Name: Diamonds, Pearls and Atomic Bomb Stones - Periodic Table of Videos
Uploaded: 2020-03-27T17:31:13.000Z
Duration: 7 min 49 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

So now I'm going to show you Raman's collection of minerals

Transition words & phrases

Lots of people had collections of minerals but his is special because he collected them all personally

So there is his own character, if you like, in his choice of things that he collected

There's a bewildering number of things to see

And one of the first things which is really very special is over here

When Raman first moved into this institute, there was no electricity

So he had this special device to reflect the Sun off this mirror into the room

As you know the Sun moves around as the time of day

But there's a special clock here and a system of levers

so that as the Sun moves, the mirror moves to keep the sun shining into the room

I'll just show you a few ... whichever ones look really interesting

These are interesting pearls which come from oysters as you know

Raman was very interested in the scattering of light

And the silvery color of pearls is due to the scattering of light between the layers of calcium carbonate that's laid down in the pearl

…and, Jade from China, samples from Brazil

Quartz, silicon dioxide (SiO2), which contains inside it some liquid that was trapped during the geological process

Using light, which can shine through this he could find out what the liquid was without damaging the crystal

and he showed that the liquid was water with a mixture of carbon dioxide and methane

So, if you think about it it's really quite clever

Without damaging the crystal, you can find out what's inside

There's a really nice story about this piece of quartz

He got it from a farmer who brought it to sell it to him

And he bought it and then discovered about the liquid afterwards

Otherwise, the farmer would've probably ask for a lot more money

Again the color is due to the scattering of light...

Over here, there are some things which are very interesting but actually rather ordinary stuff

So up here are these really nice crystals

I've never seen such big crystals of sugar in my life

I've got quite small hands but they’re still quite big

And even bigger down here are two salt crystals

These are natural salt crystals that Raman collected from a salt mine in Poland

And up here there are rather nice crystals of copper sulfate

Over here we have some nice samples of sulfur

I've got a small sample at home but it doesn't look anything as beautiful as this

And presumably this came from somewhere volcanic

And these samples here have a specially interesting story

Apparently, there was a power cut - the electricity went off for several days

And not far from here there is a steelworks or, there was, where they made steel continuously in very hot furnaces

But when the electricity stopped, Raman realized that the furnaces would stop and there might be good crystals there

and before they could start up the furnaces again he got these really nice crystals of carborundum

So now I want to show you the thing that I find the most moving in the whole of this display

Over here are two stones that come from the center of Hiroshima, the city that was attacked with the first-ever atom bomb

And these are pieces of mineral that have melted

The melting point is about 1800 degrees centigrade

And they apparently melted in the center of Hiroshima

Raman was given these pieces of stone by the city of Hiroshima in recognition of his active opposition of the use of nuclear weapons

and he had them tested for radioactivity before he added them to his collection

In here, we have series of samples of rock that don't look particularly special

and if we switch out the light with the visible light

then suddenly, you see something really quite interesting

And they glow because they are absorbing UV light and then some of the energy is lost inside the crystal structure and they emit visible light

and the large lump in the middle is artificial synthetic Ruby and the little bits round about are natural Ruby

and you can see that the natural Ruby fluoresces very nicely whereas the artificial stuff doesn't

This sample here is interesting ... something I've never seen

This rather grey mineral is called crocidolite and it is what asbestos is made from

You've probably heard that asbestos fibers - these very fine fibers - that were used for insulation can be breathed in and cause cancer

This sample is what asbestos is made from

And because it's dangerous, I'm not going to pick it up

Just as we were going, Shashi, who is the curator of this museum, produced another treasure for us

These are natural diamonds for optical windows which give you very strong windows that you can use for high pressure vessels and so on

I've seen diamond windows before but never seen natural ones of this size

These are natural diamonds which have been chopped to give you a slice of this

So the actual diamond itself must have been very much bigger

and diamonds of that size are extremely valuable

[Raman’s Nobel Prize] So this is the citation and here, as you can perhaps guess, is the medal

[Raman’s Spectroscope] Whenever he saw something interesting - a flower, a rock, whatever, he could look through this and see the spectrum

[Objectivity] Hello everyone! Welcome back to objectivity!

[Objectivity] Of course I'm wearing gloves

[Objectivity] But you know we mean business today because Keith is wearing gloves!