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2022-12-08: How Are Quasiparticles Different From Particles?

  • 06:01: In this case, the crystal lattice can vibrate at any frequency, but the amount of energy at each vibrational mode can only go up in discrete chunks.
  • 06:47: They have energy equal to the planck constant times their frequency.

2022-11-09: What If Humanity Is Among The First Spacefaring Civilizations?

  • 18:50: ... field theory, with the time-reversed signals corresponding to negative frequency ...

2022-08-24: What Makes The Strong Force Strong?

  • 18:36: Those fields have positive and negative frequency modes that cancel each other out to leave a vacuum.

2022-08-03: What Happens Inside a Proton?

  • 13:36: ... has accurately predicted many things,   from masses and decay frequencies of hadrons to the exotic properties of quark-gluon ...

2022-06-22: Is Interstellar Travel Impossible?

  • 19:30: Hawking’s original argument talked about perturbing the positive and negative frequency modes of the quantum vacuum.

2022-03-23: Where Is The Center of The Universe?

  • 18:31: ... signals that were not clearly associated with stars and had radio frequency spacing similar to Earthly ...

2021-12-29: How to Find ALIEN Dyson Spheres

  • 05:40: So yeah, we could go flicking through the frequency channels of gas clouds looking for alien TV shows.

2021-12-20: What Happens If A Black Hole Hits Earth?

  • 00:29: ... to pass through our solar system - and even the planet - with startling frequency. In fact it may have already ...

2021-09-15: Neutron Stars: The Most Extreme Objects in the Universe

  • 10:06: ... big splash and a crash, it’s a continuous   hum at exactly one frequency- twice the  frequency of the neutron star’s rotation-   ...
  • 11:29: ... dissipation of these vortices is seen by us as glitches in the frequency in the flashes of pulsars.   The rare cooper-pair protons on ...

2021-08-10: How to Communicate Across the Quantum Multiverse

  • 00:23: ... that move independently of each other, in exactly the combination of frequencies and amplitudes to encode me talking about ...

2021-06-16: Can Space Be Infinitely Divided?

  • 01:16: ... the  chunkiness of thermal radiation.   Multiply the frequency of the light by this  number and you get the energy of a single ...

2021-05-19: Breaking The Heisenberg Uncertainty Principle

  • 09:43: But that noise is less of a problem than the phase uncertainty, at least for the higher frequency gravitational waves.

2021-05-11: How To Know If It's Aliens

  • 10:35: ... of radio emission appeared at 982.002 MHz and then drifted upwards in frequency over a 3 hour observation. This weird signal was only spotted over a ...
  • 11:24: ... published its findings so we can’t say much - we know the increase in frequency is consistent with the Doppler shift of something accelerating towards ...

2021-04-07: Why the Muon g-2 Results Are So Exciting!

  • 09:57: We call this Larmor precession, and its frequency depends on the g-factor.
  • 10:02: The frequency of the precession also governs the energy of the particles that these muons decay into.

2021-03-23: Zeno's Paradox & The Quantum Zeno Effect

  • 06:18: Next they flash the atoms with a laser whose frequency matches the energy difference between state 1 and a new state, state 3.
  • 15:16: But the important thing is that the amplitude of the wave is directly encoded in the frequency of the wave.
  • 15:21: ... black holes spiral towards each other, the frequency of the last phase of the inspiral is pretty uniquely determined by the ...
  • 15:38: So, measuring the inspiral frequency gets you the power - which you can think of the amplitude before it fades over distance.

2021-03-09: How Does Gravity Affect Light?

  • 03:18: Wavelength increases, which means frequency and energy drop.
  • 04:10: These are the ticks of a clock, and the frequency dictates the frequency and the wavelength of the photon produced by that motion.
  • 04:18: But from a great distance away, those clocks run slow, and so the frequency of light emerging from within a gravitational field is lower.
  • 04:37: ... hole, gravitational time dilation is so strong that clocks stop and the frequency of photons trying to escape is brought to ...
  • 06:00: ... for the prediction - the difference in the flow of time changes the frequency of outgoing ...

2021-02-17: Gravitational Wave Background Discovered?

  • 00:00: ... has a fundamental limit it can only see those gravitational waves with frequencies around 1 to ten thousand hertz corresponding to relatively compact waves ...

2021-01-12: What Happens During a Quantum Jump?

  • 01:56: ... attempt at a quantum theory, and it very neatly explained the specific frequencies of light observed in emission spectra of hydrogen - although it failed ...
  • 06:28: ... atom - in this case mercury or barium - is bathed in a laser beam with a frequency exactly tuned to the energy difference between two of its electron ...
  • 07:37: Now flash a second laser with frequency tuned to take the electron from level 1 to level 3.

2020-10-05: Venus May Have Life!

  • 12:15: The discovery of alien life in our nearest planetary neighbor would totally change our calculations about the frequency of life in the universe.

2020-09-21: Could Life Evolve Inside Stars?

  • 14:01: ... periodic function can be represented as a sum of sine waves of different frequencies. ...

2020-09-01: How Do We Know What Stars Are Made Of?

  • 03:06: ... colors - or in other words, from photons of different energies of frequencies. ...

2020-07-08: Does Antimatter Explain Why There's Something Rather Than Nothing?

  • 09:19: ... properties in anti-matter versus matter will cause a shift in the laser frequency necessary to stimulate a transition in the atoms. Scientists measure ...

2020-06-22: Building Black Holes in a Lab

  • 06:33: ... in these analog black holes. Or at least, the perturbations in the frequencies of the surface ripples have properties that are closely analogous to ...

2020-06-15: What Happens After the Universe Ends?

  • 14:49: ... patreon supporters will have their names encoded in the orbital frequencies of colliding suppermassive black holes at the end of time to be ...

2020-06-08: Can Viruses Travel Between Planets?

  • 04:43: ... an alien world passes in front of its home star, we can see signatures frequencies plucked from the starlight due to it passing through that planet’s ...

2020-02-24: How Decoherence Splits The Quantum Multiverse

  • 03:11: ... wave mechanics, we say that a set of waves are coherent if they match in frequency and if the shape of the waves are the same, and if there’s a constant ...

2020-01-27: Hacking the Nature of Reality

  • 00:43: ... depend only on observable quantities - in this case, the mysterious frequencies of light produced as electrons jump between ...
  • 15:01: ... causes the black holes to merge faster, so that should increase the frequency of the those waves and to a lesser extend the actual shape of the ...

2019-10-07: Black Hole Harmonics

  • 02:43: When struck, a bell vibrates with many different frequencies – many overlapping harmonics.
  • 02:56: A “struck” black hole also vibrates with many different harmonic frequencies.
  • 03:12: In the latter cases we can describe a vibrating string as a series of standing sine waves of different frequencies, all happening at the same time.
  • 03:22: ... lowest frequency the string can support is called the fundamental mode – it’s usually the ...
  • 03:34: Higher frequency modes are called overtones, and they provide richness and texture to the sound.
  • 03:40: The full set of possible frequencies a string can support are called its harmonics.
  • 04:05: ... a single, pure oscillation on that spherical surface with a set frequency. ...
  • 07:35: In astronomy, the analysis of the different frequencies of light is called spectroscopy.
  • 07:41: So this sort of frequency analysis of gravitational waves is being called gravitational wave spectroscopy.
  • 10:19: ... researchers test the no-hair theorem by checking whether the frequency of oscillations and the time for the decay of those oscillations agrees ...

2019-03-06: The Impossibility of Perpetual Motion Machines

  • 14:04: We know where the sources of this emission are from observations at other frequencies and can do pretty well modeling and subtracting them.

2019-02-07: Sound Waves from the Beginning of Time

  • 05:26: ... free electrons were able to interact with any frequency of light, electrons bound into atoms are restricted to only those ...

2018-12-20: Why String Theory is Wrong

  • 08:17: These strings are vibrating with standing waves like guitar strings, and their energy also depends on the frequency of that vibration.
  • 08:25: That frequency depends on the density of wave cycles on the string.
  • 08:30: ... have a large mode number with a small radius and that gives you a high frequency ...

2018-12-06: Did Life on Earth Come from Space?

  • 00:37: ... may be able to hibernate that long but at this point the issue is just frequency of impacts is it at all likely that a microbe bearing rock from another ...

2018-11-14: Supersymmetric Particle Found?

  • 06:37: ... in the ice anywhere within 700 kilometers of ANITA, the resulting radio frequency Cherenkov can be seen by ANITA'S ...

2018-10-25: Will We Ever Find Alien Life?

  • 07:23: ... of these stars that form habitable worlds, biological factors like the frequency of the appearance of simple life and the proportion of those that lead ...

2018-10-18: What are the Strings in String Theory?

  • 06:12: All other frequencies tend to die out.
  • 06:14: The result is that for a given string, only certain frequencies corresponding to certain energies are possible.
  • 06:22: These resonant frequencies depend on the length of the string, also its tension, which defines wave velocity and so relates frequency to wavelength.
  • 06:31: For example, this leads to the specific frequencies of vibration on a guitar string.

2018-10-03: How to Detect Extra Dimensions

  • 10:20: ... of the merger event-- namely, the masses of the merging objects and the frequency of the wave combined with our independent distance ...

2018-09-20: Quantum Gravity and the Hardest Problem in Physics

  • 07:01: ... from a wide range of momentum wave functions that include extremely high frequencies or extremely high momenta, i.e., the more certain its position, the less ...

2018-04-18: Using Stars to See Gravitational Waves

  • 03:28: But with its four kilometer arm length, it's only sensitive to a frequency range from around 1 hertz to 10 kilohertz.
  • 03:35: ... roughly corresponds to the frequency of the binary orbits just before merger, which for black holes and ...
  • 03:47: The more massive the binary, the lower the frequency.
  • 07:32: Stars oscillate at particular frequencies.
  • 07:38: If a gravitation wave frequency matches the natural resonant frequency of a star, oscillations can be set up inside the star.

2018-04-04: The Unruh Effect

  • 06:00: And just as with Hawking radiation, that horizon cuts off your access to certain fundamental frequency modes of the quantum vacuum.
  • 06:20: ... here they also lead to a mixing of positive and negative frequency modes in the accelerating frame of reference, which leads to the ...

2018-03-15: Hawking Radiation

  • 02:55: They can oscillate with different frequencies, much like the many possible vibrational modes on a guitar string.
  • 03:32: One way that quantum fields are very different to guitar strings is they can have both positive and negative frequencies.
  • 03:39: A negative frequency can be thought of as a mode that travels backwards in time and can be interpreted as corresponding to antimatter.
  • 03:51: ... is in a vacuum state, there's a balance between positive and negative frequency modes, which you can crudely think of as a balance between virtual ...
  • 06:30: They describe a sort of mixing of the positive and negative frequency vibrational modes that are caused by that curved space.
  • 07:39: Hawking calculated the frequency distribution of this radiation and found something incredible.
  • 08:13: So Hawking's math describes splitting or mixing of these pure positive and negative frequency modes.
  • 10:05: We can think about positive and negative frequency modes being mixed due to scattering, perhaps, by the as yet undiscovered graviton.

2018-01-17: Horizon Radiation

  • 05:28: Sound waves can be described in terms of variation over time or variation over frequency.
  • 07:21: ... with an infinite drumstick, adding global vibrations with different frequencies that cancel out everywhere except that one ...
  • 13:32: The frequency spectra for resonant oscillations of several stars were shifted to a range audible to human hearing.

2018-01-10: What Do Stars Sound Like?

  • 01:33: ... the stellar interior, setting up global oscillations, natural resonant frequencies that carry information about stars impenetrable ...
  • 04:08: The distribution of the pattern depends on the frequency or the mode, much like on the skin of a drum.

2017-12-13: The Origin of 'Oumuamua, Our First Interstellar Visitor

  • 04:57: PZ 17 performed computer simulations to find the frequency of such kicks sending objects close to the earth at such high speeds.
  • 10:30: How can a photon's frequency be generalized as momentum?
  • 10:33: Does frequency then include information about direction of motion?
  • 10:36: Well we generalize frequency as momentum because the Heisenberg uncertainty principle applies to momentum in general.
  • 10:50: So that uncertainty is all in their frequency.
  • 10:53: And yes, also in their direction of motion, which is separate to frequency.

2017-12-06: Understanding the Uncertainty Principle with Quantum Fourier Series

  • 02:55: The sound wave for a simple pure tone, like a middle C, is a sinusoidal wave, with the frequency determining the pitch of the tone.
  • 03:03: ... be broken down into a combination of many simple sine waves of different frequencies. ...
  • 03:23: ... sound wave can be decomposed into a number of sine waves of different frequencies, each with a different strength, stacked on top of each other or ...
  • 03:36: ... intensity changing with time, you can also represent it in terms of its frequency components, each with its own weighting or ...
  • 03:48: When you switch between a time and a frequency representation, you're doing a Fourier transform.
  • 03:55: In fact, digital audio equipment stores, manipulates, and transmits sound in its frequency representation.
  • 04:02: In the physics of sound, time and frequency have a special relationship because any sound wave can be represented in terms of one or the other.
  • 04:18: So we can make any shape sound wave with a series of sine waves of different frequencies.
  • 04:24: ... example, you can build a wave packet by adding frequency components with the right phases to destructively interfere everywhere ...
  • 04:35: The tighter you want to make that time window for the wave packet, the more frequency components you need to use.
  • 04:41: ... those steep edges of the wave packet, you need to add higher and higher frequencies, because the high frequency components are the ones that give you rapid ...
  • 05:12: ... a spike at one point in time, you need to use infinitely many different frequency sine waves, each of which exists at all points in ...
  • 05:22: So then if we make a sound that is perfectly located in time, it doesn't have a frequency, or it has all frequencies.
  • 05:30: ... the same time, a sound wave with a perfectly known frequency is a simple traveling sine wave that extends infinitely in time so the ...
  • 05:41: That sounds an awful lot like a frequency-time uncertainty principle for sound waves.
  • 05:47: ... uncertainty principle, it's more a statement about the sampling of frequencies needed to produce a given wave ...
  • 06:15: Like the sound wave, it oscillates through space at a particular frequency.
  • 06:39: The second of this pair is momentum, not frequency.
  • 06:43: See, momentum is sort of the generalization of frequency for what we call a matter wave.
  • 06:49: In the early days of quantum mechanics, it was realized that photons are electromagnetic wave packets whose momentum is given by their frequency.
  • 06:58: ... and his De Broglie relation generalizes the relationship between frequency and momentum of a matter ...
  • 07:08: ... just as a traveling sound wave can be expressed in terms of time or frequency. ...
  • 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.

2017-11-29: Citizen Science + Zero-Point Challenge Answer

  • 06:57: ... from assuming that there are no virtual photons above a certain cut of frequency. ...
  • 07:06: ... you choose that to be the frequency corresponding to a photon with the Planck energy, you get a vacuum ...
  • 07:18: In this theoretical estimate, vacuum energy density is proportional to the fourth power of cutoff frequency.
  • 07:25: So my question was what cutoff frequency is needed for this theoretical estimate to give you the energy density implied by dark energy?
  • 07:49: The frequency of a photon with the Planck energy is the Planck energy divided by the Planck constant, or an insane 3 by 10 to the power of 42 hertz.
  • 07:59: And if vacuum energy is proportional to the fourth power of cutoff frequency, then this equation gives the relationship we need.
  • 08:07: There are a bunch of constants in the cutoff frequency vacuum energy relation, but they cancel out.
  • 08:17: So we get a cutoff frequency for dark energy of 3 by 10 to the power of 12 hertz.
  • 08:32: ... the simplistic approach of choosing the right maximum virtual photon frequency definitely can't give us the vacuum energy that we see as dark ...

2017-11-08: Zero-Point Energy Demystified

  • 04:31: By cutting off certain frequency modes between the plates, you lower the vacuum energy in that region.
  • 08:35: ... field is estimated by integrating the energy in all possible frequency modes up to some cutoff ...
  • 08:48: You get that the vacuum energy density is proportional to the fourth power of that cutoff frequency.
  • 09:00: What cutoff frequency is needed for this theoretical estimate to give the energy density implied by dark energy.
  • 09:09: And is this a possible maximum virtual photon frequency, given the results of Casimir experiments?

2017-11-02: The Vacuum Catastrophe

  • 01:55: ... any fuel oscillation must be half of the tiny Planck constant times the frequency of that ...
  • 02:09: ... except to properly describe a perfect vacuum, every single possible frequency mode at every point in space must have that amount of ...
  • 02:23: To calculate the density of energy of the vacuum, we should add this tiny energy over an infinite range of frequency modes for all fields.
  • 02:55: What if there's a maximum possible frequency for virtual photons?
  • 02:59: Then our sum of frequency modes would be finite.
  • 03:07: And anyway, there's an almost sensible cutoff for photon frequency.

2017-10-19: The Nature of Nothing

  • 08:51: ... string of a particular length only resonates with waves of certain frequencies, any non-resonant virtual photon would be excluded, reducing the vacuum ...
  • 09:05: However, on the outer surface of the plates, all frequencies of virtual photon are allowed.

2017-10-04: When Quasars Collide STJC

  • 04:36: Here's the radio map at 15 gigahertz frequency.
  • 06:02: Well, the researchers tested this by looking at multiple frequencies to get a crude radio spectrum.
  • 06:14: Spiraling electrons produce radio waves a lots of frequencies all the way down to very low energies.
  • 09:01: And while those waves may be powerful, they have an incredibly low frequency-- something like 1 ten trillionth of a hertz.

2017-09-28: Are the Fundamental Constants Changing?

  • 02:41: And the second is defined in terms of a particular frequency of light emitted by the cesium-133 atom.

2017-09-13: Neutron Stars Collide in New LIGO Signal?

  • 05:33: LIGO is sensitive to a specific frequency range.
  • 05:37: ... before merger, while neutron stars ring at audible gravitational wave frequencies for at least several ...

2017-06-28: The First Quantum Field Theory

  • 02:03: Anyone who's ever strummed or shredded knows that a stretched string vibrates with a certain frequency when plucked.
  • 02:17: A larger amplitude and/or larger frequency means the vibration carries more energy.
  • 03:47: If this were a quantum mechanical guitar string, then there'd be a minimum amplitude for the vibration that depended on its frequency.

2017-03-29: How Time Becomes Space Inside a Black Hole

  • 12:36: Firstly yeah, these time crystals oscillate at an integer multiple of the electromagnetic field frequency.
  • 13:38: That would be special and weird, even if the original period was defined by an external EM field frequency.

2017-03-15: Time Crystals!

  • 04:36: A laser is just a very well-ordered electromagnetic wave with a known period or frequency.
  • 05:09: ... means they should resist a change in the frequency of the input laser, or continue oscillating at least for a while if the ...

2017-02-02: The Geometry of Causality

  • 13:30: ... energetic electron transition that produces X-rays at a very particular frequency, the ion K-alpha emission ...

2017-01-11: The EM Drive: Fact or Fantasy?

  • 13:16: Since the 1960s, our own radio leakiness has diminished, with narrowing broadcast frequency bands, fiberoptics, etc.
  • 13:42: In that case, radio is still the way to go, and it's worthwhile for us to search at radio frequencies.

2016-12-21: Have They Seen Us?

  • 02:44: ... peered into the so-called water hole, a narrow frequency range in the radio spectrum between a pair of H and OH emission spikes, ...
  • 03:23: These searches often focused on the water hole or the surrounding quiet frequency window.
  • 05:07: ... is that a distant civilization's radio bubble is likely to overlap in frequency with our own ...
  • 05:24: At around 1500 megahertz, it's in the ultrahigh frequency (UHF) band.
  • 05:30: Most TV broadcasts air at the tens to hundreds of megahertz of the merely very-high frequency (VHF) band.
  • 07:40: That emission, produced at 21 centimeters wavelength, or 1420 megahertz frequency, is, by definition, one of the boundaries of the waterhole.
  • 07:58: That redshifted early hydrogen emission is now found slap in the middle of the noisy lower frequency part of our own TV broadcast spectrum.
  • 09:02: These emission spikes may also shift back and forth in frequency due to Doppler shift, as the distant technologically advanced planet orbits its star.
  • 10:31: ... out, that one month integration time requires a very consistent narrow frequency signal, which may not be consistent with typical ...
  • 11:56: It's pretty natural to want to scan the heavens at exactly the frequencies where we earthlings are the noisiest.

2016-07-27: The Quantum Experiment that Broke Reality

  • 12:32: Bike Jake would like me to talk more about resonant frequencies.
  • 12:35: My pleasure-- a resonant frequency is when two orbiting bodies have orbital periods that form a neat ratio of small integers.
  • 13:03: ... each other and that pull stops them from straying out of that resonant frequency. ...

2016-07-20: The Future of Gravitational Waves

  • 01:30: ... in the interferometer arm lengths that increased in both amplitude and frequency as the black holes approached before dying away again after the ...

2016-06-22: Planck's Constant and The Origin of Quantum Mechanics

  • 02:12: ... orbits, and importantly, the relationship between the energy and frequency of a ...
  • 03:30: And so the average frequency of the resulting particles of light, of photons, increases with temperature.
  • 03:37: This average frequency defines the color that we see.
  • 03:53: The blue super giant star Rigel is 12,000 Kelvin, and so it pumps out lots of high frequency blue light and even more ultraviolets.
  • 04:04: Your temperature is around 310 Kelvin, so your heat glow is mostly in low frequency infrared photons.
  • 04:30: ... the late 1800s, the distribution of brightnesses with frequency produced by hot objects had been mapped in careful experiments the ...
  • 05:28: This simple idea allowed our good Englishmen to figure out the frequencies of the photons produced by all of this thermal motion.
  • 05:41: For low frequency, infrared light.
  • 05:43: But for higher frequencies, like visible and ultraviolet, it predicted brightnesses that were way too high.
  • 05:51: Worse, it predicted that the intensity should eventually approach infinity as frequency increased.
  • 06:37: ... energy got packed into the countless very tiny energy states at high frequencies. ...
  • 07:38: He set this minimum energy to be the frequency of a particle's vibration times a very, very small number, a number that had yet to be measured.
  • 08:05: Because it limited how much energy those high frequency vibrations could hold.
  • 08:11: Planck's new equation described the shape of the blackbody spectrum exactly, across all frequencies of light.
  • 09:52: ... part particle, carrying a quantum of energy equal to the now familiar frequency of the wave times the Planck ...

2016-03-30: Pulsar Starquakes Make Fast Radio Bursts? + Challenge Winners!

  • 00:30: So an FRB is seen as a very quick flash of broad frequency radio emission from some spot on the sky.

2016-02-24: Why the Big Bang Definitely Happened

  • 10:09: That's actually the frequency of detectable mergers predicted by some astrophysical models.

2016-02-11: LIGO's First Detection of Gravitational Waves!

  • 02:57: ... are still distant from each other are far too weak, and have too low of frequency for LIGO to directly detect ...
  • 04:31: ... oscillations have a frequency, number of stretches and squeezes per second, that matches the rate at ...
  • 06:13: ... LIGO is sensitive to gravitational waves at frequencies produced by merging black holes and neutron stars, as well as the ...
  • 06:35: ... eLISA-- will see an entirely different part of this spectrum, much lower frequencies, opening the possibility to observe completely new ...

2015-10-28: Is The Alcubierre Warp Drive Possible?

  • 07:31: It'll be an orbiting gravitational wave observatory designed to detect much higher frequency gravitational waves than advanced LIGO.

2015-08-19: Do Events Inside Black Holes Happen?

  • 08:02: Because of time dilation, we would detect any laser pulse that the monkey sends with a lower frequency, i.e.
  • 08:10: ... is so severe that any light he emits gets redshifted to undetectably low frequencies. ...

2015-07-08: The Leap Second Explained

  • 01:58: ... the current frequency right now of leap seconds, that arises because of a preexisting ...

2015-06-17: How to Signal Aliens

  • 01:27: ... radio telescopes sending narrow pulses of high-powered microwaves at frequencies of 10 gigahertz or higher, sweeping the whole sky about once a year or ...

2015-05-13: 9 NASA Technologies Shaping YOUR Future

  • 04:16: ... funded some university researchers to experiment with targeted high frequency vibrations that trick bones into thinking they're carrying weight so ...
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