You do an excellent job, we appreciate it a lot. Could you, please, talk about axions and the strong CP problem at some point?

I love this series

I just love how you smile in between of things... It seems like you are so happy that all those things even exist and you can be part of discovering them... Makes me happy too

@josephbrandenburg4373

3 жыл бұрын

Yeah. Even if the subject matter weren't interesting (and it is!), Dr. Lincoln's obvious love of physics is so charming. It's enough to carry the whole series.

Dr. Don, This may be the best one yet. As a non scientist I obsess over gravitational waves. This episode somehow contains a clarity I was missing. Thanks, Prof!

Fantastic video. Hope to see more subatomic stories in the future. Maybe one about how photons and electrons interact to produce structural color?

@Anaesify

3 жыл бұрын

oooh i love this idea

@StitchTheFox

3 жыл бұрын

@MichaelKingsfordGray well then yes, a video on that. 👍

What's for dinner, Dr Don?

Even at home, especially under quarantine, physics is everything. Thank you for the videos!

Ah, the one constant safe spot of bliss and comfort: subatomic stories

Thanks again for an excellent episode! I think we need to cut Schwarzschild some slack as in between calculations he was fighting in the first world war :(

@markzero8291

3 жыл бұрын

It's not a criticism to say he picked low hanging fruit, it's just a fact. But it was also the low hanging fruit on the tree of GR so still far out of reach for most of us, especially given the fact he was in the war!

@Hossak

3 жыл бұрын

@@markzero8291 I know that - however I was just saying that although he was first, and no doubt the solution he found was readily accessible to others, he formulated it in extremely difficult circumstances. Gives hope for all of us :)

@josephbrandenburg4373

3 жыл бұрын

@@Hossak And really, I don't think geniuses are people who find the hardest answers. I think they are people who ask the questions that make hard problems easy. That's how Einstein changed physics-- he began by asking questions that no one had ever asked before, some of them because they seemed obvious ("what is 'now'?"). I think genius comes from intuition and creativity. Any chump can use a calculator to crunch numbers. It's all about choosing the right numbers to crunch!

I really like how that series is evolving ^^

Hi Don! First I want to (again :P) say thank you for continuing create passionately delivered content about physics, this series has helped me to understand these concepts in a much more relaxed way than more flashy high paced videos, both that and the comment responses (and interacting in them) give me time to process the information and consider the implications. At the end of this video, my mental model of the spacetime morphed a bit, from a field that is pushed upon by gravity, to a membrane being moved through by both light and gravity at the same rate, while simultaneously being stretched in all directions by dark matter. Would you say that this mental picture is appropriate?

I love this series! It reminds me of my first science class, where my science teacher gave us four matchboxes and asked us to find what was inside them and how many they were without opening the boxes. Thanks so much Dr Don! Keep it up 💪

What was the amplitude of the gravitational waves near the source? Been trying to figure this out for ages!

@rhisavbora2975

3 жыл бұрын

Same men..I always think that too..

@kalokajoe357

3 жыл бұрын

yep, and also, always positive?

@SamudraSanyal

3 жыл бұрын

And what would that feel like as space-time rippled around you. Would you notice on a human scale or since your particles are part of the space-time would it be imperceptible despite the massive energy?

@oldman6803

3 жыл бұрын

@@SamudraSanyal That is exactly what I wonder also. And if we could sense it, what would it be like ?

@Anaesify

3 жыл бұрын

I am not a math person, but wouldn't you be able to figure that out with some equation by taking the size of the black holes, the speed and direction of their motion, and density of space, and applying fluid dynamics equations to it?

@ 2:49 Anyone else rewind that statement several times just to try to comprehend it?

THANK YOU PROFESSOR LINCOLN...!!!

Don, you’re a great teacher.

Why did gamma rays arrive 1.7 seconds laters? Is it because the moments in which the graviational radiation and the electromagnetic radiation ocurred were different?

@drdca8263

3 жыл бұрын

Just a guess, but maybe the tiny amount of dust (hydrogen and such) on the way slowed the light down a tiny bit?

@benjaminshropshire2900

3 жыл бұрын

Just a guess, but that might just be how long it took to start recording? As in "When we looked 1.7 seconds later, there were already gamma rays coming from that point." In that case, it forms an upper bound on the difference in speed. If not that, then my next guess would be that, given the "small" size of the object is question, it might be that the gamma rays started to be emitted immediately, but only became visible as the hot emitting matter "splashed" out far enough to have significant surface area to emit from.

@barefootalien

3 жыл бұрын

@MichaelKingsfordGray Well... that's not actually quite right, but you have the right spirit of the matter as I understand it. Even intergalactic space is not *truly* a vacuum. Its index of refraction is stupendously close to 1, but over billions of years and tens of billions of light-years, that tiny difference adds up. This is *not* due to light being absorbed and re-radiated, however. See Dr. Lincoln's video on the subject for more detail, but the short version is that if the reason light slows down in a medium were because of absorption and re-emission, that light would be diffuse, being re-emitted in all directions. kzread.info/dash/bejne/dYme1pVvg6eZmJs.html kzread.info/dash/bejne/gICh0rCGYNbNic4.html

@barefootalien

3 жыл бұрын

@MichaelKingsfordGray Uh... wut? I "hide behind a fake name" because hackers and identity thieves exist. It's kind of a generational thing as I understand it, where younger people tend to use their real names online. I personally think it's pretty risky, not in an "oh my, someone might know my name in an online discussion" way, but in an "Oh no, someone just stole my identity, hacked my bank account, stole all my money, destroyed my credit rating, and ruined my life" sort of way. But hey, if you think putting your full legal name all over the internet is a good idea, then by all means; you do you. I suppose if I'm really honest, I also use a pseudonym because my 'real identity' is quite limiting... it comes with soul-crushing disability and a great deal of suffering. So pardon me for wanting my online presence to leave some of that behind, to be known not for the broken shell of a body I live in, but for the mind inside. So... now that your unprovoked ad-hominem attack has been dealt with, let me just say that there was nothing I intended as any sort of personal insult in what I said above. One of the things you said was incorrect. This is science, not opinion; there _is_ a right answer and a wrong answer, and yours was wrong. That isn't my fault, nor is it necessarily yours. Plenty of very good, very knowledgeable scientists get the reason why light slows down in a medium incorrect in exactly that manner, and even confidently teach it to others with fancy graphics and everything. In fact, I would say that the _majority_ of working scientists do not truly understand what is happening in this case, so please, take no offense. It isn't that they _can't_ understand it, of course; some critical thought would probably lead them, at the very least, away from the version you recited. Rather, they just haven't taken the time to examine it since they heard the "absorption and re-emission" fallacy earlier in their lives. Regardless of how butthurt you might be, however, what you said _is_ incorrect, in part. So I agreed with the correct part of what you said, while also pointing out the logical fallacy in that description of what happens. Then, rather than rehashing how it actually works in detail, I linked to a couple of videos *by Dr. Lincoln himself* who we're all watching and discussing, that explain what's really going on far better than I can.

@morkovija

3 жыл бұрын

@@barefootalien dude, you spent too much time feeding the troll. Your knowledge and patience are better used somewhere else)

How does the mass of colliding black holes get turned into "gravitational energy" and how does that work with the conservation of information?

@thephuntastics2920

3 жыл бұрын

It doesnt , its bullshit pseudo science.

Most exalted Mr Professor. You issue so many videos so I can't comprehend :) Carry on... I will try to keep up!

dude. these videos are great. and they are getting better. well done you. and thank you for all your work. perhaps a labour of love. but lobour just the same and none the less. thanks.

Kind of off topic: if two entangled particles pass near a black hole, if one is swallowed, does anything happen to the spin of the remaining one?

@pressaltf4forfreevbucks179

3 жыл бұрын

You will know immediatelly the spin of the particle inside the event horizon. Its the same as the spooky action at a distance

@bakdiabderrahmane8009

3 жыл бұрын

@@pressaltf4forfreevbucks179 what if waited for the black hole to swallow the particle then measure the second particle, what result would we get end why

@mubashshiruddin3567

3 жыл бұрын

I wonder if we consider the spin of the black hole as a whole after the particle has been swollen do we say macroscopic spin of blackhole is entangled with the particle that we have outside with us.

@ozzymandius666

3 жыл бұрын

Nothing will "happen" to it. Say you have a maximally entangled set of 2 electrons, with a total spin of 0. If we measure one at spin 1/2, then we know the other is spin -1/2. Now, if we take one of the entangled electrons and throw it into a black hole, and then measure the spin of the other electron, we will get either +1/2 or -1/2, just like any other time we measure the spin of an electron.

@burtosis

3 жыл бұрын

It may not be possible to properly isolate the particles to maintain entanglement in real situations.

How do gravitational waves preserve quantum information? I mean they too, lead to loss of mass like the Hawkins radiation(about which I heard preserves quantum information).

@burtosis

3 жыл бұрын

Good question

@LuisAldamiz

3 жыл бұрын

It brings the energy back to our side of the event horizon. I often contend that information is not lost in a black hole, only hidden, but for the likes of Hawking hidden is the same as lost, what I cannot agree with. In any case, when it leaks back to this side of the event horizon (in this case as gravitational wave energy) the paradox gets solved for good (you still lose the original quantum particles which "fell in" but that also happens in Hawking's radiation).

@BenjaminCronce

3 жыл бұрын

I think the idea goes like this. If you flip one bit of information on an infalling object that makes it into the blackhole, will there eventually be a corresponding 1 bit difference in anything like hawking or gravitational information than if you did not flip that bit. If so, then there is a connection between the input and output. While we think of it as a simple wave, that wave may be different by a plant unit because something else was different. It really doesn't matter if an observer can tell the difference, it's if the universe can.

@ozzymandius666

3 жыл бұрын

The waves carry away information about the orbits of the BHs.

@barefootalien

3 жыл бұрын

I'm of the opinion that the conservation of quantum information is only an approximation of the truth, like everything in QM and GR is. When we discover the next layer, the next theory and paradigm, I fully expect that we'll find out that information is only approximately conserved, and that black holes are precisely one of the circumstances in which that conservation (and the underlying symmetry) is broken. Yes, I'm familiar with the paper that claimed to have determined that Hawking Radiation is effectively created by tiny wormholes that reach into the black hole to preserve quantum information, but I think that's pretty far-fetched given that not only do we not have a full theory of quantum gravity, we know with 100% certainty that the interior of a black hole is outside of the regime of even our best effective field theories of gravity. Thus I feel like what is needed is not some fancy way to make sure Hawking Radiation and/or Gravitational Waves preserve information... it's merely some therapy to help us accept that conservation of information is only a tenet of a theory we know with total certainty to be flawed, and that in nature, information is probably only approximately conserved.

Excellent.... thanks 🙏.

I love Don's youthful enthusiasm describing the merger of two black holes.

So, what caused the 1.7 second discrepancy between the gravitational wave and accompanying light?

@Dragrath1

3 жыл бұрын

the gravitational waves observed were from the pre merger velocities of the in spiraling neutron stars right before merging the radiation was from the actual collision itself. The delay effectively matches the theoretically expected causal delay thus why they are thought to travel at the same speed.

@krabkit

3 жыл бұрын

could it also be that even empty space is not a perfect vacuum, and over such a large distance small interactions add up

@zeno2712

3 жыл бұрын

@@Dragrath1 Ah. Thanks for that. I was just about to ask the same question but @ Ryan Twombly got there first. So the collision itself didn't emit gravitational waves, just the final moments before the collision?

@ryantwombly720

3 жыл бұрын

krabcat The interesting thing about that observation, in my mind, is the difference effect on gravity versus light. Dragath1’s answer is sound, it’s just interesting to try to picture a propagating wave of space time and muse on its properties. Does a gravitational wave slow down as it passes a black hole? Does the hole make a break in the wave or does the wave curve around? Hopefully we’ll get more of these wave-and-light combinations so we can make the comparisons.

@zeno2712

3 жыл бұрын

@@ryantwombly720 Also, in this case, they originated from the same source so were expanding out together, one following right behind the other, but presumably if they encountered other gravitational waves coming from somewhere else on the way, would it have affected either of them?

Just for the record, the equations at 2:47 are a bit interesting (=wrong). speed of light doubled, parentheses missing, but: miraculously correct result. That's how physics is done anyway :D

Great tutorial!

First, let me say that I enjoy your videos a lot, Dr. Lincoln, particularly because despite all the simplification that you must apply, you still manage to get the point across that there's in fact way more complicated science beneath. One little thing though... and you may call me nitpicky any time: Karl Schwarzschild is not pronounced "child", the second part of the name is "schild", which means shield in English. "Schwarz"-"schild", with the "i" pronounced as in "will". Sorry for being such a grammar-freak.

11:38 "Real black holes are more complex. They rotate, have charge, all sorts of things" Those are the only things lol

@ozzymandius666

3 жыл бұрын

They also have temperature and entropy.

@burtosis

3 жыл бұрын

They also have mass and a well defined location.

@rykehuss3435

3 жыл бұрын

Michael Bishop tell me more about how black holes have "entropy". Entropy, one of the most commonly misunderstood concepts in physics. Temperature, I'll give you that one. And also no shit they have mass and location. What else, they have a name and a wikipedia page too? Thanks Captain Obvious burtosis.

@Dragrath1

3 жыл бұрын

@@ozzymandius666 Yep they likely have entropy and thus a temperature if Hawking and others are right which seems likely as the argument used to derive it is a fairly robust one that gets around the difficulties by only being interested in the properties observed far away from the black hole or really any horizon. Plus who knows what other properties might exist in a fully formed theory of quantum gravity hence it isn't entirely a wrong statement. (plus as @burtosis said don't forget mass though I'm a bit leery about saying location as quantum gravity might not depend on distances directly)

@ozzymandius666

3 жыл бұрын

@@Dragrath1 Yep. The uncertainty principle must do some weird stuff at the center. Highly localized phenomena have huge momentum uncertainties. The center should be very hot.

Is it possible for two black holes to collide in such a way that they lose enough energy so that the merged object is not a black hole anymore?

@KohuGaly

3 жыл бұрын

no. In fact, the surface of the resulting black hole can't get smaller than the total original surface of the two source black holes.

@burtosis

3 жыл бұрын

@@KohuGaly this is false. Surface area is directly proportional to mass and in all real mergers there is loss to gravitational waves. Thus every merger has a horizon area less than the sum of the two initial objects.

@burtosis

3 жыл бұрын

I think it may be possible, but only for ultra light black holes which likely don’t exist, and even if they do are unlikely to collide and merge. Something on the order of a million kg where they would have enormous energy output in Hawking radiation and would be near exploding anyhow. I’m not sure though, because I’m uncertain how that much Hawking radiation would affect a merger.

@OldGamerNoob

3 жыл бұрын

Mass is not directly what defines a black hole, but density. The colision makes the total of the singularities less massive, but not less dense.

@nathanielgregg543

3 жыл бұрын

The orbital properties and the masses of the original black holes determine what percentage of the total original mass becomes binding energy (i.e. is lost to gravitational waves after the merger), but in all cases it’s always true that the final mass is larger than either of the original masses but smaller than the combined raw masses. 5% is the amount that’s radiated away in the maximal case, where the two masses are roughly equal. If they had an incredible amount of energy in their spins and their spins were aligned, that percentage can be bumped up all the way to about 11%.

Hello there, it's the best channel on youtube. Why the speed of light is so slow and what would happen if it increased/decreased?

This one was awesomeeeee!

Dr Lincoln: Next to the “Hall of Heroes”, please also create a “Wall of Shame” for the people consistently giving wrong answers:D

@terryboyer1342

3 жыл бұрын

Wall of Shame for giving wrong info. You mean like CNN, MSNBS and the rest of the fake media?

@Hossak

3 жыл бұрын

Hehe - seriously though he is too nice and positive a guy to do that - plus the list would stretch approximately 2 light years long :)

@maythesciencebewithyou

3 жыл бұрын

@@terryboyer1342 How did a Foxtard get lost here

@juzoli

3 жыл бұрын

terry boyer What are you doing on a scientific channel?

@terryboyer1342

3 жыл бұрын

@@juzoli What are you doing? And why do you ask?

Can the energy that is converted to gravitational waves be considered "lost"? i.e. that it is impossible to convert it back to other forms of energy? And what does that mean in the context of thermo dynamics? Could the energy that is bound in gravitational waves, i.e. in space time itself, be a candidate for the dark energy?

@juijani4445

3 жыл бұрын

Theoretically, it is always possible to convert one form of energy into another as per the 1st law of thermodynamics. But in practice, the world is mean. We have all sorts of things that prevent us from using the same source of energy over and over again. The heat dissipated by the various processes on earth is the central cause of global warming. It would be a miracle if we can find a way to able to convert the energies lost into useful work.

@Anaesify

3 жыл бұрын

I don't believe the energy is lost, the fact that the waves are still travelling and carrying it after billions of years shows that if the wave is un-impacted by external forces (hitting objects, moving through gas and dust, being pulled by very massive gravitational objects), it will just keep going forever just like light. It's so so so so so so tiny because it has travelled for so long and most of its energy has been dissipated through these events; when we measure collisions that are closer i think we will see stronger waves. edit: I like the idea of the energy of these waves being dark energy, but I have no idea :P

@juijani4445

3 жыл бұрын

@@Anaesify Well said!

@LuisAldamiz

3 жыл бұрын

What Devam says: energy is never created nor destroyed, only transformed... into useless goo.

@thedeemon

3 жыл бұрын

@@LuisAldamiz In an expanding universe energy can be lost, like CMB photons lost most of their original energy. Energy conservation law doesn't work there, by Noether's theorem it's only valid when time translation symmetry holds, i.e. "tomorrow everything works the same as today". www.preposterousuniverse.com/blog/2010/02/22/energy-is-not-conserved/

I like this series

I love how your answers to questions are not dumbed down. I don't understand everything you say but close. I'm just a machinist who likes the way the universe works. I did try to get an engineering degree and took up to multi-variable calculus so I guess I was primed to like this stuff.

Is there a gravitational equivalent to the radiation cosmic background? Do gravitational waves dissipate energy in any way as they travel?

@taw3e8

3 жыл бұрын

Yup, at least we believe that there is something like Cosmic Gravitatioal Background. Although they might be too small to measure them in the next centuries :(

The more we understand the less we know..🥰 Physics forever.

@CyrilleParis

3 жыл бұрын

I prefer another analogy : we know more things, but our horizon broadens thus the questions we saks ourselves multiply and are deeper.

@ajaysasikumar6931

3 жыл бұрын

@@CyrilleParis well that's good,😇

Great subatomic stories episode!! I wonder if artificially bending of space time can be achieved and if it has some practical use or is if it is just a cool way to explain dissipation of energy when massive bodies in the universe collide

Dear Dr. Lincoln, thank you for the great videos! Is it known if gravitational waves travel exactly at the speed of light or can they be slown down by matter or different regions of spacetime? Also, have there been calculations on the dispersion of the 2017 event? Perhaps the dispersion allows us to find the exact time of the event and compare this to the arrival time of the gravitational waves. This could show that gravitational waves experience different travel speeds

For a distant observer , does merging of black Holes take infinite amount of time?

@barefootalien

3 жыл бұрын

We have observed merging black holes as distant observers, and they did not take infinite time, so... no, it doesn't, by direct experimental evidence.

@IntraFinesse

3 жыл бұрын

Keep in mind this is not a particle falling in, which would appear to dim and take forever to fall in. This is two regions of space time merging. The collision of the 2 BHs produced a gravitational wave that was detected by LIGO.

Maybe a good analogy for gravity waves would be sound waves generated by someone doing the dishes in the kitchen traveling all through the house, and being picked up by a microphone in the den 🤣

@fffUUUUUU

3 жыл бұрын

Hahaha it's a good one! 👍

@vicfitz82

3 жыл бұрын

I was watching this at 5am and paused twice because i thought something or someone was in my own kitchen. 😅

I'm an undergrad part of the ligo scientific collaboration and we're trying to minimize noise related to the input/end test mass mirror coatings.. known as brownian noise thats the result of the motion of molecules in the mirror .. quite ridiculous but its happening

@drdon5205

3 жыл бұрын

The Casimir effect writ large!

@barefootalien

3 жыл бұрын

Neat! I assume this minimization is primarily focused around cooling the mirrors?

@alfredogonzalez8735

3 жыл бұрын

@@barefootalien the mirrors used in these detectors are called dielectric mirrors consisting of many layers of alternating high (TiO2) and low refractive index (SiO2) material of course the mirrors are cooled a ton during operation at ligo or virgo but we're specifically trying to develop coatings with less of this brownian motion.. its a common practice to heat up these mirrors to improve their stoichiometry and optical properties but what happens is these glassy films will crystallize at certain temperatures which ruin the performance, during deposition of these layers these things called crystallites will form which are essentially extremely small crystal seeds which help spread crystalization during heating... these crystallites are a source of scattered light, and the interfaces between amorphous and crystallized material leads to more mechanical noise so we're trying to develop mirror coatings that have less of these crystallites so there's less scattering/mechanical noise and so we can achieve higher annealing temperatures.. the idea is to make the deposited thin films smaller than the critical size of a crystallite and we have relatively good results so far.. we analyze samples with X-ray diffraction and microscopy

Interesting video as always Dr. Don! I am hoping that you are going to discuss the temperature of Black Holes & why it approaches absolute zero. Also, what are the differences between Anyons, Fermions, and Bosons? Thanks for these awesome videos! Stay safe......

@Onnozelfilmpje

3 жыл бұрын

Anyons are not particles, they are quasiparticles. See en.m.wikipedia.org/wiki/Anyon.

Hey, If Ligo and Virgo detected the g-waves a second before the gamma ray detection, does that mean gravity is faster than light? Please explain, btw big fan💙

@abhijiths5237

3 жыл бұрын

Both travelled a huge distance and speed of light in a medium is slightly slower than in absolute vaccum so that might explain the discrepancy

@kritanjanbhattacharjee1878

3 жыл бұрын

@@abhijiths5237 but space is vastly vacum right?

@abhijiths5237

3 жыл бұрын

It might have encountered some gas clouds or nebulae

@juijani4445

3 жыл бұрын

Entering Earth's dense atmosphere would cause light to slow down significantly. This might be the foremost factor causing the discrepancy.

@kritanjanbhattacharjee1878

3 жыл бұрын

@@juijani4445 but it was detected by Satellite telescopes right?

I was 100% sure he's going to say "physics is everything" with his wizard voice

Hello sir, again a wonderful and enlightening video. You are GREAT to make us understand. If I may ask for something different (sorry, google trad...) : When we talk about entangled particles, it immediately makes me think of different pointers to a single location in memory, a classic computer bug. As if the entangled information were stored "elsewhere" (in another dimension?) To verify it, nothing could be simpler: if a "memory cell" contains the same information for two particles, it must be able to contain that of a third (or more) particles ...

Generating gravity is also a form energy and therefore a object loses some energy... learned something new here. Ty.

Anyone else hear someone putting up dishes in the background? lol *edit* Actually, may be just a squeaky chair.

@brianjuelpedersen6389

3 жыл бұрын

It does sound like dishes - or perhaps even more like cutlery being handled. Perhaps someone emptying a dish washer?

@jeffstewart1189

3 жыл бұрын

I heard dishes with utensils banging around but not complaining. Thanks to Dr. Lincoln for inviting me into his home.

@Hossak

3 жыл бұрын

Yup - it is a terrible thing when you realise than even a physics wizard has dirty dishes :(

@Hossak

3 жыл бұрын

@jumbonium I thought it was the chemists who clean the physicist's house?

So no questions asked about the however so slight difference between light speed and gravitational wave speed?

@Anaesify

3 жыл бұрын

I believe the difference at that scale (having travelled such a massive difference) could be due to quantum levels of complications involved in such a long journey, and can therefore be counted as an acceptable margin of difference. Don generally doesn't go celebrating science victories without criticizing the parameters of the experiment, so I'm inclined to trust that its "as good as the same" :D

@rc5989

3 жыл бұрын

It is more likely the result of warped spacetime near the source. Some sources of extreme magnitude such as quasars have the light arrive with small differences in time, which are conceptually easy to attribute to warped spacetime at the original source. For this example, there is likely a 1.3 second window in which the light was emitted from warped spacetime which from a far observer is indistinguishable from being emitted 1.3 light-seconds farther away than the source of the gravitational waves. The exact workings of extreme high energy events is extremely complicated, just within General Relativity without the need for quantum gravity. There are quasar emissions that do the opposite, which is to arrive early by quite a measurable amount. It is very interesting, but certainly not a flaw in General Relativity, in my opinion.

@OldGamerNoob

3 жыл бұрын

I think gravitational waves also follow the same path of warped spacetime as light does (gravity waves bent by gravity, meta, I know) so maybe the gamma rays are produced by the debris from the colision falling back onto the surface of the newly created object??? or in the force of the lumpy neutron star becoming spherical again? Otherwise, I wonder how much of a discrepency is needed before that quantum gravity theory candidate from that previous episode is no longer considered disproven...

@Dragrath1

3 жыл бұрын

The key to remember is there is a distinct difference between the emission of gravitational waves and the detection of gamma rays i.e. light gravitational waves are caused by massive objects moving quickly such as the final inspiral of two neutron stars leading up to the collision where as the light emission is a consequence of the collision itself. In this case the difference is causal i.e. gravitational waves precede the merger itself. You need to consider where the radiation is coming from

@tonywackett326

3 жыл бұрын

Is there any reason gamma rays wouldn't have been released for a longer period of time than for the creation of gravitational waves? I'd imagine the 'heat' lasted longer than the 'bang'.

Oh you've written several books! Very tasteful plug didn't even notice in previous videos

Congratulation to the hall of heroes!

Who's doing the dishes in the background?

@Hossak

3 жыл бұрын

Quantum elves.....

@Nilguiri

3 жыл бұрын

Maxwell's Demon.

@zhaokwong5544

3 жыл бұрын

Fermilab's captured aliens

His name is pronounced Schwarz-schild, not Schwarzs-child. It literally combines the German words for black (Schwarz) and shield (Schild).

Thanks for talking about gravity and wave function. Peace and agap'e.

Physics is everything!

The speed of light as it appears in the formula at 2:40 appears to be off by a factor of 2, not that it makes a big difference in the bigness of the resulting burst of power. "Hall of Heroes" is a marvelous addition. I have often used the question "what is gravity" as a way to illustrate that scientists (and others) can use a concept without fully understanding it. Gravity is an everyday experience for nearly everyone yet is extremely elusive as to what it is.

I did indeed say it with you Dr Lincoln :)

Thanks. Enjoy your easy going monologues of explanations. An interesting point came up with your video here on Black Holes. In the the past week your video was the second that I saw which explained that in the universe of quantum mechanics gravity is not a force. I didn't know that until this week. As a septugenarien non physicist that fact is hard to understand as heretofore I was under the impression that the four universal forces were, well, universal. Just a quick question. Are any of the other universal forces different in quantum mechanics? Again Thanks. Arthur Boccuti

@juijani4445

3 жыл бұрын

It is just gravity that fails in the world of quantum. We are yet to discover graviton. Speaking of other forces namely, electromagnetism, the strong nuclear force and the weak nuclear force....all the 3 have their origin in the quantum world. The word "nuclear" itself suggests this idea. Electromagnetism on the other hand is caused by charges and well, moving charges. That's all to it.

@Anaesify

3 жыл бұрын

"It's not a force that needs to be considered", I believe is the full description. Gravity exists at all scales of the universe, but we see its effects on very massive objects most easily (the bigger the object, the higher the gravity), and at a human scale the force of gravity is almost unimaginably weak, you can see this for yourself by using a fridge magnet to pick up a nail; the magnetic force of the tiny magnet is overcoming the force of gravity of the whole planet's mass to move the nail! Now think that electromagnetism is 0 to the 36th power stronger than gravity, and the strong nuclear force is 10 to the 38th stronger, and you realize why they don't need to consider the effects of gravity in their experiments, the other forces are so so so much stronger that they overwhelm it completely on that scale.

How does energy for the gravitational waves come from mass of the objects? I mean it would make sense that the energy comes from what is stored potential energy of the 2 object system .How the mass ends up as gravitational wave?

@taw3e8

3 жыл бұрын

Hmmm good question

If I might ask, the difference in detection times, is it due to gravitational waves being a ripple and gamma rays having to travel through space-time and its all an accumulation, millisecond after millisecond? Or is it just the time taken for the collision to produce gamma ray burst after generating gravitational waves?

Hi, Don, Great video as always. I am curious about the LIGO experiment you describe around 3:25. With such small differences, isn't there a possibility that it's just experimental error? Is it reproducible?

@drdon5205

3 жыл бұрын

The two detectors are separated by thousands of miles and they see the same signal.

@datapro007

3 жыл бұрын

@@drdon5205 en.m.wikipedia.org/wiki/Faster-than-light_neutrino_anomaly is why I asked

Amazing video like always. I have a question though, what if we were to drop large amounts of electrically chared matter/energy of only one kind into a black hole. I mean what would eventually happen if we "feed" a black hole with a ridiculous amount of electrons (or protons), since the electromagnetic force is so much stronger than gravity should it not take over at a certain point? If it does what would that look like? Much appreciated the quality of yoir content, keep it up.

@ozzymandius666

3 жыл бұрын

Those are called "extremal black holes".

@eduardoGentile720

3 жыл бұрын

PBS space time made a video about it, it's colled "dissolving an event horizon" or something, it will answer your question at some point

@udokahn3262

3 жыл бұрын

@@eduardoGentile720 thank you, this answers my question

If you were next to the first set of merging black holes, the ones that released more energy than the entire observable universe, how much would that impact you? Like would the waves tear you apart? It seems like it, but since you’re moving with spacetime, it might not actually cause any issues for you?

Regarding the speed of light = speed of gravity waves, what is thought to account for the 1.7 second difference in arrival times? Was that due to some process at the origin, or in the interstellar medium enroute?

How could the electromagnetic wave be detected within 1.7 seconds after receiving the gravitational wave? Is there a network of radiotelescopes ready to be pointed immediately into any direction of the sky? How does that network work, who (which organization by what means) coordinates the rapid reaction of those instruments?

@taw3e8

3 жыл бұрын

There is cooperation of experiments like gravitational wave and neutrino obesrvatories with some telescopes. The process is fully automated (noone could resppnse in 1.7s).

@ximalas

3 жыл бұрын

Radiotelescopes move slowly.

@Don, I wonder what happen to the shape event horizons of the two merging black holes? Do they form a kind of "8" shape at some point? And how this affects their properties if so?

@taw3e8

3 жыл бұрын

For a moment they can form this 8 shape but it depends from masses i believe. I'm pretty sure it will take us some time to figure out properties of such a strange and complicated thing.

Hi, I was hoping you could talk about "information", it's something that comes up a lot in weird situations; like the information content of a black hole is proportional to its surface area(?), or its part in the quantum eraser experiment. I feel like I need a full explanation of it by itself and I'd love if it came from you :)

@Anaesify

3 жыл бұрын

the "information" means everything that the mass is made up of. So like my information is my genetic matter: I am made up of atoms which are protons and neutrons and electrons just like everything else that has mass in the universe, but I am different from a log because I have more complex systems determining the arrangement of those atoms. Most of the time, if you take me and a me-sized-log and you toss us both into vacuum incinerators that instantly turn us both to ashes; scientists could look at those two piles of ash and study them to determine that one was originally made up of flesh and one from wood; the chemical components of the ash would be very different. But in a black hole, all that information is lost. We have no way of knowing if the black hole is made up of people or wood or hydrogen gas or submarines, because the electrons are stripped from the protons and neutrons of objects as they are pulled past the event horizon, erasing everything that made the object unique. So we only see the mass of the things pulled in to a black hole, not what that mass once was.

@hunterG60k

3 жыл бұрын

@jumbonium Fantastic, thank you!

What was the precision of the measurement of the LIGO detection of gravitational waves versus the maximum precision of the instrument? How can we detect things smaller than the matter available to us?

How do you filter out virtual particle interaction in collider particle collision experiments?

Ligo so cool

Considering you find Kip Thornes conclusion hasty, do you think a quark star would be plausible and if so which quark would be the most likely candidate to make up a quark star?

Can you please make a video on the direct conclusion of the einstein's theory of relativity and what it does to space? I read it in a book, that the theory of relativity talks about the possibility of a world where time tuns backwards and this is mathematically proven too. The videos are just brilliant ❤

Could you share what topics you will be covering in your Arts and Lecture series on 11th September?

@drdon5205

3 жыл бұрын

Practical progress towards a theory of everything.

„The answer to this question is both yes and no.” Sir, you really are a subatomic physicist!

About the inside of a black hole which means what’s inside the event horizon, I would think that it would be awfully bright if light can’t escape , Or is that Applying common sense ,To quantum mechanics which watchers of this channel will realize that you can’t apply that to quantum situations. Thanks Dr. Don love this channel!

Hello, Dr. Lincoln. I have some questions about particle physics outside of the contents of these videos. Is it okay if I mail you about those? (There are quite a few questions.. Sorry.. 😅)

at what point is the colision of two black holes complete and the gravity waves actually stop? when their event horizons touch? when the less massive singularity of the two is below the other's original event horizon? or when the two singularities touch under the event horizon? ...and does the event horizon distort while the two singularities reach eachother below the surface or would that be information leaving the black hole?

This topic reminds me of a sci-fi song I wrote called ‘Ripples In Time’ :-)

thanks don! is it possible there are a bunch of black holes we cant see which cause galaxies to spin as they do? dark matter?

Hearing that 3 entire solar masses just _vanished_ as gravity waves in less than second was actually shocking. That's a _lot_ more than I thought it'd be. I thought gravity was supposed to be weak!

I like the "Hall of Heroes" idea. 👍

Does a black hole have particle size lesser than the wavelenghth of its matter wave like an electron and if yes, can we consider the singularity as a new particle which has significantly higher mass and possible charge?

Prof Don has an amazing brain but appears as a most likeable chap you could happily sink a pint with in the pub. Even though I dont understand everything he explains, I keep repeating his channel. This sometimes makes my brain hurt a bit but I remain in awe of the complexity and mystery of the very small particles that make up what seems a simple world of people, nature and experiences. One of these days maybe, all will become clear, or not. Maybe its impossible to ever get to the bottom of ... the meaning of life! What is the smallest cog in the machines and what are the largest machines, how many and what powers them? 🤔

Hi Don.. are gravitational waves from supermassive blackholes formation detectable?

Very interesting. A) What is the wavelength max of the G-wave detected? At 04:13 pic 170817 at 0 the f-scale indicates perhaps hundreds on kHz due to the overshoot? B) How long was the G event? As gamma event decays the G curve is still well out of scale at 4 sec. C) Is the double-slit experiment possible (in theory, of course)? Thanks for the excellent lecture.

Hey Dr. Lincoln: I'm wondering about the detection of the gravitational waves since the light of the lasers in LIGO shouldn't be affected by the warped spacetime.

@Ni999

3 жыл бұрын

We have a great many observations of light responding to warped spacetime going back to nearly a century ago. Laser light is not immune to it. You can learn more about LIGO and how it works at - www.ligo.caltech.edu/page/learn-more And by searching KZread for _how does LIGO work,_ there are a number of helpful videos about it.

The "gravitational" energy lost from merging black holes seems to give an insight to the interior of a black hole , like the early moments of the big bang when the density of the universe could of been similar to a black hole . Primordial black holes speculated to be created at the time of the big bang and "evaporating " to create space time fabric and hence faster than light cosmic inflation could be a way of faster than light spaceship propulsion .

Don, If Gravity moves at the cosmic constant (speed of light in a vaccum) will it move slower through a denser medium? Also, if we can eventualy move faster than light then Gravity should have no effect on us?

Hey doctor Lincoln, i've a doubt: if 3 black holes collide, the gravitational waves would move promordial black holes that are in the center of a galaxy, or maybe an entire galaxy?

Dr. Don, is there some link between the hypothesized Graviton particle and Gravitational Waves, similar to Wave-Particle duality in Quantum Physics?

@ozzymandius666

3 жыл бұрын

The late Freemon Dyson said that the gravitational waves detected by LIGO could be made up of as many as 10^37 gravitons.

@Anaesify

3 жыл бұрын

@@ozzymandius666 is the idea that the gravitons *are* the wave? or are they "riding" the wave like photons in the electromagnetic field?

@ozzymandius666

3 жыл бұрын

@@Anaesify Photons are quanta of electromagnetic energy. In that sense, they are the electromagnetic wave. I think the same applies to gravitons, if they exist.

@Anaesify

3 жыл бұрын

@@ozzymandius666 Oh very interesting!!! I think of them as being at the vertexes of an infinite 3d "grid" (the field), and that when observed they manifest as particles "riding" that field in a wave. But I've never thought of the photons as **being** the wave.

@LuisAldamiz

3 жыл бұрын

@@Anaesify - There are many interpretations but one is the photon (as point particle) oscyllating with the corresponding frequency in a tiny space around its "linear trajectory" or even in just abstract mathematical "space" (extra dimensions, you name it). But sure: the photon is the wave just as the weight of the pendulum is also the wave, unless there's no such-thing as point particles, in which case "wavicles" would be waves of something else (space-time, whatever).

Is it possible to study the interior of black holes in any way by analyzing tiny black holes produced inside particle accelerators?

Physics is the ultimate science woooooh

Hi Dr Don! Are gravitational waves a good candidate for Dark Energy? If not, would exclude this vast amount of energy being constantly dumped into the gravitational field by any massive body?

SO what effect would those merging black hole gravitational waves have on normal matter at a much closer distance - say, 10 light years? Would it disrupt the nuclei of atoms?

Hi Don.. a phd astrophysicist wrote that if u solve GT equations for a point mass space time would bend with an event horizon (blackhole?).. how come? Dont we need over 5 solar masses for blackholes?

With measurments and tolerances so precise, how does LIGO differentiate a gravitational wave from other natural phenomena, such as geologic movement?

how do we know the mass of the two black holes in intial case and after collsion from such great distance. im not doubting just want to understand the process.

If there is a process converting mass (a form of energy) to gravitational waves, is there some kind of reverse process? So that one maybe could use the waves to generate power.

In a quantum theory of gravity, what would be the nature of the gravitational radiation? Would it be gravitons or some other particles could also be produced during those merges? If these detectable particles were produced, would it be possible to extract information from them in order to attest of gravitons are really a thing or not?

@taw3e8

3 жыл бұрын

It would be spin 2 particle which must be graviton. Gravitons (if exist) interact so weakly that there's no sense in makeing any detectors :/