Light seconds, light years, light centuries: How to measure extreme distances - Yuan-Sen Ting
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- Опубліковано 5 чер 2024
- View full lesson: ed.ted.com/lessons/how-do-we-m...
When we look at the sky, we have a flat, two-dimensional view. So how do astronomers figure the distances of stars and galaxies from Earth? Yuan-Sen Ting shows us how trigonometric parallaxes, standard candles and more help us determine the distance of objects several billion light years away from Earth.
Lesson by Yuan-Sen Ting, animation by TED-Ed.
The more I read about space, the less I know.
Wow so true!
تذكر الاية يا فيصل ، قال تعالى (وما أوتِيتمُ من العلم الا قليلا)، الفضاء من كثر ابعادة تخيله يتعب العقل
The more u read the more u becomes curious to know about space
Dunning Kruger Effect
The more things you realise you don't know, the list of things you don't know you don't know becomes smaller.
It really is like a time machine. On earth we are living the present, but when we look at sky we are seeing the past. Mesmerizing.
No the starts that we are able to see rn are still alive
techincally we never see anything real time. But the distance in our everyday life is so small that the delay is like 0.00000000000001 seconds, basically nothing
@@rahulsharma2402 If you don't know,Life of stars is 1 billion years
What if i tell you we're living in the present and those stars are currently in the future i.e 80 years, and we receive it's light now.
Also, we never experience the present because the time our brain process it it's already gone. If we manage to be faster than light then it will be darkness and we can go back to the past also because our eyes use light to interpret visual things thus we can time travel.Don't lose hope guys. I'm young so I could see this is possible for my future.
I appreciate that you said "Light is the fastest we know" rather than saying "light is the fastest thing in the universe" 🙂
The fastest thing in the universe might be dark matter.
@@mromen5158 Thank you for the answer before I asked the question
@@mromen5158 may be
Yeah
@@mromen5158 u mean dark energy
Imagine. Civilizations millions of light years away would still be seeing dinosaurs on earth.
The Almighty oh yes.
Supposing they have a way to observe details on earth surface from such unimaginable distance.
Great one bro! But i don,t think they can that deep. If they can then it will be a very good thing
If they have a telescope that is a few lightyear wide which can see through our atmosphere and focus on animals from that distance... then sure, that would be crazy.
That's why 👽 aliens are coming here on vacation only to be disappointed.
the universe is constantly sending us information in the form of light. all that remains is for us to decode it. wow.. amazing..
+Chris Ross lol I love their outro one liners.
You do realise if the theory is correct it would actually be impossible to see any star light years away...or even one light day away
+bmlsb69 what?o.o
It sounds more amazing than it is. Seeing the shining of a star from millions of years ago doesn't give us any useful information.
Lucas Layton yet the stars remain at the same spot all over, every year reset and have been this way a few thousand years since earth was created...
"The Universe is constantly sending us information in the form of Light.". I like that.
+Jessica Crawford well not exactly. scientists now are looking at space through neutrino telescopes which will give us more information about the history of the universe. thus photons and neutrinos together would decode the information.
@@onkarmohite7560 What is a neutrino?
Although the light is the fastest thing, how are we going to travel between planets while it's taking centuries to reach us?
@@sahinyasar9119 wanna borrow my millenium falcon
So we are actually seeing our universe how it was, not how it is. Wow
Thats a well known fact, not as surprising as you think
yea, we dont see stars in realtime , only remnants. those stars might be dead now.
I was taught this in middle school and that was 15 years ago, are you children not reading legitimate science books these days?
This is common sense
@@frayeleo0015 or in their final stagest
My night's sleep is ruined when I think of the univers.
Yes it is scary to think you are floating in space, even worse than sleeping on a plane.
Ever since i watched interstellar i just can't stop thinking about space, time and dimensions, Makes me think how tiny we are like we are not even 1% lol
@@ManOfCinema- the fact that you even said 1%. 1% is a big number. Put a few billion zeroes before . And that’s probably still too big.
@@kevinc.cucumber3697 you are right.
!
Hehe boiy
meanwhile in 1 million light speed away planet
"hey dude check this out, i found another habitable planet, its so beautiful and blue and it has one moon"
"send a message, maybe we are not alone in this universe"
"i just did"
1 million years later on earth
I think they will be pretty smart to realize that. But for the sake of the joke, Haha.
Deep😂
This comment is highly underrated, hahaha good one
It's funny that despite being 7 billions of us on earth, humans are still feeling lonely and want to find more intelligent beings. To be fair we are the only species that we know that has evolved to be an intelligent being (know that they are alive, being able to feel empathetic, being able to reason etc)
@@beluwuga2573 you are making us lonely.
"The universe is constantly sending us information in the form of light.
All that remains is for us to decoded."
Brilliant piece!
*If my mom wakes me up for school I'll say it's yesterdays's light*
8 minutes old.
and why do you worry anyway, schools will be closed for about 2 years
@Umair Jibran not really the end of the virus does not depend on when Will find a vaccine it depends on when the virus will get weaker and weaker
Does light travel infinitely?
@@tzikhan5546 good question. Unfortunately Idk
@@tzikhan5546 Well light can accelerate when it leaves a denser substance. Thus it seems it will travel forever until it is absorbed, much like an object in space will keep on moving until it hits something. The light will slow down and some of it absorbed but the light that makes it through travels fast once again until it some day hits your eye or bumps into a solar panel.
Incredibly well explained. Knew quite a bit about the topic already, but learned a lot in those five minutes.
So u saying we might be seeing stars that no longer exist !! Cuz they're far away and their lights took long time to reach us !incredible ha!
I know right. Its mind blowing.
Exactly
syg B. Yes
But you see.. time is relative so we really can't say
Lol...
I love Ted-Ed and Kurzgesagt =D
MasterXG but he rarely upload and its annoying
As Kursesagt always say, " quality > quantity"
Jojo 😂😂😂😂
How about Life noggin?
Life noggin tô
Meanwhile when we look at a star,it could not exist right now,that could be a image of a million years ago. Wowwwwww what a magic!
It's not magic, that's how physics work
ua-cam.com/video/wqsMh5erPzo/v-deo.html
@@yasin_karaaslan Maybe the person meant metaphorically.
Whenever you look at the Stars 🌟 in night sky, you look back in time. 🕛🕦🕚🕥🕙🕤🕘🕣🕗🕢🕖🕡🕕....
siva you do when you look at anything
hey buddy, religion has nothing to do with this ابو ليث الخطيب
U smart
ua-cam.com/video/sS-0W6eHfjM/v-deo.html
Is that like visual remembering?
ted-ed ! you need to use kilometers as well, people around the world watch this, im from morocco and i have no idea how long is a mile, so please use the international system of units as well
Lucas Leong 1 mile=1.609km
Lucas Leong correction . a mile is 1.6 km
If you are really interested, then you would have looked it up on the net ...
Du Duu Hi fellow 😂
Lucas Leong 1 mile = 1.6km you can take it as 1 km if you want an estimate
the greatest and the simplest explanation I've ever seen!!! Thanks Ted-Ed team!!!
"the universe in itself is a time machine." ✨
This is the most brilliant animation and visuals i've ever seen that explainig these concepts.
Great clip but please do not use imperial units eg. miles, in relation to science.
My hero.
While I agree, I understand why they used imperial. This is Ted-ed, not Ted-scientistsonly
My point is, the general citizen of USA will not be able to make sense of metric units, and any person who is scientifically inclined would be able to convert quite easily anyway.
In my opinion, they should just report it in both! At least until the US switches to metric ;)
Cheers from Canada
theres nothing scientific about the imperial system.
kingkong11ization It's less efficient but it *does* work, just because you prefer one over the other that doesn't make it unscientific.
Just because my audience members are idiots doesn't mean that I should forsake the measurement system. Metric is not only the scientific standard, it is the world standard and the US standard (look it up). Besides when a distance of 6 trillion Imperial miles is indistinguishable from the metric 10 trillion kilometers it is best to use the standard not the aberration.
Amazing. Im watching every video and learning new things. Thank you for your efforts, they are very appreciated.
precise and crystal clear. these questions have been haunting me for years. thank you!
I never understood this subject in my school life. Thanks for presenting in simple language. 😍
So, if the sun dies then can we still see the bright image of the sun for 8 straight minutes before it starts to fade away?
Not really. Before the Sun dies, it will get bigger and bigger till it reaches the Earth and burns it. It only dies after that, so basically u'll already be dead.
Sun is a star so it will explode like the rest. So youll be dead by then lol
Let's just say the sun just magically disappear. We might die right at that moment. The disappearance of heat, radiation, and gravity from sun will have big impact on living organism.
@@Dave-gs3ue It will get bigger a lot slower than 8 minutes, also we will notice it a lot faster. so he'll have even more time.
@@sunnyisson90 An explosion would happen far more than 8 minutes friend, you cannot exceed the speed of light
the fact that looking at the sky means looking at the past is soo amazing
That is why i love to looking up the night sky
Anything you are looking at is looking at past but you don't realise it just due to small distance , amazing !
This was one of my biggest obsessions and fixations while I was in high school during teens!!
Thank you so much for this informational video. I've been looking for something like this, since forever!!
The fact that we need to imagine that the worlds we saw doesn't support life by now.
As light spends years to reach us.
The other worlds must've changed throughout this time.
Man space is so scary and beautiful at the same time...
This one was top notch!
I’ve been searching for this my entire life 🙏
this is so informative. I was just wondering how they measure the distance between the planets, stars and galaxies
Looks like candles have come back with a rage. "FUCK YOU THOMAS EDISON" - Candles
In one group of variable stars the period of light fluctuation is directly dependent on luminosity, and knowledge of this fact enables astronomers to utilise such suns as universe lighthouses or accurate measuring points for the further exploration of distant star clusters. By this technique it is possible to measure stellar distances most precisely up to more than one million light-years.
This is super cool , it cleared many confusions related to space.
Ted ed is the best channel ever, I feel so satisfied and happy to know so much about the universe and Ted ed has made me even curious to know more! I would really like to give you humblest gratitude. Thank you!!
Light is the most important thing in the universe!
Ted ed pls upload more videos you are the absolute best !!! Your videos give a kind of satisfaction 😀😀😀 Keep it up!!!
The last line was Sooo incredible
I can't get enough of this information, I am constantly in amazement at how vast the universe is.
I really feel grateful to see such videos published by Ted , Vox , Spacerip etc . Just wanted to say THANKS , hope you stay eternal like the universe itself .
so if im understanding correctly, if we were looking at andromeda right now, it would be an image from the past but, in the present time it might not exist anymore?
Yes, if it somehow vanished today, then we would not know about it for another 2 million years.
@@SpottedSharks daaam bro!
What is more stunning is that not only our eyes and telescopes are not going to miss andromeda's absence for more 2 million years, but our entire galaxy would not feel the absence of its gravitational pull for about the same time. Of course, that is assuming general relativity is as accurate as we think.
The Andromeda light is 2.5 Million Years old.A big star explodes after a few Million Years.A small star like our sun
Has about 4 Billion years more to live.
ANDROMEDA actually moves toward our galaxy.When we collide with it many stars have faded away.
In 1 Million years many of our big stars in our galaxy are vanished also.Dont worry it is not your problem.
It exists right now because it's on its way towards us it's just you see it as it was due to distance.
"The universe is constantly sending us information in the form of light, all that remains for us to decode it" amazing lines 👍
These videos put my head in a spin.
Mind blowing!!!!
This is very true but I never cared to think about it that My jaw dropped as soon as I realized that the stars I see in sky at night were actually from millions of years ago which many of them may no longer exist. Wow wow my mind is completely blown away!!! This fact is so mesmerizing
I wish there were better classes on space ect wen i was in school!!! Its amazing
What if we find a watery or glassy planet which reflects lights that is maybe a 1000 years away, then by looking at our reflection in it we could see how Earth looked 2000 years ago 😱😱
Edit-Sorry light years😋
That would be too far off for earth's light to get reflected ...mind blowing concept ... But not gonna happen... Because the earth is too small... All you could see in that light is a tiny grain of sand which would be our earth ..at maximum
Reflection is not light dude 😂 like reflection of your face on mirror
A great thought but quiTe impractical
Wavelength of light increase as they travel.. So. Maybe u r getting me
Light reflected by the Earth million years ago is travelling somewhere in the universe....
All that remains is us to decode it...love it... wishing mankind the best in this field...
Just perfect! Short, very easy to understand, graphic, well told without complicated and technical terminology. Thanks for helping spread astronomy concepts.
HIPERHOGAR ARGENTINA "without complicated terminology" *cough ** cough *,miles... *cough **cough *
but how do they determine the brightness of certain object if they dont know the distance in the first place ?
I want to study Astro Physics😭😭😭😭
ya
Isha Mughal .
There are free online degrees in edx
best subject
it's really hard to make carrer in astrophysics
Thanks for the video.
Could you do one about the use of red-shift as a measure of distance, please?
I really do not know how to calculate the distance in space before, but now I can understand how we can calculate it thanks TED
incredible
Everytime I watch something about distances in space, it just blows my mind.
The great line is " The universe is sending us enormous informations in form of light. But we need to decode it"...
Bro can you elo orate it.
@@MlManoharan It doesn't need elaboration. It is quite understandble and comprehendable.
We can travel light-year by only only boon of God that ie teleportation
This is almost scary when u think about the size of our universe. How our lives is so small small to the breath things out there
To me kya job chhod du???
The last part of the video was mind blowing. Very amazing to think of it
This research and study is very educating in much simpler way. Thanks #TedEd
I’ve always wondered objects move slightly when I alternate between my right and my left eye. Now I know, it’s because of trigonometric parallax
This means whenever I look up into the stars in the night sky, I'm literally looking at a few million years ago...AWESOOOME!!! 🎉 Flinstones my man, where you at my heel drifting turbocharged leggy bruh.. 😂😂 Loved this video!! 👌
yep! it is amazing
George Kosgey
no it doesnt...every star you see in the night sky is in the milky way. the milky way is 100,000 light years across. The furthest you see back in time is less than 100,000 years. Unless you're talking about the Andromeda galaxy which is observable with the naked eye
You forgot that the Milkyway Galaxy is 100,000 lIghtyears across! and the star that we can see in the sky is a part of milkyway, so it's only thousands not million
George Kosgey sounds a lil crazy don’t you think
Thank You! I was looking for this video since some time now.
The scale of the universe is just, in the true sense of the word, incredible!
Wow... I can't believe it...
*I learned in a video instead of my teacher explaining it to me 200 times.*
It barely says that “the farther you discover, the complex it gets ”
the most important info I needed, now everything starts to add up ..thanks so much❤✌
This is the question I've searching for my whole life
Can't thank enough but thank U:
"How do we measure distances in space?"
In parsecs, of course!
Unless you're Han Solo in which case a parsec is a unit of time ;)
+Scarletpooky I don't get it. Who is Han Solo, and what does that have to do with parsecs?
han solo is in star wars
EastStandManc it is light second
in gallons.
Love this channel
+WhosFaulty you love people that sound like that know what they talking bout to feed you lies....
Now I know the light year meaning which I didn't understood 13 years ago while in school.
Thanks 👍 to this video for giving me the relief.
Very nice video. Thank you very much for this and keep up the great work
I've been in the same room with someone that I thought I was close to only to realize that I was actually a million light-years away from them so I guess measuring distance is all in ones perspective I suppose
I read the thumbnail as “How do we social distance in space.”
Thank you for the clear explanation of a complex topic
The animation is amazing once again
What if we are all subatomic in size, Earth is a germ cell we live on, and that we are a part of another being?
And what if THAT being is also subatomic to yet ANOTHER being that is subatomic, and so on and so on????
+whyguitarguy1 mindfucked! :-O
+whyguitarguy1 What if somehow it loops back around and it turns out that the universe that we're in's universe's universe's universe's..... universe, is actually the universe within the universe within the universe that is within the strings that vibrate our subatomic particles? Somehow vastness goes both outward and inward at the same time.
na brein is on faiar
Ohmygod! Finally someone said that! I always had this thought but was too embarrassed to say it out loud.
whyguitarguy1 mind boggling
i still didnt understand how we know the intrinsic brightness of certain stars and supernovae... could someone explain?
i dont get it to xD ok i understand that if you know how bright 100lumen torch is and walking away from it, you lose the light and then you can say its 40meters or 100meters. because you tested it. but how do you know how bright is the star or supernova or other object to determine how much light you lose being so far...
ua-cam.com/video/HdPzOWlLrbE/v-deo.html
ua-cam.com/video/CWMh61yutjU/v-deo.html
How vast is the universe and how it made and what is time and space .. send shivers down my spine.. are we alone?
The quote : "What we know is a drop, what we don't know is an ocean" is accurate af.
2:55 - BUT, you can't know the luminosity without "calibrating" the methodology on stars of known distance, which requires the parallax method. Beyond that, you must assume that all the stars have the same relationship between luminosity and the period, which seems like a stretch. Also, couldn't the light be diminished by obstacles, making the start appear darker than it really is?
4:04 - Same problem. The dimming function must be assumed to be the same for all supernovas. Second, this luminosity per distance relationship must be calibrated with a known distance.
I'm concerned by a LOT of assumptions happening here.
4:30 - How would relativity affect this? We have absolutely no way of knowing the time frame reference that we at nor where the time frame change to what we are looking at.
I'm concerned by a LOT of assumptions happening here."
Facts you mean. Sorry young earth creationist its over.
gracelandtm
Not facts. Have you researched this at all?
And, this is about distance, not the age of the universe.
Junk Mail
How old you think the universe is?
+Junk Mail 2:55 there are stars that we know the distance and brightness in the first place using the parallax method. Then, we use those stars to deduce the distance of other stars.
4:04 Yes, the dimming rate is the same, which is why they are categorized as type 1a supernovae. Also, the luminosity per distance relationship is calculated by short distances and known brightness, e.g. your friend holding a candle.
4:30 I think you misunderstood. Relativity has no effect on that. It is simply the time taken for light to travel from those stars to us. It is the distance divided by the speed of light. It's THAT simple.
You understand now?
+Junk Mail oh and btw 2:55 the relation between period and brightness is observed and calculated by scientists.
Also, in terms of obstacles obstructing light, there is something called Gravitational Lensing. However, they don't have a huge effect on measuring distances.
This just shows how insanely smart Einstein is to comprehend and even make the theory of relativity.
Absolutely outstanding!!
i get the light year concept now thanks for this
سنريهم آياتنا في الآفاق وفي أنفسهم حتى يتبين لهم أنه الحق أولم يكف بربك أنه على كل شيء شهيد
So Some lights are still traveling for us to see.. But when it reach us its already part of the past...
Cracking,this has knocked my boots off!
Wow TED-Ed you did it again! Once again you have proven that you don’t know how to explain things in the most simplest terms
plot, we see our species million lightyears away. They all died and travelled to earth.
+Niller Symphony . Well, I do guess you got a point that I am bad in language xD . What I meant saying that they left the planet to earth and left everyone else die. And they travelled faster than light, therefore we can possibly see them still alive when they are dead now xD
+Niller Symphony . Well, I do guess you got a point that I am bad in language xD . What I meant saying that they left the planet to earth and left everyone else die. And they travelled faster than light, therefore we can possibly see them still alive when they are dead now xD
Iba ka talaga pareng Ted 😂
lol
Andrea Gonzales qaqo ampota.
hahaha
What does "potainamo" means?
dat means youre beautiful or handsome
Thank you for sharing valuable information
Excellent illustration ❤ Bravooo 👏👏👏
I wonder how many lifetimes it would take to walk to the nearest galaxy ( assuming each life is exactly 100 years, that they walk at the exact same rate and also that you could walk through space)
I did the math out of curiosity rounding off some numbers:
Distance to Andromeda, 2.5 million light years = 15 trillion miles
Average walking speed, 3 miles per hour = 27,000 miles in a year
Walking Distance to Andromeda at 3mph = 555,555,500 years
Lifetimes to Andromeda, 5,555,555
Thats simple math actually. Try for yourself! It's fun to achive own puzzles somtimes. And if you won't succeed or want to know if its right just post it on certain forums! ;)
Oh... someone did it already for you. Fair enough.
HigherPlanes idk? That seems kind of low
Tarang Srivastava
I'm far from being a math wiz, so I could be wrong. Double check the math and let me know!
HigherPlanes I'll test in metric!
D = 2,538,000ly * (9.4605284E12km/1ly) = 24010821079200000000km
At v=5km/h,
time=24010821079200000000km*(1h/5km)=4802164215840000000hours
time converted into years=
4802164215840000000hours*(1year/8765.81hours)=
547828918929340.2435142901796868 years (woah)
If the human lasts 100 years, then it will take
547828918929340.2435142901796868years*(1human/100year)=
*5,478,289,189,293 humans* You may have been a factor off in your conversion somewhere, or I messed up! Kind of pesky to do calculations in a comment box ;)
how do you make such enormous thumbnails?
Fine presentation,! I Absolutely helpful to measure the space,! Thanks,
How are these videos better than any traditional educational experience I've known?
So if a person is standing right in front of me then technically im seeing his past woooh
That's just a less then nano second past
@@srinivas.v7902 still true past
When You listen to an Opera singer from a distance of more than 300 meter .then you can hear the Voice from the onesecond past. The
motions of the singers mouth
are not synchronized with the music. Same .Ex perience you can make with the light.
when a Person in a distance moves The lightmessage is coming from the past.
It would be nice if you provided informations in metric units.
I agree...
I think miles are useless...
I wish we would use metrics here in the states.
but miles are useful for being useless...
wait, what?
Tyler Poole lol, someone is being proud about the World War, and, please ask NASA which type of units they prefer
You should remember that the World war was just a bullshit, there was no real reason for killing enemies enemies. Thay just needed to use all the guns they had, waste lots of money, and make the US rich.
A minecraft map would be a better reason for a war, seriously, it was the dumbest war ever
Yeah I always wondered how they figured this out. So I read two books by Lawrence Krauss on this. He does a good job of explaining these things. I had to read it a few times before the light bulb went on.
Thank u....for such a great video again....💙
what if the sun exploded eight minutes ago?
We wouldn't know. Everything would look normal until 8 minutes and 19 seconds after the explosion.
BandwagonFilms 😂😂
like an internet connection delayed
OH FRICKEN HECK
You cant live 8 mins without the sun, more like 5 seconds
I love science fiction, its so creative 🤣
Assuming you understand humor, like you assume science...
Absolutely amazing ❤️
So informative! Thank you