assumption of quantization
13:02 as a mere mathematical trick nobody actually believe that the quantum
13:07 picture a flight had any basis in reality
13:09 so nobody paid much attention to it nobody
13:13 except for a nameless and faceless clerk
13:16 working in a Swiss patent office in 1905
13:21 this clip published an analysis a Brownian motion
13:24 which made predictions that ultimately led to the confirmation of the existence
13:28 of Adams
13:29 he established that the universe has a speed limit and that space in time a
13:33 relative
13:34 he constructed the most famous equation and physics
13:38 any should beyond a shadow of a doubt that planks mathematical Trek manifested
13:42 itself
13:43 in a very real way the year in which Einstein did all this became known
13:48 as the honest metropolis the yearbook miracles
13:52 when I'm sternem still a child the physicist Heinrich Hertz
13:56 whose claim to fame was his experimental vindication of electromagnetic waves
14:00 and after whom the unit a frequency was named discovered an anomalous phenomenon
14:05 that later became known as the photo electric effect
14:08 it works like this when light is shined on to
14:11 a metal surface the energy from the incoming electromagnetic waves gets
14:15 transferred to the electrons in the middle
14:17 the electrons are initially bound to the metal but the sudden kickin energy that
14:21 they receive calls a summer them to escape
14:23 we call these escaped electrons photoelectrons
14:27 the manner in which light behaved in the photo electric effect was anomalous
14:31 it didn't seem to do with electromagnetic waves were expected to
14:34 do
14:35 this experimental setup with the photo electric effect
14:38 involves a white light which is composed of of frequency is applied
14:42 shining onto a metal was outgoing photo electrons have their energy is measured
14:46 and displayed on the right
14:48 first a red filter is placed in front of the late
14:51 which means that only red light is heading the metal the needles position
14:55 is it 0
14:56 which means that no electrons are being kicked out at the metal
14:59 the process is repeated first with the yellow filter
15:03 then with the green one and finally with the blue filter
15:07 notice that in each case the needle immediately jumps to a specific position
15:11 on the energy measuring device
15:13 and that it stays there the entire time the filter is in place
15:17 this means the photo electrons are immediately being kicked out at the
15:21 metal the moment they get struck by the late
15:23 and that the energy with which they risk a ping is not changing
15:26 also notice that the energy increases as the filters admit electromagnetic waves
15:31 with higher frequencies
15:32 this suggests that the energy a photo electrons
15:35 and by extension the energy at the light waves that are knocking them out at the
15:39 metal
15:39 is related to the frequencies at the incident light to a physicist in the
15:44 early 20th century
15:45 these results were complete in Digman according to the weight picture a flight
15:50 the photo electric effect should occur at any frequency
15:53 but should rise with intensity your experiments show that the intensity the
15:57 incident light was a relevant to how energetic the outgoing photo electrons
16:02 were
16:02 it doesn't matter how much red light you shine onto a metal
16:06 the photo electric effect simply won't occur on the other hand
16:10 you could China far less intense beam ultraviolet light onto the metal
16:14 and the energies are the photo electrons will be off the charts
16:17 this shows that the photo electric effect is a sort of all-or-nothing
16:20 process
16:22 either light is energetic enough to kick the electron
16:25 out of the metal or it isn't there's a quota the energy
16:28 the threshold energy that simply isn't being met when red light is shining onto
16:32 a metal
16:33 none of this was consistent with the behavior of waves
16:37 according to the wave picture applied as more these monochromatic electromagnetic
16:41 waves were fired at the metal
16:43 the amount of energy that the release should have steadily increased
16:46 as the incoming light rays combine their energies it we clearly saw that the
16:50 energies are the photoelectrons for each separate frequency remained constant
16:55 this characteristic is more akin to that of the stream of particles