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00:00The End
00:30Before dawn on the 16th of July 1945 at Alamogordo, New Mexico, an event took place which was to change the world for all time to come.
01:00The Atomic Age was born.
01:03There is no denying that since that moment the shadow of the atom bomb has been across all our lives.
01:09All men of goodwill earnestly hope that a realistic control of atomic weapons can and will be achieved.
01:17Meanwhile, good sense requires that all of us prepare for any eventuality.
01:22But wisdom demands, too, that we take time to understand this force, because here, in fact, is the answer to a dream as old as man himself, a giant of limitless power at man's command.
01:36And where was it science found that giant?
01:39In the atom, a particle so infinitely small that it takes over a hundred billion billion atoms to make up the head of a pin.
01:47Just as other millions and quadrillions of atoms are the tiny building blocks which make up everything in the world.
01:54Although no one has ever seen an atom, scientists have learned a great deal about how they behave, and there are widely accepted theories as to what they're like.
02:11Let's start by meeting a leading authority on the subject, Dr. Atom.
02:19Now, observing the professor himself, we can see that his structure resembles, in many ways, something almost as vast as the atom is small.
02:29The solar system.
02:31And there are certain similarities.
02:34Here, the sun is the center, and the planets revolve around it.
02:37While here, the nucleus is the center, with electrons in surrounding orbits.
02:44But whereas the planet's movement is like this, neat, orderly, and predictable, the movement of electrons is slightly different.
02:54There are other differences, too.
02:57Hey, hold it!
02:59Now, the solar system is held together by gravitation, while the force holding the atom together is electrical.
03:09The electrons, which are negative, are attracted by the protons, which are positive, and vice versa.
03:16But here in the nucleus are other particles with no electrical charge, called neutrons.
03:22Very important characters, too, as we shall see.
03:24And equally important, when it comes to atomic energy, is what scientists call the atom's binding force.
03:33It's a kind of cosmic glue holding the nucleus together.
03:38This, then, is a single atom.
03:41But certainly, not all atoms are alike.
03:44There are, in nature, more than 90 basic elements, which is science term for families of atoms.
03:50To scientists, the atoms of the individual atom families, or elements, are identified by number.
03:58That is, the number of protons, or positive charges, in their nucleus.
04:04And they vary all the way from hydrogen, which has just one proton,
04:09to oxygen, with eight protons,
04:13to gold, he's rich with 79.
04:16Finally, on to the heaviest of all natural elements, uranium, with 92 protons.
04:25Now, within each element, or family of atoms, there can be different members,
04:31each one having the same number of protons, but differing in the number of neutrons.
04:36The total of an atom's protons and neutrons is its atomic weight.
04:43Thus, in natural uranium, we have U-234, U-235, and U-238.
04:52These different members of the same element or atom family, science calls isotopes.
04:58Some elements, tin, for instance, have a great many isotopes.
05:03Others, like aluminum, are lone wolves, with just one.
05:08Now, most atoms of most elements are content with their lot in life.
05:13We speak of them as being stable.
05:15But others are busy day and night, being what science calls radioactive.
05:20Like radium, throwing off powerful rays along with some of its neutrons and protons
05:26until it actually alters its own nuclear structure
05:30and changes to another family
05:35and then to another
05:38until it does become stable at last.
05:42This spontaneous changing of elements is called natural transmutation.
05:47Its discovery gave men of science an idea.
05:52If an atom could change itself,
05:54why couldn't man change an atom?
05:58Using as bullets the very particles which radium threw off,
06:01a noted British scientist bombarded nitrogen
06:04and converted it to oxygen.
06:08In terms of individual atoms, this is what happened.
06:13The radium nucleus threw off an alpha particle
06:16consisting of two protons and two neutrons.
06:20One of the protons was absorbed into the nitrogen nucleus,
06:24turning it to oxygen.
06:26This was artificial transmutation,
06:29man changing the elements.
06:32From that first experiment,
06:34others by the thousands followed
06:35as scientists devised ever more powerful particle accelerators,
06:40commonly called atom smashers,
06:43to transmute more and more kinds of atoms.
06:47All scientifically important, but hardly world-shaking.
06:51Then, in 1939,
06:53some scientists were experimenting with transmutation of uranium.
06:58What would happen, they wondered,
07:00if they fired a neutron at a uranium nucleus,
07:03already the heaviest in nature?
07:05Why not try?
07:07So they tried.
07:09And the result?
07:10Nuclear fission.
07:12Instead of a minor change,
07:14the atoms split in two.
07:16Truly a discovery to change the world.
07:20For what had happened when the uranium atoms split
07:22was a kind of double miracle of science.
07:26Half of the miracle concerned that binding force
07:29we spoke of before,
07:30that kind of cosmic blue
07:32which holds the atom's nucleus together.
07:35We still don't know all about that binding force yet,
07:39but we do know it is equivalent to mass.
07:42Therefore, we may speak of it
07:44as having a kind of weight of its own.
07:47Now, the two atoms into which a uranium atom splits
07:50also have binding force.
07:53But for some reason,
07:55it takes less of that glue
07:57to hold them together,
07:58and in the process of fission,
08:00a tiny fraction is left over.
08:03What happens to it?
08:04It explodes as energy,
08:07proving Einstein's theory
08:09that mass and energy are really the same.
08:13But we spoke of a double miracle.
08:15To understand the second one,
08:17let's slow down that fission
08:19a million or so times.
08:22A single particle starts the reaction,
08:25splitting the uranium atom.
08:26Here now is the release of energy
08:29as heat and blast.
08:32Here are powerful rays being given off,
08:35similar to x-rays.
08:36But here,
08:38here are free neutrons
08:39driven out with tremendous speed.
08:42And provided there is sufficient U-235 present,
08:46what science calls a critical mass,
08:49those neutrons bombard other uranium atoms,
08:52causing them to split
08:53and split still others.
08:55The result?
08:57A chain reaction.
08:59Over a million, billion, billion atoms
09:02exploding within two seconds.
09:06And the force?
09:07It would take Yankee Stadium
09:09full of dynamite
09:10to equal the energy released
09:12in the complete fission
09:14of an amount of U-235,
09:16the size of a baseball.
09:18With this discovery,
09:22at the time the free world
09:23faced a war for survival,
09:25it was little wonder
09:26the first thought was a weapon.
09:29But how to obtain enough material
09:30for even a single bomb?
09:33Only a small fraction
09:34of natural uranium
09:36is the U-235 isotope,
09:38which will fission in a chain reaction.
09:41And to separate enough U-235 quickly enough
09:44seemed all but impossible.
09:46But the impossible became reality
09:48as industry, labor, science,
09:51and the military
09:52combined their efforts
09:53to build Oak Ridge,
09:55where enough U-235 was separated
09:58to build the first atomic bomb.
10:00At Hanford, Washington,
10:04another impossible project
10:06proved possible
10:07when a huge plant was built
10:09for the mass production
10:10of the artificial element plutonium.
10:14This process involves
10:15what may be called
10:16the furnace of atomic energy,
10:19the reactor pile.
10:21Here is a structure,
10:22or pile, of graphite blocks.
10:25In the reactor
10:26are placed rods of natural uranium
10:28containing both U-235
10:31and U-238.
10:34As U-235 begins to fission,
10:37the graphite slows down
10:38the free neutrons,
10:40and some of them
10:41hit other U-235 atoms,
10:44keeping the chain reaction going.
10:46But others of those
10:47slowed down neutrons
10:49hit U-238 atoms.
10:52And here's what happens.
10:54Remember, we said that U-238
10:57wouldn't support a chain reaction.
10:59However, it will capture neutrons
11:02from U-235 fission
11:03and start a process
11:05which converts the U-238
11:07first to neptunium,
11:09then to plutonium.
11:12And plutonium will fission
11:14in chain reaction.
11:16Thus, the reactor itself
11:18is a source of atomic fuel.
11:20Besides producing plutonium,
11:23the nuclear reactor
11:24makes possible two very important
11:27peacetime uses of atomic energy.
11:30Remember that the chain reaction process
11:32in the reactor
11:33creates tremendous heat
11:35which scientists have learned
11:37how to control.
11:39Thus, a reactor may be substituted
11:41in many industrial applications
11:42where heat is now provided
11:45by coal or petroleum.
11:47But such uses
11:48in the foreseeable future
11:49are limited.
11:50For one thing,
11:52a reactor pile must be shielded
11:54to protect the workers around it
11:56from dangerous radiation.
11:58And this shielding
11:59adds tremendous weight.
12:01However,
12:02an atomic energy power plant
12:04has already proved feasible.
12:06The future supplying
12:07of electric power
12:08to entire cities
12:10is far from impossible.
12:12While nuclear power
12:13in locomotives,
12:15submarines,
12:17ships,
12:17and even very large airplanes
12:20may all but revolutionize
12:22future transportation
12:23on land,
12:25sea,
12:25and air.
12:27But perhaps the most valuable
12:29byproduct
12:30of the nation's reactor piles
12:31is radioactive isotopes.
12:34Research has revealed
12:36that many elements
12:37not naturally radioactive
12:39became so
12:40when placed
12:41in a nuclear reactor.
12:43And these isotopes,
12:44working as tracers
12:45with such measuring devices
12:47as a Geiger counter
12:49became invisible detectives,
12:51aiding the cause of science
12:53in many different fields.
13:01In agriculture,
13:03isotopes are now used
13:05to test such things
13:07as the effect of fertilizers
13:08on plant growth
13:10and the proper timing
13:11for their use,
13:12helping to assure
13:13bigger and better yields
13:15from tomorrow's farms.
13:19In industry,
13:21isotopes have found
13:22literally hundreds
13:23of new uses,
13:25such as the automatic
13:26thickness control
13:27of sheet aluminum,
13:29saving hundreds
13:29of man-hours of labor
13:31and assuring accuracy
13:32never before possible.
13:35In the fields
13:36of medicine
13:36and biochemistry,
13:38isotopes are performing
13:39near miracles
13:40of diagnosis
13:41and discovery.
13:42With radioactive sodium,
13:45doctors are solving
13:46more of the seeming mysteries
13:48of heart disease
13:49and circulatory disturbances.
13:52Radioactive phosphorus
13:53has been used
13:54to locate tumors
13:55in the brain
13:56and greatly simplify
13:57operations
13:58for their removal.
14:00Iodine-131
14:01finds one of many uses
14:03in revealing conditions
14:05of the thyroid
14:05and there are many more.
14:08New ways
14:09of using isotopes
14:10are being discovered
14:11constantly through
14:12the tireless work
14:13of modern pioneers
14:14in such fields
14:16as chemistry,
14:17metallurgy,
14:18medicine,
14:19and biology.
14:21Truly,
14:21the superpower
14:22which man has released
14:24from within
14:24the atom's heart
14:25is not one,
14:27but many giants.
14:29One is the warrior,
14:31the destroyer.
14:32Another is the engineer
14:34seeking to provide
14:35vast quantities of energy
14:37to run the world's machines.
14:40Another is the farmer
14:41helping to better feed
14:43tomorrow's world.
14:45Still another
14:46is the healer
14:47helping to diagnose
14:48and cure the sick.
14:50And the last
14:51is the research worker
14:53working on
14:54in the fields
14:55of pure science
14:56to reveal more
14:57of the mysteries
14:58of the universe.
14:59but all
15:01are within
15:02man's power
15:03subject to
15:04his command.
15:06On man's wisdom,
15:08on his firmness
15:08in the use
15:09of that power
15:10depends now
15:11the future
15:12of his children
15:12and his children's children
15:14in the new world
15:16of the atomic age.
15:18The End