassblower for over 40 years and used and/or tried a variety of different eye protection. I used some cobalt glasses for a long time for quartz work until I found a better solution. Yes, they do cut down the amount of light as well as the IR range (which is important for quartz work) but do not cut down the sodium frequency as well as your standard didymium lenses. Regular borosilicate glass does not emit anywhere near the amount of IR radiation as quartz.
Can anyone tell me if the Royal Institute's Christmas lectures are being streamed online in some way? I live in Ireland and I don't have any United Kingdom Channels on my tv but I really want to see the lectures.
Thanks
Where can I get those cool glasses the guy who's glassblowing is wearing?
what brand of safety glasses are those?
I wonder how this was discovered. Must have taken a lot of trials to find something suitable.
I'd love to see what those glasses are like under sodium street lamps...
Dark.
@@yohaijohn Only if they're low pressure sodium, and that's so rare nowdays. High pressure sodium is used, and in those, mercury glows, too. So it wouldn't be dark, but darker, sure.
So if I wore those glasses out in the street at night (where the streets are illuminated by SON lights), would they behave in the same way? i.e. darkness?
Is there an application for this type of filter for astronomers that complain about light pollution?
It would not cancel out light pollution at all. Just one section of the wavelength.
someone should adapt firefighters air masks with didymium or even their eyeshields that are mounted to their helmets {bourkes}
That's brilliant.
Bad idea. It would lead to firefighters getting into very bad situations because they could not see flames. I understand that it might help in see through flames, but I want to know where the fire is so I can predict it's behavior and not being able to see flames would preclude that. Thermal imaging makes much more sense.
Blitz350 Just one question, how do thermal imaging helps in a building with fire?, I think you wouldnt be able to even see a person, because the IR will be saturated with the intense heat of the fire.
Also you could have just half of your vision with that kind of glass, or a mixture of both that does not fully block the flames, then you will be able to se through fire and know where the flames are.
That is a pontential situation with a TIC but rarely happens. Part of a how a TIC works is based on an objects transmission and reflection of IR radiation and a group of objects at the same temp will rarely have identical rates of transmission and reflection. It was a bigger issue with older TIC's. Newer ones have much better detectors and screens to allow for higher definition to avoid complete wash out.
charlie lange There is a difference between sodium emission and the emission from carbon particles from a fire. The sodium emission has a couple of emission lines in the yellow that is very intense. The emission from a fire has more of a blackbody radiation spectrum (full spectrum).
Oh hey that’s my prof
My fav element is Cu because in Portuguese it means ASS.
Wait a sec is this the mercury bell guy?
Hey this guy was on periodic videos, I thought he liked mercury O__O
I dont want to sound stupid but what if you looked at the sun with these?
The glare of the sun has nothing at all to do with Sodium emission... you'd still go blind!
The sun produces more wavelengths and 10,000 lumens, much more than glass. You need a lens shade 10 at least to stare safely at the sun. Didymium alone also doesn't provide IR protection.
That guy kind of sounds like Nicolas Cage....
This guy summarises nicely that UCL chemistry sucks