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Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:07.26,0:00:10.81,Default,,0000,0000,0000,,The Heisenberg Uncertainty Principle\Nis one of a handful of ideas
Dialogue: 0,0:00:10.81,0:00:14.69,Default,,0000,0000,0000,,from quantum physics to \Nexpand into general pop culture.
Dialogue: 0,0:00:14.69,0:00:18.11,Default,,0000,0000,0000,,It says that you can never simultaneously\Nknow the exact position
Dialogue: 0,0:00:18.11,0:00:22.89,Default,,0000,0000,0000,,and the exact speed of an object\Nand shows up as a metaphor in everything
Dialogue: 0,0:00:22.89,0:00:26.41,Default,,0000,0000,0000,,from literary criticism\Nto sports commentary.
Dialogue: 0,0:00:26.41,0:00:29.43,Default,,0000,0000,0000,,Uncertainty is often explained as a result\Nof measurement,
Dialogue: 0,0:00:29.43,0:00:34.56,Default,,0000,0000,0000,,that the act of measuring an object's\Nposition changes its speed, or vice versa.
Dialogue: 0,0:00:34.56,0:00:38.38,Default,,0000,0000,0000,,The real origin is much deeper\Nand more amazing.
Dialogue: 0,0:00:38.38,0:00:41.76,Default,,0000,0000,0000,,The Uncertainty Principle exists\Nbecause everything in the universe
Dialogue: 0,0:00:41.76,0:00:46.32,Default,,0000,0000,0000,,behaves like both a particle and a wave\Nat the same time.
Dialogue: 0,0:00:46.32,0:00:50.46,Default,,0000,0000,0000,,In quantum mechanics, the exact position\Nand exact speed of an object
Dialogue: 0,0:00:50.46,0:00:51.90,Default,,0000,0000,0000,,have no meaning.
Dialogue: 0,0:00:51.90,0:00:53.15,Default,,0000,0000,0000,,To understand this,
Dialogue: 0,0:00:53.15,0:00:57.05,Default,,0000,0000,0000,,we need to think about what it means\Nto behave like a particle or a wave.
Dialogue: 0,0:00:57.05,0:01:01.86,Default,,0000,0000,0000,,Particles, by definition, exist in \Na single place at any instant in time.
Dialogue: 0,0:01:01.86,0:01:05.29,Default,,0000,0000,0000,,We can represent this by a graph\Nshowing the probability of finding
Dialogue: 0,0:01:05.29,0:01:09.03,Default,,0000,0000,0000,,the object at a particular place,\Nwhich looks like a spike,
Dialogue: 0,0:01:09.03,0:01:13.71,Default,,0000,0000,0000,,100% at one specific position,\Nand zero everywhere else.
Dialogue: 0,0:01:13.71,0:01:17.62,Default,,0000,0000,0000,,Waves, on the other hand,\Nare disturbances spread out in space,
Dialogue: 0,0:01:17.62,0:01:20.34,Default,,0000,0000,0000,,like ripples covering \Nthe surface of a pond.
Dialogue: 0,0:01:20.34,0:01:23.77,Default,,0000,0000,0000,,We can clearly identify features\Nof the wave pattern as a whole,
Dialogue: 0,0:01:23.77,0:01:25.93,Default,,0000,0000,0000,,most importantly, its wavelength,
Dialogue: 0,0:01:25.93,0:01:28.64,Default,,0000,0000,0000,,which is the distance between two \Nneighboring peaks,
Dialogue: 0,0:01:28.64,0:01:30.46,Default,,0000,0000,0000,,or two neighboring valleys.
Dialogue: 0,0:01:30.46,0:01:33.02,Default,,0000,0000,0000,,But we can't assign it a single position.
Dialogue: 0,0:01:33.02,0:01:36.28,Default,,0000,0000,0000,,It has a good probability of \Nbeing in lots of different places.
Dialogue: 0,0:01:36.28,0:01:39.10,Default,,0000,0000,0000,,Wavelength is essential for\Nquantum physics
Dialogue: 0,0:01:39.10,0:01:42.42,Default,,0000,0000,0000,,because an object's wavelength\Nis related to its momentum,
Dialogue: 0,0:01:42.42,0:01:44.02,Default,,0000,0000,0000,,mass times velocity.
Dialogue: 0,0:01:44.02,0:01:46.91,Default,,0000,0000,0000,,A fast-moving object has lots of momentum,
Dialogue: 0,0:01:46.91,0:01:50.02,Default,,0000,0000,0000,,which corresponds to \Na very short wavelength.
Dialogue: 0,0:01:50.02,0:01:54.56,Default,,0000,0000,0000,,A heavy object has lots of momentum\Neven if it's not moving very fast,
Dialogue: 0,0:01:54.56,0:01:57.16,Default,,0000,0000,0000,,which again means a very short wavelength.
Dialogue: 0,0:01:57.16,0:02:00.93,Default,,0000,0000,0000,,This is why we don't notice\Nthe wave nature of everyday objects.
Dialogue: 0,0:02:00.93,0:02:02.64,Default,,0000,0000,0000,,If you toss a baseball up in the air,
Dialogue: 0,0:02:02.64,0:02:07.03,Default,,0000,0000,0000,,its wavelength is a billionth of a \Ntrillionth of a trillionth of a meter,
Dialogue: 0,0:02:07.03,0:02:09.36,Default,,0000,0000,0000,,far too tiny to ever detect.
Dialogue: 0,0:02:09.36,0:02:12.32,Default,,0000,0000,0000,,Small things, \Nlike atoms or electrons though,
Dialogue: 0,0:02:12.32,0:02:16.14,Default,,0000,0000,0000,,can have wavelengths big enough\Nto measure in physics experiments.
Dialogue: 0,0:02:16.14,0:02:19.48,Default,,0000,0000,0000,,So, if we have a pure wave, \Nwe can measure its wavelength,
Dialogue: 0,0:02:19.48,0:02:23.10,Default,,0000,0000,0000,,and thus its momentum,\Nbut it has no position.
Dialogue: 0,0:02:23.10,0:02:25.25,Default,,0000,0000,0000,,We can know a particles position\Nvery well,
Dialogue: 0,0:02:25.25,0:02:28.49,Default,,0000,0000,0000,,but it doesn't have a wavelength,\Nso we don't know its momentum.
Dialogue: 0,0:02:28.49,0:02:31.60,Default,,0000,0000,0000,,To get a particle with both position\Nand momentum,
Dialogue: 0,0:02:31.60,0:02:33.76,Default,,0000,0000,0000,,we need to mix the two pictures
Dialogue: 0,0:02:33.76,0:02:37.16,Default,,0000,0000,0000,,to make a graph that has waves,\Nbut only in a small area.
Dialogue: 0,0:02:37.16,0:02:38.80,Default,,0000,0000,0000,,How can we do this?\N
Dialogue: 0,0:02:38.80,0:02:41.55,Default,,0000,0000,0000,,By combining waves \Nwith different wavelengths,
Dialogue: 0,0:02:41.55,0:02:46.53,Default,,0000,0000,0000,,which means giving our quantum object some\Npossibility of having different momenta.
Dialogue: 0,0:02:46.53,0:02:49.28,Default,,0000,0000,0000,,When we add two waves, \Nwe find that there are places
Dialogue: 0,0:02:49.28,0:02:52.06,Default,,0000,0000,0000,,where the peaks line up,\Nmaking a bigger wave,
Dialogue: 0,0:02:52.06,0:02:55.82,Default,,0000,0000,0000,,and other places where the peaks of one\Nfill in the valleys of the other.
Dialogue: 0,0:02:55.82,0:02:58.28,Default,,0000,0000,0000,,The result has regions where\Nwe see waves
Dialogue: 0,0:02:58.28,0:03:01.11,Default,,0000,0000,0000,,separated by regions of nothing at all.
Dialogue: 0,0:03:01.11,0:03:02.59,Default,,0000,0000,0000,,If we add a third wave,
Dialogue: 0,0:03:02.59,0:03:05.71,Default,,0000,0000,0000,,the regions where the waves cancel out\Nget bigger,
Dialogue: 0,0:03:05.71,0:03:09.89,Default,,0000,0000,0000,,a fourth and they get bigger still,\Nwith the wavier regions becoming narrower.
Dialogue: 0,0:03:09.89,0:03:13.09,Default,,0000,0000,0000,,If we keep adding waves,\Nwe can make a wave packet
Dialogue: 0,0:03:13.09,0:03:16.17,Default,,0000,0000,0000,,with a clear wavelength\Nin one small region.
Dialogue: 0,0:03:16.17,0:03:20.22,Default,,0000,0000,0000,,That's a quantum object with both\Nwave and particle nature,
Dialogue: 0,0:03:20.22,0:03:23.31,Default,,0000,0000,0000,,but to accomplish this,\Nwe had to lose certainty
Dialogue: 0,0:03:23.31,0:03:25.80,Default,,0000,0000,0000,,about both position and momentum.
Dialogue: 0,0:03:25.80,0:03:28.22,Default,,0000,0000,0000,,The positions isn't restricted \Nto a single point.
Dialogue: 0,0:03:28.22,0:03:30.92,Default,,0000,0000,0000,,There's a good probability\Nof finding it within some range
Dialogue: 0,0:03:30.92,0:03:32.84,Default,,0000,0000,0000,,of the center of the wave packet,
Dialogue: 0,0:03:32.84,0:03:35.59,Default,,0000,0000,0000,,and we made the wave packet\Nby adding lots of waves,
Dialogue: 0,0:03:35.59,0:03:38.01,Default,,0000,0000,0000,,which means there's \Nsome probability of finding it
Dialogue: 0,0:03:38.01,0:03:41.29,Default,,0000,0000,0000,,with the momentum corresponding\Nto any one of those.
Dialogue: 0,0:03:41.29,0:03:44.74,Default,,0000,0000,0000,,Both position and momentum\Nare now uncertain,
Dialogue: 0,0:03:44.74,0:03:46.82,Default,,0000,0000,0000,,and the uncertainties are connected.
Dialogue: 0,0:03:46.82,0:03:49.21,Default,,0000,0000,0000,,If you want to reduce \Nthe position uncertainty
Dialogue: 0,0:03:49.21,0:03:52.63,Default,,0000,0000,0000,,by making a smaller wave packet,\Nyou need to add more waves,
Dialogue: 0,0:03:52.63,0:03:54.86,Default,,0000,0000,0000,,which means a bigger momentum uncertainty.
Dialogue: 0,0:03:54.86,0:03:58.05,Default,,0000,0000,0000,,If you want to know the momentum better,\Nyou need a bigger wave packet,
Dialogue: 0,0:03:58.05,0:04:01.01,Default,,0000,0000,0000,,which means a bigger position uncertainty.
Dialogue: 0,0:04:01.01,0:04:03.22,Default,,0000,0000,0000,,That's the Heisenberg Uncertainty Principle,
Dialogue: 0,0:04:03.22,0:04:08.21,Default,,0000,0000,0000,,first stated by German physicist\NWerner Heisenberg back in 1927.
Dialogue: 0,0:04:08.21,0:04:12.59,Default,,0000,0000,0000,,This uncertainty isn't a matter\Nof measuring well or badly,
Dialogue: 0,0:04:12.59,0:04:17.11,Default,,0000,0000,0000,,but an inevitable result\Nof combining particle and wave nature.
Dialogue: 0,0:04:17.11,0:04:20.66,Default,,0000,0000,0000,,The Uncertainty Principle isn't just \Na practical limit on measurment.
Dialogue: 0,0:04:20.66,0:04:23.73,Default,,0000,0000,0000,,It's a limit on what properties \Nan object can have,
Dialogue: 0,0:04:23.73,0:04:28.16,Default,,0000,0000,0000,,built into the fundamental structure\Nof the universe itself.