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  • I just think it's so wonderful.

  • We always think of these scientists in the past

  • as being saints.

  • And here he is sitting in his office thinking

  • "Hee hee I've made my competitor feel uncomfortable"

  • And in a way it's sad that we lose these

  • bits of information because

  • it makes science seem so much more exciting.

  • We're in the library of the Royal Society

  • Looking at letters about Radon.

  • Radon is the heaviest of the noble gases

  • and in the early nineteen hundreds

  • there was still a big argument about

  • the work and trying to isolate Radon.

  • Radon is given off as a gas

  • in the radioactive decay of Radium.

  • Radium decays radioactively

  • emitting an alpha particle - that's a nucleus of Helium

  • with the mass 4 - and generates Radon.

  • Radon is itself radioactive and decays so

  • you have to have it, as it were, freshly made. Rather like

  • you can only get fresh meat. If you keep it for a long

  • time it decays away.

  • The half life of the most stable isotope of Radon

  • is just over three days so it's really relatively

  • short lived. That means if you have a certain amount of

  • gas, after three days you'll only have half of it.

  • Another three days a quarter of it.

  • And by the time you come back from your holidays

  • most of it's gone.

  • In the days that this letter was written,

  • the way they were getting it was from

  • the decay of Radium. In fact I've read - and this is quite

  • exciting. It's the first time you've ever seen a glass

  • in the library because they're strictly forbidden. -

  • The way they did it was to take a glass vessel

  • and fill it with water.

  • Imagine now you have a container of water with a

  • piece of Radium metal at the bottom.

  • It is breaking down, generating Radon gas

  • and bubbles of this gas

  • will go up to the top.

  • very small amounts of gas, bacause Radium

  • doesn't decay very fast.

  • And so, we can imagine that

  • Rutherford and Ramsay are really competing to get

  • the first sample to characterize it.

  • And because it also contains alpha particles,

  • it will be contaminated with Helium.

  • You've got to realize that these famous scientists

  • were extraordinarily competitive.

  • They wanted to get there first.

  • And they considered the other one,

  • really a bit of a scoundrel.

  • And so there was a sort of competition which is

  • difficult for us now to imagine.

  • And in fact Rutherford was really rude about

  • Ramsay's work. He says, his work - that's Ramsay's

  • work - is all right superficially, on the surface,

  • but when you get down in it you begin to see

  • the nothingness of it all. So he thinks it's rubbish.

  • So this is in a private letter to his friend Schuster -

  • Schuster was his surname -and he begins,

  • "My dear Schuster", because in those days you called

  • your friends by their surnames. No first names;

  • It wasn't right.

  • And this was written on July 30th 1908,

  • so more than a hundred years ago.

  • The reason he's written this letter,

  • is because he's real excited he has got a spectrum

  • of this Radon gas.

  • It wasn't called Radon then; It was called

  • Radium Emanation - Emanation means "coming out

  • of Radium."

  • And he's got a spectrum, and Ramsay hasn't.

  • It was really quite exciting.

  • And so he sent a photograph.

  • And, this is the photograph.

  • So, Rutherford has signed this

  • and he said, "Some of the lines run together

  • in the reproduction" - that's the print - "

  • and ??? they're quite clear in the negative"

  • So, he had an experiment in which he had a small

  • amount of this gas, not more than 0.2

  • of a cubic centimeter, so it's not very much, in which

  • presumably, though he doesn't say so, he put

  • an electric discharge through it so that the gas glowed.

  • Rather like a Neon sign glows red in a shopping center.

  • And he then photographed this light coming out

  • with a photographic film, using a spectroscope to

  • spread out the different colours.

  • All these gases give a whole series of lines

  • and this is a print of his photograph,

  • because you get a negative in the pho... originally

  • and then he's printed it.

  • If you come close you can see it says the

  • "SPECTRUM OF RADIUM EMANATION"

  • There are actually three spectra here.

  • At the top and the bottom are the spectra of

  • Helium gas as a calibration so that he can see

  • what the wavelengths are.

  • And he's written, all the way down here, the

  • wavelengths of the Helium lines.

  • You can see Rutherford has fantastically good

  • small handwriting, or it might have been his assistant,

  • Kay, who wrote this, because his handwriting looks

  • pretty difficult to read.

  • And then, in the middle, is the spectrum of Radon -

  • Radium Emanation

  • It shows that Radon is a completely separate element.

  • And he's really excited because this is the first spectrum

  • that he believes in.

  • Ramsay claims to have got a spectrum, but Rutherford

  • doesn't believe him.

  • I don't know, because it doesn't say here, whether

  • Rutherford ever published this spectrum apart

  • from just sending it to his friend, but it sounds as if he's

  • going to publish it, because he wrote, "I think Royds" -

  • that's his colleague - "and I, have certainly succeeded

  • in making Ramsay temporally very unhappy."

  • We always think of these scientists in the past as

  • being saints. And here he is sitting in his office thinking,

  • "Hee hee I've made my competitor feel uncomfortable."

  • Do you ever feel like that when you get one up on

  • your scientific colleagues/collaborators/rivals?

  • You say it's a wonderful thing and a human thing.

  • Let me put you on the spot. Do you ever take delight

  • in beating people to things?

  • I don't usually get quite so aggressive, perhaps it's not

  • my nature, though I did get quite excited when I made a

  • compound that my German friend, Friedrich, couldn't

  • and I felt really quite good about that, but in a friendly

  • sort of way. I was not hoping that he would be sitting

  • there, um, crying or whatever, but there are stories of

  • Nobel prize winners tearing up journals or jumping

  • up and down on the journals when their rival

  • has published something else.

  • And I think it's important to realize that it's good

  • to feel emotional about these things because then

  • you may have better ideas.

  • If you're sitting there, cold and calculating and not very

  • involved, perhaps you won't have the brilliant

  • breakthrough that you might do otherwise.

  • I don't know what happened. I suspect that Rutherford

  • became more interested in the structure of the atom

  • and, having got this and so on, lost his enthusiasm

  • or got more excited about something else, because

  • in the end, if you look in the books, it's Ramsay who's

  • credited with discovering Radon, though according to

  • some sources, he didn't want to call it Radon and he

  • thought of a nice name, he wanted to call it Niton

  • for some rather obscure Latin derivation.

  • But I think Radon is a nice name. It sounds a bit

  • like Argon or Xenon and also, it connects it very nicely

  • with Radium. So, as names go, it's really quite a good

  • and understandable name.

  • As far as I know nobody has really studied the

  • chemistry of Radon in much detail but, because it's

  • below Xenon in the periodic table there will be quite an

  • extensive chemistry. You will be able to make Fluorine

  • compunds, probably oxides and a variety of other ones.

  • And generally, as you go down the periodic table

  • the chemistry of the noble gases gets richer and richer.

  • A couple of years ago, Brady and I went to an institute

  • in Germany, in Darmstadt, and they had a display

  • for the public of a cloud chamber.

  • Ok we have a cloud chamber here and I will now inject

  • radioactive Radon gas into the chamber and you will see

  • that there is a lot of radioactive decay going on

  • when I inject it.

  • So now we have to wait a second for the gas inside

  • And Brady and I sat there for some time, watching these

  • trails, which look really very beautiful.

I just think it's so wonderful.

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氡 - 視頻的週期表 (Radon - Periodic Table of Videos)

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    林宜悉 發佈於 2021 年 01 月 14 日
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