Perhaps the list will be interested in Melvyn Bragg's BBC Radio 4 'In Our
Time' discussion this week.  The link to listen again is at the bottom of
his weekly newsletter.

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http://www.uclmail.net/users/neil.barton/

----- Original Message ----- 
From: <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, March 02, 2007 3:06 PM
Subject: Melvyn Bragg's In Our Time Newsletter - 2/03/2007


> Hello
>
> Good weather came to London this morning which meant that I could walk
from
> Broadcasting House, through Soho, edging Covent Garden, over Waterloo
Bridge,
> on to the South Bank.  On mornings like this you can see why Dr Johnson
said
> what he said and believe that he's right.
>
> One thing that struck me in the preparation for this morning's programme
was
> the number of amateurs involved.  As Jim Bennett indicated, buying a
telescope
> became a craze.  London became a world centre for the production of the
very
> highest quality telescopes and it replaced the sword as something that a
> gentleman should carry with himself through town.
>
> There were amateurs who purchased telescopes who made enormous
contributions
> to astronomy.  I believe I've said before that I'd love to do a series at
some
> stage about the contributions made by amateur scholars to the mountains of
> scholarship and learning piled up in this country over the last four or
five
> centuries.
>
> William Herschel was a case in point, as Emily Winterburn said.  He began
life
> as a musician and took up making telescopes as a hobby.  His discovery of
> Uranus gave him fame and eventually fortune.
>
> I know I'm not supposed (constrained by friends) to quote at any length
from
> notes on the contributors, but as we did run short on this one I think
you'd
> enjoy what Emily wrote about Herschel:
>
> "William Herschel received lots of grants from the King in order to build
his
> telescopes, the last of which includes a salary for himself and an annual
> income for his sister Caroline, integral to the running of the telescope,
for
> the rest of her life.  The 40ft telescope did not have a building of its
own
> but was kept outside.  It had a big wooden frame to support it and two
> interchangeable mirrors in case one became dirty.  In fact it was not used
> very much and only 10ft of it remains today.  When John Herschel,
William's
> son, lived in the family house, he was worried that the decaying telescope
> posed a risk to his small children and in 1840 it was thoroughly
dismantled in
> a special ceremony on New Year's Day.  Sketches remain of the ceremony
with
> John Herschel's children lined up in the tube of the telescope, prior to
it
> being taken apart and sealed in a container, later to be demolished by a
> falling tree."
>
> To compound this I'm going to end with a quotation from Simon Schaffer,
who is
> a brilliant contributor whenever he comes onto the programme.  In this, he
> combines what I've said about the amateur with the final destiny of light
> waves.  He is discussing how it became possible, using light, to describe
the
> chemical composition of the stars.
>
> He says:
>
> "The person who actually worked out what the different gases were was a
grocer
> called William Huggins (1824-1910) who was a pioneer of spectroscopy.  He
made
> so much money from being a grocer he was able to retire fairly young and
built
> a private observatory in Tulse Hill (where he lived).  He purchased a very
> high quality telescope and placed prisms in front of it, turning it into
an
> astrospectroscope.  He measured the spectra of nebulae and stars and
invented
> astrophysics - the science that tells you what the stars and the nebulae
are
> made of.
>
> The other development came when the same men who started to argue that
light
> was a wave eventually realised by the middle of the 19th century that
light
> waves were inextricably linked to electricity and magnetism.  Through
> ingenious experiments and brilliant mathematical analysis between 1860-1,
> James Clerk Maxwell (a very bright Cambridge graduate from Edinburgh)
showed
> that the speed of light is just what you would expect if it was a wave in
the
> substance that produces electric and magnetic effects.  Light is therefore
> electromagnetic radiation and a wave.
>
> This new knowledge suggested all sorts of new optical techniques.  On the
one
> hand, it led Maxwell's German friends (above all a young physicist called
> Heinrich Hertz) in 1887 to make electromagnetic waves directly with a
spark
> gap which was the invention of radio.  On the other hand, it convinced
> brilliant young American engineers, like Thomas Edison, to see if electric
> light could be made by running a strong electric current through a metal
wire
> and getting it to incandesce in empty space (it had to be empty because if
not
> the wire would just burn out.  It had to be glass so you could see through
> it).  The electric current had to be manipulated so that the resistance
and
> the electric current were balanced and by 1878/9 Edison had managed to
build
> the system that could do this.  He travelled to Paris in 1881 and suddenly
the
> electric light system was born.
>
> Therefore, by the 1880s you have modern life - electric light and radio
> waves."
>
> And finally, finally, although I should quote from Jim Bennett I am still
too
> embarrassed by calling him Jim White on live radio at the end of a
programme
> to which he had contributed so magnificently and helpfully.  I can only
think
> White came from me suddenly being struck at the spectrum of colours in
white
> light.  Or perhaps I was thinking of snooker!
>
> Best wishes
>
> Melvyn Bragg
>
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>
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