my
0:03up
0:10the year was nineteen hundred max plank had finally devised a means of solving
0:14the problem that haunted him for the better part of the decade
0:17what was the relationship between the intensity of a blackbody
0:21like the SUN in the frequency of the liked it admitted
0:24though he had at last arrived at an answer frank was dissatisfied
0:28his solution utilize the ideas that Ludwig Boltzmann
0:31idea so outrageous that almost nobody accepted them
0:35but because no conventional attempt at a solution was forthcoming
0:38plan complete these highly unorthodox ideas out of desperation
0:42little did he know that in doing so yet plunged headfirst into realms of Physics
0:47had there too unknown and untested
0:49what he discovered would fundamentally change our understanding of nature
0:53forever
0:56up
1:02up
1:09in
1:09order to begin to understand what motivated the development of quantum
1:13theory
1:13one must first understand the status a physics at the end of the 19th century
1:17at the time there were three main branches a physics first there was
1:21mechanics
1:22which was designed to predict the motions have masses things that were
1:25influenced by gravity
1:27then there was thermodynamics which was concerned with the relation to Pete
1:31in temperature to energy and forces finally there was electromagnetism
1:36which dealt with interactions between charged particles it is within the realm
1:40of electromagnetism
1:41that the story of quantum mechanics begins in the early 1860s
1:47James Clerk Maxwell had produced to set up the questions that summarized
1:51electromagnetism
1:52before Maxwell electricity and magnetism were considered to separate forces
1:57but as the 19th century progressed its deadly became more and more clear that
2:01these two interactions were fundamentally related
2:04as it turned out they were both the product of charge
2:07charge is an analog mass
2:10like mass charges an inherent property of matter that is associated with the
2:15fundamental interaction
2:16mass produces gravitational fields in these fields cause mass is to attract
2:21one another
2:22similarly charge produces electric fields
2:25which interact with other charges by causing them to either attract or repel
2:29the concept to fields can be somewhat counterintuitive
2:32so it might be helpful to think of them as odors the closer you are to the
2:36source
2:37have an odor the more strongly you feel its effects if you dislike the older
2:41you'll tend to move away from the source but if you find the older attractive
2:45you'll turn to come in closer electric fields work analogously
2:49obvious the charges will be pulled toward each other because their fields
2:53her odors attract one another like charges will move away from each other
2:57because their fields repel them
2:59when these charges begin to move they generate magnetic fields
3:03which further affect the motions have other charges additionally
3:07it was discovered that not only to change in electric fields generate
3:11magnetic fields
3:12but changing magnetic fields will also produce changing electric fields
3:16moving a charged particle will produce magnetic effects
3:20moving a magnet
3:21will generate electric voltage taken together
3:24what this all suggests is that electricity and magnetism
3:27are different aspects have the same force the theory of electromagnetism
3:32involved many difficult derivations and meticulous experiments
3:36but when the dust finally settled it became clear to all that not only are
3:40electric and magnetic phenomena fundamentally the same force
3:43but that electric and magnetic fields could together
3:47produce a wave a wave is a disturbance that travels through some material
3:51called a medium when this string experiences an impulse
3:55a disturbance passes through it the same general principle applies to sound waves
4:00which in the common case are a disturbance passing through air
4:03molecules
4:04waves at the beach are also based on the same concept
4:07disturbances passed through the water manifesting themselves and is familiar
4:11forms
4:12was crucial to recognize is that in each case
4:15the medium itself the string the air molecules the water
4:19is not moving from one end to the other they're simply being displaced by the
4:24energy that's passing through
4:26so what happens when you take an electric charge
4:29and start to shake it back and forth analogously to the way this boy is
4:32shaking the string
4:33the electric field surrounding the charge will start
4:37also laid as a result of this change in the electric field
4:41and also leading magnetic field will be generated which in turn will create an
4:44also leading electric field
4:46and on and on a lil girl the result is an electromagnetic wave
4:50according to Maxwell's equations the speed with which an electromagnetic wave
4:54travels is equal to the speed of light
4:57this led him to conclude that light is a type of electromagnetic