
20220928: Why Is 1/137 One of the Greatest Unsolved Problems In Physics?
 11:33: ... force, Planck's Constant is the relationship between the uncertainty in measuring position and ...


20220914: Could the Higgs Boson Lead Us to Dark Matter?
 09:19: ... if we just looked at the total momentum, there’d be a lot of uncertainty due to the fact that there’s variation in the speed of the colliding ...


20220601: What If Physics IS NOT Describing Reality?
 02:44: ... components also have weird properties like fundamental uncertainty in their values and strange correlations between ...
 04:05: ... like quantum indeterminacy, entanglement, and the uncertainty principle turn out to be the expected behaviors of this sort of ...
 08:49: ... to some other staples of quantum theory  like the Heisenberg uncertainty principle. In a previous episode we saw how the ...
 09:26: ... tools of information theory we can derive an even tighter uncertainty relation  something known as entropic uncertainty. ...
 10:02: ... by a team of physicists in 2014. They applied entropic uncertainty to analyze Wheeler’s “delayedchoice” experiment. This ...
 10:33: ... the notion of entropic uncertainty to the situation, the team said that the wavefunction ...


20220420: Does the Universe Create Itself?
 05:56: ... But remember I said that the quantum world appears to live in a state of uncertainty until it’s ...


20220216: Is The Wave Function The Building Block of Reality?
 13:19: ... Ben Dimock who’s supporting us at the Big Bang Level. Ben there are many uncertainties in the world of physics. Is the wave function objectively real? Or is it ...


20211210: 2021 End of Year AMA!
 00:02: ... perfectly defined momentum and as we know from the heisenberg uncertainty principle if a particle has perfectly defined position perfectly ...


20211013: New Results in Quantum Tunneling vs. The Speed of Light
 02:31: The key to the escape is quantum uncertainty.


20210818: How Vacuum Decay Would Destroy The Universe
 04:42: ... Heisenberg uncertainty principle tells us that there’s a fundamental ...


20210707: Electrons DO NOT Spin
 10:51: And by Heisenberg's uncertainty principle increasing your knowledge of one, means increasing the unknowability of the other.


20210623: How Quantum Entanglement Creates Entropy
 17:55: ... Heisenberg microscope to measure position, I said that the uncertainty in the final momentum of the particle is roughly equal to ...


20210616: Can Space Be Infinitely Divided?
 03:14: ... you know the speed of light. But that distance measure has an uncertainty because you can only clock the instant of the return ...
 03:47: ... how the momentum transfer will happen, you’ll always have an uncertainty in the particle’s final momentum that’s roughly equal ...
 04:30: ... momentum of the measured object, and replace wavelength with uncertainty in its position. Rearrange and voila, Heisenberg. Or close ...
 04:49: ... experiment the Heisenberg microscope. We now know that the uncertainty principle is far more fundamental than just the effect of ...
 05:08: ... point I want to focus on today is that through the uncertainty principle we see that the Planck constant represents the ...
 06:02: ... field changes the distance to the object, adding a new uncertainty to the ...
 06:39: ... one last dip into the math to see how big this uncertainty is. Space is stretched by a factor equal to the effective ...
 07:10: ... reducing its wavelength also reduces the regular Heisenberg uncertainty, but at the same time this new uncertainty increases. You’re ...
 08:37: ... that volume down as much as possible. But the Heisenberg uncertainty principle says that when we do that we increase the ...
 11:26: ... at least for any intuitive conception of space. Quantum uncertainty thwarts our attempt to understand the universe by simply splitting ...


20210525: What If (Tiny) Black Holes Are Everywhere?
 11:17: ... not aliens yet, and then the one on how to mess with the limits of the uncertainty principle in detecting gravitational ...
 13:36: ... onto the episode where we looked at how the Heisenberg uncertainty principle can be gamed to improve measurements  in particular in ...
 15:08: ... of you criticized our title from last week  we called it “Breaking the Uncertainty Principle”, but you rightly  if pedantically  pointed out that it ...


20210519: Breaking The Heisenberg Uncertainty Principle
 00:07: And in some cases succeeding, by squeezing the Heisenberg uncertainty principle to its breaking point.
 00:47: ... against the absolute quantum limit  the limit defined by the Heisenberg Uncertainty ...
 01:05: Today we’re going to see how the uncertainty principle can be hacked to make measurements more precisely than should ever be possible.
 01:13: ... Heisenberg uncertainty principle tells us that there exists a fundamental unknowability to ...
 01:41: ... we call these pairs of properties complementary variables, and the uncertainty principle tells us that the uncertainties in our knowledge of such a ...
 01:58: Werner Heisenberg discovered the uncertainty principle when he was inventing his version of quantum mechanics back in the 1920s.
 02:05: That version is called matrix mechanics, but we get the same uncertainty principle using the wave mechanics of Schrodinger.
 02:13: ... to think about it  so to get an idea of the fundamental source of the uncertainty principle, you can watch our episode on how it comes about from thinking ...
 02:37: ... give the particle a momentum kick, which would account for a greater uncertainty in its momentum after the ...
 02:47: ... photon, which would kick the object even harder, causing an even greater uncertainty in the ...
 02:56: Basically, he thought the uncertainty principle arose as a result of the measurement disturbing the system.
 03:13: He thought the uncertainty principle was hinting at a far more fundamental law of the universe.
 04:10: The Heisenberg uncertainty principle prevents us from being able to know everything about a quantum state all at once.
 04:23: Remember, the uncertainty principle places a lower limit on the product of the uncertainties of pairs of complementary properties.
 04:40: That’s not as easy as it sounds  normal quantum states tend to share the uncertainty between complementary partners fairly evenly.
 04:47: ... that enable us to manipulate quantum states to push the limits of the uncertainty ...
 06:21: And this is where the uncertainty principle comes in.
 06:24: Because there’s always an inherent uncertainty in any quantity, the phases of the two beams never really perfectly match up.
 06:53: Unless we can hack the uncertainty principle.
 07:07: To improve our ability to detect faint gravitational waves we need to reduce the uncertainty in the phase of the laser beams.
 07:20: But we don’t care so much about uncertainty in the amplitude.
 07:25: ... light from a laser beam obeys the Heisenberg uncertainty principle in a very specific way—it has equal amounts of uncertainty in ...
 07:35: ... area of the circle is proportional to Planck’s constant, satisfying the uncertainty ...
 07:55: By playing quantum tricks on the light, we can squeeze the uncertainty in one direction at the cost of greater uncertainty in the other.
 08:03: ... phase space, this amounts to a shrinking of the uncertainty in one dimension, and a corresponding stretching in the opposite ...
 08:16: Light in which uncertainty has been manipulated in this way is called squeezed light.
 08:22: In the case of LIGO, the phase of the light is squeezed  its precision increased  at the expense of increased uncertainty in amplitude.
 09:26: ... always a price  you pay for the improved phase precision with more uncertainty in the number of photons traveling in your laser ...
 09:43: But that noise is less of a problem than the phase uncertainty, at least for the higher frequency gravitational waves.
 09:50: There is always a price, but the price is worth it if you invest your uncertainty in the right place.
 10:17: ... willing to bend a few fundamental laws  in this case, the Heisenberg uncertainty principle  we can push the limit beyond what we thought possible to ...


20210421: The NEW Warp Drive Possibilities
 17:32: ... but now But now I see it’s an ancient viking metaphor for the Heisenberg uncertainty ...


20210316: The NEW Crisis in Cosmology
 04:42: ... not worry about the weird units right now. But they also claim an uncertainty of about half a percent, making it the most ...
 10:40: ... far we’ve only done this with a small number of lenses and so the uncertainty is large  but published results give a Hubble constant in the low ...


20210224: Does Time Cause Gravity?
 07:11: ... occupies only a single, perfectly defined position in space  quantum uncertainty means that everything is always at multiple places at once, and so ...


20201215: The Supernova At The End of Time
 08:14: Suddenly it’ll find itself one row over  teleported due to fundamental quantum uncertainty in its position.


20201111: Can Free Will be Saved in a Deterministic Universe?
 08:05: ... is a direct consequence of the Heisenberg uncertainty principle, which tells us that measuring one property perfectly leaves a ...


20201104: Electroweak Theory and the Origin of the Fundamental Forces
 03:48: ... with massive force carriers is usually attributed to the energytime uncertainty relation, and we’ve presented it that way ...


20201020: Is The Future Predetermined By Quantum Mechanics?
 04:15: At least as far as the Heisenberg Uncertainty Principle allows.


20200527: Does Gravity Require Extra Dimensions?
 09:34: The meticulous care paid off—Cavendish measured a gravitational constant that agrees with our modern value, with 1% uncertainty.


20200422: Will Wormholes Allow Fast Interstellar Travel?
 12:51: ... of spacetime may fluctuate wildly, its form shifting due to Heisenberg’s uncertainty principle. The result is what we call the spacetime foam, and it may ...


20200106: How To Detect a Neutrino
 04:46: ... sort of cheats energy conservation by taking advantage of the Heisenberg uncertainty principle, ♪ ♪ which tells us that there's a fundamental uncertainty ♪ ♪ ...


20191217: Do Black Holes Create New Universes?
 10:33: Now perhaps the extra .17 can be factored into the uncertainties of the theory...


20191202: Is The Universe Finite?
 04:46: ... was consistent with being zero  flat  but there’s always a degree of uncertainty due to the imperfect nature of any ...
 09:19: ... universe would look like a positively curved universe just due to random uncertainties. ...


20191015: Loop Quantum Gravity Explained
 03:54: Certain properties have an inbuilt uncertainty and only take concrete values after measurement.


20191007: Black Hole Harmonics
 10:29: They do – at least within the uncertainties of the experiment.


20190806: What Caused the Big Bang?
 08:29: ... to randomly fluctuate to different values, thanks to the Heisenberg uncertainty ...


20190509: Why Quantum Computing Requires Quantum Cryptography
 04:21: Each highlights a different fundamental weirdness of quantum mechanics – the Heisenberg uncertainty principle and quantum entanglement.
 04:38: ... uncertainty principle tells us that we cannot simultaneously know the values of ...
 06:37: You just switched between different quantum representations of reality and then back again, and so invoked the uncertainty principle.


20190306: The Impossibility of Perpetual Motion Machines
 06:55: Due to the intrinsic quantum randomness of all particles, as expressed by the Heisenberg uncertainty principle, everything moves.


20190124: The Crisis in Cosmology
 03:42: But this calculation involves assumptions and uncertainties.
 04:07: With each step on the ladder, uncertainties compound.
 04:10: Add this to our uncertainties in the behavior and observation of Cepheids themselves,...
 05:51: ...kilometers per second per megaparsec That 2%ish uncertainty...
 05:55: ...is a hell of a lot better than the old factor of 2 uncertainty.
 10:53: First: there are unknown systematic sources of uncertainty...
 12:44: Perhaps the uncertainties will be refined, and the two results will converge.


20181107: Why String Theory is Right
 06:05: ... into wave equations with various quantum weirdness added in like the uncertainty relation between certain ...


20181031: Are Virtual Particles A New Layer of Reality?
 07:29: The Heisenberg uncertainty principle tells us that the perfectly defined momenta of virtual particles means completely undefined position.
 09:20: ... mechanics, nothing can be so exact thanks, again, to the Heisenberg uncertainty ...
 10:21: Regarding its particle content, it remains in a steady state of uncertainty.


20180920: Quantum Gravity and the Hardest Problem in Physics
 05:50: The Heisenberg uncertainty principle tells us the minimum energy of our beam for a given precision.
 06:28: Steady viewers will remember that the uncertainty principle talks about the tradeoff between position and momentum.
 06:37: The uncertainty principle also defines the precision tradeoff between time and energy.
 06:54: For those of you who already watched our episode on the Heisenberg uncertainty principle, here's another way to think about this.


20180823: How Will the Universe End?
 16:09: In practice, the Heisenberg uncertainty principle makes this impossible.


20180815: Quantum Theory's Most Incredible Prediction
 10:54: Electron spin axes are always slightly misaligned with an external magnetic field, due to quantum uncertainty in the spin direction.


20180725: Reversing Entropy with Maxwell's Demon
 10:01: In a sense, it's a measure of the uncertainty of the event.
 10:16: There are more potential outcomes in the former, so more uncertainty has been eliminated when the die is cast.


20180523: Why Quantum Information is Never Destroyed
 07:58: But all of this talk of quantum mechanics being deterministic seems a bit at odds with the idea of quantum randomness and the uncertainty principle.
 08:18: And the precision of the knowability of that value is defined by the uncertainty principle.


20180328: The AndromedaMilky Way Collision
 04:51: Even taking uncertainties into account, Andromeda is racing towards us much faster than it's moving to the side.


20180315: Hawking Radiation
 03:14: They fluctuate in energy due to quantum uncertainty.
 09:00: And they tell us that there is an enormous quantum uncertainty in the location of these particles.
 10:29: The common thread is quantum uncertainty.
 10:32: ... example, uncertainty in position or momentum can lead to particle pairs that we'll want in ...
 10:43: Alternatively, uncertainty in energy can lead to particle creation.


20180110: What Do Stars Sound Like?
 05:05: We've spoken in depth about Fourier analysis in a recent episode on understanding the uncertainty principle, so I won't go to too much detail here.


20171213: The Origin of 'Oumuamua, Our First Interstellar Visitor
 10:36: Well we generalize frequency as momentum because the Heisenberg uncertainty principle applies to momentum in general.
 10:42: In the case of matter, uncertainty in momentum can manifest in both velocity and mass.
 10:50: So that uncertainty is all in their frequency.
 11:03: ... in the location of the photon passing through the slit, we increase the uncertainty in its momentum and hence, its direction of motion after it exits the ...


20171206: Understanding the Uncertainty Principle with Quantum Fourier Series
 00:16: ... wave is going to open the door to really understanding Heisenberg's uncertainty principle, and ultimately, quantum fields and Hawking ...
 00:28: [MUSIC PLAYING] One of the most difficult ideas to swallow in quantum mechanics is Werner Heisenberg's famous uncertainty principle.
 00:49: See, the apparent weirdness of the uncertainty principle hints at an even weirder underlying reality that gives rise to it.
 01:31: But as you'll see today, in that unraveling, we are led unavoidably to Heisenberg's uncertainty principle.
 01:40: The uncertainty principle is most often expressed in terms of position and momentum.
 01:51: Try to perfectly nail down a particle's position, and we have complete uncertainty about its momentum.
 02:06: The uncertainty principle exists alongside this observer effect.
 02:16: To understand the origin of the uncertainty principle, we don't need to know any quantum mechanics, at least not to start with.
 02:29: However, it turns out that something like the uncertainty principle arises in any wave mechanics.
 05:41: That sounds an awful lot like a frequencytime uncertainty principle for sound waves.
 05:47: ... about the fundamental knowability of a sound wave, as is Heisenberg's uncertainty principle, it's more a statement about the sampling of frequencies ...
 07:41: And of course, this means that position and momentum have the same kind of uncertainty relation that time and frequency had in the sound wave.
 09:22: ... the position of a particle by narrowing the slit, we also increase the uncertainty of its momentum as it passes the ...
 09:40: So that's exactly the uncertainty principle.
 10:06: Precision in one is actually constructed by the uncertainty in the other.
 10:45: The uncertainty principle, therefore, tells us that they must be completely unconstrained in position.
 11:59: ... series, "Quantum Mechanics," which includes a great episode on the uncertainty ...


20171102: The Vacuum Catastrophe
 00:44: We saw in our recent episode that we can thank the Heisenberg uncertainty principle for this bizarre behavior.
 01:55: ... satisfy the Heisenberg uncertainty principle, the vacuum state of any fuel oscillation must be half of the ...


20171025: The Missing Mass Mystery
 12:09: The energy is borrowed from the energy of the vacuum for the minuscule time allowed by the uncertainty principle.


20171019: The Nature of Nothing
 01:09: ... perfectly defined, and this is impossible according to the Heisenberg uncertainty ...
 03:34: But here we run up against that pesky Heisenberg's uncertainty principle once again.
 05:33: But the ultimate price is that virtual particles can exist only for the instant allowed by the Heisenberg uncertainty principle.


20171011: Absolute Cold
 05:04: The Heisenberg Uncertainty Principle tells us that there is an absolute limit in the knowability of particular combinations of properties.
 06:21: For example, the quantum fields that fill our universe also fluctuate due to the Uncertainty Principle resulting in what we know as vacuum energy.
 07:24: For example, Brian Greene's Exploring Quantum History delves much more deeply into the Heisenberg Uncertainty Principle.


20170707: Feynman's Infinite Quantum Paths
 00:36: The Heisenberg uncertainty principle tells us that the more precisely we try to define one property, the less definable is its counterpart.


20161208: What Happens at the Event Horizon?
 15:42: This uncertainty leads to the range of potential future trajectories, including trajectories through one slit or the other.
 15:51: More generally, it allows pilot wave theory to agree with Heisenberg's uncertainty principle.
 15:57: In the Copenhagen interpretation, the uncertainty principle describes the intrinsic randomness of the quantum world.
 16:05: ... BroglieBohm pilot wave theory states that this uncertainty just arises from our imperfect knowledge and that the universe itself ...


20161109: Did Dark Energy Just Disappear?
 04:32: ... repeated this experiment many, many times, about 0.27% of the time the uncertainties, so the messiness in the data, would cause a universe with no dark energy ...


20160921: Quantum Entanglement and the Great BohrEinstein Debate
 03:30: And yet we refrain from measuring these properties to preserve quantum uncertainty.


20160629: Nuclear Physics Challenge
 00:31: One consequence of this uncertainty in position is the phenomenon of quantum tunneling.


20160622: Planck's Constant and The Origin of Quantum Mechanics
 01:14: As your distance to the tortoise becomes unthinkably small, there arises a quantum uncertainty in your location.
 01:35: ... and more formally, the Heisenberg uncertainty principle, describes the smallest distance for which an object's ...
 02:12: ... Heisenberg uncertainty principle and the de Broglie wavelength, but also the Schrodinger ...


20160601: Is Quantum Tunneling Faster than Light?
 01:19: For now, let's just look at the strange consequences of quantum uncertainty in an object's location.
 08:26: That uncertainty in location allows tunneling.
 08:30: But even without a barrier, this location fuzziness leads to uncertainty in the arrival time of the photon.
 08:59: This can look like an increase in the speed of light, but only within the uncertainty range defined by the de Broglie wavelength.
 09:07: ... accurately, it's within the uncertainty range defined by the Heisenberg uncertainty principle, which is perhaps ...
 09:28: But in the quantum realm, Heisenberg uncertainty does seem to allow instantaneous motion, and even perhaps causality violation within quantum limits.


20160224: Why the Big Bang Definitely Happened
 09:28: A theory may still have parts that aren't so well established, but such uncertainties don't invalidate the overall picture.


20151209: How to Build a Black Hole
 03:15: ... of quantum theory, the Pauli exclusion principle and the Heisenberg uncertainty ...
 05:10: The Heisenberg uncertainty principle tells us that the properties of a quantum entity are fundamentally uncertain.
 06:04: ... Heisenberg uncertainty principle tells us that particular pairs of quantities, position and ...
 06:32: Therefore, the Heisenberg uncertainty principle tells us that they must have highly undefined momenta.


20151118: 5 Ways to Stop a Killer Asteroid
 06:26: The real trick is getting politicians to agree to something that involves scientific uncertainty and long term thinking.


20150930: What Happens At The Edge Of The Universe?
 06:21: It's very possible that the universe has curvature just inside the uncertainty range of the best measurements to date.


20150506: Should the First Mars Mission Be All Women?
 01:45: ... vision is a pretty critical faculty on a Mars mission, and given the uncertainty about underlying causes, this might be a major checkmark in the proall ...
