Have you come to the wrong lecture? This is physics and very important physics it
needs expert help and Dr. Evans has come over here especially he is the one of
the top experts in radiation safety and he is going to offer to this tomato
plant which has been specially grown for you
a cocktail of radioactive water the water contains radioactive phosphorus
and we want - it's very strong - the cocktail is in the mug inside the
greenhouse so far the plant has not drunk any has it?
Dr Evans: No, it's perfectly safe
EM Rogers: He's using a Geiger counter. We have to start with this because we have to give
the plant time to drink and we shall return to it at the end of the lecture
and see how well it has enjoyed its cocktail and so we're going to go
straight ahead with Dr Evans giving the tomato plant in a safe arrangement a
drink of radioactive phosphorus. The little sounds you hear are small
background counts of radioactivity which belong with the building- they belong
with all London for that matter. He's putting on a protective glove - it isn't
too safe inside of the greenhouse, he's being very careful
the growers are so enthusiastic they grew us a larger plant than we bargained for
The smaller one which was only four inches high was tested out at Emerson
radioactive Supply Center. He's lowering the plant into the liquid which is water,
radioactive phosphorus and some common phosphorus in phosphate neutral form
which we believe the tomato plant will drink - but you never know when you
offer somebody a drink
It is time to ask Dr Evans to look after the health of the tomato
plant
Dr Evans: Should we take a top leaf off first? EM Rogers: Take a top leaf off first
By the way, nobody must leave the room until the
last remains of radioactive material have been taken away by ribbons - that's a
general precaution of safety. He's bringing a top leaf high up on the tomato
plant. This is a tracer to find what happened to it. It drank, it did! Take a bottom leaf and see if
drank more to the bottom leaf this is absolutely genuine, there's no
fake, it would be easy to fake but we wouldn't do it
Dr Evans: There are not very many good bottom ones EM Rogers: Any respectable looking bottom ones
Dr Evans: That's a reasonable one there let's hope that that one will work EM Rogers: I'm very grateful to
the Emerson radioactive Supply Center for providing the phosphorus. It's had
come here by special messenger Dr Evans: I think that's the one, let's try it
It looks a bit sorry but it may have worked? No.
EM Rogers: No the sorry leaf didn't drink, do you want to try
one of the healthy leaves, somewhere about here? When you've seen this
you have seen radioactive tracers put to use to measure growth in plants,
to measure your bloodstream carrying salt in a drink
radioactive salt down to your big toe, to see the measurement of a thickness of a
steel sheet
Dr Evans: It's rather more because it's a smaller EM Rogers: And because it's nearer
the source of supply. You have seen real radioactivity put to use
you