+Ryan B How do you know? Hyperinflation is a yet unproven theory. The universe could be MUCH older or younger than previously conjectured. Also the maths keep getting convoluted, with recent studies of "standard candles" suggesting that, even with hyperinflation the universe is accelerating 25% faster than it should be. You can google this, I'm not making it up (also, I didn't do the measurements).
NickeTMD My religion states that a magic bearded man created the universe exactly half a billion years earlier than your "science". Also, the earth is perfectly spherical instead of slightly ovoid. #eggshapedearthconspiracy Or I was wrong. Probably that.
For real, how can this channel be so awesome? I never had any channel that made me anxious like this. I would love to see the content covered here becoming a TV series someday. The production team and the host are amazing, the content is amazing, I think we can't go wrong with that. Thanks a lot for your great work.
I know you have alot of videos planned but you are the best youtube channel for physics out there, so please, do some videos on stringtheory. Alot of us will appreciate it!
I dont watch the PBS TV channel very much but i love their RUclips channel. I do prefer SciShow though, but both channels are pretty close in terms of quality and content, and they're less competitors and more colleagues since they work together quiet often
+Austin Pinheiro - If we add the bite rate term to the PBS equation, we can predict that the size of individual PBSs decrease over time. To balance this out, we need a term on the right side that describes the creation rate of these PBSs. We can see from the first equation that PBSs are annihilated almost immediately after being created, with very little waste. That waste is non-zero however, so we must now determine what effect the excess PBSs will have on the universe over vast timespans. Will the PBS-filled universe ultimately turn out to be crunchy or smooth? That's the big question of the day.
4:19 I accept that k=+1 is a spherical geometry and is necessarily finite. However, I was under the impression that k=0 could be either finite *or* infinite. In fact, I feel like I remember this being stated in a previous PBS Space Time video.
+The Science Asylum It can be finite if the universe is connected to itself, if you can 'go off one side and appear on the opposite side'. However this is a special case not being considered by this video. Such 'closed universes' may e an interesting topic in future though.
***** He's talking about a simple universe, one where a single value k is the ONLY variable that the curvature. The only way to have a finite universe in that model is to have a hyperspherical universe. However there are more complex models where k describes some of the curvature but there are other elements that also contribute. A donut shaped universe for example has two types of k in 2D, one going around the 'equator' and one perpendicular to it. Another would be a cube where if you went off one face you appeared on the opposite face. Such a universe would have no edge and be finite but it could be flat. Many video games use such models in their levels. Such models however are a subject by themselves and treating them here would involve adding a footnote or something and risk confusing people. This article is a very brief treatment of one such model, a 30 billion ly wide dodecahedron: physicsworld.com/cws/article/news/2003/oct/08/is-the-universe-a-dodecahedron
is it not possible that geometry of the universe is actually hyperbolic and since we can only see the obersvable part of the universe, we are only able to see a very small part of it which may actually be close to being flat? much like what we notice on earth?
Give this one a gold star! I completely agree with your direction of thought +Pravar Parekh -- I believe we are -literally- _metaphorically_ the size of sand _(our observable universe)_ in an hourglass _(the 'hourglass' being our entire universe.)_
+Pravar Parekh There is a theory that points out, if the universe is expanding fast enough and the critical barrier is reached then the "edge" of this would be forever lost to a local viewer. I think this is ENTIRELY possible. It could also explain the microwave background as it could be matter transitioning outside the actual field of view creating a ghost image.
Description of all the constants: a - awesomeness y - yeets per min L - lit factor m - memes (dank) since beginning of universe o - OP (op listed it as zero since he ain't og)
this has become my favorite thing to watch on youtube. thank you for making some of the most complex topics in the universe feel accessible. keep up the good work.
You pitch your videos at such a good level, I'm a mechanical engineering Masters student and learn heaps from this, but the way you go through the math and make sure everything is clear makes me feel like someone without a background in physics or calculus would be able to understand too. Really nice finding a channel that doesn't go super basic or so complex that I doubt they even understand either! Keep it up :)
Love the series, and love the bloopers we finally got. Keeping giving us more great Space Time, and feel free to share more bloopers. Ya know, if you feel like it.
I laughed my ass off at that last part... But Matt, seriously... Okay maybe this is just the coffee talking but this was a great lesson. I don't actually understand the Math but I can't wait for the next equation. The topic you're on right now is one of the most fascinating things I wish to keep learning about my entire life. P.S.- More bloopers please! :D
First observation of gravitational waves - Wikipediaen.wikipedia.org/wiki/First_observation_of_gravitational_waves...Drever, Thorne, Weiss, and the LIGO discovery team also received the Gruber Prize in Cosmology. ... The Nobel Prize in Physics 2017 was awarded to Rainer Weiss, Barry Barish and Kip Thorne "for decisive contributions to the LIGO detector and the observation of gravitational waves". Total energy output: 3.0+0.5; −0.5 M☉ × c2 Date: 14 September 2015 Distance: 440+160; −180 Mpc Redshift: 0.093+0.030; −0.036 Dark Invisible Energy All four states of matter solid, liquid, gas, and plasma which go into the makeup of the cosmos, are comprised of elementary energy particulates which exist at the fundamental microcosmic level of the cosmos, and atoms which exist at the physically apparent level of the macro-cosmos. As such, and given the recent observation of gravitational waves being propagated through space from the collision of two black holes, and given that all waves regardless as to whether they are generated within and transit through outer-space, the gaseous ocean of our atmosphere, or the watery oceans of our planet, all waves are particulate in their makeups and all waves can only be instigated within and transit through a fluidic medium. And Given The Fact: For there to be an output of energy, there must be an input of energy. It follows, that for there to be any output of motion extending from infinitesimal vibrations, up to and through the waves the electromagnetic spectrum, up to the orbital motions of particles around the nucleus of an atom, and up to the orbits of planets around stars. All forms of motion require an energy input, and the recently discovered gravitational waves are not and cannot be considered to be an exception to this rule. Additional Rational There are only two choices concerning the fundamental nature of outer-space. The first choice is that of the old schools of physics, who believed outer-space to be an energy-less void of nothingness. The second choice is that of the modern schools of physics, who believe outer-space is made up of 90% dark invisible energy, and the remaining 10% is made up of dark invisible and solid matter. Nothingness- Hypothesis If we were able to do the impossible, and use a remote control device to manifest (Note I am aware that it is impossible to manifest nothingness, as this is a contradiction in terms, however this is a hypothetical scenario, not a reality to be taken literally), a wave of particles or a body of matter within a totally energy-less void of nothingness, what would happen? All particles regardless as to whether they exist within a wavelength or within a body of matter *radiate energy outwardly from their structures*, which serves to drive their rotations of spin and forward motion, and fuel their energetic interactions with other particles. Therefore given the manifestation of particles into an energy-less nothingness void, and their constant outputs of energy without any inputs of energy, they would simply blink out of existence, as their energy dissipated into the void. Vis-a-vis Hypothesis If we were able to do the impossible, and use a remote control device to manifest an energy-less void of nothingness into the airless (devoid of atoms only) vacuum of a science laboratory bell jar. what would happen as a result? The surrounding particles of the glass jar would instantaneously be drawn into the energy less void, and the glass bell jar would disappear. Conclusive Facts Energetic wave motions, can only be instigated within and transit through a fluidic medium. Energy waves cannot exist within an energy-less void of nothingness. Energy-less nothingness cannot exist within a wave of energetic motion. There must be an input of energy for there to be an output of energetic wave motion. Gravitational wave energy output has been measured as to being 3.0+0.5; −0.5 M☉ × c2 Gravitational wave energy input from surrounding outer-space is 3.0+0.5; −0.5 M☉ × c2 Conclusive The greater ocean of outer-space consists of a fluidic medium of dark invisible energy, which serves as the primal fuel input source for all electromagnetic activity and phenomenon throughout the Cosmos. As Above So Below - All Things From Little Things Grow. THREE OCEANS OF LIFE Microcosmic ocean of dark invisible energy particles, and positive and negative electromagnetic particles. Macro-cosmic oceans of + & - electromagnetic particles of water and fish. Macro-cosmic oceans of + & - electromagnetic particles of gases and birds. FOUR EARTH ELEMENTS Water Electromagnetic + & - particles and atoms of fluidic liquid matter. Wind Electromagnetic + & - particles and atoms of fluidic gaseous matter. Earth Electromagnetic + & - particles and atoms of solid matter. Fire Electromagnetic + & - radiant particles of electric storms, and heat waves of deconstructing atomic matter. www.fromthecircletothesphere.net
Your answers at the end are often just as fascinating if not more so than the core content. Are there any theories on where the dark energy force comes from in the vast spaces between large collections of matter such as galaxy clusters? Also whether it is stronger perhaps in the center of these voids where spacetime is not being bent by mass?
+DangerZone The most popular theory currently is that it's the energy of space itself, that all the fields and 'virtual particles' in empty space have an energy. This seems to be the case, the amount of dark energy in our universe seems to be related to the amount of space present.
Director Guy: "Action!"Matt: *stares intently at the camera, eyebrows moving* "Now before we do any general relativity..."Director Guy: "Start again. Had some eyebrow stuff going....?"Matt: "That was my... acting."Everyone: *laughter*
No need to tell how great this channel & it's quality is... But I need to say that seeing you guys having fun while recording and bloopers thing made me smile space time :)
Im smarter for having subscribed to this channel. Every video is spot on and informative. What you are doing is important, more important than some may realize or admit. Creating a dialogue is all some of us have and its great to see so many people are interested. Thank you.
Amazing show, this is the BEST physics channel I've yet to come across. I'm graduating right now with my bachelor's in Astrophysics, it's so refreshing to see a serious science show delve into the math a bit more and hit details. Plus you do it with pretty graphics. Nothing wrong with old chalkboard. This is awesome.
CHIBCHART Maybe try keeping your negativity to yourself mate. No need to give people shit for finding things interesting, especially something like physics/mathematics.
+CHIBCHART your tone is pretty dismissive, but as an adult with ADHD, Crash Course and similar resources are actually really valuable, and can be much easier to learn from than textbooks or certain lecturers at certain times. I don't see what's so wrong with helping those that society tends to disadvantage...
This was a great show, loving the equation based explanations! I hope you guys continue to use math up front to explain different concepts. I know a lot of these concepts are extremely math intensive, but I think it's important to show the actual science and math.
you guys are awesome I love what you do. It's not that i'm super serious about astronomy and particle physics and such but the way you guys present it is so interesting I could watch it every day for the rest of my life and not get bored one second
Hi Matt, Speaking of degrees and jobs, I've got a bachelors degree in physics but then I went into a masters degree in civil engineering. I found out that it wasn't really my thing and I would love to do research work in physics. Is it possible for me to do a PhD in physics with my current masters degree or should I retake a masters course in physics?
+Aymen Hassoun As long as you have decent grades in your upper level undergrad physics courses - quantum mechanics, electricity & magnetism, stat mech, etc. then you may be competitive for physics Ph.D. programs. If your BSc was a while ago then you should certainly take a new GRE subject exam in physics to prove to admissions committees that you still have the physics chops.
+Aymen Hassoun Nearly all physics PhD programs in the US follow this tract: Bachelors -> Enroll in grad school -> take core graduate level physics courses (around 2 years worth) -> take qualifying exams (sometimes called 'quals, GDE's, or 'entrance' exams) -> find a research group that can pay you -> do research -> write dissertation -> graduate. Your problem is going to be the quals. The difficulty varies from school to school, but in my experience they require *significant* work to pass. If you don't take graduate level courses there is no way you are going to pass most schools qualifying exams.
+Jason Owlbright They aren't very good, if you compare to, say, a PhD in optics, semiconductors, or something else. There are way more degree holders than positions for astrophysicist*, so sometimes you end up doing something you don't really want to do, with a degree that can't really get you much. * I see a lot of demand for numerical relativists, perhaps the one exception to a shrinking job window in space physics.
Awesome delve into the details of what I've been reading about for years. It's pretty brave to include those equations, as it's a known fact that one mathematical equation will scare away a large percentage of viewers, but it's so helpful to those of us with some math or physics education. Thanks so much, I've never even seen these equations before. Question: I've often wondered if the geometry of complex numbers (with a real component and an imaginary component based on the square root of -1) could have a role to play in cosmology? I read a book about the nature of zero that said zero and infinity can be represented as opposite poles on a sphere in this complex space. If the axis running through those poles was time, then we could experience the universe as some projection of this sphere. We seem to experience it as a 3D projection of some type of other geometry or dimension in any case, and I've heard that this complex geometry already has real world applications.
Great video guys, but don't you think the title is a little too much teleological? I mean, it's not that the universe "needs" dark energy, it just the way it is and saying it needs something implies a purpose and I know we agree it is not the case. Maybe you were trying to say something like "Why relativity theory, as we know it today, needs dark energy?". That is something semantically more exact.
What if the universe isn't expanding faster, but time is slowing down? And, when we look at distant galaxies, since we are seeing them as they were in the past, they look like they are accelerating apart faster the further back you look, because time was moving faster then? Regardless of whether or not that's true though, I think it just seems like a slight leap in logic to assume the existence of "dark energy".
That's an interesting thought. The only issue I can think of is that as far as we know. Time dilation only occurs in areas of high energy/mass density. It wouldn't make sense then that time would slow down as the energy and mass in the universe becomes increasingly diffuse. Also, I think our observations of universal expansion are based somehow on the speed of light, so for that to be true, I think the speed of light would have to be changing, which seems like a no-no.
You guys are almost always over my head, even Crash Course Physics is getting there already. But that's not why I watch you guys. I watch to gain more interest in the math side of things and I enjoy knowing there is math behind the ideas, even if it happens to be far past my understanding. Easily one of my favorite science channels. As always, thanks, I love you guys.
Could you please do an episode on why physicist are having such a hard time to reconcile general relativity with quantum mechanics? Why is it so hard to produce a quantum theory of gravity?
+Sandy Crotch Basically the two view gravity in totally different ways, relativity sees it as curved spacetime, as not a force at all. QM sees it as a force in static, uncurved space mediated by particles. The weakness of gravity makes measuring small effects that might offer clues difficult.
Mine GWAWD I actually followed and understood this! Like, seriously assimilated the knowledge you put forth, Matt! I was really skeptical after Gabe left...namely because I liked his speedy delivery of information and you're much more deliberate and paced, but wow...You're doin' it! Keep it up!!!
Dude, you're the best. Thank you for doing what you do. I've learned more from you than I ever learned from any science teacher. It's mostly my fault though; I'm not the type that can sit in a classroom and take notes. That just isn't effective for me. Sure, I struggle to understand most of what you're talking about. I was a straight D student, and got an associate's degree in Automotive Science a few years after high school. Yeah, not exactly Ivy League. But I've learned more about the world from watching geeks like you on RUclips. I mean that as a compliment. Teachers often hate their jobs (or hate me, at the very least). They seem to go through the motions for a paycheck. But you, and other geeks, light up in a way that makes it exciting to listen. I'm a geek myself. I can go on for days about music and time signatures. I'm fascinated by space exploration as well, and even when my primitive brain can't keep up with you (I didn't make it past 10th grade geometry), I get so excited when I hear you explain what something means for the rest of us. I had a conversation with my 9 year old daughter the other day about gravitational waves, after watching your episode on their discovery; I must have been ecstatic, because the way I explained it to her (the few parts I grasped), she actually listened and asked questions. I wish there was an alternative for people who don't learn by classroom. I'm sure I'm not the only one of your fans who's had an experience like this. Thanks for striving to connect with your audience, and thank you for not taking yourself too seriously. The gag reel at the end was great. Keep up the good work, man.
Arthur if the universe is hyperbolic then it will expand forever and we'll die of dilution and freezing, if it's a hypersphere we'll die of heat death, if it's a flat plane at some infinite point the universe will stop expanding and things will just stay the same. At least that's what I got from this.
No. No we really don't. What you're calling 'regular TV' needs to die, for so many reasons I just can't be arsed to write a rant. EDIT: I'll give two examples to support my conclusion. TLC (The Learning Channel) Discovery
I Study a lot of advanced graduate-level mathematics, and that truly is my passion. But lately quantum physics, quantum mechanics, has really caught my attention and also cosmology.
I've been watching science videos on RUclips for many years now and once I found this channel some months ago, I literally spent the whole day watching all the videos. There are many great science channels on RUclips, but PBS Space Time is my absolute favorite. Hopefully you get enough support to never stop
+illusion z That's the point behind the question...the answer is that what we don't understand about dark energy massively outweighs all the things we do know about it, so most modern theories probably account for this by saying that dark energy (which is a bit of a misnomer anyway) isn't actually energy, just a property of empty space. And since empty space is defined as nothing, it can break all the laws of physics that *nothing* can break.
Once you move to a subject that involves general relativity, the law of conservation of energy no longer holds (at least within the same sense). In fact if I remember right, the law of conservation of energy only continues to apply on a local level. On another note specific to dark energy, they explained in another video that as far as dark energy is concerned, it is inherent to the space-time it embodies. So that it's not directly violating the law of conservation of energy which applies to utilizing energy already present in a system. On this note, I believe this is what illusion z and ThePCguy17 are referring to.
"by saying that dark energy... isn't actually energy, just a property of empty space." Actually it is still energy, though I believe you're right on saying that they consider it an inherent property of space. Keep in mind though, that the phrase "law of physics" is, put simply, a very loaded phrase although I suspect that you're aware of that. All "laws" as well as theories only hold within a specific range of applicability. Because of that, none of these laws are actually being broken (or rather, there's no reason to believe that the current laws and theories are being violated WITHIN their current defined boundaries), but rather they are being enclosed in a larger, more general theory and/or law.
8 лет назад
energy must be deleted as the universe impands or implode in a way. Is this the path to rid of the zombie apocalypse?
this channel is awesooooome!!! I love it. you explaining this beautiful equations with such easy language that anybody can understand. thanks you very much.
+Harshit Jain If I find myself like zone out even for a couple of seconds he'll move on and I'll be lost. I'm 17 and you kind of have to watch past videos. This is pretty hard to keep up with if you don't focus or have a background in it. I mean it's easy to watch but hard to actually learn, unless you make a effort.
Very good advice on the physics careers. I know 2 people with degrees in physics, the one with the PhD is now a professor, and the other with the masters works in development and testing of products in a construction industry (and as you alluded to cashing in, makes way more money than any friend of mine is worth).
You're a naturally funny guy, according to the blooper reel and little jokes you sometimes get in in other episodes. Maybe you guys should podcast too, if you have time, so we can hear your more naturalistic approach and see your humor more vividly. Anyway, another great episode, and once again I can't wait for the next one.
Hahahaha That last part was great. XD I'm sure bloopers after every episode would get old but it was awesome to see this time. Especially the eyebrow thing. lol
I'm looking forward to starting my masters in physics and eventually getting my PhD , I'm passionate about physics but this channel seriously reinforces that feeling, thanks so much! :)
Hey! Recently I asked for a "Physics for Dummies" channel that briefly goes over the basics of physics. I'm only in grade 9 and haven't learnt many physics concepts definitely none at the level of this channel. Good to know they take feedback and are putting things into motion.
1) Isn't it possible for a flat universe to also be closed, by being toroidal? 2) I have been playing a game called HyperRogue recently, which takes place in a negatively-curved 2D geometry - a 6,6,7 tiling which is about as flat as you can get with a nice tiling. It demonstrates other interesting properties of hyperbolic geometry by basing key game elements on horocycles, non-straight equidistants, regions bounded by infinitely many non-intersecting straight lines, the tendencies of pursuing enemies to end up in a long queue, various regular patterns on top of the base tiling, and occasional challenges around the difficulty of long-distance navigation, as well as your eternal explorations never crossing your own path.
Could you please do a show on what more do we expect to learn in the next 10 years? In this period, we will have James Webb Space Telescope, many other huge ground based telescopes, Square Kilometer Array (giant radio telescope), more powerful particle accelerators, gravitational wave detectors, more powerful computers/software.... (and what else do we expect to have in the next 10 years?)
The story was determined 14.3 billion years ago. And somehow these guys always manage to end on a cliffhanger anyways.
+Joshua Pearce this comment was so amazing i experienced self induced deja vu
+Joshua Pearce 13.7?
+NickeTMD 13.8 actually. :D
+Ryan B How do you know? Hyperinflation is a yet unproven theory. The universe could be MUCH older or younger than previously conjectured. Also the maths keep getting convoluted, with recent studies of "standard candles" suggesting that, even with hyperinflation the universe is accelerating 25% faster than it should be. You can google this, I'm not making it up (also, I didn't do the measurements).
NickeTMD My religion states that a magic bearded man created the universe exactly half a billion years earlier than your "science". Also, the earth is perfectly spherical instead of slightly ovoid. #eggshapedearthconspiracy
Or I was wrong. Probably that.
this channel will make humanity last longer. Thank you guys.
That awkward moment when Matt is a better career counsellor than most people.
thumbs up for "PBS Space Time Bloopers" channel!!
+Aj our whole universe is a huge spacetime blooper.
+Aj
I... I thought this is the bloopers version?
+Aj lol i feel famous now
Mr B
shit just got REALLLLL!!!!
Gregory Khvatsky
YUP! banging the poor apple to the roof!! damnnnnn..
I love PBS. You guys bring so much great content to RUclips.
So true. Good quality educational videos
We need to cut their funding to pay for more missiles and tax cuts.
For real, how can this channel be so awesome? I never had any channel that made me anxious like this. I would love to see the content covered here becoming a TV series someday. The production team and the host are amazing, the content is amazing, I think we can't go wrong with that.
Thanks a lot for your great work.
5 years later I have found this and couldn't agree more😊
Yup, found it just now and I agree. Unfortunately, dumb and dumber conspiracy theories or negative news are the bread and butter of television today.
I know you have alot of videos planned but you are the best youtube channel for physics out there, so please, do some videos on stringtheory. Alot of us will appreciate it!
Yes i agree man.. Videos on String theory!
+Alexander Nåt I've seen a video of Brian Greene on that subject once. That stuff is wicked.
Would be great if PBS can break it down for us.
The topics in these videos are so well explained, I wish I had been taught like this when I was in school!
I'm impressed by his steady stance
+Can Turkleton
lol wtf
Every video, its impressive.
Probably the best science channel on RUclips!
I dont watch the PBS TV channel very much but i love their RUclips channel. I do prefer SciShow though, but both channels are pretty close in terms of quality and content, and they're less competitors and more colleagues since they work together quiet often
i like to think PBS stands for peanut butter sandwich
for no apparant reason
Lol
+Austin Pinheiro dammit now so do I
+Austin Pinheiro - If we add the bite rate term to the PBS equation, we can predict that the size of individual PBSs decrease over time. To balance this out, we need a term on the right side that describes the creation rate of these PBSs. We can see from the first equation that PBSs are annihilated almost immediately after being created, with very little waste. That waste is non-zero however, so we must now determine what effect the excess PBSs will have on the universe over vast timespans. Will the PBS-filled universe ultimately turn out to be crunchy or smooth? That's the big question of the day.
+Austin Pinheiro it's peanut butter space time.. peanut butter spacetime..
+Austin Pinheiro That used to be a PBS commercial
I love the Miskatonic U. shirt!
Lol that blooper.
Loving this channel even more. Quality stuff everytime.
This episode was kinda scary and i learned alot of new stuff, also i really like this host guy he seems so friendly and smart!
4:19 I accept that k=+1 is a spherical geometry and is necessarily finite. However, I was under the impression that k=0 could be either finite *or* infinite. In fact, I feel like I remember this being stated in a previous PBS Space Time video.
+The Science Asylum It can be finite if the universe is connected to itself, if you can 'go off one side and appear on the opposite side'. However this is a special case not being considered by this video. Such 'closed universes' may e an interesting topic in future though.
Gareth Dean
Matt made it sound like k=0 was *necessarily* infinite. It could have just been an ambiguous choice of words.
*****
He's talking about a simple universe, one where a single value k is the ONLY variable that the curvature. The only way to have a finite universe in that model is to have a hyperspherical universe.
However there are more complex models where k describes some of the curvature but there are other elements that also contribute. A donut shaped universe for example has two types of k in 2D, one going around the 'equator' and one perpendicular to it.
Another would be a cube where if you went off one face you appeared on the opposite face. Such a universe would have no edge and be finite but it could be flat. Many video games use such models in their levels.
Such models however are a subject by themselves and treating them here would involve adding a footnote or something and risk confusing people. This article is a very brief treatment of one such model, a 30 billion ly wide dodecahedron: physicsworld.com/cws/article/news/2003/oct/08/is-the-universe-a-dodecahedron
Gareth Dean
Thanks for the help!
@@ScienceAsylum BTW love your vids
sometimes these videos are way over my head. I love them.
+Tony P so true.
+Tony P
Isnt that why we all come here for?
+kistuszek I think I assumed that everyone else was studying these topics to begin with and I was the odd one out :)
is it not possible that geometry of the universe is actually hyperbolic and since we can only see the obersvable part of the universe, we are only able to see a very small part of it which may actually be close to being flat? much like what we notice on earth?
Give this one a gold star! I completely agree with your direction of thought +Pravar Parekh -- I believe we are -literally- _metaphorically_ the size of sand _(our observable universe)_ in an hourglass _(the 'hourglass' being our entire universe.)_
+Pravar Parekh
absolutely
+Pravar Parekh There is a theory that points out, if the universe is expanding fast enough and the critical barrier is reached then the "edge" of this would be forever lost to a local viewer. I think this is ENTIRELY possible. It could also explain the microwave background as it could be matter transitioning outside the actual field of view creating a ghost image.
+Aeoster As far as I know, physicists have already explained the microwave background radiation.
+Corvaire Wind yep
This channel is perfection! I love how you use equations AND keep it interesting. Colleges could take a lesson from you
As a fan of H.P. Lovecraft i love your tshirt with Miskatonic University :)
+FullmoonW0lf That would be located in Arkham, Mass.
Seriously, I feel infinitely grateful for your excelent job with this channel. Keep it going like this!
dank energy = (a * y * y) % (Lm/4 + 0)
Thiago what does that even mean
if you can tell at a glance then dont bother
ayy lmao
Description of all the constants:
a - awesomeness
y - yeets per min
L - lit factor
m - memes (dank) since beginning of universe
o - OP (op listed it as zero since he ain't og)
IT MEANS... Tszu hoa PING tai.. Tsung li.. Fong PONG. Pi wong.. 👈🤓
this has become my favorite thing to watch on youtube. thank you for making some of the most complex topics in the universe feel accessible. keep up the good work.
Hey man, nice shirt!
#NiceShirt ?
What a good shirt, man.
"Ex Ignorantia Ad Sapientiam
Ex Luce Ad Tenebras"
+Emile Locas hissss
Perfect college for studying non-euclidean geometry!
You pitch your videos at such a good level, I'm a mechanical engineering Masters student and learn heaps from this, but the way you go through the math and make sure everything is clear makes me feel like someone without a background in physics or calculus would be able to understand too. Really nice finding a channel that doesn't go super basic or so complex that I doubt they even understand either! Keep it up :)
Play at 75% twice plus I dab but I'm 67 so practically dead anyway.
"That was my acting" one-liner of the Year :)
This is an awesome channel. A breath of fresh air from all the other nonsense on RUclips!
u came at the right time, sir
I am so high right now :3c
+Shadowprince 4-20 ayyyyy
+Shadowprince Happy 420 my friend
+zeebadz10 Thats how you get on space time
+Shadowprince Happy 420! I only got an hour left before the day is over :c
+Shadowprince blaze it
Love the series, and love the bloopers we finally got. Keeping giving us more great Space Time, and feel free to share more bloopers. Ya know, if you feel like it.
A green screen? You mean all those equations and diagrams in the background weren't real this whole time? I feel so betrayed...
My life is a lie
Rest assured. It's Matt who's unreal.
This channel takes me back to the days when I used to watch TV, because I anxiously wait for the next episode to come out.
I laughed my ass off at that last part... But Matt, seriously... Okay maybe this is just the coffee talking but this was a great lesson. I don't actually understand the Math but I can't wait for the next equation. The topic you're on right now is one of the most fascinating things I wish to keep learning about my entire life.
P.S.- More bloopers please! :D
First observation of gravitational waves - Wikipediaen.wikipedia.org/wiki/First_observation_of_gravitational_waves...Drever, Thorne, Weiss, and the LIGO discovery team also received the Gruber Prize in Cosmology. ... The Nobel Prize in Physics 2017 was awarded to Rainer Weiss, Barry Barish and Kip Thorne "for decisive contributions to the LIGO detector and the observation of gravitational waves".
Total energy output: 3.0+0.5; −0.5 M☉ × c2
Date: 14 September 2015
Distance: 440+160; −180 Mpc
Redshift: 0.093+0.030; −0.036
Dark Invisible Energy
All four states of matter solid, liquid, gas, and plasma which go into the makeup of the cosmos, are comprised of elementary energy particulates which exist at the fundamental microcosmic level of the cosmos, and atoms which exist at the physically apparent level of the macro-cosmos.
As such, and given the recent observation of gravitational waves being propagated through space from the collision of two black holes, and given that all waves regardless as to whether they are generated within and transit through outer-space, the gaseous ocean of our atmosphere, or the watery oceans of our planet, all waves are particulate in their makeups and all waves can only be instigated within and transit through a fluidic medium.
And Given The Fact: For there to be an output of energy, there must be an input of energy.
It follows, that for there to be any output of motion extending from infinitesimal vibrations, up to and through the waves the electromagnetic spectrum, up to the orbital motions of particles around the nucleus of an atom, and up to the orbits of planets around stars.
All forms of motion require an energy input, and the recently discovered gravitational waves are not and cannot be considered to be an exception to this rule.
Additional Rational
There are only two choices concerning the fundamental nature of outer-space.
The first choice is that of the old schools of physics, who believed outer-space to be an energy-less void of nothingness.
The second choice is that of the modern schools of physics, who believe outer-space is made up of 90% dark invisible energy, and the remaining 10% is made up of dark invisible and solid matter.
Nothingness- Hypothesis
If we were able to do the impossible, and use a remote control device to manifest (Note I am aware that it is impossible to manifest nothingness, as this is a contradiction in terms, however this is a hypothetical scenario, not a reality to be taken literally), a wave of particles or a body of matter within a totally energy-less void of nothingness, what would happen?
All particles regardless as to whether they exist within a wavelength or within a body of matter *radiate energy outwardly from their structures*, which serves to drive their rotations of spin and forward motion, and fuel their energetic interactions with other particles.
Therefore given the manifestation of particles into an energy-less nothingness void, and their constant outputs of energy without any inputs of energy, they would simply blink out of existence, as their energy dissipated into the void.
Vis-a-vis Hypothesis
If we were able to do the impossible, and use a remote control device to manifest an energy-less void of nothingness into the airless (devoid of atoms only) vacuum of a science laboratory bell jar. what would happen as a result?
The surrounding particles of the glass jar would instantaneously be drawn into the energy less void, and the glass bell jar would disappear.
Conclusive Facts
Energetic wave motions, can only be instigated within and transit through a fluidic medium.
Energy waves cannot exist within an energy-less void of nothingness.
Energy-less nothingness cannot exist within a wave of energetic motion.
There must be an input of energy for there to be an output of energetic wave motion.
Gravitational wave energy output has been measured as to being 3.0+0.5; −0.5 M☉ × c2
Gravitational wave energy input from surrounding outer-space is 3.0+0.5; −0.5 M☉ × c2
Conclusive
The greater ocean of outer-space consists of a fluidic medium of dark invisible energy, which serves as the primal fuel input source for all electromagnetic activity and phenomenon throughout the Cosmos.
As Above So Below - All Things From Little Things Grow.
THREE OCEANS OF LIFE
Microcosmic ocean of dark invisible energy particles, and positive and negative electromagnetic particles.
Macro-cosmic oceans of + & - electromagnetic particles of water and fish.
Macro-cosmic oceans of + & - electromagnetic particles of gases and birds.
FOUR EARTH ELEMENTS
Water Electromagnetic + & - particles and atoms of fluidic liquid matter.
Wind Electromagnetic + & - particles and atoms of fluidic gaseous matter.
Earth Electromagnetic + & - particles and atoms of solid matter.
Fire Electromagnetic + & - radiant particles of electric storms, and heat waves of deconstructing atomic matter.
www.fromthecircletothesphere.net
I love it that you don't simplify your presentations down to pablum. Even when I don't understand, I still enjoy watching.
Your answers at the end are often just as fascinating if not more so than the core content.
Are there any theories on where the dark energy force comes from in the vast spaces between large collections of matter such as galaxy clusters? Also whether it is stronger perhaps in the center of these voids where spacetime is not being bent by mass?
+DangerZone The most popular theory currently is that it's the energy of space itself, that all the fields and 'virtual particles' in empty space have an energy. This seems to be the case, the amount of dark energy in our universe seems to be related to the amount of space present.
DangerZone black hole like qualities?
I kind of regretted not watching this before. This is the best channel along with It’s Okay To Be Smart! Good Job PBS! 💪🏻👏🏻
Director Guy: "Action!"Matt: *stares intently at the camera, eyebrows moving* "Now before we do any general relativity..."Director Guy: "Start again. Had some eyebrow stuff going....?"Matt: "That was my... acting."Everyone: *laughter*
No need to tell how great this channel & it's quality is... But I need to say that seeing you guys having fun while recording and bloopers thing made me smile space time :)
The bloopers were hilarious!
I am so glad I finally stumbled on these PBS channels. Been learning like a madman during downtime nonstop all week.
This channel needs more bloopers :)
Im smarter for having subscribed to this channel. Every video is spot on and informative. What you are doing is important, more important than some may realize or admit. Creating a dialogue is all some of us have and its great to see so many people are interested. Thank you.
I'd love to see a blooper reel like that every now and then! XD
please continue a small blooper reel once an episode/ month. I loved it! the show continues to be one of my all time favorites on RUclips.
please make a "bloopers" video! that will be great!
Amazing show, this is the BEST physics channel I've yet to come across. I'm graduating right now with my bachelor's in Astrophysics, it's so refreshing to see a serious science show delve into the math a bit more and hit details.
Plus you do it with pretty graphics. Nothing wrong with old chalkboard. This is awesome.
Happy 4/20 everyone
+Marco J yay man, auf das Volk, auf den F.
you too~
+Marco J Happy 21/4 everyone
+Marco J
VAPE NAYSH Y'ALL!
Best 4/20 ever
PBS Space Time gets all their takes right on the first time. They went back and made those bloopers after they read the post asking for bloopers.
Crash course physics?!?!
SOLD!!!
Crash course is for ADD kids in midterms
CHIBCHART Maybe try keeping your negativity to yourself mate. No need to give people shit for finding things interesting, especially something like physics/mathematics.
+CHIBCHART your tone is pretty dismissive, but as an adult with ADHD, Crash Course and similar resources are actually really valuable, and can be much easier to learn from than textbooks or certain lecturers at certain times. I don't see what's so wrong with helping those that society tends to disadvantage...
This was a great show, loving the equation based explanations! I hope you guys continue to use math up front to explain different concepts. I know a lot of these concepts are extremely math intensive, but I think it's important to show the actual science and math.
In fact, I think there should be a short behind-the-scenes clip at the end of every episode henceforth.
Absorbing more and more each episode. Great stuff guys!
The universe needs dank energy, not dark energy.
+Fat Autist
Ayyyy Nevermore
+Fat Autist 420, got it
+Fat Autist Literally my thoughts before opening the video, also posted on 4/20
+Fat Autist Dank energy the hidden force the drives all creations of memes. Memes are constantly expanding through the power of Dank Energy.
+Fat Autist ppp
you guys are awesome I love what you do. It's not that i'm super serious about astronomy and particle physics and such but the way you guys present it is so interesting I could watch it every day for the rest of my life and not get bored one second
Crash course videos are amazing!!!!!
This is an Excellent Channel! I am increasingly looking forward to each epsiode. Keep it up and ignore any pressure to dumb things down.
Hi Matt, Speaking of degrees and jobs, I've got a bachelors degree in physics but then I went into a masters degree in civil engineering. I found out that it wasn't really my thing and I would love to do research work in physics. Is it possible for me to do a PhD in physics with my current masters degree or should I retake a masters course in physics?
+Aymen Hassoun As long as you have decent grades in your upper level undergrad physics courses - quantum mechanics, electricity & magnetism, stat mech, etc. then you may be competitive for physics Ph.D. programs. If your BSc was a while ago then you should certainly take a new GRE subject exam in physics to prove to admissions committees that you still have the physics chops.
+PBS Space Time What are my options if I get a PhD in AstroPhysics?
+Aymen Hassoun Nearly all physics PhD programs in the US follow this tract: Bachelors -> Enroll in grad school -> take core graduate level physics courses (around 2 years worth) -> take qualifying exams (sometimes called 'quals, GDE's, or 'entrance' exams) -> find a research group that can pay you -> do research -> write dissertation -> graduate. Your problem is going to be the quals. The difficulty varies from school to school, but in my experience they require *significant* work to pass. If you don't take graduate level courses there is no way you are going to pass most schools qualifying exams.
+Jason Owlbright They aren't very good, if you compare to, say, a PhD in optics, semiconductors, or something else. There are way more degree holders than positions for astrophysicist*, so sometimes you end up doing something you don't really want to do, with a degree that can't really get you much.
* I see a lot of demand for numerical relativists, perhaps the one exception to a shrinking job window in space physics.
Corey Small To me though, astrophysics is like food or air. I cant live without it. 😢
Awesome delve into the details of what I've been reading about for years. It's pretty brave to include those equations, as it's a known fact that one mathematical equation will scare away a large percentage of viewers, but it's so helpful to those of us with some math or physics education. Thanks so much, I've never even seen these equations before. Question: I've often wondered if the geometry of complex numbers (with a real component and an imaginary component based on the square root of -1) could have a role to play in cosmology? I read a book about the nature of zero that said zero and infinity can be represented as opposite poles on a sphere in this complex space. If the axis running through those poles was time, then we could experience the universe as some projection of this sphere. We seem to experience it as a 3D projection of some type of other geometry or dimension in any case, and I've heard that this complex geometry already has real world applications.
11:55
Matt: "We don't stoop to blooper humour"
Crash Course: *Gets triggered*
Great video guys, but don't you think the title is a little too much teleological? I mean, it's not that the universe "needs" dark energy, it just the way it is and saying it needs something implies a purpose and I know we agree it is not the case. Maybe you were trying to say something like "Why relativity theory, as we know it today, needs dark energy?". That is something semantically more exact.
Your "acting" is very good ;)
Been watching a lot of these videos of late and just came to this one. Totally adore the t-shirt. Need it.
Thumbs up for "eyebrow stuff"!
SpaceTime is awesome, I really love this channel
I hope they pay you enough that you never leave us! :*(
PBS needs to make this a full time show.
What if the universe isn't expanding faster, but time is slowing down? And, when we look at distant galaxies, since we are seeing them as they were in the past, they look like they are accelerating apart faster the further back you look, because time was moving faster then?
Regardless of whether or not that's true though, I think it just seems like a slight leap in logic to assume the existence of "dark energy".
Time already speeds up or slows down depending on how fast you go, it's all relative
MegaFatcat100 Time for galaxies, relative to other galaxies.
That's an interesting thought. The only issue I can think of is that as far as we know. Time dilation only occurs in areas of high energy/mass density. It wouldn't make sense then that time would slow down as the energy and mass in the universe becomes increasingly diffuse. Also, I think our observations of universal expansion are based somehow on the speed of light, so for that to be true, I think the speed of light would have to be changing, which seems like a no-no.
+AFastidiousCuber what if we aren't jumping off of the ground, but it's the universe that is jumping off our feet? See I can sound mysterious too.
Edward Ramos insert in soviet russia joke here
You guys are almost always over my head, even Crash Course Physics is getting there already. But that's not why I watch you guys. I watch to gain more interest in the math side of things and I enjoy knowing there is math behind the ideas, even if it happens to be far past my understanding. Easily one of my favorite science channels.
As always, thanks, I love you guys.
Oh the cliffhanger is turning me crazy.
+mergele1000 This series is getting better than GOT.
+Ivo Koporcic ^^this hahaha
Absolutely beautiful, the cosmological constant is such an intriguing thing, I can't wait to learn more.
Could you please do an episode on why physicist are having such a hard time to reconcile general relativity with quantum mechanics? Why is it so hard to produce a quantum theory of gravity?
+Sandy Crotch Basically the two view gravity in totally different ways, relativity sees it as curved spacetime, as not a force at all. QM sees it as a force in static, uncurved space mediated by particles. The weakness of gravity makes measuring small effects that might offer clues difficult.
Mine GWAWD I actually followed and understood this! Like, seriously assimilated the knowledge you put forth, Matt! I was really skeptical after Gabe left...namely because I liked his speedy delivery of information and you're much more deliberate and paced, but wow...You're doin' it! Keep it up!!!
Can a type 3 civilization escape freezing from expanding of universe???
Dude, you're the best. Thank you for doing what you do. I've learned more from you than I ever learned from any science teacher. It's mostly my fault though; I'm not the type that can sit in a classroom and take notes. That just isn't effective for me. Sure, I struggle to understand most of what you're talking about. I was a straight D student, and got an associate's degree in Automotive Science a few years after high school. Yeah, not exactly Ivy League. But I've learned more about the world from watching geeks like you on RUclips. I mean that as a compliment. Teachers often hate their jobs (or hate me, at the very least). They seem to go through the motions for a paycheck. But you, and other geeks, light up in a way that makes it exciting to listen. I'm a geek myself. I can go on for days about music and time signatures. I'm fascinated by space exploration as well, and even when my primitive brain can't keep up with you (I didn't make it past 10th grade geometry), I get so excited when I hear you explain what something means for the rest of us. I had a conversation with my 9 year old daughter the other day about gravitational waves, after watching your episode on their discovery; I must have been ecstatic, because the way I explained it to her (the few parts I grasped), she actually listened and asked questions. I wish there was an alternative for people who don't learn by classroom. I'm sure I'm not the only one of your fans who's had an experience like this. Thanks for striving to connect with your audience, and thank you for not taking yourself too seriously. The gag reel at the end was great. Keep up the good work, man.
Just a little advice: You should type such long texts in paragraphs so it is easier to read :)
Does that mean the entropy will increase and lead the universe to the heat death?
+Arthur seems like
Arthur if the universe is hyperbolic then it will expand forever and we'll die of dilution and freezing, if it's a hypersphere we'll die of heat death, if it's a flat plane at some infinite point the universe will stop expanding and things will just stay the same. At least that's what I got from this.
We NEED this on regular TV sooo badly. America needs Science like a human needs oxygen.
No.
No we really don't.
What you're calling 'regular TV' needs to die, for so many reasons I just can't be arsed to write a rant.
EDIT:
I'll give two examples to support my conclusion.
TLC (The Learning Channel)
Discovery
Nothing could be better for your career than a degree from Miskatonic University. ;^)
+An Evolving Ape Indeed. On the second thought, do you have to moment to talk about Nyarlathotep, our Lord and Master?
zchen27
LOL!
+An Evolving Ape ia ia cthulhu fhtagn
Ciphon
*stares at wall giggling with a line of drool off his chin*
6 months later.....
You're fantastic!! Loved the bloopers!😂😂😂😂
Love the shirt. Hail Cthulhu....
...He hasn't noticed you yet. :)
I Study a lot of advanced graduate-level mathematics, and that truly is my passion. But lately quantum physics, quantum mechanics, has really caught my attention and also cosmology.
So, what is the difference between Dark Energy and Dark Matter? Is there even a connection between the two?
I've been watching science videos on RUclips for many years now and once I found this channel some months ago, I literally spent the whole day watching all the videos. There are many great science channels on RUclips, but PBS Space Time is my absolute favorite. Hopefully you get enough support to never stop
+Konsta Peltoniemi By the way I just bought a "I'll science anything i want" shirt. Glad to support you guys!
If dark energy is created as the universe expands, wouldn't that violate conservation of energy?
No because new space is literally being created containing the energy.
+illusion z That's the point behind the question...the answer is that what we don't understand about dark energy massively outweighs all the things we do know about it, so most modern theories probably account for this by saying that dark energy (which is a bit of a misnomer anyway) isn't actually energy, just a property of empty space. And since empty space is defined as nothing, it can break all the laws of physics that *nothing* can break.
Once you move to a subject that involves general relativity, the law of conservation of energy no longer holds (at least within the same sense). In fact if I remember right, the law of conservation of energy only continues to apply on a local level.
On another note specific to dark energy, they explained in another video that as far as dark energy is concerned, it is inherent to the space-time it embodies. So that it's not directly violating the law of conservation of energy which applies to utilizing energy already present in a system. On this note, I believe this is what illusion z and ThePCguy17 are referring to.
"by saying that dark energy... isn't actually energy, just a property of empty space."
Actually it is still energy, though I believe you're right on saying that they consider it an inherent property of space. Keep in mind though, that the phrase "law of physics" is, put simply, a very loaded phrase although I suspect that you're aware of that. All "laws" as well as theories only hold within a specific range of applicability.
Because of that, none of these laws are actually being broken (or rather, there's no reason to believe that the current laws and theories are being violated WITHIN their current defined boundaries), but rather they are being enclosed in a larger, more general theory and/or law.
energy must be deleted as the universe impands or implode in a way. Is this the path to rid of the zombie apocalypse?
this channel is awesooooome!!! I love it. you explaining this beautiful equations with such easy language that anybody can understand. thanks you very much.
Happy 4/20.
+Lucas Balaminut Curvin' this joint, bioooooootch
I love this! So glad channels like these exist.
That was a little too high level for my little brain..
how old are u??
29
+Harshit Jain If I find myself like zone out even for a couple of seconds he'll move on and I'll be lost. I'm 17 and you kind of have to watch past videos. This is pretty hard to keep up with if you don't focus or have a background in it. I mean it's easy to watch but hard to actually learn, unless you make a effort.
+TimmacTR Keep mashing the "J" button every 10 seconds.
LeadHase I didn't get it?
Very good advice on the physics careers. I know 2 people with degrees in physics, the one with the PhD is now a professor, and the other with the masters works in development and testing of products in a construction industry (and as you alluded to cashing in, makes way more money than any friend of mine is worth).
СЛАВА УКРАИНЕ, ГЕРОЯМ СЛАВА!!!
Здесь то зачем это?
Антон Бородинто есть агенты путина к темной энергии никакого отношения не имеют, ага - конечно
Such a great channel! The bloopers litteraly made me lol.
What a waste, kids in Africa could have eaten Einstein's theory.
You're a naturally funny guy, according to the blooper reel and little jokes you sometimes get in in other episodes. Maybe you guys should podcast too, if you have time, so we can hear your more naturalistic approach and see your humor more vividly.
Anyway, another great episode, and once again I can't wait for the next one.
You explain really difficult stuff in an easy and entertaining way!!
Keep up the awesome work :D
Excellent show and presenter. Thanks for doing this.
Hahahaha That last part was great. XD I'm sure bloopers after every episode would get old but it was awesome to see this time. Especially the eyebrow thing. lol
I'm looking forward to starting my masters in physics and eventually getting my PhD , I'm passionate about physics but this channel seriously reinforces that feeling, thanks so much! :)
Hey! Recently I asked for a "Physics for Dummies" channel that briefly goes over the basics of physics. I'm only in grade 9 and haven't learnt many physics concepts definitely none at the level of this channel. Good to know they take feedback and are putting things into motion.
The bloopers at the end were fun, you should do them at the end like that more often!
1) Isn't it possible for a flat universe to also be closed, by being toroidal?
2) I have been playing a game called HyperRogue recently, which takes place in a negatively-curved 2D geometry - a 6,6,7 tiling which is about as flat as you can get with a nice tiling. It demonstrates other interesting properties of hyperbolic geometry by basing key game elements on horocycles, non-straight equidistants, regions bounded by infinitely many non-intersecting straight lines, the tendencies of pursuing enemies to end up in a long queue, various regular patterns on top of the base tiling, and occasional challenges around the difficulty of long-distance navigation, as well as your eternal explorations never crossing your own path.
+Simon Clarkstone If my understanding is correct, a torus shaped universe could only be produced by positive curvature. It is closed, but not flat.
Could you please do a show on what more do we expect to learn in the next 10 years? In this period, we will have James Webb Space Telescope, many other huge ground based telescopes, Square Kilometer Array (giant radio telescope), more powerful particle accelerators, gravitational wave detectors, more powerful computers/software.... (and what else do we expect to have in the next 10 years?)
Dude, You give good eyebrow ''acting'' every episode! I was a skeptic when You came on board, but You have won Me over!
More outtakes please, that was freakin awesome.