The Weird Way We Measure An Entire UNIVERSE

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Since the time of the ancient Greeks, scientists have been constructing a cosmic measuring tape to measure the universe from our own backyard all the way to its ever-expanding edge: the cosmic distance ladder. In this video, we climb that ladder and explore how each rung has revealed something new and previously unthinkable about the universe we live in.
References: sites.google.com/view/cosmic-...
0:00 How far away are things?
1:05 Near, far, parallax that star
3:25 Island universes and Hubble's blinking star
5:51 Redshifted rainbows and the expanding universe
7:41 Supernovae and the end of everything
9:08 Conclusion: The ladder of discovery
10:00 I'm hosting a game show!
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[@NelsonBrown]

Galaxies are red, galaxies are blue Depending on their velocity Relative to you!

[@BackYardScience2000]

💯♥️

[@jonhattanrai]

amazing poem!

[@c.jishnu378]

Jitsuni Subarashi desu, kore wa!

[@paraceratherium255]

I love this comment.

[@OmniGuy]

​@@c.jishnu378😢

[@MyNameIsSonsky]

Hey Joe, smart people here ✌️😅

[@user-Haleema.]

𝑀𝑒 𝑡𝑜𝑜 𝑏𝑎𝑏𝑒𝑠❤😂

[@flyaroundyourfire]

My name is Johir and often people mispronounce my name and say it as Joe-here 🤦🏽‍♂️ 😂

[@thomaswilson4127]

✌️🤓👍

[@macdietz]

Lol​@@flyaroundyourfire

[@oscarkhoza7852]

Hey smart people✌🏾

[@AstroKobi]

My favourite part about the distance ladder concept is how simple (yet useful) it is! Last year in my final astrophysics course at university we were tasked with constructing a distance ladder (just as real astronomer had over the last ~100 years) using data from a simulated universe! Using parallax, variable stars and X-ray flash data my Universe was found to be CONTRACTING at an extremely fast rate (~5000 km/s/Mpc). This gave my theoretical Universe just 200 million years left before it would meet its ultimate demise. In the process of constructing the distance ladder, we learnt so much about the Universe (stellar classifications, galaxy types and cluster distribution throughout the Universe, we found SMBHs existed and disproved dark matter, assessed the homogeneity and isotropy of the Universe etc), much like the real history of astronomy you covered in this video! All this to say that this video is great and the distance ladder concept is maybe the most fruitful tool ever developed in astronomy, literally unlocking the cosmos from Earth.

[@prymexxxx]

Love your content!

[@BattlewarPenguin]

Can we appreciate how using angles and equations people were able to find the distance of astronomical objects before modern tech? It really speaks volumes to our human intelligence to find solutions to 'impossible' problems

[@lmost]

Some can, some can’t. Depends on who you ask, as to whether they’ll appreciate what you’re pointing out. There are many who lack even the most basic understanding of Euclidean geometry, as they have no need for it in their daily lives.

[@BattlewarPenguin]

@@lmost I always wonder for those who don't find Math useful why is that, I've yet to encounter something in which Math is not involved in some way. But the basic tools for learning are out there, the only limiting factor is people will to use them. Thank you for your comment

[@firestarter6039]

In the future there will be even more precise and powerful technologies and observation methods, I imagine that people in this new era will ask themselves exactly the same thing, how did people in the 21st century know so much about the universe with such little evolved technology? :v

[@shnilikmw]

@@BattlewarPenguinbecause everybody doesn’t use math in their everyday life, not in the detail aspiring scientists use math. Most are able to intuit simple mathematical calculations without the numbers, i.e. athletes, writers, musicians and so on… we all use math intuitively, like the ancient civs and large structures. The “when will I use Pythagoras’ theorem in my everyday life?” is true to an extent cause 9/10 most won’t

[@zxzxzzxx7396]

"Hey, smart people" Me: Oh. Excuse me. *clicks off*

[@_dave977]

😂

[@xkumanekox]

I learned about our universe expanding just over a year plus ago, and it still blows my mind thinking about it. Astronomy and astrophysics truly are cool.

[@MBMCincy63]

Aside from not being able to fully grasp the math... I too am amazed at how we have learned about our existence in space, and the universe.

[@spencerthompson1049]

Science is the closest we as bipedal apes can get to the truth of this universe we live in, it's truly awe inspiring.

[@John_SalchiChon69]

have you been living in a cave all this time? O_O

[@animememes7531]

​@@John_SalchiChon69 All that matters is he's learning, getting a life to live is the luckiest thing to have happened to a person, our only goal should be to learn all that we can about this universe whilst we are alive, and I'm pretty sure he's doing that.

[@LandonAshworthComedy]

As an astrophysicist myself I can confirm astrophysics is cool.

[@IwanPieterse-iwanzbiz]

This seems more important than the work I have to do now…

[@AbbeyRoadkill1]

The Standard Candles would be a good band name.

[@francoislacombe9071]

There are actually several music groups with that and similar names, including a rock band. Google is your friend. 🙂

[@Sbenbobb9]

Nah.

[@1112viggo]

Either that or a candle-making company😂

[@WhiskyOctober]

Fork handles?

[@AbsWrld885]

Day by day Joe is starting to look like Bruce Banner 😃😃😃. I hope there's no Gamma radiation experiment going on at your home/studio 😂😂😂

[@vinoveritas757]

No joke, I was literally up at 3am this morning thinking about measurements in space. Perfect timing!

[@tannermcnabb4836]

What a great video. You and your teams content is always such high quality

[@shisir_nayak2377]

So much information in a single video, I am overwhelmed.

[@mouliasnestoras]

I wish you'd go deeper into the topic. I almost felt nostalgic, you took me back to when first started watching PBS Space Time!

[@chuckpatterson7006]

thank you for making this so digestible!

[@nil1473]

👌👌amazing work,thank you "be smart" channel team...

[@yecto1332]

That example u used for standard candle was brilliant I hope more science channel use such comprehensible example

[@rahabintemotiul7418]

I found out about the parallax thing by myself as a kid and kept asking adults why the place of an object seemed different for either one of my eyes

[@lattomemes4091]

might have to go to the DMV for this one

[@bryandraughn9830]

I've recently learned that the universe will double in size in 10 billion years. The thing that blows my mind is the fact that 1 cm of space will also take 10 billion years to double in size.

[@manavtiwari5321]

OK, I have a doubt, what do you exactly mean by 1 cm of space ? , like 1 cm of distance between two things,eg: galaxies ? ... I mean what exactly is expanding in an expanding universe ?

[@user-of5lw4oy3c]

Very informative.

[@artisarium]

Awesome episode! Perfect format! Every kid should show this to their parents!

[@altosack]

Umm… Maybe every parent should show it to their kids!

[@GurpreetSinghmadsfan]

Loved the lucidity!

[@CheifR0cka]

I was today years old when I realized that Joe is not Hank Greene... And vice versa.

[@NewMessage]

Ugh... My my arms can't spread wide enough to explain the distance anyway.

[@jerry-ox5ml]

i guess you arent sigma

[@alexterra2626]

@@jerry-ox5ml👶

[@likebot.]

A sport fisherman might be able to.

[@jerry-ox5ml]

@@alexterra2626 🛬🤯💀

[@jerry-ox5ml]

@@alexterra2626 what the sigma

[@jamesbusald7097]

I once asked a little kid how far away the moon was and he said, "It's right there. I can see it."

[@Monika007]

It's time to sleep but I can't wait for next day 😂

[@thestoryofscience5291]

Very good video 👏

[@eLindemann]

0:24 This graphic is incorrect. Since the mirrors on the moon are retro reflectors, the incident ray and the reflected ray would overlap.

[@Just.A.T-Rex]

Over simplification and it’s just for illustrative purposes only.

[@jahosaphat]

Thank you.

[@Leo99929]

I suppose that we don't know for certain that the universe is still currently expanding at an increasing rate, the further away you look. Could it be that we are instead looking back in time and seeing that universal expansion WAS faster before, and the rate on closer objects tells us that it is slowing down? This is a problem with not being able to measure the relative position and velocity of cosmically separated bodies simultaneously due to the time it takes to communicate that information over that distance.

[@chichiboypumpi]

fascinating how Joe’s hair evolved through time.

[@YoSoyRaulTV]

I was asking myself that question a while ago. LEST GOOOOOOOOOO. 0:49

[@Kadsistency]

Hey Joe! I’d love to see a deep dive on why humans have food aversion. It’s quite obvious for anything toxic to the human body but what about some folks not liking brussel sprouts, beets, peas, or avocados for example. Always enjoy learning something every video!

[@garethdean6382]

A fun thing about natural processes is that they tend to be broad. Your kidneys, for example, don't filter out individual poisons, they filter out *everything* then filter back *in* only selected compounds. So even if there's a poison your body is unprepared for,it'll get automatically filtered anyway. Likewise a lot of aversion mechanism are general too; all it takes is an experience that convinces the brain something's bad (a bitter or unpleasant taste or food poisoning) and the brain will often develop an aversion. Generally it's a safe route.

[@Elora445]

I know there's some genetic mutation that is probably the cause to why some of us think cilantro taste like soap. Personally, I think it taste more like shampoo, but still. Wish I could like it though, considering how many foods that uses coriander.

[@jimlitterick4957]

How hard is it becoming not only that measured in the ruler expands, but also as the ruler expands, should the ruler represent the true boundaries of our universe and not just that of which we've been able to observe expanding?

[@JLchevz]

Fascinating Joe

[@KuruGDI]

5:45 As a thinking human I understand what you mean, yet as I photographer say that the highlights in the area of both lights are blown and in this image there is no measurable difference.

[@CharlieUhl]

have fun sleeping tonight ;)

[@byzantinebird]

From parallax trigonometry to spatiotemporality to spectral calculus, our study of the heavens is also a window into the evolution of thought itself.

[@byzantinebird]

An empirical Jacob's Ladder, into the physical heavens.

[@berrybannanas]

Can you do a phantom limb syndrome episode? How can I feel what’s not there?

[@berrybannanas]

Available to give a first hand description of this feeling too!

[@justindie7543]

On June 1st, 2030 there will be another total solar eclipse that will pass through northern africa and greece, following nearly the exact same path of the eclipse Hipparchus used to measure the distance to the moon 2170 years prior.

[@MariaMartinez-researcher]

The David Butler channel has a playlist called "How far away is it?" which teaches the story and the maths involved in these steps to measure the Universe.

[@danhonks6264]

This video makes me wonder when light pollution from populated areas got so intense that we stopped seeing the universe like we used to

[@aniksamiurrahman6365]

Light pollution, space pollution, and so on and so on.

[@lmost]

It really kicked off right around the time electricity was invented.

[@RichardIresonMusician]

There was a telly programme in the UK when I was a kid called "Top of the Form" similar to your high school quiz.

[@ssjenforcer191191191]

Very cool to learn the origin of the Cinema 4D render engine 'Redshift'.

[@mydogisbailey]

Joe’s body is amazing. He is so tall and muscular with wide shoulders ❤

[@doomjunyu_]

I'd like to imagine that the area which the universe hasn't expanded to is actually a grey and white checkerbox pattern

[@RePotHead]

Blow my mind

[@TheEducat0r]

This video just made me realize how mind-bogglingly vast our universe truly is! Who's ready to measure it with me?

[@thomaswilson4127]

Its 12:30 already my mom told me to go to sleep na bro dropped a knowledge banger ma i goda see these one to be smarter.

[@dadsonworldwide3238]

Locating newly expanded 1 minute old space between galaxies gravity manifolds to draw a maze timeline on gets rather difficult in point corridenates

[@ronaldkemp3952]

Galaxies that are redshifted are moving away from the observer. Galaxies that are blueshifted are moving towards the observer. Galaxies that their overall wavelength of their light is not shifting, indicates they're moving relative to the observer. The shift in the wavelength of light occurs to all objects radiating or reflecting visible light. Example, gas in our galaxy's core near the supermassive black hole Sagittarius A produces both a redshift and blueshift in the light according to the Doppler image by ALMA radio telescope, released in October of 2019.

[@qarljohnson4971]

High School Quiz Show sounds a lot like Canada's "Reach For the Top". A teenager quiz show which has been around in a variety of forms since the '60s.

[@replica1052]

infinite acceleration gives the brain the ability to grasp/fathom infinite space (what can foresee movement is intelligence -as in from where brains origin ) to surrect planets is how to live in a universe - life as center of the universe in an infinite universe it makes sense to catch solar wind to master a solar system as identity has become a talent to explore (rockets are eternal )

[@Monkey_D_Luffy56]

It's mind-blowing to think that after these advancements, there are still people believing the Earth is flat

[@h3lldr0p]

This felt like an early go at a Connections script

[@nicholasb8900]

These videos are great for general knowledge. The only down fall is that it doesn’t explain how we calculate our basic assumptions. For example, how do we know when we are on direct opposite sides of the sun and how did we calculate that distance. Seems like we are making assumptions then using those assumptions to make calculations.

[@MetalStorm66]

Hey Joe, I’ve thought about this a lot and I could never figure out what tool/tools someone like Hipparchus used to measure these angles. I still don’t know the answer. But when I find out the first thing I’ll do is use those tools to measure the distance to the moon firsthand. Help meeee!

[@Mr-wv1tu]

Some people can take just a few pieces of information, and get an enormous amount of knowledge out of them; other people still think the earth is flat..... Scary, when you start thinking about it!

[@EvanTheBlue]

This feels like we just started and it ended

[@Robert_Emu_Lee]

Did anyone else immediately think of Earth snorting a galactic line when looking at the thumbnail ?

[@justsomeguy6474]

Hey Joe!

[@likebot.]

Alex Trebek got his start as a gameshow host while hosting a quiz show on CBC just like this one you will be hosting.

[@ThatCookieDoughBoy]

If things that are farther away are father in the past and things that are farther away appear to be moving faster doesn't that mean that things are not accelerating but actually slowing down?

[@prixalternative4201]

Wow super genius

[@austiniscoolduh]

does the expanding universe theory assume we are the center of the expansion/center of the universe? or do they consider that it would be expanding faster/more on one side of us?

[@marcosmith6613]

The theory is that it is expanding in all directions and all points look like they are the centre. Common illustration is to think about a point on the surface of a balloon that is being inflated (note: the universe is not a balloon nor do the planets and stars get bigger as the universe expands).

[@targuscinco]

Uhhh yeah all my pipes are for mystique as well. Yep, I love mystique.

[@Ese_osa]

Man got me trying out parallax 😂😂

[@georgesos]

The 14 billion is our best guess so far. We dont really know the exact size.

[@DemonEyes23]

I've heard of Cepheid stars a few times, but none of the channels I follow done a deep dive into exactly HOW we know that the brightness and frequency are correlated. You know if you are in need of ideas😅

[@xyuv6769]

Well i always wonder in what the space is expanding,

[@martixbg]

The latest rung of the cosmic distance ladder is called "The crisis in cosmology" :D

[@byzantinebird]

Based on the speed of the universal frontier, is it possible it's moving so fast as to be invisible to the naked eye? Is it possible for the doppler effect to be infrared? That woulf suggest to me that gravity's counterforce could have something to do with dark energy.

[@byzantinebird]

We know gravity is a generally weak force. It's easy to conceive of some universal energy that could eternally outpace it.

[@kthfox]

Does red shifting only come from the distant star's considerable relative velocity, or is it also a product of the expansion of the space as light travels through it?

[@dl2839]

The Redshift isn't caused by the expansion of the Universe, I would say that this effect is caused by a phenomenon of light that causes it to lose energy as it travels.

[@trevinbeattie4888]

It’s _only_ due to the expansion of space that it travels through. It any given frame of reference along its journey light is always travelling at the same constant speed, but as the space is expanding that causes the light’s waveform to stretch out.

[@ZennExile]

JWST found like 9 perfect lenses in the ultra deep field images and the data coming from those is undermining every preconceived notion in cosmology.

[@Ceelvain]

Looks like the intro about Hubble wasn't removed from the subtitles.

[@vinkuu]

Except measuring using light; Veritasium explained that there's no way to measure if light takes the same time to send and receive. The time light takes to be sent to the reflective medium on the moon may not be the same time it takes for it to be reflected back, and observed. And in a way, it shouldn't, because of gravitational differences.

[@JustinMShaw]

Though lucky for us that distance measurement doesn't care if light varies its velocity en route. It just needs the overall time.

[@surrakasurovec3641]

Whatsup smart people haha

[@tusharsharma7513]

the doppler effect example got me giggling

[@ralts6464]

Lets extend the ladder again! Whats beyond the event horizon :)

[@Neilfrozn]

The High School Quiz Show has been called the Brain Game for decades. Have fun with it. I'll check some episodes out.

[@KuruGDI]

_Check out this cool trick that astronomers love but tape makers hate!_

[@joseville]

1:50 I can't only close my right eye.

[@sobczakboys2]

at 42seconds into the video you state using light is a accurate physical way to measure distance but it’s not 100% because we don’t know exactly the speed of light or if it has a speed for sure

[@efrainhernandez645]

I measure the Universe w my eyes.I'm like,"it's ye wide"!That's about right.(lol yeah right).!!

[@vocalsunleashed]

Even if the universe wasn't expanding it would be a movie and not a picture. Everything is moving to begin with. Most celestial bodies orbit something, spin on their axes or both.

[@dgr8nikhilsrivastava]

may its never a time to see a star and call it a "full-stop"

[@seattlegrrlie]

Parallax is my favorite word

[@Curryking32000]

All well and good if light travels in straight lines but it doesn't does it, it gets bent by gravity. So how do they factor this in?

[@bjh3612]

Even when light gets bent that doesn't change its speed, just the place it ends up so you can account for it curved path. objects on a scale that can bend light tend to be spherical due to their own gravity( massive stars, black holes, etc.), or entire galaxies. either way this causes doubleing in the image due to light bending around both sides of the object. There are photos of galaxies with the duplicates galaxies behind them due to this bending of light(sometime . By measuring the offset between the duplicates, the knowledge that light travels in a straight line, and properties indicative of size of the object bending the light. you can estimate its size and the added distance that it caused the light to take.

[@Maxtyur]

​@@bjh3612Incorrect.

[@Yezpahr]

10:00 Were you doing the Rule of Thumb test for a nuclear explosion that Kyle Hill just debunked hours before?

[@DomyTheMad420]

"oh look, another video explaining that thing everyone already knows."

[@pjay1438]

I literally just watched the episode of the big bang theory where they shoot the laser to the moon.😂😂😂

[@dr.victorvs]

If you think the ruler against the universe is a good analogy to the difficulty of measuring the universe, imagine how it works when I teach classes in psychometrics 😂 No depression ruler, people!

[@michaels9595]

I'm still stuck on how hiparcus knew the distance between his two eyes hellespont and Alexandria. 2:10

[@CheifR0cka]

God I paused at the funniest possible moment. Everyone go to and pause precisely at 1:50. And thank me later.

[@kkevinj1]

We take a fraction of the earths orbit and spin and call it TIME

[@natinajohnson6462]

I guess you could say it’s… the ruler of everything. ;)

[@yeetbigly5827]

🎶Juno was mad, he knew he’d been had…

[@yume2727]

Jerma do be smart ngl 🥶

[@doggygaming950]

If we can measure how far away the farthest objects are all around us, and they are moving away from us, imagine us in an expanding balloon, no matter where inside we are the expanding ballon is moving away from us on all sides, but can we use the distances all around us to calculate where the center is and where in the universe, not just when, the big bang atarted, ie the center.

[@magilviamax8346]

That would work if space geometry was curved but to the best of our knowledge it isn't. So it's not a like a balloon but a rubber sheet stretched in every direction.

[@oneplaneteer1708]

Is there a distance at which nothing is blueshifted?

[@Kessoku]

FYI, the closest galaxy near you is the Green Bubble Galaxy which still closer than Milky Way and Andromeda Galaxy. 🙃