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2022-11-23: How To See Black Holes By Catching Neutrinos

  • 06:28: If we only pay attention to signals from below we eliminate atmospheric muons.
  • 10:52: That makes the neutrino signal from M77 far more exciting, because we’re approaching certainty in this case.

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

  • 18:41: If there are multiple possible effects, then the cause gets to choose between them by picking from the time traveling signals.
  • 18:50: ... is equivalent to standard quantum field theory, with the time-reversed signals corresponding to negative frequency ...

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

  • 11:05: ... all, signals could have travelled to both the calcium atom and the random number ...
  • 16:12: ... all, we’re having a hard time keeping track of the Voyager’s faint signals, and the gravitational lens focal range is  at least 4 times further ...

2022-07-20: What If We Live in a Superdeterministic Universe?

  • 07:40: ... by a spacetime event in its causal past - so, near enough to have sent a signal. ...

2022-04-20: Does the Universe Create Itself?

  • 06:24: ... cancel out  in detector 2 - destructive interference leaving no signal . For that to work this pair of “possible photons” had to travel both ...

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

  • 18:20: Anarchy Antz asks if there’s any update on the radio signal from the direction of Proxima detected by the Breakthrough Listen project.
  • 18:31: ... astronomer Sofia Sheikh found around 60 similar signals that were not clearly associated with stars and had radio frequency ...
  • 18:49: Or in other words, the Proximans realized we were onto them and hacked the database and injected fake signals to put us off their tracks.

2022-01-27: How Does Gravity Escape A Black Hole?

  • 09:46: ... star does appear to go black, but really the faintest signals of that collapsing star continue to make their way out into the universe ...

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

  • 00:00: In our search for alien lifeforms we scan for primitive biosignatures, and wait and hope for their errant artificial signals to happen by the Earth.

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

  • 00:10: ... be possible, while still managing to avoid the paradox of superluminal signaling. ...
  • 05:27: ... relativity explains that if you move faster than light, you can send signals into the past, and create a whole bunch of ...
  • 12:15: Perhaps yes, but it seems only in cases where faster-than-light signaling is impossible.
  • 12:28: All signals in our universe, whether via quantum tunneling or quantum entanglement, seem to be bound by the same limits imposed by relativity.

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

  • 10:06: ... in circles,   making a very weak gravitational wave  signal. These gravitational waves are   much weaker than the signals ...

2021-07-13: Where Are The Worlds In Many Worlds?

  • 06:37: ... the screen, as action potentials down our optical nerves, and finally as signals in our ...

2021-05-19: Breaking The Heisenberg Uncertainty Principle

  • 06:16: Any variation in the relative phase of the two beams can generate a flicker in the signal.
  • 06:32: Quantum fluctuations result in a low level of noise - a flickering signal where you should see darkness.
  • 06:39: And that noise will obscure faint gravitational wave signals.
  • 09:05: Less flickering due to random phase shifts means that we can see real signals due to much weaker gravitational waves.

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

  • 09:58: ... satisfactory natural explanations. Many of you have heard of the WOW signal. This was a weird spike of radio emission detected by the Big Ear radio ...
  • 10:31: Nor has such a signal ever been seen again.
  • 10:35: ... then drifted upwards in frequency over a 3 hour observation. This weird signal was only spotted over a year later when a student working with the ...
  • 11:24: ... around the star. Now there are very good reasons to think that this signal isn't aliens. For example, Proxima is a dangerously active red dwarf - ...

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

  • 09:21: Physicists however, refer a five-sigma signal before declaring a discovery.
  • 09:25: For five-sigma, there's only one in 3.5 million chance of random noise resulting in the same signal.

2021-02-24: Does Time Cause Gravity?

  • 10:56: ... effects would have been very important, so if we can get any type of signal from then perhaps we can learn ...

2021-02-17: Gravitational Wave Background Discovered?

  • 00:00: ... away since then ligo and its partner virgo have detected 50 similar signals from merging black holes and neutron stars across the universe these ...

2020-11-11: Can Free Will be Saved in a Deterministic Universe?

  • 07:43: ... of a brain, of neurons, their activity, the molecules involved and their signaling, et ...

2020-10-20: Is The Future Predetermined By Quantum Mechanics?

  • 05:56: Or at least the parts of that wave function for which signals actually reach our awareness.
  • 09:59: However, light speed signaling is the surest way to transfer quantum correlations so this is still a useful picture.

2020-10-13: Do the Past and Future Exist?

  • 06:22: ... of the block universe that we can possibly perceived with a light-cone - signals from things inside that cone have had time to reach ...
  • 06:33: The boundary of the cone holds the paths of light-speed signals.
  • 07:22: As that happens, signals begin to reach you from the time-slice you’re trying to map.
  • 07:57: They are racing towards one set of incoming signals and away from the other.

2020-10-05: Venus May Have Life!

  • 03:58: This can be done at far infrared and submillimeter radio wavelengths where the star’s own glare doesn’t kill the signal.

2020-04-28: Space Time Livestream: Ask Matt Anything

  • 00:00: ... one merging neutron star pair that followed that gravitational wave signal indicated that in fact gold may be forged in the mergers of neutral ...

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

  • 09:43: ... electrons in a pixel on the screen, which results in an electrical signal passing along wires to a computer and eventually into our ...
  • 10:01: ... excited and not excited across the screen, and superpositions of signals traveling from those pixels ultimately to the brain of the ...
  • 11:07: ... system also ensures that the phase offset changes between one incoming signal and the ...

2020-02-18: Does Consciousness Influence Quantum Mechanics?

  • 04:17: ... to light-sensitive molecules in our retinas, which initiate electrical signals to our visual cortex, and more electrical signals in other parts of the ...

2020-01-27: Hacking the Nature of Reality

  • 15:30: It may be easier with neutron star mergers, which we see a LIGO signal up to a minute before the merger.

2020-01-06: How To Detect a Neutrino

  • 03:33: ... 𝘴𝘺𝘯𝘵𝘩 𝘱𝘶𝘭𝘴𝘦𝘴) ♪ (title) "ICARUS (Imaging Cosmic And Rare Underground Signals): Liquid Argon Neutrino Hunter" ♪ ♪ MATT: Down here, we have the ICARUS ...

2019-12-02: Is The Universe Finite?

  • 10:38: If this lensing signal is real then maybe there’s curvature, or maybe its an indication of some unknown physics.

2019-10-15: Loop Quantum Gravity Explained

  • 14:20: But first the context: this year LIGO detected two black hole merger signals within 20 minutes of each other and in similar patches of the sky.
  • 14:53: If those paths were different lengths we'd see the same signal separated by a small time delay.
  • 15:09: ... of this particular example it's not really the favored explanation - the signals don't look like they were from quite the same location after all, and ...

2019-10-07: Black Hole Harmonics

  • 05:20: The problem is, at the tail-end of the ring-down the LIGO signals are probably too weak to detect the overtones.
  • 06:10: ... of first trying this with a simulation is 1) you don’t have to use a signal degraded by a billion years of travel, and 2) you know exactly what ...
  • 06:55: This means that these overtones are potentially detectable in the real merger signals from LIGO and VIRGO.
  • 07:22: ... much greater precision than if they’d just used the gravitational wave signal from the lead-up to the ...
  • 08:04: looked at the merger and ring-down signal from the largest black hole merger we’ve seen.
  • 11:31: The LIGO team typically waits until the run is complete to announce findings because it takes a while to fully confirm each signal.

2019-09-03: Is Earth's Magnetic Field Reversing?

  • 01:21: The magnetic field is currently undergoing rapid changes, possibly signaling the imminent flipping of its polarity.

2019-08-12: Exploring Arecibo in VR 180

  • 01:02: ... that correct the blurred focus of the spherical dish and transmit the signal into a sophisticated suite of receivers and that long thing Well, it's ...
  • 03:24: ... Over the years actually not just the search it blasted out the Arecibo signal in 1974 and a new signal is currently being planned we spoke to dr bill ...

2019-07-15: The Quantum Internet

  • 03:34: ... and many can be lost or altered en route without compromising the signal. ...
  • 03:44: If too many photons are lost you can just run the channel through a repeater, which reads the signal and boosts it with extra photons.
  • 03:59: And it’s fundamentally impossible to boost that signal by duplicating those photons.

2019-06-17: How Black Holes Kill Galaxies

  • 14:07: or in the detailed shape of the gravitational wave signal before collision.

2019-05-16: The Cosmic Dark Ages

  • 05:13: ... specific photons were in particular danger: in one case that absorption signaled the end of the dark ages and the second the end of the epoch of ...
  • 14:26: ... distance is very difficult, requiring relays to reprepare and boost that signal. ...

2019-05-01: The Real Science of the EHT Black Hole

  • 10:17: ... cool fact is that, just like those gravitational wave signals from a couple of years ago, the black hole looks just like we predict ...

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

  • 10:36: ... baryon acoustic oscillations signal was first spotted in 2005 by the Sloan Digital Sky Survey in the ...

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

  • 03:17: Even the famous wow signal has likely been explained as a mission from a pair of comets.
  • 07:23: ... factors like the fraction of intelligent life that transmits radio signals and how long that communicative civilization ...

2018-10-10: Computing a Universe Simulation

  • 13:30: ... the neutron star merger started slightly after the gravitational wave signal. ...

2018-10-03: How to Detect Extra Dimensions

  • 09:58: ... electromagnetic signal from these merging exploding neutron stars allowed us to measure its ...

2018-07-04: Will A New Neutrino Change The Standard Model?

  • 08:56: Combined with the 4.8-sigma MiniBooNE result, the author's claim a 6.1-sigma signal, which would be considered extremely significant.

2018-06-13: What Survives Inside A Black Hole?

  • 02:20: Nothing beneath the event horizon can influence the exterior universe because no signal can escape the event horizon to carry that influence.

2018-04-25: Black Hole Swarms

  • 02:26: ... five and 15 solid amasses, although, the recent gravitational wave signals detected by LIGO, suggest they may be even more ...
  • 07:57: Now, we keep seeing these gravitational wave signals from black hole merges, and as I've discussed previously, they're kind of confusing.

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

  • 02:09: Perhaps these gravitational waves signals were amplified by another phenomenon predicted by Einstein's general relativity, gravitational lensing.
  • 02:19: ... also be warped by intervening gravitational fields which can amplify the signal and stretch out the ...
  • 02:45: For the first time, the event behind a gravitational wave signal was also seen in light.
  • 02:59: ... like this should allow us to figure out where the gravitational wave signals are often also gravitationally ...
  • 06:13: It looks for shifts in the time of arrival of their signals.

2018-03-28: The Andromeda-Milky Way Collision

  • 09:40: ... experiment integrated for hundreds of days and added together the radio signal from the whole sky to measure their signal of the first ...
  • 09:49: ... should be able to map the signal across the sky and so create images of the structures in which those ...

2018-03-21: Scientists Have Detected the First Stars

  • 00:34: In a nature paper published just a few weeks ago, Judd Bowman and collaborators, report a signal from the very first stars to form in our universe.

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

  • 13:23: Sukuraslight suggested that Seti@home use its computing cycles to mine bitcoin instead of look for alien signals.

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

  • 03:53: ... example, spotting supernovae or looking for gravitational wave signals in LIGO and finding planets forming in the debris disks of new solar ...
  • 05:08: This all started with the City at Home program, which looks through radio data for signs of signals from intelligent life.
  • 05:15: But there's also Einstein at Home, which searches for LIGO gravitational wave data for signals produced by rotating neutron stars.

2017-11-22: Suicide Space Robots

  • 08:58: ... the long silent Pioneer spacecraft, Voyager 1 still sends faint radio signals, bringing us our first and only direct measurements from beyond our home ...
  • 09:09: But the signal is fading.

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

  • 01:45: ... whether the rumor is true, in fact, before we talk about the supposed signal at all, let's refresh our memory on neutron ...
  • 06:19: After all, LIGO can only constrain the origin of its signals to a wide band across the sky.
  • 06:25: ... that the Italian Gravitational Wave Observatory, VIRGO, also spotted the signal, which helps triangulate the location, but not enough to get an exact ...
  • 09:32: Seeing a gravitational wave signal from merging neutron stars would allow us to determine pretty exactly how much mass is lost in the merger.
  • 10:27: They want to analyze the data fully to ensure the signal meets their very strict statistical standards for claiming a detection.
  • 10:57: Public announcements will happen when the team is sure of the significance of the signal.

2017-03-15: Time Crystals!

  • 05:54: The analogous phase diagram for time crystals plots interaction strength between atoms versus imperfection in the spin-flip driving signal.
  • 06:08: ... the variations in the forcing signal become too messy and the interaction strength is too weak, then the time ...

2017-02-02: The Geometry of Causality

  • 05:33: ... every future tick of my clock, a signal arrives from the left and the right, and I use that to build up a set of ...
  • 05:44: Our traveler does the same thing, but from my point of view, their clock is slow, so I see them register signals at a different rate.
  • 05:53: ... the same time, they're moving away from the signals coming from the left and towards the ones originating on the right, ...

2017-01-25: Why Quasars are so Awesome

  • 02:30: ... on the occultation and registered the exact instant that the radio signal vanished behind the ...

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

  • 06:15: ... radiation field to see if that heating produces a similar false positive signal, but this hasn't been done ...
  • 06:25: ... authors identify several other potential sources of false positive signal, and either make reasonable arguments against them or propose tests to ...
  • 12:54: But as Gareth Dean points out, lasers suck for broadcast, so sending a signal broadly.
  • 13:08: And Richie is correct in countering that an advanced civilization may not be so leaky with their own broadcast signals.

2016-12-21: Have They Seen Us?

  • 00:16: What are the chances that alien civilizations have detected and even decoded these signals?
  • 02:01: What tech level would be needed to actually decode the signal it carries?
  • 03:35: ... 1977 Wow! signal is the most compelling, a narrow-frequency radio blast detected in the ...
  • 04:57: signal.
  • 05:18: This is another advantage for searching for alien signals in and around the water hole.
  • 06:16: A signal that appears in one, but not the other, must be an earthly transmission.
  • 09:12: So that's enough to identify a technological source, but not to actually decode the signal.
  • 09:44: That signal is now 50 light years away.
  • 10:31: ... one month integration time requires a very consistent narrow frequency signal, which may not be consistent with typical ...
  • 12:43: Any civilization within 40 to 50 light years could have sent a return signal that will reach us any day.

2016-12-08: What Happens at the Event Horizon?

  • 07:08: Our space-faring simian begins its journey and emits a regular light signal that we observe from a safe distance.
  • 07:14: ... increasingly curved space-time and so the interval between receiving signals also ...
  • 07:25: The progress of the monkey appears to slow to a halt very close to the event horizon, and the final signal at the moment of crossing never reaches us.
  • 10:12: That means that the monkey's signal can still reach us, although it might be more accurate to say that we catch up to the monkey's outgoing signal.

2016-09-29: Life on Europa?

  • 12:47: ... no need for a faster-than-light signal to tell particle a what measurement has been carried out on particle B ...

2016-08-17: Quantum Eraser Lottery Challenge

  • 04:56: Oh, I do get a signal-- nice work, future me.
  • 05:00: And that signal does contain the interference patterns from my future choices with perfect fidelity.

2016-08-03: Can We Survive the Destruction of the Earth? ft. Neal Stephenson

  • 00:43: ... climate change, wiped out up to 3/4 of all animal and plant species and signaled the end of the 80-million-year-long Cretaceous ...

2016-07-20: The Future of Gravitational Waves

  • 00:31: ... signal was in the form of oscillating changes in the path lengths of the LIGO ...
  • 01:46: Also, the same signal was seen in the two LIGO detectors located in Livingston, Louisiana and Hanford, Washington.
  • 01:54: It's calculated that LIGO would need to observe for over 200,000 years to see the same signal arise from random vibrations.
  • 02:01: Or another way to put this is that there's a one in 20 billion chance that this signal was from random vibrations.
  • 02:08: The weaker December signal doesn't look nearly as clear, at least to the eye.
  • 02:12: ... new signal caused a change in LIGO's arm lengths of about 1/1000, the diameter of a ...
  • 02:32: We're able to be this certain because the signal lasted much longer, nearly a second compared to 1/10 of a second of the early detection.
  • 02:50: One, extremely sophisticated signal processing technology is used to "see" the signal.
  • 02:56: It's the same very well-understood tech that we use to process radar signals and at this point, we have a lot of confidence in how this works.
  • 03:05: Two, exhaustive computer simulations test how often this signal processing tech gets tricked into falsely reporting a detection.
  • 03:15: The answer is almost never for signals of the sort that were seen last year.
  • 03:20: ... a testament to LIGO's carefulness, they already knew about the December signal when they announced the first gravitational wave detection back in ...
  • 03:30: However, they hadn't had time to give due care to the newer signal so they decided to keep quiet about it until they were sure sure.
  • 03:59: It's kind of amazing that the signals observed look exactly like what we expect them to from the predictions of general relativity.
  • 04:47: They were always expected to produce the strongest signal, which means they'd be detectable more often.
  • 05:10: ... the wave came from, which is determined by the time difference in the signal between the two ...

2016-06-08: New Fundamental Particle Discovered?? + Challenge Winners!

  • 04:32: At that point, the signal will either solidify or vanish, assuming no more attacks by cute animals.

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

  • 12:03: So a few people were wondering how that probe sends its signal back to Earth.
  • 12:20: The signal will be weak, but we'll know exactly where to look and can use gigantic detectors here on Earth.
  • 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.

2016-02-17: Planet X Discovered?? + Challenge Winners!

  • 05:14: ... chases after its own photons, condensing the distance between the light signals that carry those ...
  • 05:25: ... direction, stretching out the distance, and hence the time, between tick signals. ...

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

  • 01:04: Almost as soon as it was switched on, a signal was seen.
  • 04:21: Now these mergers have very distinct signals.
  • 05:22: ... the merger signals deviate significantly from the expected signal, then it may be a clue ...
  • 05:33: Now as far as I know, there's no indication of that from the detected signals.
  • 05:49: The signals are expected to carry information about the strange warping of space in the region of the event horizon.

2016-01-27: The Origin of Matter and Time

  • 08:18: One of them-- a point on the space time diagram-- can influence another if a signal can travel between the two.

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

  • 08:12: So now, the money is on the signal actually being due to dust, not G waves.
  • 09:03: Check out the actual signal that reveals this eclipsing material.

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

  • 05:33: ... signal is seen, but if a gravitational wave passes by, it will shrink one of ...
  • 05:46: And you'll get these little blips of signal.
  • 08:07: ... are so cautious that the team deliberately injects false signals into the system to check the verification process, and make 100% sure ...
  • 08:19: In fact, only three team members know whether a given signal is real or fake.
  • 08:30: Now, even the fake signals are meant to be secret.
  • 08:50: A little birdie told me that it's the signal of two black holes in-spiralling towards each other.
  • 08:59: Except another rumor is the signal was actually in the engineering data taken before the official turn-on date.

2015-09-30: What Happens At The Edge Of The Universe?

  • 03:05: There's a region of this universe from which we can never receive any new signal.
  • 03:09: That is, any signal that's emitted today.
  • 03:13: This is because the distance that signal has to travel to get to us will be expanding faster than the speed of light before the signal reaches us.

2015-09-23: Does Dark Matter BREAK Physics?

  • 08:39: ... signals from the monkey to the outside universe can be received at arbitrarily ...

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

  • 06:04: ... of "Space Time." Last week we talked about different possible ways to signal aliens, including maybe putting planet-sized geometric objects in orbit ...

2015-06-17: How to Signal Aliens

  • 00:13: [THEME MUSIC] Let's leave aside for the moment the fact that signaling aliens might not be a good idea.
  • 00:24: Today, I'm going to summarize three different signaling methods that have been discussed in the literature along with their pros and cons.
  • 00:45: I want to discuss signaling without the added complications of messaging.
  • 03:13: You have to keep transmitting for a very long time to increase the odds that someone will see the signal or there's not much point.
  • 03:19: But there's another signaling option that wouldn't require us to transmit anything at all.
  • 05:07: So to signal aliens very far away near the galactic center, you'd still need high-powered microwaves.
  • 05:12: ... all in all, a billboard seems like a distinct, cheap, ongoing signal that aliens could notice just by doing exoplanets astronomy, even if ...
  • 05:24: ... conclude that billboards are the most efficient, most noticeable way to signal aliens, or at least one of them, that aliens might apply Princess Bride ...
  • 05:33: They might think that we'd think that they'd think that billboards are a good signal so that we would go looking for them.
  • 05:44: To my knowledge, no one has actually analyzed exoplanet transit data to look for these signals.
  • 05:55: ... besides looking for radio signals and laser pulses, which SETI does now, should SETI also be looking for ...

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

  • 01:15: ... the ear with just the right vibrations could sync up the electrical signals going to the brain from the auditory system and from the vestibular ...

2015-04-29: What's the Most Realistic Artificial Gravity in Sci-Fi?

  • 04:46: ... ear that moves back would curve in opposite directions, sending mixed signals to your vestibular ...

2015-04-22: Are Space and Time An Illusion?

  • 03:27: When it's zero or negative, signals or things can get from one event to the other and everyone agrees on their sequence.
  • 07:45: ... the authors of salmonella study theorised that the signal to bacteria in microgravity might be lower shear forces on their cell ...

2015-02-18: Is It Irrational to Believe in Aliens?

  • 01:19: The details are different, since Drake, the founder of SETI, was estimating the number of detectable alien radio signals.
  • 04:17: ... other such species that's jetted around the cosmos, something like radio signals, space station probes, a broken down Millenium Falcon, I don't know, an ...
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