Hey Space Timers! Due to some Corona related issues, we had a challenging time getting this episode ready and we ultimately left out the on screen credit for our very valued Patreon Supporters. So we'd like to give our Patreon supporters a top comment shoutout and let everyone know that regular on screen credit will return next week. Big Bang Supporters Alexander Tamas David Nicklas Fabrice Eap Juan Benet Morgan Hough Radu Negulescu Quasar Supporters Christina Oegren Mark Heising Vinnie Falco Hypernova Supporters Chuck Zegar Danton Spivey Donal Botkin Edmund Fokschaner Hank S John Hofmann John Pollock John R. Slavik Jordan Young Joseph Salomone Julian Tyacke Mathew Matthew O'Connor Matthew Ryan Syed Ansar Timothy McCulloch William bryan

In the alternate universe where Matt is a cook instead of a physicist, his show is called "Spice Time."

Wow. I remember when it was only 13.7 Billion years old. They grow up so fast!

The universe was smaller and hotter when it was young, weren't we all?

Given how mind-glowingly far away galaxies are, I kinda like Kant’s characterization of them as island universes

If we were to discover definitive proof that the universe were significantly older than we currently believe, which of our assertions about the universe would most likely be to blame for the miscalculation?

1.99m subs. Almost to 2m! Congrats Matt, and everyone behind the scenes!

Easy: just cut the universe down and count the rings!

I feel kinda cheesy making a comment like this because of course everyone appreciates these videos, but I do want to say thank you for taking the time to make these. Of course thank you to the awesome people supporting on Patreon too. Space stuff has always brightened my day and I feel like I've learned a lot from these videos, I really appreciate it.

Could you guys do an episode on the nature of time, and the theories about it? Love from Australia, hope you are staying safe Matt.

if the human race ever does get to be space fairing and be able to visit other worlds, let's just make patterns in their crops and leave.

the history of things being named by those who intended to mock such things is wild

Speaking about the history of the universe, Matt O'Dowd says "Long story short." Got to love the way he just leaves irony on the floor waiting for someone to pick it up.

Thanks for using my image on the thumbnail! I'm glad it's useful! Awesome content PBS Space Time as always!

"Vesto Slipher" sounds like a supervillain name.

Hey! I really love your videos. They help me understand so much that my college doesn't have time to cover in our classes. I'm trying to write a paper based on some things I have learned in other videos, and I was wondering if you guys kept track of your sources for these different videos? i am trying to dive a little deeper into some of the content, and I want some more sources for my paper.

I just want to take a moment and thank PBS Space Time for not putting 5+ ads within one video like a lot of other KZfaqrs.

How We Know The Universe is Ancient... Just look at the greyness and greatness of Matt's beard.

Well, I got to know this channel maybe a couple of weeks ago. It is an amazing one and reminds me that I could be there understanding fully all notes if I had chosen a different carrier path. But still, great way of sharing knowledge to all. I will probably watch all back from the start of your playlists one day. Thumbs up!

_"How do you learn the age of the universe when there's no trace left of its beginnings?"_ *You count the Birthday Candles!*

Thank you Matt and PBS Spacetime for bringing some relief during the pandemic. I always look forward to your videos

i feel like matt is talking to a ghost that is behind me

One of the first episodes in a long time I /think/ I actually understand after a single watch... when I watch it a second time I'll realize it's all going over my head.

I wish I could like more than once. This deserves a like for the content, for the Q&A and, of course for Simone. gorgeous kitty!

So if the universe is precisely 13,8 billion years old, does that mean that the Universe began on a Monday?

When James Webb is launched in 2050 this number might change again

Probably my favourite moment from back in the day when Adam Spencer & Wil Anderson did breakfast radio: Adam: The universe is 13.8 billion years old. Wil: *sings* Happy birthday to you, happy birthday to you… should we get it a present? Adam: What do you get the universe that has everything?

as always gorgeous, thank you PBS👍

Still having trouble reconciling "the universe is infinite in size" and "the universe has a finite age". Especially if the universe started from a singularity. Going from infinity small to infinitely large in a moment of planck time queues the meme "well, that escalated quickly." :)

"Vesto Slipher" is an amazing name.

Rewatching this over a year later because obviously and i still would love to be able to paint like the beautiful background there. Genuine reason i miss lockdown is not seeing this in newer videos.

These are the still best videos on KZfaq. Thanks for all the hard work errbody.

this is such a positive show... maybe there’s a hope for humanity

Can a galaxy be so redshifted that the light it emits arrives to us in radio frequency?

So a number of things occur to me after watching this video. 1. Seeing the ways that people in the past have theorized and observed the universe is always kind of amazing to me. It's easy to forget that grand ideas and theories are often just an amalgamation of smaller observances of the past. It's humbling. No matter how much you learn/know, perspective is just as important. 2. The Big bang theory is effectively built in a kind of chain of observations and discoveries. If any of these observances or discoveries turn out to be wrong then the chain breaks. Not necessarily the whole chain however. The further back in the chain a hypothetical link breaks the more hypothetical damage could be done to the theory itself. 3. this is kind of an expansion on thought number 2. All of this information has been obtained by looking up and scribbling numbers. it's amazing. With the new Webb telescope in orbit we're going to be learning mind blowing discoveries and seeing that certain assumptions were wrong. This could be relatively small things or they could be game changers in terms of grand theories. We might make discoveries that definitely prove the General Relativity, Quantum theory, or even disprove the both of them somehow. Just as perspective is so important to discovery, so is clarity. The Webb telescope is effectively our next step in both clarity and perspective. I wonder how much of our current understanding will change, expand, and/or collapse. 4. Final note. It was kind of just thrown in there but I have to point out what I see as a totally inane point. When it was mentioned that he Pope saw the Big Bang as evidence for Creation the host narrator also mentioned Maitre's point. Which was along the lines of the Big Bang being beyond any metaphysical understanding. what a ridiculously inane and highly erroneous statement. Whether or not I believe in a hypothetical religion or Creation of any kind will be kept secret, because I feel it's of no importance. My bugbear with his statement is purely in it's logic. The Big bang being a product of an all powerful entity snapping their cosmic fingers seems just as likely as the work of quantum forces spontaneously creating the world. Making an absolute statement about it's place in the universe is totally narrow-minded and quite stupid. It has been said that these two things need not even be separate ideas. That both could easily be true at the same time. Not sure how I feel about it but I find the argument quite compelling. Is it possible, I wonder, for a phenomenon to be both totally scientific and natural while also being supernatural and metaphysical? Are we, as a society, pushing a paradigm of opposing binary perspectives where a binary need not exist? Something the chew on. I certainly do not have the answer.

I tend to think the Universe is incredibly young, compared to its expected lifespan of trillions of years.

12:45 "... when the universe was much smaller and much hotter ..." ( ͡° ͜ʖ ͡°)

Great video. The difference between a type 0 and a type 3 civilization has been estimated to be 1 million years. It is is amazing to think that an alien civilization that appeared just 1 million years earlier than humanity, may now have the resources to visit us.

Big set lighting improvement, kudos

The universe was four billion years old when I was in grade school. I hope to see my ten billionth birthday soon.

For all creationists the first structures humans built date back 12,000 years & are older than any of your estimates

Is there still a recording of that programme in which the term "Big Bang" was coined? It's kind of a historic moment, isn't it?

This is really a great video. Well done.

I was watching the series of videos on string theory and related stuff and found the concepts are explained as best as they can be in layman's terms! One other project I was fascinated by when I was exploring the modern physics landscape was The Amplituhedron project of Nima Arkani Hamed. It would be great if you could do a video on that in the future! Would love to learn more on that.

Congrats in advance for reaching *2 million subscribers*

•Watching PBS space-time: FREE (or for contributors, the amount that you contribute ;-) •Seeing an astrophysicist calm & coddle his kitty: PRICELESS

Your do such an amazing job. Thank you

I love your youtube chanel, keep up this brilliant work. Space videos are my way to escape from daily life.

Confirmed: cats know way more about quantum space than we do.

Ask Simone the cat, cats can move between universe's to get in and out of rooms or even the house

Actually that's the question I have since beginning ,, thanks PBS Space time ....Your video's r quite fascinating for Physics lovers....wow!!

Somehow I read the title "How we know the universe is an accident"

I can't thank you enough for helping me (sort of) understand these things. I was late to the space nerd party, but i'm damn happy to be here now. The excitement i feel about the James Webb launch is almost too much. What amazing new things will we discover?!

"The Hitchhiker's Guide to the Galaxy" claims that mice are hyper-intelligent pan-dimensional beings, responsible for the Earth's ten-million-year research program to find the Ultimate Question, but I think it got it wrong. It's actually cats. 😼

The hardest part for me to conceptualize is cosmic inflation - even more than the size of the universe it’s hard for me to comprehend it getting larger as there’s nothing outside it (not just the observable, but total universe). The CMB makes sense and is powerful evidence for a whole host of theories.

It's been over a year since this was published. Time to update the age of the universe on the title to 13,800,000,001.

I'm curious about the CMB map. I have seen it many times before and have always wondered, how it is oriented? I assume it is a projection of the celestial sphere analogous to maps of Earth, right? But where is the north and south on the sky? The stars (and also regions of universe containing them) visible from Earth are different, depending on the place on the Earth's surface, current time of day and of year. There are also no other good reference points, since everything is constantly moving with regard to everything else. Then how do you even go about orienting the CMB map, or any map of the sky for that matter? Do you pick a particular time of day and year, a particular location on Earth, and just ignore miniscule year-to-year differences, or is there some other trick behind it?

I've heard all of this stuff before but I love the way matt explains things I'd watch him explain anything I swear

Hey man, was really cool seeing you in the latest season of How The Universe Works!

Not only is this the best channel on youtube, but It has one of the funniest and most thought provoking comment sections on the site.

A few years ago I asked the question that this episode brilliantly answers. Now, I have a follow-up: do we know if dark energy has remained the way it is since the beginning? If it hasn't, do we know when it "took over" and how would that influence the age calculation of the universe? Could our lack of understanding about dark matter and dark energy throw these calculations off? By how much?

"Vesto Slipher", isn't that a Yu-gi-oh character?

Çok faydalı bilgiler var. Teşekkür ediyorum size

Nice I always pondored about this

A massive F to Radu Negulescu, pay your respects fellas.

This guy would have to be amazing to get into a conversation with!

Thank you for the video :)

I need a shirt like that one.

Everyone: We know everything there is to be known about Universe Hubble: Hold my telescope

But do we know if time always passed in the same pace?

Can you guys do an episode on Superluminal communication or faster than light communication? Real time interplanetary communication? Through worm holes or quantum entanglement or quantum locality?

Videonuzu beğenerek izledim çok keyifliydi böyle keyifli videoyu bize sunduğumuz için teşekkürler yalın bir anlatım olmuş

The T-Shirt! "Morty, there is literally EVERYTHING in space!"

Just wait for the day that everything we think we know now is chucked right out the galactic window.

The Universe. Best thing imagined happening ever since nothing not happened. Nothing that lasts can withstand an infinite timeline passage except foreverimaginary everlasting Universe.

I like to think of the Internet in geological terms. One day someone will be able to look back and see this interesting layer in the upload dates where we met every KZfaqr’s cat.

How does the current "crisis in cosmology" inform the age of the universe? I was surprised to hear Matt say "precise age" a couple times when describing the 13.8 billion year old universe. Doesn't our understanding of the age lean heavily on whether the supernova data or CMB data or neither or another are the more true measure used to derive the Hubble Constant? Just looking for a little clarity. I know Matt is well aware of all this and would love to be set straight in my head about whether I should be thinking "precise" or "up in the air" when I hear 13.8 billion. Thanks

Did you ever try to put that kitty into a box with a contraption that will kill it when a radioactive particle decays?

~ 13:30 - A.k.a. "crisis in cosmology" - confidence intervals of those different methods don't overlap. But I am sure you made an episode on thet, too, in the meantime.

Congratulations on 2 million Subscribers!

Can't wait till we get the age of the universe down to one hour precision :)

Para phrasing feynman Time is something that happens when nothing else does..

great vid

No ads. Thumbs up 👍🏻

It's truly remarkable how you can still produce this high-quality content, even during the pandemic. It even has the same high-quality animations! That's far better than what much of mainstream media has been able to do. Everyone at PBS Space Time should be proud of what they've been able to accomplish during these trying times.

Just wanted to drop a comment saying "Thank You!" for such nice and educating videos.

My theory is the universe restarts itself, everything is expanding and it will reach a point where it stops and begins to contract, eventually forming a singularity resulting in another big bang

This is Russell Brand having never fallen off of the wagon.

Did I just hear the coolest science guy on youtube say Lala Fafa, im actually dead

Well just for the record, Cephid variables were discovered in 1908 by Henrietta Swan and not Edwin Hobble.

Fr. Georges Lemaitre is an amazing astrophysicist. He suffered from anti-Catholic prejudice in his career. A good roll model

I never realized our understanding had changed so much, so recently. We are usually taught about the most modern understanding. But we're so rarely taught about how we got there, and how we built off of it. In 1861, Louis Pasteur came up with germ theory, and in 1928 we discovered penicillin. In 1954, we developed silicon transistors, and the first computers were the size of a room. Einstein came up with special relativity and general relativity and e=mc2. The universe is estimated to be 13.8 billion years old. We know those things. But we don't know the whole picture.

Hi, could you address what has been referred to as "The Great Attractor", which I understood to reference our entire visible universe moving in unison TOWARD something unknown, but apparently so massive, that it's gravitational "pull" is sufficient to cause our entire visible/detectable universe to move at a detectable speed toward it. First, I heard of this years ago, but nothing since; and second, am I completely off base in my understanding of this? I'm an adult, and would welcome your corrections, even should they reveal me to be an idiot (or is "mentally challenged" the preferred term these days). Thank you, Frank Seiler, Esq.

Here is something I've been struggling with: "The expansion of the Universe is accelerating, because we observe that the further a galaxy is from our own, the faster it is moving away from us." BUT, since we are also, in essence, looking back in time the further out we look, we are seeing those most distant galaxies and their velocities, not at they are at the present, but rather how they appeared billions of years ago; billions of years closer in time to the Big Bang. Shouldn't we expect that galaxies were all moving away from each other at greater velocities the further back in time we observe? Aren't bits of debris moving away from each other faster near the beginning of a conventional explosion and they slow down as the explosive energy is dissipated? (not a perfect analogy, I know). Wouldn't the observation that galaxies ever closer to our own, are moving away from us at ever slower velocities support the conclusion that the expansion of the Universe is in fact decelerating? I should probably join the Space Time Patreon and ask this on the Discord. =)

Radu Negulescu? Weee, a fellow Romanian is supporting PBS Space Time!

That zoom in to the stars in Andromeda, combined with thinking about the distances between any of those stars, makes me feel so, so, small. I don't think I can handle considering that that ratio doesn't begin to cover my actual size in comparison to the universe. Am I even equivalent to a quark in all of this? A self-aware quark, thinking itself special? And then 11:39 came..

Would we ever be able to harness heat energy from quantum fluctuations? As the energy can never reach abosoulute zero, isn't there always energy there to harness from nothing?

How can you say "precisely" when it is more accurately "our best prediction with modern science"

I think this background is great 👍🏻

Yeah ok not gonna lie I thought when you started talking about the cat that it was going to go the way of The Cat That Walks Through Walls by Robert Heinlein