Transcript Lise Meitner 1878 - 1968

Lise Meitner
1878 - 1968
A physicist who never lost her
humanity
The most significant woman
scientist of the 20th century



Born in Vienna, Austria
in a Jewish family
First person to realize
that the nucleus of an
atom could be split into
smaller parts.
Element 109, Heaviest
known element in the
universe bears her name
Meitnerium.



First woman to earn a doctoral degree in physics at the
university of Vienna.
Was actively involved in the scientific field since 1917,
culminating into discovery of an isotope of
Protractinium with Chemist Otto Hahn.
With her own physics section at the Kaiser Wilhelm
institute of chemistry, she went on and discovered the
cause of the Auger Effect (Emissions from surfaces of
electrons with signature energies.)

The discovery of neutrons, and speculation
about the possibility of synthesizing heavier
elements than uranium triggered the Nuclear
Race involving some of the great scientists at
the time like Ernest Rutherford, Otto Hahn etc..

When Adolf Hitler came to power in 1933, all her colleagues and
top jewish scientists were forced to resign from their posts. But
she maintained immunity due to her Austrian citizenship. Instead
of leaving or saying something, she totally immersed herself in
her work which she openly later voiced regrets about.

In the july of 1938, with the help of a dutch physicist named
costner, she emigrated into hollands after losing her citizenship
during the Anschluss. An anecdote about this is that her great
friend and chemist otto hahn gave her a diamond ring passed
down from his mother to be used to bribe the frontier guards if
need be. She openly professed that she made it to Holland with
10 marks, without her belongings.




She had a chance to work with the likes of Niers Bohr
in stockholm, and Max Planck and faced constant
prejudice in a male dominated world of science.
She was 1st person to realize that the nucleus of an
atom could be split into smaller parts:
The Uranium nuclei for example splits to form barium
and Krypton, accompanied by ejection of several
neutrons and mass amounts of Energy.(account for
loss in mass).
This release of energy triggers an ongoing chain
reaction with energy levels exponentially growing.

To have somewhat of an idea about Nuclear Fission, you must understand a
few basic Principles.

Chemical isotopes that can sustain a fission chain reaction are called nuclear
fuels, and are said to be fissile.

The most common nuclear fuels are 235U (the isotope of uranium with an
atomic mass of 235 and of use in nuclear reactors) and 239Pu (the isotope of
plutonium with an atomic mass of 239).

These fuels break apart into a range of chemical elements with atomic masses
near 100 (fission products). Most nuclear fuels undergo spontaneous fission
only very slowly, decaying mainly via an alpha/beta decay chain over periods
of millennia to eons. In a nuclear reactor or nuclear weapon, most fission
events are induced by bombardment with another particle such as a neutron


Typical fission events release several hundred
billion eV of energy for each fission event. By
contrast, most chemical oxidation reactions
(such as burning coal or TNT) release at most a
few eV per event, so nuclear fuel contains at
least ten million times more usable energy than
does chemical fuel.
Nuclear fuels are made to undergo induced
fission by bombardment with excess neutrons


Even the first fission bombs were thousands of times more
explosive than a comparable mass of chemical explosive. For
example, Little Boy weighed a total of about four tons (of which
60 kg was nuclear fuel) and was 11 feet long; it also yielded an
explosion equivalent to about 15,000 tons of TNT, destroying a
large part of the city of Hiroshima.
Modern nuclear weapons (which include a thermonuclear fusion
as well as one or more fission stages) are literally hundreds of
times more energetic for their weight than the first pure fission
atomic bombs, so that a modern single missile warhead bomb
weighing less than 1/8th as much as Little Boy (see for example
W88) has a yield of 475,000 tons of TNT, and could bring
destruction to 10 times the city area.



Discovery of nuclear power had an electrifying effect
on the scientific community, and its capacity as a
weapon especially in the hands of the Nazi Regime
wasn’t that good of an idea.
Edward Teller and Eugene Wigner persuaded
Einstein(who was popular) to write a letter to Franklin
D. Roosevelt which was basically a catalyst for the
Manhattan project.
A Nuclear Weapon is basically a fission reactor
designed to release as much energy as possible and as
rapidly as possible before released energy destroys the
reactor, therefore stopping the chain reaction.
And What would Meitner Do ?
HECK NO!!!!!!!


She lost her Nobel prize to Han(for chemistry)
in 1944 for the discovery of Nuclear Fission.
Most of the experiments in her collaborative
work with Hanh took place in Hahn’s lab in
Germany due to her exiled status.
Hahn published his lab findings in January 1939,
but couldn’t explain the physics of it which was
done so by Meitner in February of the same
year.

Lise's Grave in Bramley
"You all worked for Nazi Germany. And you tried
to offer only a passive resistance. Certainly, to buy off
your conscience you helped here and there a persecuted
person, but millions of innocent human beings were
allowed to be murdered without any kind of protest
being uttered... [it is said that] first you betrayed your
friends, then your children in that you let them stake
their lives on a criminal war - and finally that you
betrayed Germany itself, because when the war was
already quite hopeless, you did not once arm yourselves
against the senseless destruction of Germany