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

  • 07:21: You can think of sound as a coherent beam of phonons, like a laser, while heat is a random buzz of phonons.

2022-10-26: Why Did Quantum Entanglement Win the Nobel Prize in Physics?

  • 09:11: Aspect’s setup was very similar to Clauser's, with a beam of calcium atoms excited by light - this time a laser rather than an arc lamp.

2022-06-30: Could We Decode Alien Physics?

  • 16:39: ... an example is something like a giant laser array pushing a light sail.   So this concern is very valid. ...

2022-06-22: Is Interstellar Travel Impossible?

  • 02:35: ... sails, which would be accelerated to 20% light speed by a giant array of lasers back on ...
  • 05:35: ... of junk in the ecliptic plane - and maybe we blast a path ahead with lasers or something from ...

2022-03-08: Is the Proxima System Our Best Hope For Another Earth?

  • 13:56: The plan is to use a giant laser array to accelerate a train of mylar light sails to 20% the speed of light in the direction of Proxima.

2022-01-12: How To Simulate The Universe With DFT

  • 19:27: ... real gas guzzler, so perhaps Dyson spheres are made to power light sail lasers that accelerate craft to 99.9999blahblah% the speed of light ...

2021-10-13: New Results in Quantum Tunneling vs. The Speed of Light

  • 11:02: In this experiment, they fired ultracold rubidium atoms at a laser field that was spread out over a small area.
  • 11:20: ... those ones, their spins were altered by the magnetic field of the laser, and the longer they spent inside the barrier, the more their spins ...

2021-09-21: How Electron Spin Makes Matter Possible

  • 01:44: ... stack as many bosons on top of each other as you like. For example in a laser beam, there’s no limit to the number of photons you can add - all of ...
  • 05:59: ... If you have two such wavefunctions overlapping - like two photons in a laser beam, a shift in one of them by half a wave cycle puts the two out of ...

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

  • 03:14: ... say you’re trying to measure the distance to an object. You shine a laser beam at   it, which reflects back to a detector that ...
  • 03:47: ... object with a powerful short-wavelength X-ray   laser and you may get an amazing distance measure, but you’ll transfer a ...

2021-05-25: What If (Tiny) Black Holes Are Everywhere?

  • 13:57: ... might know that regular laser light is produced when an incoming photon causes an electron in a ...

2021-05-19: Breaking The Heisenberg Uncertainty Principle

  • 05:01: ... Laser Interferometer Gravitational Wave Observatory measures ripples in the ...
  • 05:36: ... Laser light is split and sent along those paths and then later recombined in ...
  • 05:58: the recombined laser no longer perfectly cancels, and so flashes of light are observed.
  • 06:44: ... quantum fluctuations in the phase of the laser beams are larger than the change in the arm lengths due to a ...
  • 07:07: To improve our ability to detect faint gravitational waves we need to reduce the uncertainty in the phase of the laser beams.
  • 07:25: ... light from a laser beam obeys the Heisenberg uncertainty principle in a very specific ...
  • 08:35: The laser is sent through a special material called a non-linear crystal, which converts incoming photons into pairs of photons.
  • 09:26: ... with more uncertainty in the number of photons traveling in your laser ...

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

  • 05:55: To recap - we have a collection of laser-cooled atoms in an electromagnetic trap.
  • 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.
  • 06:25: ... the electron is in state 1 when the laser pulse hits, it absorbs a laser photon and jumps to 3, and then ...
  • 06:47: But what if the laser hits while the electron is in the middle of a transition - in a superposition of states 1 and 2?
  • 07:02: ... to the researchers, the laser acts like a measurement - and remember, measurement should be able to ...
  • 07:15: To test this, the researchers start the atoms all in state one, and then hit them with a series of very rapid laser pulses.
  • 08:41: In this case, hitting the atoms with a laser pulse.
  • 09:11: ... showed that each laser photon perturbed the system in such a way that the electron had an ...

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

  • 02:39: A spider breaks through the front hull and you fire your laser at it.
  • 02:49: The spider still observes the laser traveling at the speed of light - because the speed of light is invariant to all observers.
  • 03:04: ... the front peak of your laser pulse reaches the spider the ship continues to accelerate - which means ...
  • 03:22: Your laser’s power rating goes from kill to tickle - good news for the giant alien spider, not so much for you.
  • 05:19: This time you fire your laser across the deck perpendicular to the direction of acceleration.

2021-02-17: Gravitational Wave Background Discovered?

  • 00:00: ... element of space itself the gravitational wave background when the laser interferometer gravitational wave observatory ligo turned on in 2015 it ...

2021-01-19: Can We Break the Universe?

  • 00:02: Black holes, gravitational waves, he was even the first to realize that friggin lasers could be a thing.

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

  • 06:16: By the 80s we’d learned how to trap and cool a single atom with lasers.
  • 06:28: ... single atom - in this case mercury or barium - is bathed in a laser beam with a frequency exactly tuned to the energy difference between two ...
  • 06:41: If the electron is in level 1, it should jump to level 2 by absorbing a photon from the laser light.
  • 07:33: So, we have our atom happily fluorescing in the original laser beam.
  • 07:37: Now flash a second laser with frequency tuned to take the electron from level 1 to level 3.
  • 09:09: They then placed these artificial atoms inside a microwave cavity - analogous to the laser, which could cause the “atom” to transition between states.

2020-07-20: The Boundary Between Black Holes & Neutron Stars

  • 02:13: A laser beam is split, sent down these tubes, then recombined.
  • 02:18: ... in these arm lengths, which in turn causes the peaks and valleys of the laser’s electromagnetic wave to line up differently, and so those changes can be ...

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

  • 09:19: ... energies between the various positron orbitals in the anti-atoms using laser spectroscopy. The exact energy of one of these states is determined by ...

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

  • 09:19: ... done experiments with super-cold rubidium gas in a BEC state. Using a laser, it’s possible to effectively create a flow within the ...
  • 09:59: When the laser pushes on the gas, the rubidium atoms want to move out of the way of the beam.
  • 10:04: Here, the edge of the laser acts as the event horizon—the rubidium atoms don’t have enough energy to jump back up over the waterfall.
  • 11:04: ... pointed to experimental observations of analog Hawking radiation—in laser pulses, fluids, and BECs—as proof-positive of Hawking radiation in black ...

2020-05-18: Mapping the Multiverse

  • 15:40: ... has been performed with much higher precision using other methods - lasers, vacuum chambers, strange quantum mechanical states of light - you name ...

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

  • 03:29: Laser light is an example of a coherent wave.

2020-01-13: How To Capture Black Holes

  • 00:24: ... September 2015 the laser interferometer gravitational wave observatory - LIGO - detected its ...

2019-12-02: Is The Universe Finite?

  • 13:33: ... speculative, and philosophical stuff over a beer, and some who are laser focused on their own field and don't really think far beyond ...

2019-07-15: The Quantum Internet

  • 03:19: We can already send photons of light very long distances using lasers or fiber optics - and those photons are pretty quantum.
  • 10:22: So the current state of the art is that entangled quantum states have been transmitted with photons using fibre optics and lasers.

2019-06-20: The Quasar from The Beginning of Time

  • 04:20: ... in real time, Gemini creates its own artificial guide star by shooting lasers to twinkle off sodium atoms at 90km height, right off the edge of ...

2018-08-30: Is There Life on Mars?

  • 07:31: ... 1996 with the advent of high-resolution scanning electron microscopy and laser mass ...

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

  • 00:31: We've already talked about the Laser Interferometer Gravitational-Wave Observatory, LIGO, and the first discovery of gravitational waves here.
  • 04:08: That's LISA, the Laser Interferometer Space Antenna.

2017-10-11: Absolute Cold

  • 01:00: Using lasers and magnetic fields, we've now managed to cool certain substances to less than a billionth of a Kelvin.

2017-09-20: The Future of Space Telescopes

  • 08:58: A laser can find a glitter cloud, if you will.
  • 09:01: ... would be fractions of a millimeter in size, small enough that commercial lasers could corral and shape the particles into an effective mirror or ...

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

  • 00:37: ... the Laser Interferometer Gravitational Wave Observatory, LIGO, detected ...

2017-07-19: The Real Star Wars

  • 04:28: It included much-expanded surface launch anti-ballistic missile ABM networks, but also, get this, an atomic bomb-powered x-ray laser satellite.
  • 04:50: A quick review on lasers.
  • 05:22: X-ray lasers were seen as extremely promising in missile defense because they can completely vaporize metal.
  • 05:31: But in the vacuum of space, these lasers can have ranges of many hundreds, even thousands of kilometers.
  • 05:37: Now, normal lasers bounce the beam back and forth through a gain median to build up power.
  • 05:45: So a powerful x-ray laser needs to start with a powerful x-ray source.
  • 05:50: For Excalibur, that source was a nuclear bomb set off behind an array of laser tubes.
  • 06:00: One blast is enough to pass several dozen x-ray lasers, and each of those can take out an ICBM.
  • 06:32: One, it was never clear whether any of the 10 underground test detonations produced anything near the promised laser amplification.
  • 07:41: So non-nuke powered lasers, and also the potentially very deadly kinetic impact weapons.
  • 10:08: ... super-villains, the USSR also played around with powerful ground based lasers, which supposedly blinded some US spy satellites, and particle beams, ...
  • 10:24: ... full-fledged orbiting the battle station that would have had a megawatt laser designed to take out the as-yet unlaunched US anti-missile ...

2017-03-15: Time Crystals!

  • 04:32: Now cause those spins to flip back and forth using a laser.
  • 04:36: A laser is just a very well-ordered electromagnetic wave with a known period or frequency.
  • 04:43: The spin-flip oscillation will be determined by the period of the laser.
  • 04:48: That laser is what takes the system out of equilibrium, because you are basically pumping in energy.
  • 04:54: Causing spins to flip in a laser isn't particularly exciting.
  • 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 input EM field is ...
  • 05:19: ... theorized that spins should not oscillate at the same period as the laser, but at an integer multiple of the driving ...
  • 05:29: So two, three, four, et cetera spin oscillations for every EM field oscillation in the laser.
  • 06:54: ... up a chain of ions, linking 10 ytterbium ions and driving them with a laser. ...
  • 07:23: The ytterbium ions oscillations were twice the laser period.

2017-02-15: Telescopes of Tomorrow

  • 06:53: ... track this turbulence in real time, GMT will shine six powerful sodium lasers 90 kilometers into the upper atmosphere, where their light will produce ...

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

  • 12:36: Mr. Rich suggests that lasers and even grasers, gamma ray lasers, are much more efficient for targeted long-distance communication.
  • 12:46: There are even plans to use lasers to communicate between the hopefully upcoming Starshot Shot light sail mission to Alpha Centauri.
  • 12:54: But as Gareth Dean points out, lasers suck for broadcast, so sending a signal broadly.

2016-08-24: Should We Build a Dyson Sphere?

  • 04:13: It would reflect light into a small solar power plant that would then beam energy somewhere useful, perhaps with a laser or a maser.

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

  • 06:24: ... starts its journey wherever we put the laser or electron gun or buckyball trebuchet and it releases its energy at a ...

2016-07-20: The Future of Gravitational Waves

  • 00:14: ... September 14, 2015, the Laser Interferometer Gravitational Wave Observatory, LIGO, detected the ...

2016-06-01: Is Quantum Tunneling Faster than Light?

  • 05:42: Laser beams are sent down paths at right angles and then brought back together.
  • 06:00: We want to send individual photons instead of lasers.

2016-05-18: Anti-gravity and the True Nature of Dark Energy

  • 12:09: Well, the idea is to beam the data back with low-power lasers, or perhaps alternatively to use the sail itself as an antenna for radio transmission.
  • 12:27: If the signal sent by laser, then the same phased array that projects the launched laser will also be able to spot the returning later signal.
  • 12:48: The impulse generated by the laser is many orders of magnitude greater than that of the star at the other end.
  • 13:34: The analogies to Moore's Law for laser power, material science, battery tech, et cetera, are also alive and well.

2016-05-04: Will Starshot's Insterstellar Journey Succeed?

  • 01:31: A spacecraft is propelled as the light from the sun-- or from a giant laser-- accelerates a sail of reflective material.
  • 01:57: Light sails need no onboard propellant and the power generation stays back at home, whether it's the sun or an Earth-based laser.
  • 02:51: The solution is lasers.
  • 02:54: The solution is so often lasers.
  • 03:06: ... be a kilometers-wide carbon fiber mesh sail propelled by a microwave laser-- a maser, which would be focused by a 1,000 kilometer diameter microwave ...
  • 03:33: The basic concept is the same-- an extremely low mass laser powered light sail.
  • 04:09: ... and would include multiple detectors, including a camera, small lasers that work both as thrusters and as communication devices, and perhaps ...
  • 04:24: Another big difference compared to Starwisp is that Starshot will be powered by a visible light laser, not a maser.
  • 04:31: This is important because visible light lasers can maintain a much tighter beam than a maser can.
  • 04:41: The ultra low mass means that the nanocraft can be accelerated to a decent clip with a giant laser that we could plausibly build in a generation.
  • 04:51: So less vast alien mega structure slash planet destroyer and more Bond super-villain laser.
  • 04:58: It would be a ground-based phased array of mini lasers called a light beamer that will produce a combined 100 gigawatt beam.
  • 05:23: Build a laser that big and you want to use it, right?
  • 06:32: The laser propulsion array needs to combine and direct its beams with incredible precision through a turbulent atmosphere.
  • 07:00: It's assumed that processor size, camera pixel density, laser power to mass ratio, et cetera will continue their exponential improvement.

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

  • 00:37: On September 18, the Laser Interferometer Gravitational-Wave Observatory switched back on after three years of upgrades.
  • 06:35: ... upcoming Evolved Laser Interferometer Space Antenna-- eLISA-- will see an entirely different ...

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

  • 07:25: LISA is amazing, although now it's ELISA, the Evolved Laser Interferometer Space Antenna.

2015-10-22: Have Gravitational Waves Been Discovered?!?

  • 05:01: With lasers, of course-- in fact, with a giant Michelson interferometer.
  • 05:07: This is the LIGO experiment, and it goes something like this-- shoot a laser beam.

2015-10-15: 5 REAL Possibilities for Interstellar Travel

  • 06:13: ... kilometer wide sapphire coated sail, riding the beam of a gigantic space laser blasting the power equivalent of 100 nuclear ...
  • 06:44: ... we're going to need to a bigger boat, which means a proper visible light laser and a larger sail, coated with advanced, reflective and heat resistant ...
  • 06:55: ... laser is going to have to be ridiculously large, possibly built on the moon ...
  • 07:07: Because we aren't carrying any fuel, maximum speed is only limited by the power and collamation of our laser and the size of our sail.
  • 07:56: ... sufficient energy density of laser light focused in a small enough region would bend the fabric of space ...
  • 09:04: The only drawback is that the lasers creating the black hole would need to be vastly more powerful than even the black hole they created.

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

  • 07:57: A laser pointer carried by the monkey never enters the black hole, as far as we're concerned.
  • 08:02: Because of time dilation, we would detect any laser pulse that the monkey sends with a lower frequency, i.e.

2015-07-29: General Relativity & Curved Spacetime Explained!

  • 05:37: Fire a laser pulse from the ground floor of a building up to a photon detector on the roof.

2015-07-15: Can You Trust Your Eyes in Spacetime?

  • 02:51: And at that same moment, I shoot a photon from a laser pointer to the right.

2015-06-24: The Calendar, Australia & White Christmas

  • 06:32: However, they might be using optical laser pulses if they have limited resources or the kind of alien billboards that we discussed in the episode.

2015-06-17: How to Signal Aliens

  • 02:14: So let's move on to method two, lasers.
  • 02:17: Nowadays, lasers can produce high-power ultra-short pulses that can outshine the sun for less than a nanosecond.
  • 02:23: Nothing natural pulses with stellar brightness for a nanosecond at a time, so laser pulses would look distinctly artificial to our Vulcan friends.
  • 02:40: Attenuation from interstellar dust makes the range for optical lasers less than that for microwave beacons.
  • 02:48: But at those distances, a laser's spot size would only grow to around the size of Jupiter's orbit.
  • 02:58: With a lot of lasers, you could even flash several star systems per second, re-aim, and repeat over and over.
  • 04:59: ... like the lasers, billboard transits could only be seen within a few light years of earth ...
  • 05:55: ... besides looking for radio signals and laser pulses, which SETI does now, should SETI also be looking for geometric ...

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

  • 05:18: Answer, infrared laser strobe lights connected to a video camera.
  • 05:27: ... timing the return time of the laser pulse echos and using image rendering software, NASA funded researchers ...

2015-03-18: Can A Starfox Barrel Roll Work In Space?

  • 00:19: Ships that bob and weave, laser cannons galore, and giant explosions all make for good drama but bad physics.
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