The Crisis in Cosmology: We Don't Know How Big the Universe Is

Scientists are unsure about the age of the universe. Two methods of measuring the universe's expansion have yielded different results, leaving scientists in a crisis of cosmology. The discrepancy in the two different calculations is known as the Hubble tension. Recent data has only further widened the gap between the two values. This means the math might be wrong or our current understanding of physics is incomplete.
Biographics: / @biographics
Geographics: / @geographicstravel
Warographics: / @warographics643
MegaProjects: / @megaprojects9649
Into The Shadows: / intotheshadows
TopTenz: / toptenznet
Today I Found Out: / todayifoundout
Highlight History: / @highlighthistory
Business Blaze: / @brainblaze6526
Casual Criminalist: / thecasualcriminalist
Decoding the Unknown: / @decodingtheunknown2373

[@danidavis7912]

I had to send this link to my dad. He was an astronomer for the USAF and for AAVSO (American Association of Variable Star Observers) for many years. Even when I was a kid and we would go out to his backyard observatory to record observations of star brightnesses, the Cepheids were the most fascinating to me. Thanks for yet another great presentation, sir.

[@whyjnot420]

A specific cepheid is a key factor in aligning older style telescope mounts like German Equatorial Mounts, which need to be manually setup, as in manually aligned to a polar axis. Good old Polaris itself. Also the closest of the type as well. I always loved that bit of trivia. Sounds like your dad had good jobs and nice kit. I just have a setup that fits into what is basically a big padded duffelbag. Still plenty of fun to be had with it though. Just requires a 20 min drive or so to get out of the light dome of my little city.

[@danidavis7912]

@@whyjnot420 I like the trivia on the scope mounts! When we were moving around a lot for his military duties, he did much the same with his two scopes. (A refractor and a reflector). When we lived in the desert of the southwest portion of the US, he and I would drive far out into the darkness where he would set up his equipment - small table, light box for the star maps, a thermos of coffee and of course, his scope. Occasionally, we would get to see the rare treat of the red trail of a rocket launching from Vandenburg Air Force Base that was about 150 miles straight west of us. Ah, memories.

[@whyjnot420]

@@danidavis7912 Man, I would kill for the dark skies of the southwest. I live roughly halfway between Boston and NYC. Light pollution here is atrocious. That said, I live 20-30 min from one of the darkest areas in southern New England, so at least I can easily escape the majority of the local light pollution. I just have a little GEM with a 150mm f/5 newtonian on it. I like to print up a couple of charts showing different targets at different times of the night. (you know the deal with those) As well as an old laptop for running Stellarium if I get bored. I always bring a coleman stove so I can make coffee on the spot with a french press. My main interest is astrophotography. Though all of my kit is adapted to it, rather than being designed with astrophotography in mind (with the exception of the various adapters I have to fit a, now old but still really good 350D/Rebel XT onto the scope). Go out by myself to some places I know are good spots as well as a couple of fields I have permission to use a few towns away. No phone, no internet, just an ancient Creative Zen mp3 player and the stereo in my pickup. Then set up before evening twilight and just stay out the whole night. The best is when I image an area where I know something should be, since I was meticulous in pointing my scope to the precise location, but could not see anything with my eye in the scope. But after a 3 min exposure or something, out pops a galaxy or three (like the Leo Triplet... I am still proud of getting an image of that, even if it wasn't the greatest quality, since I didn't have a good guide star for my finderscope, so there is more blurring than I would have liked) My favorite place to go is actually not ideal as it is right next to a main road between towns. It doesn't get a lot of traffic at night and since I am likely taking photos, keeping my eyes dark adapted isn't as critical (though I use the eyepatch trick all the time to keep one eye dark adapted, which along with an LED flashlight is what I use to read my maps). It is my favorite because people stop and ask me about what I am doing. Most of them never having used a decent telescope in their lives. It is a joy to show them what they have been missing out on. Pointing out the ISS or an Iridium flare in the evening, letting them check out the moon or Jupiter through the scope or just talking about the sky until they are dark adapted enough to see the Milky Way (so many people have told me that they have never once seen it like that). It never gets old Sorry, didn't mean to go on, but yeah, there is so much fun to be had in the night sky. Its no wonder it was essentially television for people before there was such a thing as electric lights. edit: I hadn't thought of it until just now, but I really need to see how well Space Engine runs on my Steam Deck. Could make a great addition to the stuff I bring out. Also that reminds me, I should be able to install Stellarium on it as well. :D

[@magnificentfailure2390]

@@whyjnot420 You're welcome to set up in my yard, some evening. I live on the property of the old Robles Ranch, in Robles Junction, AZ. Just 28 miles from Kitt Peak. I don't even own a telescope. My binoculars are wildly entertaining as it is.

[@whyjnot420]

@@magnificentfailure2390 Are you familiar with the 2011 Halloween Nor'easter? Which dropped 3 feet of snow when the trees still had more than enough leaves to catch them. By the end of the storm ~28-30" inches had fall where I live. 98% of the state of Connecticut had no power. The next night was crystal clear. I was about 30 when that happened. Not once in my entire life had I ever seen a sky that dark. Nor have I seen anything remotely close to that since then. A crystal clear sky, extremely dry from the cold of the storm (so very little water in the air). Perfect transparency and perfect seeing. With the mk. 1 eyeball I was able to see things I can normally only see by mounting my camera on top of my scope and using a 100mm f/2 lens on it and then taking exposures that last several minutes. Which then have to be processed later to remove light pollution. That night let me get a single glimpse into what people in truly dark areas can see on the regular. Though I was only able to take the finderscope off my telescope. I couldn't get anywhere, even though I had a 4x4, no room outside my apartment building either since there was 2.5 feet of snow and the shoveled paths were like 15" wide. I didn't even have space to set up my regular static tripod for the camera (and even with a 100mm f/2 lens, I couldn't get anything using it handheld. So that was the only optic I could bring anywhere. Little 7 degree fov finderscope (I forget its magnification off the top of my head, but obviously it isn't a whole lot, as it is a finderscope.) They were literally using bucket loaders to plow the streets here after that storm. On the 2nd night after the storm, roads were drivable, but we had overcast skies that night and the night after. By the next clear night, something like 2/3 of the power had been restored. A majority of the outtages being caused by the downing of transmission lines, not the in city distribution ones. At the end of the day, I am likely not leaving New England for any place 2k+ miles away anytime in the predicable future. Even if I can save the money for a little trip somewhere. I am going to Portsmouth, England. So that I can walk the deck of Victory & Warrior. Something I have wanted to to since around the first time I visited Constitution. (I am a giant naval history nerd.) But the thought of finding a cheap hotel or motel somewhere out in the SW and staying there for a week or so during the winter (I love me my deep sky objects) is up there in the list of things I would love to do, but a bunch of history related things are way above it. (I have always desperately wanted to visit The Hermitage in St. Petersburg and more than that, Yokosuka in Japan, where Mikasa is and the Viking Ship Museum up in Norway.) All that said, whenever I get people asking me about where to start, when it comes to using some form of optic. Even here in the Northeast I tell them to just get some good quality binoculars, two if they can afford it (a decent set of astronomical binoculars is amazing addition to lower powered and presumably far cheaper one that can be stabilized with just the hand, while standing). I tell them to just lie back on the ground, using the ground itself to stabilize their heads. Then just engrossing themselves in visual splendor. Placing emphasis on doing this during summer and Large Sagittarius Star Cloud. Even with the light pollution up here, you cannot go wrong there.

[@ignitionfrn2223]

1:35 - Chapter 1 - The distance ladder 6:35 - Chapter 2 - Cosmic microwave background 9:00 - Chapter 3 - The implications

[@ambassadorcartwright9127]

"Think about it. The Earth looks around and sees nothing but expanding space. What's it gonna do, say no?"

[@janeclark1881]

@@TheDogGoesWoof69 Well, yes. Women were denied the requisite access to education in earlier centuries. Even today more men train to be astronomers than women, so you are likely to get more contributions from men than women. This effect will swamp out any small differences in ability that have yet to be shown to exist. It is also true that access to higher education is better for people from affluent backgrounds than for people from deprived backgrounds. Astronomers from poor backgrounds have historically been the exception, not the rule. Nevertheless, your glib assertion gave me a bad irony attack because the team leading the study into star-based measurements of galactic distances is led by a woman: Wendy L. Freedman.

[@dewiz9596]

@@TheDogGoesWoof69 No star of Astronomy, you are

[@Dre_Key]

They’re wrong about a Big Bang and base everything from that

[@titan5064]

​@@TheDogGoesWoof69 breaking news: people unreasonably denied from participating in the field were unsurprisingly unable to contribute to the field until recently, more on that on 8.

[@Clearlight201]

It seems to me the weakest link in the distance ladder is type 1a supernovae, being such massive and complex phenomena and likely affected by so many factors - some of which we probably don't even know yet. How can these events be used in any kind of standardisation? Great presentation Simon, thank you!

[@dastiffmeister1]

I've always been skeptical of too much conjecture concerning space-related topics. It needs to be irrefutable before it become "standard" in scientific terms.

[@markgallaway5574]

There are some issues with Type 1a that came up after the paper was originally published. There are known now to be at least two types. However, going back over the data it doesn't;t look like it impacts on the results significantly as one is much more common than the other. What might be an issue is that Type 1a should be rarer in the early Universe.

[@shanehill2411]

@@markgallaway5574 yes that's the puzzle one among many. An amazing he time to be alive in the cosmos.

[@GeronimoPlaz]

No consideration of electromagnetism. It's such a joke. Someone has to pretend to know, and that makes them gatekeepers. The equipment required to actually observe anything is wildly exclusive, and we just have to trust the people saying these things are true. That has rarely worked very well lol. I don't know. And I don't think any of us actually know yet. I think a sophisticated alien civilization would laugh at us for being wrong about basically everything.

[@GeronimoPlaz]

@@dastiffmeister1 You're absolutely right. There's too little observation and too much modeling. We don't know shit. I'm not convinced that red shift is something we should base literally our entire understanding on. I hate when they talk about "14 billion years ago, this is what it was like". It's so cringe and they have absolutely no way of knowing that.

[@arthorim]

"We don't know, but more important we don't know why we don't know" Such a enlightening frase!!

[@e-moshe]

The different measured age of the universe might be a crisis in science and knowledge, but it’s actually exciting. The universe might then still have amazing physics and effects to be discovered, which we still have no idea about.

[@adamwu4565]

Science is one of those fields where a "crisis" is when everyone is drooling in excitement and anticipation, rather than being anxious or afraid.

[@zetsumeinaito]

@@adamwu4565 yeah, cause it generates jobs, funding, and the potential to be famous, which gets more research funding and jobs.

[@Grim_and_Proper]

Exactly! I was going to comment something similar and Simon even mentioned that the more exciting, although less likely, solution is that the value from the CMB is incorrect because our fundamental understanding of the universe's expansion contains an error. Errors in theories are essentially missing pieces of the puzzle, an indicator of where we should be investigating for a better understanding of the universe.

[@TheSCPStudio]

Of course it does. Even if our models on the age ARE correct, the universe still has many things we don’t understand. Gravity itself is something we aren’t fully capable of understanding.

[@brianargo4595]

@@zetsumeinaito yeah, none of us ACTUALLY care about the expansion of human knowledge. It's all fame and fortune in the scientific community.

[@martinstallard2742]

1:30 the distance ladder 6:30 cosmic microwave background 8:56 the implications

[@stephenmorton8017]

when's the wrap up?

[@prioris55555]

@@stephenmorton8017 here is the wrap up Hubble's conclusion was that there was no expansion. The big bang theory, gravity based universe, microwave background radiation, black holes, dark matter/energy, solar system accretion , thermonuclear sun are FICTION built on suppression, fraud, corruption and dogmatism. Even Einstein died realizing his theories were all wrong. It will eventually be replaced by an electromagnetic based plasma cosmology. The big elephant in the room is all the magnetism found all over the universe. You can't have magnetism without electricity with only small exception.

[@stephenmorton8017]

@@prioris55555 electric universe hooey.

[@prioris55555]

@@stephenmorton8017 one day all their lies will crumble we are in the year 2023 and they still can't admit to the existence of a sasquatch

[@Steve1257]

As always, amazing work explaining a complex, multi-factorial situation in clear, accessible terms; so well done!

[@Google_Does_Evil_Now]

I'm so old that stuff I learned in physics when I was young has been proven incorrect. Which is excellent. And keeps me interested and intrigued.

[@KidNoah2012]

Then you had some really bad teachers.

[@thedayidied]

I would like to note that not only did we used to believe that the Milky Way was the entire Universe - we believed it less than 100 years ago! It was 1928 when it was finally realized that the Andromeda Nebula was actually a galaxy. My grandfather was 8! That's so bonkers to me, that not even 100 years ago we knew NOTHING of anything outside the galaxy!

[@fixxa6455]

And we still dont know anything. Are we inside a black hole?

[@keithnicholas]

1917.... and then 1922 it was confirmed.

[@SG-dg6oi]

I always knew!

[@BiscuitsOfWrath]

@@fixxa6455 great theory but science has disproven this possibility. Theres a few cool documentaries about it. Definitely worth watching

[@BennyNegroFromQueens]

@Fixxa why are some people postulating we are in a black hole?

[@diyeana]

I love space and the universe. There's no doubt we're wrong on many things, but that's why we keep searching for answers. This is a great script, Kevin and a fantastic read, Simon.

[@HelicopterShownUp]

We need to stop sending signals out there, never know who might be listening.

[@chase5298]

@@HelicopterShownUp Alright Todd....

[@diyeana]

@@HelicopterShownUp it's too late for that.

[@lifePaultheball]

@@HelicopterShownUp I don't think anyone listening. Causality is very local in the universe. It is simply too vast for mere electromagnetic waves to reach someone else in the emptiness of space.

[@chuckschillingvideos]

I'm so happy my tax dollars can be spent on your curiosity.

[@royfeely7145]

Thanks, I didn’t understand any of that but it sounded really interesting. If I keep listening to this type of content I might eventually start to remember and relate to a few bits. I suppose that’s how learning works.

[@mevinkoser8446]

You are just facing the wrong way. This is the crisis. Understanding is behind us. Start with paying attention to form and you will realize the tension formed

[@shawnpulkkinen1557]

Wow, I just came across this channel. Guess my nights planned out. Excellent explanations, I was able to understand each step thru the evolution of our current science on the subject.

[@elliotsmith9812]

Really well done Simon. A seriously complex issue well handled. I really think you do much better when you are a bit more serious. The more flashy, jumpy episodes are less credible in my eyes (as a sometime science and engineering educator).

[@Sideprojects]

Thank you. I like doing a bit of both, if it were just one or the other the whole time, I'd just get bored :)

[@tony2888]

Can you please do something to tone down your sharp S's. Very distracting.

[@pastverb1]

...slowly minimizes that Brain Blaze episode and walls away...

[@davidtatro7457]

Part of me really hopes that the problem lies with the CMB calculations. That would give us the simultaneous comfort that we kind of know our place in the universe relative to other objects while also opening up very intiguing possibilities for new physics.

[@LukeKendall-author]

Yep, it's another failure for the hypothesis of dark matter.

[@Traildude]

@@LukeKendall-author Um, what? What does dark matter have to do with the CMB?

[@sethdelaat2471]

This isn't even a crisis. "Oh no humanity doesn't know our place in the universe"? Big deal. the laws of physics arnt even laws, it's just our current understanding of physics.

[@korinogaro]

I don't see how this is a crisis. It changes nothing for us, there is new stuff to learn and understand just like there always was...

[@OmegaVideoGameGod]

Everything in space is bigger than we think it’s beyond amazing when we can explain it!

[@myusername111]

im so happy when you release new videos honestly they are fun to watch and i appreciate you

[@peterhall8572]

The more we learn, the more we realise how little we really know

[@scorcher5083]

The inverse is true as well. The less we know, the more we claim to know.

[@SeraphX2]

@@scorcher5083 and that's how a good chunk of scientists, unfortunately, act. they act like we are certain that things work certain ways and so many of them are loathe to give up what they think they know. they go down a path, unwilling to divert if something comes up that's different. instead of investigating, many of them scoff. you would think that scientists, of all people, would learn this is not a good attitude to have after all the times they've scoffed at the wrong things.

[@jamielonsdale3018]

@@scorcher5083 I think that's the Dunning-Kruger Effect.

[@hillstrong715]

@@SeraphX2 Scientists are just people too. They may have a particular extra education in some field, but that extra education may never include the history of past failures. I have had conversations with university level educators and the response to whether or not they would encourage university students to follow up on different non-standard non-consensus models and theories was a resounding No. This was disappointing to me as my undergraduate engineering days emphasised that all of our theories and models had limits beyond which those theories and models would fail to give you usable results. Though over the last 4 decades, there appears to be a lessening of this kind of understanding being taught in undergraduate engineering as these ideas are often unfamiliar to newer graduates. Of course this lack can vary quite considerably and some are very very aware of this particular idea.

[@Leeds71]

Thats why non-political, non biased science is required and its why its such a shame there seems to be less and less of it and its also why the current state of humanity is a shame as less people seem to be believing in science

[@charlesjmouse]

For a popular science channel that was really very well done, thank you.

[@ArcAudios77]

Thanks Simon, wonderful delivery of a wonderful Education. Appreciated 👍

[@RaySpillane]

Excellent delivery, Simon communicates all this like he knows what he's talking about. So much information, even more confused now than ever!

[@carrite]

Here, I'll help... The universe is really, really, really big.

[@TheFailLord72]

Usually informational explanatory videos like this are a constant stream of new ideas and facts I'm not all that informed about. Feels weird having already looked into this information on my own. I see many professionals speak with confidence that our current model is correct, while each day we find more evidence to the contrary. Thank you Scishow man, we need to keep asking questions until every answer is found. This fear of the truth is getting old.

[@amlord3826]

Because it has no experiments, cosmology isn't really science. It's observation and guessing. The guessers assume they are right (sometimes fanatically so) until enough observers see things that don't fit. Then they change their guess and vehemently deny they ever guessed that in the first place.

[@bobbabai]

@@amlord3826 but each new idea results in predictions being made about what should be observed. We go out, we confirm or debunk those predictions and thus learn by doing science.

[@bobbabai]

@@amlord3826 You're falling for the "I have to touch it with my own fingers and see it with my own eyes in order for it to be true" fallacy.

[@amlord3826]

@@bobbabai predictions are only a part of the scientific method. A pivotal part, of course, but only a part. Observations have biases and errors. We are relying on an infinitesmially small snapshot in time to figure things out. 100 years in a 15,000,000,000 life span.

[@bobbabai]

@@amlord3826 have you looked up objections to this particular point you're trying to make? Do you know what the arguments against it are? Do you know what the evidence against it is? Is there any work you've done that would convince anyone you've made any effort at all to falsify it?

[@odranoelmusicremixes8453]

great video and very informative. but as a headphone user i feel like i must point out that your "s" 's are very sharp! you should apply a de-esser to the audio, (or use an equalizer to to remove some of the high frequencies around 5 - 8khz) i literally had to turn down the volume a lot so my ears didnt hurt :(

[@RedfishCarolina]

We aren't sure how big or how old the universe is and every day what we don't know keeps getting bigger.

[@JohnGardnerAlhadis]

I love the name "standard candle". Makes me think of a candle burning far off in the distance, shrouded by darkness.

[@Snaakie83]

Well, the intensity of luminosity is measured in Candela...so it makes sense in a way 😊

[@kitko33]

Correction: it's officially called Hubble-Lemaitre Constant - Lemaitre, author of the Big Bang theory, discovered expansion, and defined the consant before Hubble. Hubble derived it more precisely working with better data.

[@prioris55555]

Hubble's conclusion was that there was no expansion. The big bang theory, gravity based universe, microwave background radiation, black holes, dark matter/energy, solar system accretion , thermonuclear sun are FICTION built on suppression, fraud, corruption and dogmatism. Even Einstein died realizing his theories were all wrong. It will eventually be replaced by an electromagnetic based plasma cosmology. The big elephant in the room is all the magnetism found all over the universe. You can't have magnetism without electricity with only small exception.

[@axeman2638]

expansion wasn't discovered, it was invented and is totally wrong.

[@wades2132]

I listened to a podcast just a few days ago that talked about Leavitt and her work that Hubble then expanded on. Pretty neat.

[@ophelia1867]

The problem isn't the maths, it's the initial starting assumptions. Maybe the "red shift" isn't what we think it is. If that's true, all the other assumptions are false.

[@rebeccadubois8270]

It gives us something to work towards almost indefinitely. This is amazing

[@raizil0513]

Now if only the rest of humanity could focus like this... How far and fast we could advance...

[@anirudhmitra4232]

@@raizil0513 not everyone is interested in space or science for that matter it is very small and vocal minority.

[@raizil0513]

@@anirudhmitra4232 Sad, but true.

[@timothyodonnell8591]

And then there's the Hubble constant measurement from gravitational waves generated from the merger of one pair of neutron stars. That number lies almost exactly in the middle between the Hubble constant measurements listed in the video. We will need many more neutron mergers to solidify the gravitational wave measurement of the Hubble constant.

[@jowrjowr]

standard siren error bars are too large to say either way but LIGO O4 is about to start with a huge sensitivity upgrade. i'm hoping we'll get some improved standard sirens with snugger margins than "lol who knows"

[@prioris55555]

gravitational waves are FICTION. gravity based universe is FICTION our universe is electromagnetic based

[@timothyodonnell8591]

@prioris55555 Oh, please enlighten me with why you think gravitational waves and a gravity based universe are each a fiction. Please be specific and provide references to support your explanation.

[@jowrjowr]

@@prioris55555 why don't dipole gravitational waves exist?

[@prioris55555]

@@timothyodonnell8591 The don't even know what gravity is. gravitational waves were hypothesized on the fiction of black holes. they used lasers which have a wave length that is larger than the supposed gravitational waves einstein if your young, you will witness all the lies of mainstream astronomy collapse in your life time Hubble's conclusion was that there was no expansion. The big bang theory, gravity based universe, microwave background radiation, black holes, dark matter/energy, solar system accretion , thermonuclear sun are FICTION built on suppression, fraud, corruption and dogmatism. Even Einstein died realizing his theories were likely all wrong. It will eventually be replaced by an electromagnetic based plasma cosmology. The big elephant in the room is all the magnetism found all over the universe. You can't have magnetism without electricity with only small exception.

[@Bobby-fj8mk]

It would have been nice if Simon could have mentioned Red shift and compared it to the luminosity of distant galaxies.

[@samuela-aegisdottir]

Thanks for the video, the topic was intreoduced well, I heard about the comsic ladder before but I did not know what it is made of. Now I undertsand. I have just a problem with the visualisation of the two estimated being different, as shown in 0:47 and 9:11. As far as I know, it is not correct and it gives the audience a bad prospective about the problem. The two estimates used to overlap, but with higher precision measurements, they are not overlaping any more. So I thing the visualisation should show two lines shortening to such extend that they are not overlaping any more and not even close to each other. Apart from that, thank you for a great video.

[@rogerlevasseur397]

Looking forward to when gravitational wave astronomy gets a larger data set of black hole mergers so it can contribute its Hubble constant calculation. On the currently small data set its initial value is between the two values presented here.

[@axeman2638]

gravitational waves are nonsense, it's just noise filtered to fit a predetermined conclusion.

[@philrobson7976]

But that’s only the size from the Big Bang. How large is the space that we are expanding into? That hurts my head.

[@semaj_5022]

So as far as I'm aware it's generally accepted that we're not really expanding *_into_* anything. We're just expanding. We're like a balloon inflating inside a room, except there's no room and the balloon is functionally infinite. Yeah, it doesn't do my head much good either.

[@w13rdguy]

Nothing has ever been _directly_ observed to have been expanding or accelerating, i.e. by parallax or by increase/diminishment in size. It has only been derived from what we think we know about matter, space, energy and time.

[@philrobson7976]

@@semaj_5022 I’ve heard the balloon expansion idea too. But a balloon has an inside and outside. Head still hurts.

[@umami0247]

I disagree with the theory that we are expanding into nothing. Just because we can’t see it doesn’t mean it’s not there. What is beyond what we can see is more of what we do see. Seriously what else could be out there but more space and endless galaxies. I believe the big bang was just a local event in the region we occupy and other big bangs have and are happening all around us. Remember everything is moving we go around the sun the Milky Way revolves around and our universe revolves around all so. And from the time earth was developed we have made approximately 12 revolutions in the Milky Way that’s based on it takes about 250 to 300 million years to take that trip. And we have been a planet for approximately 5 billion years give or take so imagine how long it takes for the Milky Way to make it around the universe that should blow your mind. Bottom line is we have been around way longer than we will ever truly know. And we should be okay with that there are things we just aren’t ready to know or should we know.

[@semaj_5022]

@scott stutzman These things aren't mutually exclusive and the expansion idea is usually paired with either inflationary theory or infinite inflation. However, it seems the most easily it can be described, to my understanding, is that a quantum vibration leading to a junp in energy level in the inflaton field(a hypothetical scalar field existing "alongside" the other quantum fields, such as the electromagnetic or highs fields) led to an area of space exponentially expanding in volume in an extremely short period of time(something like 10^-32 seconds for our universe.) This point in the field then went back down in energy level, leading to a dramatic slowing of expansion, allowing the energy inside this expanded bubble to take over as a primary driver of change within the newly formed bubble universe. This same process, which expanded our own universe is happening at infinite points in space at all times and will continue to happen for an infinite amount of time. Now have we proven any of this? Not yet, and sadly it is very hard to formulate experiments to properly test this hypothesis, but it does at least line up with our observations of our own region of the universe.

[@ranima_tv2514]

I think the real exciting part of the varying data and ideas is that they test us so much, which set of data is accurate, what if they are both accurate, maybe we live in an amalgamate universe. Either way spending time worrying over something demonstratively bigger than yourself isn't worth the effort, but I would still love to know how far our appreciation for existence can take us.

[@xptechmikie]

By golly... You hit the nail on the head, this time. There certainly is a technology that space scientists needs to learn. Firstly, it's to realize THAT all cosmological bodies are growing. Secondly, it's about HOW planets and stars are growing. And then, to recalculate the math, to WHERE they are growing toward, and WHY everything is growing. Then everything will start fitting together, without any conflicting data. Regardless of all of this, your presentations are always exceptional. GOOD JOB !

[@makeracistsafraidagain]

The universe is old, really old. The universe is big, really big.

[@bryanpropp2179]

“Space is big, really big. I mean, you might think it’s a long way down the street to the Chemist, but that’s just peanuts to space” Douglas Adams

[@rodchallis8031]

@@bryanpropp2179 Every time I watch a video that relates to space, I think of that quote.

[@carrite]

Correct answers.

[@brothermine2292]

Prior to 2015 there was no Hubble tension, because each of the calculations using the CMB techique had resulted in values close to the values that resulted using the Distance Ladder technique. In other words, the CMB results changed after 2014. We're told the CMB results after 2014 are more accurate and more precise than the earlier CMB results, but the fact that all of the CMB results after 2014 disagree with all of the earlier CMB results is a hint that a systematic error may have been introduced in 2015, causing the 2015+ results to be wrong, despite their smaller error bars (improved precision). Perhaps greater scrutiny of the changes of CMB methodology that occurred around 2015 is warranted, to verify no systematic error was introduced, particularly if the Webb telescope reinforces the Distance Ladder value instead of resolving the Hubble tension.

[@Ender7j]

AI has started being employed to find patterns and make connections that humans generally wouldn’t on their own. I’d imagine that had a lot to do with this discrepancy in the datasets we’ve had for a while, we are finding things that have been there for a while with these new analytical tools.

[@Llortnerof]

The whole issue here is that we don't know why the results are different. Checking for possible systemic errors was probably one of the first things they did, yet all that resulted in was making it worse. It's not just one person or group getting different results here, and the more they get refined, the clearer it becomes they don't match.

[@Ender7j]

@@Llortnerof if checking for errors and refining the math made it worse, that means there were errors to be found. Making it worse is part of improving it, from a math sense, in the fact that being worse means accuracy is on the rise.

[@Llortnerof]

@@Ender7j They didn't to my knowledge discover any significant systematic errors. They just refined the measurements and reduced uncertainty. The error bars got shorter, not longer. What got worse is the Hubble Tension, i.e. the difference between the two methods of measurement, both in significance and distance between the two mearuments. Scientists expected the measurements to get closer as they refined them. Instead they diverged more.

[@brothermine2292]

@@Llortnerof : 1. I think a wider group should review for systematic error, to guard against the possibility that group-think prevented them from discovering a shared incorrect assumption. 2. What do you mean by "checking for systematic error made the Hubble tension worse?" Although the tension has grown worse with recent, more precise CMB measurements, I don't see how checking for systematic error could account for any of the improved precision (unless they found and fixed a systematic error, which we presumably would have heard about).

[@rustyshackelford3781]

Are they basing these calculations on the measured distances to stars which are moving away from us in a straight line? If we are basing these measurements on objects which are moving away from us at an angle but not factoring that into the equation it could drastically impact the results.

[@FirstNameLastName-okayyoutube]

The intro ( and outro) to this video is amazing and it is almost therapy for me as a scientist. Far too often in science we have these indisputable facts, which more more seem to get in the way rather than be true. The CMB just does not make sense. It reminds me of the South Park episode of The Underpants Gnomes. The critical step in the explanation is skipped over every time. Which is how can light escaping a very dense object reflect off of nothing then be returned at a much later date after it has expanded. Are we trying to say that the light has experienced some kind of space-time expansion lense effect? No nothing is being said. I've been trying for years to find an answer that didn't just presume I wasn't interested in the evidence of the mechanism as to how light that was once close by could be then seen as far away. I've seen in textbook models that suggested time-space had an edge. It's just ridiculous. For all I know the CMP is massive amounts of gamma rays originating trillions of light years away from Universe size black holes

[@MrDeltoric]

They call it the Hubble Tension, I like to call it the Hubble Struggle

[@TheBritt47]

For reasons I don't care to delve into, I call it the Hubba Hubba.

[@lilypaddington1797]

The Hubble Hubbub

[@MooseMeus]

'

[@samuela-aegisdottir]

I think that "Hubble Tension" is an understatement. Crisis in Cosmology is much better term. You can call it Hubble Crisis.

[@hasher2265]

Fascinating with such a limited snapshot of the universe we can estimate it on the whole. Even if there persists an error.

[@whyjnot420]

I know you were being flowery with the words you used, but it is far from a 'limited snapshot'. But to think of it that way is doing a great disservice to both yourself and the field of astronomy as a whole. It is a collection of thousands of years of observation from countless people using the most clever, sophisticated and precise instruments of any given time (look at the stuff designed to work without optics. E.g. the kit Tycho Brahe was using). We have found out how to judge the speed of things we cannot see move. We can tell the makeup of objects we could never take samples of. We have even assembled a pretty detailed map of what is either the single or 2nd most complex object in the universe. We can even prove the existence of things that we can literally have zero interaction with, e.g. the Great Attractor and things we cannot see, e.g. things in the zone of avoidance. It is precisely because our knowledge is so wide, deep, and is continuing to grow on a daily basis, that we know so much. So it is hardly "limited" due to how vast the field is and is not a "snapshot" because it is always evolving. addendum: btw, we can actually observe some parts of the universe as they existed at multiple times in history. We can observe light as it echoes off of other objects. For example: a supernova 250 light years away happens 500 years ago, it hits another object that is 250 light years away from it as well as 250 light years away from us. We see that initial supernova 250 years after it happened, but also the echo 500 years after it happened. Gravitational lensing caused by galaxies does something similar, because the light takes different amounts of time to get around the galaxy depending on its route, so the light we see coming towards us will be made up of different periods of the history of that light. addendum 2: It is suggested that a map of the neural network of the human brain might be more complex than the structure (large scale structure, look up a map of filaments and voids to see what I mean) of the universe itself, hence why the structure of the universe might be the 2nd most complex thing in the universe.

[@hasher2265]

@@whyjnot420 So how do we observe anything outside of the obserable universe then? It's what I meant by a snapshot. Even in terms of time. The thousands of years of observation are a tear drop in an ocean considering the size of the universe. We can't even observe population III stars.

[@stixoimatizontas]

@@hasher2265 everything outside the observable universe that we can observe, we do so through secondary events. We cannot see particles yet we observe their behaviour through the effect they have on their surrounding environment.

[@eddievangundy4510]

Great, clear presentation! Thank you!

[@nobleaxiom]

My first time hearing about the CMB & it is fascinating . Thank you

[@Psittac20]

I would love it if you guys did more on the James Webb space telescope

[@whyjnot420]

The closest cepheid variable is one of the most famous stars in the night sky. See if you can answer it off the top of your head. Polaris. The North Star. Not that most people could actually point it out in the night sky as it is not exactly all that bright. But I have always found that little fact rather amusing. That fact always pops into my head whenever using the polar alignment scope built into the GEM I use for my little Newtonian (150mm f/5).

[@jonmcdaniel8492]

It's right off the lip of the Big Dipper. Look north and you'll see it.

[@QiyuLiu]

Regarding potential issues with the distance ladder method, how do astronomers account for the movement of the solar system when making parallax measurements from opposite ends of the Earth’s orbit? Or does this not really matter?

[@Hold_the_Front_777]

Isn't it unusual how in light of the hubble tension problem we don't even ponder the assumptions of universal expansion, which would be the usual approach, because the expansion is absolutely needed to explain the CMB, another cosmological crisis. Usually when we find crisis in science it's imperative to go back and check underlying assumptions founding the theory.

[@728709jay]

Could the Universe be expanding at different rates in different places because of things possibly affecting it?

[@Noise-Bomb]

We don't know (yet?)

[@ProdigyWright]

I've thought this too. PBS spacetime had a video on the universe's asymmetry

[@DaddyHensei]

Could be. We still don’t know if Dark matter exists or not. There could be less or more of it in different areas for all that we know. Could also be something we never even hypothesized about as well. Gotta love a good mystery

[@728709jay]

@@DaddyHensei I'm hoping it's a realm of Physics yet to be discovered.

[@murraymadness4674]

Or it could not be expanding at all...we assume redshift can only be caused by expansion, yet we make up dark energy and dark matter which exists that don't conform to known physics, so we can explain redshift only using known physics. See how that works?

[@justuseodysee7348]

AFAIK one of more reasonable candidates for the disparity is that perhaps the assumption of the universe being uniform on the largest scale is incorrect. There isn't enough statistical significance around this, but it seems to be growing with more and more measurements

[@jowrjowr]

we have no reason to think the universe isn't uniform. in fact, we have some really good reasons to think it is. like the CMB, or actual studies of objects in the universe.

[@JgHaverty]

we have an ENORMOUS amount of statistical relevance on why the universe is isotropic, what do you mean? lol

[@justuseodysee7348]

@@JgHaverty kzbin.info/www/bejne/gHa3eIZsadCHr9U Sabine Hossenfelder quotes research that suggest the standard model is incorrect

[@justuseodysee7348]

@@jowrjowr Not my words but somones who knows better kzbin.info/www/bejne/gHa3eIZsadCHr9U Recent research suggest there's something wrong with the isotropic universe assumption

[@JgHaverty]

@Just use Odysee the cosmological principle is indeed flawed at best; the cmb, the hercules wall, gamma ray burst wall, great attractor, super voids; etc are specific points that poke holes in our current understanding. However; those are exceptions we dont understand; not specific events we should toss out our fundamental understandings for. The counter argument to this is maybe we just dont have a scale big enough to see the homogeneous distribution.

[@llibressal]

I'd imagine that it's most likely were not factoring in the movement of things were using as a stable reference. ...and/or optical density changes( and lensing effects), in different parts of the universe were peering through.

[@zoehope1089]

Oh my, so well presented and explained. Thank you.

[@MrPink-qe1rm]

I have a feeling there's a trick or two left in black holes yet to clarify a few things. A little math problem gave me a hunch lol. ER=EPR, so close lol. Hr definitely seems to be part of the equation.

[@aaronmicalowe]

I think the reason why we're not getting the right answers is because we're asking the wrong questions. Maybe the universe doesn't have size.

[@stixoimatizontas]

Or it has a different sort of size, not the standard 3D that we know. It definitely doesn't have time, though.

[@goofygoober779]

I always feel extremely uncomfortable when I think about how extremely, unfathomably vast space is. So many different suns, so many planets, so many unknowable dark and bright places, too many. It feels like a sensory overload.

[@roop1801]

And what is there before big Bang ?

[@kcxw499]

It’s like I would love to see it makes me humble really that I’m not as important as I think I am or I should say the things I stress over really aren’t that important the universe doesn’t play by our rules nor does it care too which I weirdly like

[@kcxw499]

@@roop1801 it was nothing 🤷🏾‍♂️ but we don’t know at least not yet we probably never will

[@phantomechelon3628]

Great video! I'm an avid watcher of science documentaries, but I'd never seen anything covering this until today. Also, I don't think Simon has ever looked or sounded more like an actual scientist! 😁

[@unicaller1]

It is just amazing that we are so sure we "know" something that is based on stacks of assumptions. Then we are so shocked when we discover that we were wrong.

[@mayipluginmycordless]

Presuppositions are an mf.

[@-Devy-]

This mindset is of the average layperson, not of scientifically minded people. The, unfortunately pervasive, idea that scientists think they know everything is extremely ignorant, to the point of stupid.

[@Taz6688]

We are like ants looking at an aeroplane, so-called experts keep saying they know all there is about the universe, truth is we have little idea of what's going on.

[@JanBruunAndersen]

Like a lot of people "know" that Trump is a traitor, Kurds are terrorists, and COVID-19 is a dangerous disease?

[@abousono1]

@@Taz6688 There are no real experts who say they know everything about the universe, that is a lie or misinformation used to push a narrative. Show me one well respected who says they know everything about the universe? You can't because there isn't one.

[@Silverfirefly1]

If local time everywhere is modified by local gravity then isn't the constant going to seem both constant locally and at a great distance across multiple gravity systems despite the photons themselves having been 'delayed' relatively by frames of 'heavier' time?

[@JgHaverty]

You're trying to blend human perception with fundamentals of physics. "Time" isnt regarded as a singular entity in this regard; terms are based around "Space-time". But light moves at light speed; regardless. What I *THINK* you're trying to talk about is called "gravitational lensing"; its a known and calculated for variable in these regards. The most conceptually easy (in my opinion anyway) way of wrapping your head around why what youre discussing isnt specifically relevant are called "penrose diagrams" (forgive the quotes, Im just using them to highlight technical terms you can go look at is all); these are essentially 2d diagrams of infinite space-time and time-space (black holes get fucky here) and how light ALWAYS moves on this diagram should get you answers you look for.

[@Silverfirefly1]

@@JgHaverty The question is about perception yes, but it doesn't need to be a human, any detector of light is good enough. My point is that if there is a perceivable difference in relative time between the surface of the planet and the upper orbit due to gravity, despite light being constant in both frames, can we account for the relative differences in time as light moves through millions of frames of varying gravity? I understand about lensing, though it's always described as positional distortion of the light rather than temporal.

[@JgHaverty]

​@@Silverfirefly1 lmao that first reply was not for you; sorry! Yes; gravitational lensing and doppler shifts are fascinating subjects but require more than a youtube comment to explain effectively. As long as you understand light is constant (despite 80% of this comment section that seems to think otherwise lol). I would imagine doing some studies on penrose diagrams and how they function will give you the most approachable way to wrap your brain around this subject. Hawking, Penrose, and Dirac all have done extensive studies on this subject that have been covered extensively.

[@tekannon7803]

Once again Simon, you have shown yourself to be someone who can get to the heart of a subject and keep us all enraptured in your enthusiastic and professional way of describing a subject. The universe is something that is so pleasureable to ponder on as the anniversary of the Ukraine war is coming soon and the plight of our species could be in the balance if one of the dirigents of the war goes off the rails and starts a nuclear exchange and then we all might be blown back to stardust. I have a theory of the universe and it's not from my professional background, because I have not studied astronomy. What I think is that it doesn't make sense that the universe would not have a transit system----like underground rivers----to get from point 'A' to point 'B'. That's right; I think there are probably other dimensions that we cannot decipher and that it is possible to visit the entire universe by knowing how to use the links between the stars. Why do I say this? Because from what I have gathered, there have been spacecraft that have visited our planet and we would have seen them coming in from, say, Jupiter, if they flew in the traditional way. They have come to us via unseen passageways and some sort of portal system. It's a theory.

[@peterpayne2219]

This was really well done!

[@cleverusername9369]

I really don't understand what's stopping Simon from starting an Astrographics channel. Has he hit a KZbin channel limit or something?

[@Noise-Bomb]

Nobody knows what the SWCU will bring us next but man this guy must be busy as hell.

[@mikeygallos5000]

He has been releasing space videos on several of his channels like Geographics and MegaProjects, and now this one. For a while I thought this channel would turn into the Archiologics channel though.

[@Meshamu]

The expansion of the Whistlerverse is also difficult to understand.

[@Mapantz1]

There's a slight problem with white dwarf supernovas.. adding mass slowly means a critical point is indeed reached, but two white dwarfs colliding adds a larger amount of mass almost instantaneously, and the supernova will be brighter.

[@adamwu4565]

IIRC that has been proposed as a possible solution to the paradox. However, for that to work as an explanation it would mean that white dwarf collisions are occurring more frequently than our current theories say they should, in order for the brighter-than-expected Type Ia supernova to be common enough to bias the measured average brightnesses enough, so it would still mean something is off with some of our best theories of what the universe is actually like.

[@VergilArcanis]

I have a dumb conjecture: we're missing over half of the universe in observation. I'm basing that on the observed experiment with firing a projectile backwards at the speed you are moving fowards, courtesy of MythBusters. Extrapolating to Lightspeed, could it be done where an object moving away faster than light from an observer (both observer and observee are moving close to the speed of light away from each other), would the light still be perceived? So let's say a whole other half (possibly more) of the universe is exceeding the limit because both halves are moving away faster than light from each other. This could help rectify the confusion

[@Holphana]

Wouldn't you need the relative position change from origin of each galaxy for the 2 points you are measuring? I assume we're not all moving away from the big bang in the same straight lines, a slight diagonal vs straight line would change the speed it took to reach each destination exponentially. From the big bang it would be nearly 0 but as things expand this number makes an impact. Hence our measurements slowly seperating. One of them is clearly factoring in that change. I don't know how because I don't understand any of this but it seems logical.

[@showandtell4265]

I see your logic... You could do a series of paralax measurements on different targets in 360 degrees so that you could understand and account for that relationship and then it could be a non issue? For me its the 6 parameter variables of the cosmic microwave background that is shaky.... Dark matter and dark energy has never been observed but needs to exist in order for our current model of physics to make sense. And its not a small number... It needs to be that 95% of all matter is dark matter???

[@logtothebase2]

That's the thing with universes, you never know how big they are until you develop hyper luminal travel.

[@jamesmarkham9464]

I've been thinking about this.. since light can in fact be affected by gravity, has this all been factored in correctly in the calculations of red shift and therefor the speed of expansion of the universe. Im assuming so but yea lol

[@nigh7swimming]

Brightness is the amount of light, red shift affects the colour/frequency /energy of lights waves, not their amount.

[@MaxBrix]

There are two things everybody in cosmology agrees on: 1. There are some inconsistencies in current theory and better theory probably exists. 2. Don't question current theory because it is infallible.

[@MaxBrix]

Yes gravity red shifts light. No this is not factored in because it assumed that the universe is homogeneous per the cosmological principle. If there is the same amount of matter in every direction then there is no acceleration. There is no evidence for the cosmological principle. It is an assumption. Personally, I think you are on to something.

[@TheBritt47]

@@MaxBrix I assume this is an attempt at humor, and I missed it? I've never heard anyone actively working in the field state that any of these theories are "infallible." Actually, ditto for other disciplines as well. Only those who know very little about a subject claim that their opinions relative to that subject are infallible.

[@The24Gamer]

@@MaxBrix Nothing scientific is infallible, it's a fundamental part of science, you're either chatting rubbish or trying to be funny and failing.

[@Lilitha11]

It seems likely there is definitely stuff we don't understand, since we still have no idea what dark matter is, or even if it exists(in which case there are big problems with our models of gravity).

[@Infinite.Worldz]

Dude, you're beard should have it's own channel at this point. Great video.

[@bergec0]

I feel like all the space stuff should be collected under AstroGraphics. :)

[@hillaryclinton2415]

We don't know what it is, how big it is, how it came to be, what it will become, where we are in, why it exists, how long it was, is, or will be in existence..

[@watercolourmark]

I've always thought you can't really make assumptions about the size, age and expansion of the universe until you know your point of perceptive. You could assume that the universe is expanding by the local observable universe observations. But without knowing your position in the entire universe, and the true scale for that, then an observed expansion could just be local swirl rather than a wider expansion. It's like with the balloon metaphor for explaining expansion, which is all well and good, before you ask; are you on the surface of the balloon? Are you inside the balloon? Or are you outside the balloon? And depending on your position a perceived expanding could actually be a contraction or indifferent. So until we know the size of the universe, outside the observable universe, then these are massive assumptions that are as naive as thinking we are at the center of the universe.

[@Vastin]

I'm wondering if the expansion rate of the universe has perhaps been variable over the course of its history. By which I don't mean accelerating or decelerating according to some formula, but *actually* variable, increasing or decreasing from era to era. I presume such variability would result in distinctly different results from different measurement methods - rendering them each inaccurate by different amounts as they all seem to assume some non-random formula of expansion. The issue being that if we turn out to be in a form of matryoshka universe (such as a black-hole universe), then fundamental factors such as its expansion could be influenced by events external to it, such as the amount of infalling matter. From our point of view these would appear somewhat arbitrarily random.

[@L8rCloud]

Whenever we’re observing something Billions of light years away….We also need to remember that it happened Billions of years ago

[@stixoimatizontas]

THANK YOU!!!

[@DrFiero]

There's totally a crisis... I mean, you're bald. I'm largely bald. There's LOTS of us! How are they going to stay employed and.... Oh. Wait. That's Cosmetology. NVM!

[@TeensierPython]

I hear that. At least he can grow a beard. I get bald and no facial hair. 😭

[@andy2950]

@@TeensierPython Commiserations, Madam. 😉✌️

[@johnn3542]

"Keeps" wasn't around, I tried Rogaine my freshman year in college.

[@the80hdgaming]

Simon isn't bald... his hair has just migrated south... 🤣🤣

[@jordanstafford5110]

More like Drdamndragginmydude

[@jonmcdaniel8492]

The first problem comes in assuming the values of the constants are indeed constant. c has been measured at different values at different times. Are constants actually constant and equal across the space time of the expanse of the universe? That may be unknowable.

[@ianp3112]

Where in the scientific community has the value of c been measured differently? Just because you're gullible to any random video doesn't make it true! Or are you just mad because you don't have the skills to understand or it doesn't fit your narrative!

[@benjaminmalisheski6494]

I find the explanation of cepheids being biased bright to be a very reasonable and plausible explanation of the tension

[@grippen3273]

What if it's so big that it only seems to be expanding from our point of view?

[@stixoimatizontas]

THANK YOU! What we call expansion towards every direction could actually be shrinking, to one point; a super massive black hole of a 4D hypersphere.

[@Traildude]

@@stixoimatizontas If expansion in every direction away from us is actually shrinking, that would mean that Earth is in the unique position of being at the farthest point away from the center of the shrinking, no?

[@MichaelClark-uw7ex]

I've always wondered; since we know light if effected by gravity, does the gravity of the source of light contribute significantly to the red shift? For example: 2 galaxies of very different masses, both at the same distance from Earth, each emit a photon of the same wavelength at the same time, would the photon from the more massive galaxy exhibit more red shift than the photon from the less massive galaxy? Would that be compounded over time so that the farther away the source, the larger the difference? And would that have implications for the red shift of the CMB?

[@kitmoore9969]

Gravity alters the path, but not the speed. Redshift tells us how far away the galaxy is "now" compared to how far away it was when it emitted the light. It's similar to the Doppler effect.

[@normanstewart7130]

In the 1970s we had a similar situation with respect to the value of the Hubble constant. Alan Sandage said it was 50 +/- 5, while Gerard de Vaucouleur said it was 100 +/- 5. Nowadays we think it's 72 +/- 1. So both Sandage and de Vaucouleur were wrong and both under-estimated their errors. This has been happening since the beginning of modern cosmology, we always under-estimate the errors. The smart money says it's the same here, error bars too small, no real discrepancy.

[@normanstewart7130]

And let's not forget that Hubble got a value for the Hubble constant that was a factor of 8 too big. This was due to a systematic error deriving from his unwarranted assumptions regarding Cepheid variables. Error bars too small!

[@julianaylor4351]

The James Webb telescope has already found some very ancient cosmological objects, some of which are close in age, to what it is currently thought to be, the age of the Universe.

[@jowrjowr]

yes but none of those measurements contradict what we know.

[@p53k]

@@jowrjowr How are these objects not a contradiction to the current model of the universe according to which they could not come into existance until hundreds of millions of years later?

[@jowrjowr]

@@p53k where does "the model" say that? how do you differentiate between "the model" (lambda-CDM) vs different models of early universe formation?

[@stuckerfam]

I am a teacher of Astronomy. When I watch videos like this, sometimes I agree, sometimes I disagree, sometimes I am confused. But always, always, always I am reduced to a position of awe. Being a theist (which I would invite everyone to consider) I fall on my face--normally in a symbolic fashion--in worship and reference of our Creator. While I believe that my atheist and agnostic friends have this capacity for awe and reverence which they may interpret as an overwhelming sense of smallness in this vast cosmos, I also love to chat with them about how I and many theistic cosmologists see God's mysterious hand at work fine-tuning this universe of ours to house and to host us. On the other hand, my atheist or agnostic friends seem to relish in the randomness of the parameters of the universe and are "awestruck" in their own way in the "luck" that we live on a planet in a habitable zone in a universe whose physics are fine-tuned, or lucky to a nearly infinitely degree, that we even exist and can observe these wonders. So whether you are a theist, an atheist, or an agnostic, please permit me a little freedom here to say, "The heavens declare the glory of God, and the sky proclaims the work of His hands." --King David PS- I invite any and all friendly debaters, provided it is in good will and charity. We are unlikely to change any hearts being angry keyboard warriors. However, we have every likelihood of stretching and challenging one another when we engage in friendly, kind-hearted debate. And permit me one more freedom: May God bless you all this day or this evening as you read this, and may He grant us all wisdom of His creation and charity toward one another.

[@greer2402]

I like that answer. "The universe is very big but we dont know how big". instead of trying to do a wrong guess of how big it is

[@orneryoverwatch7031]

Can any astronomers or astronomy buffs help me out here... I've a couple questions regarding the expansion theory. So if everything is moving away from "us", is us referring to the milkyway galaxy? To add to that, if *everything* is moving away from us, if I'm not mistaken, wouldn't that mean scientists are suggesting the millkyway is the center of universe? I would think there would be at least a few galaxies, or a sizable segment of the universe, that we're actually moving towards/is moving towards us, right?

[@wombatdk]

That's what I like about science: It's not afraid to be wrong. In fact, it just refines more and more by discovering better and better explanations. Unlike pseudo-science which just says "we're right, because REASONS!"

[@semaj_5022]

Science seeks to disprove its ideas, whereas pseudoscience seeks to confirm them.

[@dejapoo5508]

Or like religion which just makes up Fairy tales to secure it's own power base .

[@GeorgieB1965]

@@semaj_5022 Might want to clarify that in today's woke scientific world.

[@semaj_5022]

@@GeorgieB1965 "Woke scientific world," what does that even mean?

[@Vaeldarg]

@@semaj_5022 It means they want reality to be the way they want it, rather than what it is. (edit: to clarify, those calling it "woke science" do)

[@simonjackson7269]

And now Prof Brian Cox has postulated that our known universe is contained within a black hole!!

[@jowrjowr]

it isn't. spacetime behaves differently.

[@saladgas]

Please allow me to geek out a bit, its so hard to hold it in most of the time. I feel the same way, that the resolution of the Hubble tension requires a rigorous examination of the available data, systematic errors, and physical models. One approach is to perform a joint Bayesian analysis that combines the CMB and galaxy data, incorporating all sources of uncertainty, including measurement error and astrophysical systematics. The posterior probability distribution of H0 can then be inferred, providing a more robust comparison of the two measurements. The potential impact of new physics, such as modifications to general relativity or the presence of additional forms of matter/energy, can be explored through the incorporation of modified Friedmann equations in the analysis. The goal is to determine the most likely explanation for the observed discrepancy in H0 measurements, resulting in a more accurate and self-consistent determination of the universe's expansion rate.

[@JohnBakerJr]

I really like Sideprojects presentations, I just wish that the audio was better attenuated to his rising and falling voice+accent. Makes understanding difficult without raising volume high enough to hear two rooms away. I could care less but my neighbors, not so much.

[@chutechi]

Thank you for the scientific credibility to one of my long-term astrophysics hunches: The age of the universe, Big bang cosmology, and something going on with gravity. I don’t know if these three are related I’m sure they are in some way but as we learn more and more about quantum mechanics the science of the ridiculously small became an entire new branch of physics, although the term is paradoxical, quantum astrophysics would be a type of physics of the ridiculously large. I’ve been waiting for the science to coalesce coalesce around a new model of physics and I think the dark matter dark energy questionsI just beginning of this new physics of the very large, quantum astrophysics.

[@EdgarAllan2pointPoe]

You want to hear something else that's crazy? Some scientists are starting to think that the sense of smell has something to do with quantum entanglement too. I don't really remember the exact details but they gave an extreme yet glaringly obvious example that makes me think they're on to something: sharks. We all grew up being taught that sharks can smell a single drop of blood from miles away but if you stop to think about it logically that doesn't make any sense at all.

[@MCsCreations]

Well, with every new experiment it looks less and less likely that the ladder is wrong. Which could be fantastic for physics.

[@nehorlavazapalka]

the ladder is OK, the universe is about 13.3 billion yo, it will reach maximum size in about 150 million years

[@theexchipmunk]

@@nehorlavazapalka Bold of you to throw stuff we know either not for sure, or have no idea exept that it´s unlikely, around like its a fact.

[@brothermine2292]

The CMB results prior to 2015 agreed with the ladder results. Perhaps a systematic error was introduced into the CMB methodology around 2015 while trying to improve its precision.

[@prioris55555]

Hubble's conclusion was that there was no expansion. The big bang theory, gravity based universe, microwave background radiation, black holes, dark matter/energy, solar system accretion , thermonuclear sun are FICTION built on suppression, fraud, corruption and dogmatism. Even Einstein died realizing his theories were all wrong. It will eventually be replaced by an electromagnetic based plasma cosmology. The big elephant in the room is all the magnetism found all over the universe. You can't have magnetism without electricity with only small exception.

[@brothermine2292]

@@prioris55555 : It's irrelevant that Edwin Hubble didn't believe in expansion. That was many decades ago.

[@Miller54K]

I love how scientists (and this guy) glosses over the "the universe is not only expanding but accelerating". Ok, but for something to accelerate, a force but act on it to push or pull it along to increase that velocity. What force is that? The big bang still?

[@Oliveir51]

Firstly. Is red shift due solely to speed ? We know photon charge interaction leads to a small energy loss each time. And from voyager data there is much more ions out there. And these interactions lead to red shift as well. I know this complicates the picture even more as a first time but I guess can we simulate that and maybe find some clues ?

[@Oliveir51]

This might mean only direct measurements like using paralaxe is for sure. Brightness included ?

[@ShawnHCorey]

Here's something to think about. Take the speed of light and divide it by the distance to the CMB. You get 71 kps/Mpc. This means if the Hubble constant is greater than this number, we can't see the CMB because the universe is expanding too fast. This value is significantly different from the two values mentioned in the video. Something strange is going on.

[@TomTom-rh5gk]

They are lying.

[@malkeus6487]

@@TomTom-rh5gk you're lieing

[@eroraf8637]

Not exactly. The Hubble constant is the CURRENT expansion rate. Also, space and time are a bit more complicated than that.

[@ShawnHCorey]

@@eroraf8637 If it's the current expansion rate, then it's not constant. And if it's not constant, nobody knows why it's changing.

[@TomTom-rh5gk]

@@ShawnHCorey That is my point The current ideas on the subject cannot be falsified or confirmed. They are nothing but empty headed speculation to fool the ignorant.

[@brentonjoseph]

this was a particularly excellent episode. thank you

[@chrisoakey9841]

And the cmb measurements have not come up with the same constant first because it's not a constant,but an average. And an average based on removing source's of energy. But we have found stuff in the dark spaces that cmb is based on. So it isn't a constant, it isn't background, and it is estimated by ignoring the stuff that doesn't fit.

[@SAJR1986]

Right or wrong, finding out the truth is far more important than fear of losing old modelling that could potentially have been holding back progress.

[@jujubucks12]

it's not a conspiracy holding back progress it's just something we can't possibly measure or comprehend

[@SAJR1986]

@@jujubucks12 I never said it was a conspiracy

[@undignified2843]

God's creation only seems to get MORE complex the smaller we look, the bigger we look. Marvelous.

[@robinharwood5044]

One of the many things we don’t know is whether the universe is God’s creation or not.

[@KAEFARIK]

We're missing physics. And not only that - who would've imagined that we can't just sit on a rock and know everything there is to know about eternity? Including how old it is?

[@keithnicholas]

for this particular topic, no, we don't know that, that might be the case, and some hope that is the case, but as mentioned it might just be flawed measurements. Declaring it to be the case is foolish, even if it turns out to be that we are missing physics. At the moment the best thing to say is we don't know, but we are investigating.

[@alasdairwhyte6616]

since the universe is expanding, surely the 'constant' would be different early on and greater later, since the universe is expanding and now accelerating?

[@shiningbright3743]

WAIT WAIT WAIT, the paralax thing taking to points of observations to see its distance....the thing is stars move as well, so the result could be in a way wrong with every day the testing is conducted.

[@bruce5579]

What does it matter how old the universe is? Does it have a expiration date? No such thing as dark matter. Have you seen it? This topic is out there. It’s 4:20 EST.🤪