Ludvig Faddeev is a Russian theoretical physicist 
and  mathematician.
He is one of the towering figures of 
modern mathematical physics.
To Faddeev, mathematical beauty is the 
most important guiding principle in physics.
I’m Russian, I was born in Leningrad 
which is now St. Petersbrug.
I’m 81 years old, so I lived a lot already.
I finished physics at the department of 
Leningrad University.
But we had very good mathematics there.
And so I became a mathematical physicist,
which must be defined.
And of course there are a lot of different 
understandings of what is mathematical physics
but my definition is as follows: 
it is the same as theoretical physics.
But it stresses first mathematical intuition, 
and not what is called physical sense.
So in this respect I had problems with
the school of Landau, because physical sense
must be the main thing and I  that most
physicist really do the same.
But I somehow decided that I will believe
in the beauty of mathematics,
that it could be also usefull. 
And a couple of times I was able to prove it so.
Ludvig Faddeev invented a remarkable method
in the quantisation of gauge fields.
In the early sixties, Richard Feynman already
suspected the existence of a fictitious particle
in the theory, but he couldn’t pin it down.
Ludvig Faddeev and Victor Popov showed that
these fictitious particles are actually
auxiliary fields in the theory: 
the Faddeev-Popov ghosts.
Faddeev-Popov ghosts relates to the 
quantisation of Yang-Mills field.
And Yang-Mills field is the main field  
which enters the Standard Model.
And when it was introduced by Yang, 
it was considered to be very unphysical.
But I liked it for the geometrical origin,
and decided to worked on it.
Feymnan himself thought about it, 
but he did not do it to the end.
So in one of his sayings, 
[Martinus] Veltman said that
Faddeev and Popov overplayed 
Feynman in his own field.
Meanwhile in the Soviet Union, quantum field
theory was considered a dead end
by the respected physicist Lev Landau.
Under his influence a generation of Soviet physicist 
ignored quantum field theory.
To publish our paper with Popov was impossible.
And we sent it abroad.
And [Martinus] Veltman was editor, and Veltman 
said that he don’t understand any word of it.
But nevertheless he decided it might be 
published because he knew my name.
It was published in Physics Letters.
A very new journal at that time. 
It was a European journal, not American.
They did not require payment. 
And so we were allowed to publish there.
As I like quantum field theory - I still like it -
I think that string theory for instance 
did not show that it has future.
Unfortunately, well, the new generation of
young people in America,
they were pressed  very much by there own censors
that they have to do only string theory.
The good thing is they got a 
very good mathematical education.
So they are much more mathematical 
then young people in my time.
Well I would say, don't ...
Do what you want, if it is possible. 
As much as you want, as is possible.
And read lots.
Don’t concentrate on the theme the
professor gave to you. Look around.
I remember I was reading a lot.
When I was young.
At that time journals were ... 
There were no journals, no computers.
Journals were in the library, so I went to the library. 
I had a book, I was writing things up there.
I have this thick number of cahiers.
So work hard.
If your girl or boyfriend allows.
