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Hearing about scientists sharing knowledge between countries is one of those things that help me keep faith in humanity. If we enavled that love of learning and sharing in every domain, the world would be a much nicer place to live.
The most profound thing to me about space science is this: There is a star out there, or an object out there or some structure in space that I can look at where the light I'm seeing was broadcast when my Grandfather was still alive. So I may not be able to travel back in time and hug him but I can see a light that was cast during his lifetime. It's like looking at the same moon as someone you love on the other side of the world at the same time and thereby being closer. :)
You reminded of my first 2 years of marriage. My wife was a nurse in the Middle East and I was in South East Asia. "Video call" thru internet is not a thing yet back then, only overseas call. We would look at the moon at the same time from opposite sides of the planet, just to feel we are closer. We are together now, 19 years and counting. Time really runs fast.
@@funky555that's just not true. Every star you see at night is between 4 and several thousand light years from earth. The far away stars in our galaxy are blocked from our view by dust and gas. Now in a sense, you are actually correct on a technicality: The Andromeda galaxy can be seen (barely) with the naked eye. It contains more stars than the Milky Way so you could say that it counts, but I'm sure you also see why that's not a great answer.
I really like this. If you look closely, there’s always a connection to be found between two people, and really, things. No matter what happens, you are always connected. Thanks for sharing your thoughts.
Imo, this is THE coolest astronomy news I've ever heard. It's beyond incredible that not only someone though to do this, but we also exist at a time with the computational power to process that much information. Science is incredible
Yeah, it is pretty trippy. Especially considering if the universe all started from a point, you could say everywhere is the centre of the universe that has just expanded out a lot. And everyone stands in the centre of their own observable universe since we can all only see 13.8 billion light years away in theory but the actual universe might be many orders of magnitude bigger than that.
@@DemonXeronYou can't say that everywhere is the centre of the universe, the universe is a physical thing therefore it has a specific centre, you can only say that everywhere is the centre of it's observable universe.
I know people on this paper and shared this video with them. They have zero complaints with it, so your credibility score has gone up drastically. Thank you for your work @SciShow
Interesting thing that wasn't brought up in the video is the possibility that pairs of supermassive black holes may not be able to merge. It's called the final parsec problem. It's worth looking it up if interested.
The gravity wave source problem like you talked about on the water...there are Native Hawaiians who (at least in the past) were able to figure out how islands thousands of miles away could influence waves and navigate and find those islands.
@@filonin2 yeah maybe they could have, but you could also just look it up.... when given a problem you don't just throw the problem out, you look for a solution. It blows my mind that we have all of human knowledge at our fingertips and yet people are to lazy to type to do something for themselves, but not lazy enough to type to tell someone else to do it... literally just highlight from where they said "native" onward and right-click or hold down, then click search, google tells you straight up what's up...
@@forksandknivesssssss Of course it is. This is like saying people shouldn’t have been able to figure out that wind patterns/weather are influenced by nearby mountains or valleys.
@@terryjones573 developing an understanding of how waves interact with islands that's accurate enough to navigate by without tools IS really neat, though. i don't know if its obvious that people would be able to do that, it sounds like a really impressive skill.
The baby photo analogy is interesting, it's like we've found the ultra-sound of astrophysics. In that context I wonder if we'll ever find the "egg", an actual answer to why this all started.
Nice. Also gravitational waves from inflation can be detected as B-modes (they have shape as produced by a magnetic field) in the cosmic background radiation map. There was a false detection in 2015, but precise Planck data showed that it was produced by galactic dust.
So this means that reality is literally wobbly and wavy like a psychedelic video effect. If gravity squishes and squeezes spacetime around, and we are stuff that is moving around in spacetime- than we are constantly wobbling and wiggling around. changing size and speed within the ripples of distant cosmic bodies. If there is a gravitational wave background squishing and squeezing reality, it makes sense to me that it would explain that reality seems to get all mushy and wavelike at the smallest levels. Like we can only see electrons as probability fields because the small thing that is there, is actually changing shape and speed. Or maybe if not at that level, the background could help to explain what drives Brownian motion. Maybe atoms move around like that because they are all surfing on the waves of the gravitational background.
No. None of those effects are due to gravity. Electrons don't have a shape and have almost no mass. Their orbitals are due to them have a wavelength and probability of the peak of the wave being at any one point changes. Brownian Motion is caused by particles vibrating due to kinetic/heat energy.
If atoms were moving around like that because they’re surfing on the waves of the gravitational background, WE would also be surfing along on those waves.
@@filonin2 I am pretty sure I understand and agree with what you are saying. In that I recognize that electrons do not interact with gravity and Brownian motion is what we experience as heat. But I am not a scientist, I'm just a science interested person smart about some other stuff. I was recognizing that gravity doesn't directly impact electrons, but electrons are influenced and moved around by the nucleus that they are attached to. so the model built by my science-dumb brain was imagining a situation where the atoms themselves are getting squished around by the fabric of reality, so maybe when one part of the atom is being squished while the other side is getting stretched. At the levels where we can detect and witness this behavior it looks like relativistic probabilities instead of actual little things moving around.
Ps i mean there is no way mass on large scales is affected by relativity and literally what it's made up of isn't. That's like saying gravity holds you down as a human but not your blood inside of you (it does hold your blood down hence why lower extremities have valves in veins). As we go smaller and smaller there is never a point in which constitute matter isn't affected ‐ otherwise the atoms on tips of your head would fly off earth
what perfect timing! I just within the last few days read up all about this in the book "the universe in a box" by andrew pontzen, meaning it's so fresh in my mind that I got to excitedly predict what hank would bring up next! highly recommend to anyone interested in this kind of stuff, the book as a whole is about how we can use simulations to learn about the universe (due to the fact that we cannot make a black hole in a lab and see what it does, pretty hard to run cosmology experiments) but in order to understand how those simulations are valuable it goes into real depth on stuff like this and specifically in a way that is so well thought out in a way that I personally understood it really well. sometimes you've gotta reread a paragraph but that's science for you, it takes some thinking to really solidify it in your mind
Those observations could lead to insights into quantum gravity. That would be huge, because physic has been somewhat stagnant in this area since the Standard Model.
As usual, SciShow videos trigger a myriad of questions in my brain about an aspect of the nature of reality: ▪ Do Gravitational Waves ever lose so much energy over distance/time that they cease being waves? Or, to put it another way, are there any quiet/smooth regions of the Universe? ▪ What proportion of these Primordial Gravitational Waves have cancelled each other out over time? Could we use this data to calculate the age of the Universe? ▪ If waves could form out of Primordial (pre-Expansion) Space-Time, what other distortions in the "fabric" are possible? Are there entirely self-contained "Bubbles" of Primordial Space-Time which haven't Inflated at the same rate/degree as the rest of the universe? Or at all? ▪ What happens when two of these "Bubbles" collide? Could collisions of Primordial Space-Time "Bubbles" have contributed to the Expansion of the Universe? (Think of this as being analoguous to a Matter/Antimatter collision generating vast amounts of energy. Two PST "Bubbles" colliding to generate a proportion of Cosmic Inflation.) ▪ Could areas of Primordial Space-Time have accelerated/distorted into "Conduits" which link vastly separated regions of the post-Expansion Space-Time? (Think of two swirling vortexes - one swirling clockwise & the other swirling counter-clockwise, linking to form a long tube at their narrow ends & the stronger vortex eventually causing the entire conduit to become a one way hourglass shape - swirling in -> through -> and out ->)
1.) No; like light waves (another massless wave through space) they have no minimum energy. But given how weak they are, most of the universe can be considered quite quiet,since the warping of space by regular matter will be many, many times greater. 2.) The waves do not cancel out,in the same way that you can't cause two laser beams to cancel out when they combine. There are interference patterns as the waves pass through each other, and they lose a little bit of energy when they pass through matter, but otherwise we expect them to be largely conserved. 3.) Theories of 'eternal inflation' involve a large inflating universe with 'bubbles' of 'regular' space in them, each one starting with a big bang. Since inflation is thought to happen faster than light, these bubbles could never fill all of the inflating space (They grow only at light sped) leading to essentially infinite universe production. In our universe MACHOs (Massive Compact Halo Objects) such as cosmic strings or spacetime defects, might be possible; collapsed ripples or folds in space itself, or various fields. 4.) For the above mentioned things, such collisions might produce things like The Great Attractor (A strange asymmetry in our universe that seems to pull things towards it) in the case of 'universe bubbles' or things like fast radio bursts and gamma ray bursts in the case of cosmic strings (Which are much smaller than a single universe.) 'Brane' theories suggest the big bang was caused by two higher dimensional 'membranes' colliding and bouncing apart, the energy of their collision creating our universe. 5.) Wormholes of various sizes have been postulated, though they're generally not stable unless fed with negative energy -which doesn't seem to exist. So it's unlikely we have a gateway to the distant cosmos lying about, but you never know.
I’m glad to see hank back, even if he looks like Walter White XD. But seriously you have been a massive inspiration to my learning since Sci-Show first gained traction! Here’s to many years and continuing to inspire new generations
The thought occurs that if the universe is finite, not infinite, no matter how massive it may be that reverberation waves bouncing off of the outer limits of the universe add to the background. Specifically for those oldest of gravitational waves. It would depend on the formation of these theoretical walls of the universe. It could be that any gravitational waves reaching there would simply be absorbed by the walls like the shore of an ocean, or like a rocky cliff reverberates waves in an ocean, the wall of the universe might do the same with gravitational waves.
Hey Hank and team, What do you think it would mean to find prim-grav-waves that expand radially from a source vs ones that move linearly? Sort of like the difference between a pebble's wave and a boat's wake.
This explains the Schrödinger equation! An object is in multiple places at once AS A RESULT of being pushed around by gravitational waves, making it so that time dilation and length contraction change the properties of the quantum particle relative to the observer!
@@douglaswilkinson5700agree but disagree. Everyone need to de-escalate. Right now we (the humans/ the nations / the blocks) are are not, its a slippery slope and we're picking up speed....
The US could almost certainly cut back the military spending a lot, but it turns out the military does a LOT of scientific research. Sometimes that research directly improves observation technology (like improved cameras or radar systems), but even indirect improvements can help science progress. From what I've seen, the military is the most reliable way to convince congress to fund research. For example: The GPS system was setup by the US military, but ended up being really useful for just about everyone. Aside from the usefulness for tracking things on Earth, the GPS system has helped provide more data about time dilation due to gravity and velocity. Now we just need to find a way to convince our representatives that a reliable fusion reactor is vital for future-proofing the military.
One obvious question is if movement of Earth itself would add a noise signal to those pulsar measurements and how to cancel that out . Besides positional wobble, they also need to cancel out surface movement due to tidal forces stetching the mantle .
2:45 I found glitch in this explanation which is - When ever someone explains about gravitational waves they says - gravitational waves also stretch the object " but in other scenario whenever anyone talks about bending or stretching space-time -" bending or streching of spacetime doesn't so same to the matter inside it " so which one is true in reality!!
This is rather subtle. In this case the space between objects warps; it shrinks or grows. When it does this, the objects themselves DON'T warp... but those 'objects' are individual atoms. (And indeed, subatomic particles) So the object that they make will ALSO squash or stretch,though its individual atoms do not. The difference is that this warping is 'active'; something that changes over time. Something moving into Earth's gravitational field is an objects whose atoms together move into warped spacetime, able to maintain their spacing. Likewise a 'big rip' scenario would tear the universe apart on an atomic level as expanding space separated everything from everything else.
I think we need another LIGO observatory around, say, equatorial Africa. That way, we'd get better coverage of three dimensions, which would make it easier to detect smaller waves. I mean, Washington state an Louisiana still works, it's just that the warping from "top down" gravitational waves for one wouldn't have much room to warp on the other one. Earth is round, so they aren't perfectly aligned, so you do technically have all dimensions covered. Another advantage to having at least three is that if one does go down you'll still have the third, so with two still working it would be easier to rule out measurement error.
Its fascinating, but i find it frustrating how they overstate the utility of their experiments. A lot of things being taught as "what we know" now is clearly not our best understanding, just as a lot of science in recent history was completely wrong, it seems pretty clear most of our current understanding will be revised in a similar way
Something I'm having a hard conceptual time with is if gravity waves bend space itself, wouldn't it bend any "yardstick" we use to measure them? I know it's something that's been observed, but it's still making my head do a bellyflop. Even if the wave goes over only part of LIGO, the light should have to take the same amount of time to cover the distance independent of the arm? I mean gravity bends the path of light (or rather it follows the contours of spacetime), so I wouldn't think that light is free of the affects of gravity and gravitational waves.
You're correct... that's the point. Imagine a string stretched between two points and you know where both points are: that's your LIGO or your pulsar array. You've documented the pitch of this string when it's plucked, just as it is. We're talking about strings made of light here. Now imagine putting your finger on the string: this is your passing gravitational wave bending the light string. You record the current pitch. Then you can subtract the new pitch from the old pitch to find the difference. Your "yardstick" is the old measurement. You need to observe the same spot over a sustained period to gather this data. In particular I would think the primordial waves would be difficult to detect, since they would be so stretched out. Thinking in musical terms, it would be like vibrato rather than a true pitch change: the passing wave would only cause a very small distortion, but it would be sustained for a long period. Think of a violinist holding the last note of a concerto for multiple bow-strokes. Multiple pulses of the same pulsar would be affected, so you would need to observe the same array for quite a long time to determine when gravitational waves were passing versus what the regular pulse pattern is.
I have noticed that people assume that gravity waves must and do move at the speed of light. Since Space apparently did and does expand faster than light I wonder if gravity waves would be so constrained. Determining speed limits for gravitational waves seems like a fascinating study. I hope someone more intelligent than I is looking into this problem
We've done some work with LIGO and its neutron star mergers, which released both light and gravity waves, as well as studying the waves themselves. (If they move faster than light while the things that create them, like black holes, cannot, then the wave will look different.) So far evidence shows they don't move *faster* than light, and if they move slower then it's not by much: en.wikipedia.org/wiki/Speed_of_gravity#Measurements
2:50 the problem comes when the ripple of gravity thru spacetime should make everything contract and expand relative to the experiment, so the length of one side shortens yeah but so does the way the light travels thru that space, or we would be sending information quicker than the speed of light, causality changes in the wake of that field if it is truly a ripple in space time. Think of spaghetification around a black hole, would you really be stretched out to a noodle, or would spacetime be so distorted that your frame of reference actually stays pretty normal, like if you was to imagine yourself in a 2mtr cube box around a black hole would you witness the walls changing, or would you all be stretched out perfectly with space time, so your frame of reference stays constant, to the outside observer your reference box would look squished and elongated, but only because space isn't flat anymore I like to think of a black holes event horizon like a flooded grand canyon, imagine you are one side of the river, you are trying to get to the other side, the only way is thru the rapids, and the river is always bending away from you, so you end up getting kicked back to the starting shore every time you try to cross the river, the torrent is just too strong for you to pass Thats how I imagine things heading into a black hole find themselves, no matter how true your aim or how hard you throw mass into the stream nothing is ever going to make it directly into another black hole, one possibility is a black hole can only merge with other black holes, and we dont know what happens past the event horizon, they need to lose some inertial momentum tho if they ever want to meet. But no Ligo's main problem is its size, being only 4Km or so in length means it can't measure any ripples bigger than that, we need to look out to stars and have multiple observations of the same pulsars, we should witness some difference in the frequency of pulsars if we can observe them from far enough apart, the problem comes with how far we are from them, it might as well be 2 parallel lines to source tho unless we could go light years out in one direction and get some readings from over there.. even then its barely measurable as a difference in the angle of observation Ha yeah but going back to the analogy @ 5:39 you can see that the ripples in spacetime actually make C a little less than constant, there are no such things as straight lines when it comes to space, we see it from our earliest times and observations, every hubble image is distorted, its not all from the mass of galaxies, its probably quite some bit of it coming the ripples in space time.. things will seem blurred as they ripple on a long exposure, unfortunately we need long exposure times to get really nice images
I wonder if a sheet of material large enough and thin enough, supspended in the vacuum of space, could in time, wrinkle in shape as it is vibrated by the frequency. I suppose it would be more influenced by local objects though.
That’s an incredibly misplaced bit of contempt you have there. If, as you said, that you’re only JUST smart enough to understand the gist of something, therefore quite obviously not having a clue about the deeper mechanisms and math at work, how can you possibly, ever expect to have developed such an idea yourself? 🤨 By definition, if you develop a novel physical theory, which is as accurate as GR, that would necessarily mean you know more about it than does anyone else. 🤔 I don’t think anyone would ever profess to understand GR better than Einstein did, so for someone who only understands the gist of a thing, you literally never had even a minute chance of being able to conceive of the original process. 😱 Don’t beat yourself up too bad but at the same time, don’t give yourself THAT much credit, you’d never be able to invent such a robust concept anyway.🤓
You mentioned that some gravitational background might be caused by supermassive black hole mergers. But I thought supermassive black holes never merge because of the last parsec problem.
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Not familiar with Chapter 54. THE UNIVERSE IS NOT COOLING DOWN (The Big Bang failed again, now on CMB.) in "Time Matters, 6th direction"?
I just love that we live in an era of science when a phrase like "garden variety black holes" can happen.
It's still not as easy as you might think. I ordered some black hole seeds for my garden this year, but only got a few neutron stars.
@FrozenWolf150 lucky, all I got were brown dwarves.
@@FrozEnbyWolf150Lucky.
THE SINGULAR BIG BANG IS A FAIRY TALE FOR VARIOUS REASONS. YOU ALL HAVE BEEN CONNED.
@@FrozEnbyWolf150lucky... my project burst and collapsed to less than the Schwartzchild Radius!
Hearing about scientists sharing knowledge between countries is one of those things that help me keep faith in humanity.
If we enavled that love of learning and sharing in every domain, the world would be a much nicer place to live.
The reverse is so depressing, too. I was really excited for potential Venusian exploration as a result of collaboration between NASA & Roscosmos.
The most profound thing to me about space science is this: There is a star out there, or an object out there or some structure in space that I can look at where the light I'm seeing was broadcast when my Grandfather was still alive. So I may not be able to travel back in time and hug him but I can see a light that was cast during his lifetime. It's like looking at the same moon as someone you love on the other side of the world at the same time and thereby being closer. :)
You reminded of my first 2 years of marriage. My wife was a nurse in the Middle East and I was in South East Asia. "Video call" thru internet is not a thing yet back then, only overseas call. We would look at the moon at the same time from opposite sides of the planet, just to feel we are closer. We are together now, 19 years and counting. Time really runs fast.
most stars you see outside is from light atleast 100,000+ years ago
@@funky555that's just not true. Every star you see at night is between 4 and several thousand light years from earth. The far away stars in our galaxy are blocked from our view by dust and gas. Now in a sense, you are actually correct on a technicality: The Andromeda galaxy can be seen (barely) with the naked eye. It contains more stars than the Milky Way so you could say that it counts, but I'm sure you also see why that's not a great answer.
@@funky555my grandpa was pretty old
I really like this. If you look closely, there’s always a connection to be found between two people, and really, things. No matter what happens, you are always connected. Thanks for sharing your thoughts.
Imo, this is THE coolest astronomy news I've ever heard. It's beyond incredible that not only someone though to do this, but we also exist at a time with the computational power to process that much information. Science is incredible
Wow, that's cool! I love science😍
And I am happy seeing that Hank is back😍
It's good to see you, sir. You're looking good! Keep fighting the good fight.
One of the few channels I hit the like button before I can even skip the first ads to see the actual video 🥰
Edit: Your hair’s looking good Hank!!!
Thanks for bringing great education to YT!
S-tier
It's trippy to think that the further back in time you look, the greater the distance yet the universe was smaller.
Yeah, it is pretty trippy. Especially considering if the universe all started from a point, you could say everywhere is the centre of the universe that has just expanded out a lot.
And everyone stands in the centre of their own observable universe since we can all only see 13.8 billion light years away in theory but the actual universe might be many orders of magnitude bigger than that.
@@DemonXeronYou can't say that everywhere is the centre of the universe, the universe is a physical thing therefore it has a specific centre, you can only say that everywhere is the centre of it's observable universe.
@@eriosyce688 I guess everywhere would be the center if it's infinite, but that might not be the case. I think probably not, so you're probably right.
@@eriosyce688 I think trying to define the centre of the universe is like trying to define the centre of the surface of a sphere.
@@QuasarMusics GOOD ONE!!!! That is not just a hyper-dimensional perspective, but a perfect reduction.
So cool to see Hank healthy again 😍🫶🏻
So glad channel's like this exist
I know people on this paper and shared this video with them. They have zero complaints with it, so your credibility score has gone up drastically. Thank you for your work @SciShow
Good to see you get better, love your shows!
Interesting thing that wasn't brought up in the video is the possibility that pairs of supermassive black holes may not be able to merge. It's called the final parsec problem. It's worth looking it up if interested.
The gravity wave source problem like you talked about on the water...there are Native Hawaiians who (at least in the past) were able to figure out how islands thousands of miles away could influence waves and navigate and find those islands.
Citation needed.
@@filonin2 yeah maybe they could have, but you could also just look it up.... when given a problem you don't just throw the problem out, you look for a solution. It blows my mind that we have all of human knowledge at our fingertips and yet people are to lazy to type to do something for themselves, but not lazy enough to type to tell someone else to do it... literally just highlight from where they said "native" onward and right-click or hold down, then click search, google tells you straight up what's up...
@@filonin2 look at Polynesian navigation on Wikipedia. it seems like its a real thing.
@@forksandknivesssssss Of course it is. This is like saying people shouldn’t have been able to figure out that wind patterns/weather are influenced by nearby mountains or valleys.
@@terryjones573 developing an understanding of how waves interact with islands that's accurate enough to navigate by without tools IS really neat, though. i don't know if its obvious that people would be able to do that, it sounds like a really impressive skill.
The baby photo analogy is interesting, it's like we've found the ultra-sound of astrophysics. In that context I wonder if we'll ever find the "egg", an actual answer to why this all started.
Excellent episode Hank!
BTW you look cooler without the hat! Praying for your complete recovery.
Great video, Sphincter Boy! Hope you're feeling well!
Nice. Also gravitational waves from inflation can be detected as B-modes (they have shape as produced by a magnetic field) in the cosmic background radiation map. There was a false detection in 2015, but precise Planck data showed that it was produced by galactic dust.
So this means that reality is literally wobbly and wavy like a psychedelic video effect. If gravity squishes and squeezes spacetime around, and we are stuff that is moving around in spacetime- than we are constantly wobbling and wiggling around. changing size and speed within the ripples of distant cosmic bodies. If there is a gravitational wave background squishing and squeezing reality, it makes sense to me that it would explain that reality seems to get all mushy and wavelike at the smallest levels. Like we can only see electrons as probability fields because the small thing that is there, is actually changing shape and speed. Or maybe if not at that level, the background could help to explain what drives Brownian motion. Maybe atoms move around like that because they are all surfing on the waves of the gravitational background.
No. None of those effects are due to gravity. Electrons don't have a shape and have almost no mass. Their orbitals are due to them have a wavelength and probability of the peak of the wave being at any one point changes. Brownian Motion is caused by particles vibrating due to kinetic/heat energy.
If atoms were moving around like that because they’re surfing on the waves of the gravitational background, WE would also be surfing along on those waves.
@@filonin2 I am pretty sure I understand and agree with what you are saying. In that I recognize that electrons do not interact with gravity and Brownian motion is what we experience as heat.
But I am not a scientist, I'm just a science interested person smart about some other stuff.
I was recognizing that gravity doesn't directly impact electrons, but electrons are influenced and moved around by the nucleus that they are attached to. so the model built by my science-dumb brain was imagining a situation where the atoms themselves are getting squished around by the fabric of reality, so maybe when one part of the atom is being squished while the other side is getting stretched. At the levels where we can detect and witness this behavior it looks like relativistic probabilities instead of actual little things moving around.
@@KurtColliersounds to me like you just came up with an interesting hypothesis to merge quantum mechanics and relativity. I think you could be right.
Ps i mean there is no way mass on large scales is affected by relativity and literally what it's made up of isn't. That's like saying gravity holds you down as a human but not your blood inside of you (it does hold your blood down hence why lower extremities have valves in veins). As we go smaller and smaller there is never a point in which constitute matter isn't affected ‐ otherwise the atoms on tips of your head would fly off earth
Thank you and the team for another video! Looking good Hank!
Keep getting better Hank. You're a star.
what perfect timing! I just within the last few days read up all about this in the book "the universe in a box" by andrew pontzen, meaning it's so fresh in my mind that I got to excitedly predict what hank would bring up next! highly recommend to anyone interested in this kind of stuff, the book as a whole is about how we can use simulations to learn about the universe (due to the fact that we cannot make a black hole in a lab and see what it does, pretty hard to run cosmology experiments) but in order to understand how those simulations are valuable it goes into real depth on stuff like this and specifically in a way that is so well thought out in a way that I personally understood it really well. sometimes you've gotta reread a paragraph but that's science for you, it takes some thinking to really solidify it in your mind
Those observations could lead to insights into quantum gravity. That would be huge, because physic has been somewhat stagnant in this area since the Standard Model.
This is the ep I’ve been waiting for all summer. So exciting! Thanks! 🤩
You and everyone else on this show are amazing. (And you have hair again!) Thanks for all the eye-opening videos.
Looking great Hank!
As usual, SciShow videos trigger a myriad of questions in my brain about an aspect of the nature of reality:
▪ Do Gravitational Waves ever lose so much energy over distance/time that they cease being waves? Or, to put it another way, are there any quiet/smooth regions of the Universe?
▪ What proportion of these Primordial Gravitational Waves have cancelled each other out over time? Could we use this data to calculate the age of the Universe?
▪ If waves could form out of Primordial (pre-Expansion) Space-Time, what other distortions in the "fabric" are possible? Are there entirely self-contained "Bubbles" of Primordial Space-Time which haven't Inflated at the same rate/degree as the rest of the universe? Or at all?
▪ What happens when two of these "Bubbles" collide? Could collisions of Primordial Space-Time "Bubbles" have contributed to the Expansion of the Universe? (Think of this as being analoguous to a Matter/Antimatter collision generating vast amounts of energy. Two PST "Bubbles" colliding to generate a proportion of Cosmic Inflation.)
▪ Could areas of Primordial Space-Time have accelerated/distorted into "Conduits" which link vastly separated regions of the post-Expansion Space-Time? (Think of two swirling vortexes - one swirling clockwise & the other swirling counter-clockwise, linking to form a long tube at their narrow ends & the stronger vortex eventually causing the entire conduit to become a one way hourglass shape - swirling in -> through -> and out ->)
1.) No; like light waves (another massless wave through space) they have no minimum energy. But given how weak they are, most of the universe can be considered quite quiet,since the warping of space by regular matter will be many, many times greater.
2.) The waves do not cancel out,in the same way that you can't cause two laser beams to cancel out when they combine. There are interference patterns as the waves pass through each other, and they lose a little bit of energy when they pass through matter, but otherwise we expect them to be largely conserved.
3.) Theories of 'eternal inflation' involve a large inflating universe with 'bubbles' of 'regular' space in them, each one starting with a big bang. Since inflation is thought to happen faster than light, these bubbles could never fill all of the inflating space (They grow only at light sped) leading to essentially infinite universe production. In our universe MACHOs (Massive Compact Halo Objects) such as cosmic strings or spacetime defects, might be possible; collapsed ripples or folds in space itself, or various fields.
4.) For the above mentioned things, such collisions might produce things like The Great Attractor (A strange asymmetry in our universe that seems to pull things towards it) in the case of 'universe bubbles' or things like fast radio bursts and gamma ray bursts in the case of cosmic strings (Which are much smaller than a single universe.)
'Brane' theories suggest the big bang was caused by two higher dimensional 'membranes' colliding and bouncing apart, the energy of their collision creating our universe.
5.) Wormholes of various sizes have been postulated, though they're generally not stable unless fed with negative energy -which doesn't seem to exist. So it's unlikely we have a gateway to the distant cosmos lying about, but you never know.
I’m glad to see hank back, even if he looks like Walter White XD. But seriously you have been a massive inspiration to my learning since Sci-Show first gained traction! Here’s to many years and continuing to inspire new generations
A pulse from a pulsar is never late, nor is it early. It arrives precisely when it means to.
No, thank you. We don't want any more black holes, neutron star mergers, or distant quasars.
The thought occurs that if the universe is finite, not infinite, no matter how massive it may be that reverberation waves bouncing off of the outer limits of the universe add to the background. Specifically for those oldest of gravitational waves. It would depend on the formation of these theoretical walls of the universe. It could be that any gravitational waves reaching there would simply be absorbed by the walls like the shore of an ocean, or like a rocky cliff reverberates waves in an ocean, the wall of the universe might do the same with gravitational waves.
Hey Hank and team,
What do you think it would mean to find prim-grav-waves that expand radially from a source vs ones that move linearly? Sort of like the difference between a pebble's wave and a boat's wake.
This explains the Schrödinger equation! An object is in multiple places at once AS A RESULT of being pushed around by gravitational waves, making it so that time dilation and length contraction change the properties of the quantum particle relative to the observer!
Minute and a half in and im in awe and wait what, that was the intro? Oh boy, time to get some big boy space pants on.
mind bending stuff. imagine if we had governments incentivized to spend as much on science and well-being as we do on war and corporate subsidies.
We just need to be invaded by some kind of aliens, so we have a common enemy; historically speaking that is the only thing which has united humans.
Protecting freedom has a price.
@@douglaswilkinson5700agree but disagree. Everyone need to de-escalate. Right now we (the humans/ the nations / the blocks) are are not, its a slippery slope and we're picking up speed....
In an altruistic society, we would. Unfortunately, in today's society, altruism is a, "four letter word," and is taboo.
The US could almost certainly cut back the military spending a lot, but it turns out the military does a LOT of scientific research. Sometimes that research directly improves observation technology (like improved cameras or radar systems), but even indirect improvements can help science progress. From what I've seen, the military is the most reliable way to convince congress to fund research.
For example: The GPS system was setup by the US military, but ended up being really useful for just about everyone. Aside from the usefulness for tracking things on Earth, the GPS system has helped provide more data about time dilation due to gravity and velocity.
Now we just need to find a way to convince our representatives that a reliable fusion reactor is vital for future-proofing the military.
so good to see you back.
Looks like Hank's getting his hair back - the chemo is done??
I WANT MY FAVORITE NERD IN THE WORLD TO BE HEALTHY AND HAPPY!!!!!
Well if I was 13.8 billion years old I would probably have wrinkles too.
The earliest moments were not just mind-bendingly dense, but time-bindingly dense, because relativity.
One obvious question is if movement of Earth itself would add a noise signal to those pulsar measurements and how to cancel that out . Besides positional wobble, they also need to cancel out surface movement due to tidal forces stetching the mantle .
congrats on recovering hank green
Thats very interesting humans can know this kind of stuff
Hank you are melting my brain man. And I’m not even high
Hello! Can you please do a video about how motion sickness glasses work and vertigo?
2:45 I found glitch in this explanation which is -
When ever someone explains about gravitational waves they says - gravitational waves also stretch the object " but in other scenario whenever anyone talks about bending or stretching space-time -" bending or streching of spacetime doesn't so same to the matter inside it " so which one is true in reality!!
This is rather subtle. In this case the space between objects warps; it shrinks or grows. When it does this, the objects themselves DON'T warp... but those 'objects' are individual atoms. (And indeed, subatomic particles) So the object that they make will ALSO squash or stretch,though its individual atoms do not.
The difference is that this warping is 'active'; something that changes over time. Something moving into Earth's gravitational field is an objects whose atoms together move into warped spacetime, able to maintain their spacing.
Likewise a 'big rip' scenario would tear the universe apart on an atomic level as expanding space separated everything from everything else.
@@garethdean6382 ok thats makes sense since all atoms are 99.99 percent empty space.
Glad to see you healthy dog!
I was expecting Pinkman to just say “Yeah, science!” but this was much more thorough. ;)
I need to know more about your t-shirt!
The entirety of everything that exists being compressed into an area the size of a marble? My mind can’t even comprehend that 🤯
No. Way smaller than that.
Marble size comes 1 second after.
the next stage of physics is to determine the effects of higher dimensions and/or membrane universes and/or parallel universes on our own.
I am so frickin happy to see you again :)
I think we need another LIGO observatory around, say, equatorial Africa. That way, we'd get better coverage of three dimensions, which would make it easier to detect smaller waves. I mean, Washington state an Louisiana still works, it's just that the warping from "top down" gravitational waves for one wouldn't have much room to warp on the other one. Earth is round, so they aren't perfectly aligned, so you do technically have all dimensions covered. Another advantage to having at least three is that if one does go down you'll still have the third, so with two still working it would be easier to rule out measurement error.
Hey Hank. Sick shirt man! Love your content.
Lookin' F-in' good, Hank.
Love ya, Bud.
You are a legend and this channel is legendary ✨🦋
glad to see the hair coming back ... cancer sucks ... keep on rocking!
brain doesn't really comprehend any of this, thank you for the lake analogy
Exciting news! Thank you
Fun to see somewhere I actually went on the channel (LIGO in Louisiana)
Hank, You are awesome!
Thanks a lot, absolutely clear 👍
If we ever create a warp drive engine, it will be made by taking advantage of gravitational waves.
Thanks Hank!
Looking great, Hank
Totally new! Haven’t thought of this one before.
Thank you for fueling my current hyperfixation on the creation of the universe
Its fascinating, but i find it frustrating how they overstate the utility of their experiments. A lot of things being taught as "what we know" now is clearly not our best understanding, just as a lot of science in recent history was completely wrong, it seems pretty clear most of our current understanding will be revised in a similar way
LIGO has got to be the least observatory-shaped observatory ever built.
Thank you
2:22
Laser
Interfermeter
Gravitational Wave
OBSERVATOR
Something I'm having a hard conceptual time with is if gravity waves bend space itself, wouldn't it bend any "yardstick" we use to measure them? I know it's something that's been observed, but it's still making my head do a bellyflop. Even if the wave goes over only part of LIGO, the light should have to take the same amount of time to cover the distance independent of the arm? I mean gravity bends the path of light (or rather it follows the contours of spacetime), so I wouldn't think that light is free of the affects of gravity and gravitational waves.
The bending of the yardstick is how gravity waves are measured.
You're correct... that's the point.
Imagine a string stretched between two points and you know where both points are: that's your LIGO or your pulsar array. You've documented the pitch of this string when it's plucked, just as it is. We're talking about strings made of light here.
Now imagine putting your finger on the string: this is your passing gravitational wave bending the light string. You record the current pitch.
Then you can subtract the new pitch from the old pitch to find the difference. Your "yardstick" is the old measurement. You need to observe the same spot over a sustained period to gather this data. In particular I would think the primordial waves would be difficult to detect, since they would be so stretched out. Thinking in musical terms, it would be like vibrato rather than a true pitch change: the passing wave would only cause a very small distortion, but it would be sustained for a long period. Think of a violinist holding the last note of a concerto for multiple bow-strokes. Multiple pulses of the same pulsar would be affected, so you would need to observe the same array for quite a long time to determine when gravitational waves were passing versus what the regular pulse pattern is.
you look cool with the 3 day on your head :) hope you are feeling as well you look!
The possibility of knowing what the super early universe was like has left me awestruck.
Nice to see you! You look great!
That shirt takes the big bang to another level🤧💥
I have noticed that people assume that gravity waves must and do move at the speed of light. Since Space apparently did and does expand faster than light I wonder if gravity waves would be so constrained. Determining speed limits for gravitational waves seems like a fascinating study. I hope someone more intelligent than I is looking into this problem
We've done some work with LIGO and its neutron star mergers, which released both light and gravity waves, as well as studying the waves themselves. (If they move faster than light while the things that create them, like black holes, cannot, then the wave will look different.)
So far evidence shows they don't move *faster* than light, and if they move slower then it's not by much: en.wikipedia.org/wiki/Speed_of_gravity#Measurements
great show!..lQQkin' good Hank! :D
2:50 the problem comes when the ripple of gravity thru spacetime should make everything contract and expand relative to the experiment, so the length of one side shortens yeah but so does the way the light travels thru that space, or we would be sending information quicker than the speed of light, causality changes in the wake of that field if it is truly a ripple in space time.
Think of spaghetification around a black hole, would you really be stretched out to a noodle, or would spacetime be so distorted that your frame of reference actually stays pretty normal, like if you was to imagine yourself in a 2mtr cube box around a black hole would you witness the walls changing, or would you all be stretched out perfectly with space time, so your frame of reference stays constant, to the outside observer your reference box would look squished and elongated, but only because space isn't flat anymore
I like to think of a black holes event horizon like a flooded grand canyon, imagine you are one side of the river, you are trying to get to the other side, the only way is thru the rapids, and the river is always bending away from you, so you end up getting kicked back to the starting shore every time you try to cross the river, the torrent is just too strong for you to pass
Thats how I imagine things heading into a black hole find themselves, no matter how true your aim or how hard you throw mass into the stream nothing is ever going to make it directly into another black hole, one possibility is a black hole can only merge with other black holes, and we dont know what happens past the event horizon, they need to lose some inertial momentum tho if they ever want to meet.
But no Ligo's main problem is its size, being only 4Km or so in length means it can't measure any ripples bigger than that, we need to look out to stars and have multiple observations of the same pulsars, we should witness some difference in the frequency of pulsars if we can observe them from far enough apart, the problem comes with how far we are from them, it might as well be 2 parallel lines to source tho unless we could go light years out in one direction and get some readings from over there.. even then its barely measurable as a difference in the angle of observation
Ha yeah but going back to the analogy @ 5:39 you can see that the ripples in spacetime actually make C a little less than constant, there are no such things as straight lines when it comes to space, we see it from our earliest times and observations, every hubble image is distorted, its not all from the mass of galaxies, its probably quite some bit of it coming the ripples in space time.. things will seem blurred as they ripple on a long exposure, unfortunately we need long exposure times to get really nice images
I wonder if a sheet of material large enough and thin enough, supspended in the vacuum of space, could in time, wrinkle in shape as it is vibrated by the frequency. I suppose it would be more influenced by local objects though.
The speed of light is just the speed of sound for spacetime.
Nice to see you're starting to get your hair back.
You're looking great!
we went from detecting cosmic microwave background radiation to trying to detect cosmic gravitational background ripples. this is science my friends
"Imagine the lake growing"
Is it getting deeper or gaining surface area? Or both?
Gaining surface area,waves in this analogy are surface phenomena.
Yeah Mr. Green! Yeah science!
I have a degree of self-contempt that I am just smart enough to understand the gist of this but not smart enough to have developed the idea myself.
That’s an incredibly misplaced bit of contempt you have there. If, as you said, that you’re only JUST smart enough to understand the gist of something, therefore quite obviously not having a clue about the deeper mechanisms and math at work, how can you possibly, ever expect to have developed such an idea yourself? 🤨 By definition, if you develop a novel physical theory, which is as accurate as GR, that would necessarily mean you know more about it than does anyone else. 🤔 I don’t think anyone would ever profess to understand GR better than Einstein did, so for someone who only understands the gist of a thing, you literally never had even a minute chance of being able to conceive of the original process. 😱 Don’t beat yourself up too bad but at the same time, don’t give yourself THAT much credit, you’d never be able to invent such a robust concept anyway.🤓
Thank you 🎉
You mentioned that some gravitational background might be caused by supermassive black hole mergers. But I thought supermassive black holes never merge because of the last parsec problem.
I'm struggling to understand how light wasn't present during the big bang. How does something so energetic not shine light for 380,000 years?
Jason Statham as a Science Guru?.....yes please.
Seriously though, so much Love to you Hank!
its like Dorothy, inside the cyclone, asking herself "but what kind of butterfly made this?"
Ty for being
Hi Hank!
My brain can't comprehend a growing lake. :(
Boy just wait until your first flood.
@@garethdean6382 Flood my brain with knowledge!
IMPRESSIVE
How did the LIGO experiment isolated itself from the effects of gravitational waves?
Hi Hank
Great way to end my day!❤
Science is Awesome!
JESSE! WE NEED TO COOK!
I love Hank can move his ears! (3'37'')