Wow, I'd consider myself a long time cosmology and astrophysics casual-learner and I've never actually known this was a thing - you're right that no one talks about it. It's always fascinating to learn something entirely new
I'm not sure why barely anyone talks about this. Maybe because the information can't be used to solve any problems cosmologists are facing, so they see it as unimportant? I don't know.
Makes me wonder whether the CMBR that we detect is actually ultra-zoomed-in relative to nearby galaxies. Could that be true? What might we see instead if the CMBR weren't so zoomed-in?
@@ScienceAsylum I agree, topics that don't seem to address current issues or popular topics don't get much funding an any field. I quit studying particle physics when it became apparent I would be chasing grants for the rest of my life. I joined the dark side and became an engineer instead!
@@ScienceAsylum It kind of sounds like you were saying it's not seen as having a practical application. Coming from someone who doesn't really understand the application of cosmology, isn't it all about understanding how the universe works, (or worked rather 😉)? Is this something that you have to get an intuition for as a cosmologist so maybe it doesn't get talked about because it feels intuitive?
@@peterburgess9735 The plasma that emitted the CMB we're currently receiving today? It was (roughly) 40 _million_ lightyears away when it emitted that CMB. What that plasma ultimately became (i.e. a bunch of distant galaxies) is now 46.5 _billion_ lightyears away. However, the CMB itself has only traveled 13.8 _billion_ lightyears since it was emitted. Expanding space is weird.
These days it’s not perceived as special anymore to access science channels like this when being able to watch 100 of channels that are competing with each other. But I’m amazed by your way of presenting and explaining topics like this. Completely free and without self promoting. Thank you.
Looks like a Light "Teardrop" to me. And dang. Space gets weirder and more confusing the more I learn about it. It hurts my brain. In a good way. There's so many cases where we taking 'seeing' for granted. Both in distant space and the quantum level. Thanks for all the great content!
The comments really show you hit the nail on the head with the topic choice. I've never heard or seen about this effect while it's mind bending. No other Phys channel i follow mentioned it. The amount of comments sharing the same sentiment just show how underrated this effect is. Kudos. And super big props for openly admitting all the shortcuts and omissions. Chapeau bas dear sir.
Please explain why spiral mirrors when used with a radiometer, allows us to observe Alcione in the Pleiades where it is currently compared with observation of light. This has been published in a couple of abstracts. What is special about a spiral mirror? Do they detect tachyons? That appears to be a plausible explanation. What are your thoughts?
Usually, when something blows my mind, it takes some time and further researching to understand it. Somehow, you managed to blow my mind and make me understand the issue at the same time.. Kudos.
I've never heard of that and trust me, i watch tons of content in cosmology and physics. You did a very good job at explaining it, this channel really shines on many levels. all my respect!
Even though I know all these concepts and how it works basically, it still amazes me that even observing a single image has all these many factors impacting it. Still, there is always some great content from this channel. Thumbs up.
I would call it a teardrop shape. I knew about the lightcone and that early expansion was faster than lightspeed but I had never put the two concepts together before to get this turnabout point. The universe gets weirder every day.
Amazing work, as always! As for the shape, in Brazil we have a chicken snack called "coxinha", which is fried. It has a potatoey carb, and ground chicken breast. It is delicious. Be sure to have one if you ever spend vacations here hahah
So if I understand earth's past light teardrop correctly, the reason distant equal-sized objects appear larger the more distant they are from us is this: we're seeing them when they were closer, and closer objects appear larger. And we may not be able to see the most distant objects for the same reason we can't see our own galaxy: we are (were?) inside them! And the big bang happened right here, a long time ago. Pretty cool stuff!
I love how almost every video I watch of yours I think, "oh no I'm not going to understand this" and somehow you explain it so that I do. I haven't been notified of your videos in a while so I need to keep a lookout.
“Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.” ― Douglas Adams, The Hitchhiker's Guide to the Galaxy
@@johnbennett1465 I was actually just listening mostly as I was doing other things, but any time I hear the words space and big, I automatically think HHGTTG.
Wow...thanks Nick. The thing that made it click for me was realising that at 8:51 the overly-large past galaxies at the bottom of the 'teardrop' were closer, on the horizontal axis, to the vertical line running up the centre with the Earth on it... and it makes me smile realising that for the bottom 2/3rds of that light'cone' the Earth doesn't even exist yet and I sub-in the term 'closer to the _Milky way'_ rather than 'closer to _us'_ . Brilliant explanation, thanks again.
Mind=blown. Great video, Nick. I haven't enjoyed my mind getting stretched so well since I took quantum physics 30 years ago. Thanks for the wonderful work.
Wow just wow. Never knew this was a problem. But the way you explained it with one small digestible fact at a time to bring it all together was really amazing 👏
You gave enough clues at the beginning that I figured out it's because of expansion by 3:30. I definitely didn't expect the effect to be big enough to make distant galaxies appear to be the same size as close ones. Amazing. Thank you!
I've followed cosmology as an amateur for 40 years. All the pieces you put together such as light-cones and expanding universe, I'm familiar with those. This particular implication, based on how these things work together? This is new to me. Thank you!
I am an astrophysics student. My mind blew off when I first came across this. I immediately thought that if I'm getting this right, how come I haven't heard anyone talk about it. You put a very apt title to the video. Good job. 🌹
Not an easy concept to explain - really well done, Mr Lucid. I've never heard of this angular diameter effect before, so you not only introduced a new detail (to me) but I understood the 'why' of it in less than eleven minutes! Kudos.
I followed the idea, that space is dragging light along with it and that produces the tear drop shape and the fact that really distant objects start to look bigger. But I missed on the geometry. Why does the tear drop shape the galaxies to look bigger? I could use another diagram showing the size increase.
Awesome! Thank you! I had often tried to think of how light was affected from an expanding early universe. I knew it wouldn't be straight forward, but I could never really visualize it. (Of course I never tried to, you know, actually research it either. ) This was a great visualization.
Yes, however, why hasn't Orion's belt become fatter? Also, why where they able to use stars to navigate for thousands of years. That's thousands of light years, this should have made that impossible if space is expanding at such a rapid pace. This video gives me more questions than answers, sorry that I choose you to ask, but care to take a stab?
@@GrandKai9 If you don't mind my butting in, all the stars we can see are in our region of our galaxy, the Milky Way, and the stars in our galaxy will never recede from us. Also, none of the galaxies in our galactic cluster, the Local Cluster will ever recede from us due to cosmological expansion. The stars do move in their individual orbits around the center of the Milky Way, but so slowly (in angular dimension) that it takes thousands of years for the constellations (like the Big Dipper) to change their shapes.
@@numbersix8919 Thank you so much for your input, I was honestly just looking for anyone to explain, because I knew I was wrong somewhere and didn't even know where to begin to look into it. However, from your answer, I have another question, and if you don't mind me asking. wouldn't the consultations only change as we enter into the accelerated orbit of the center of our galaxy? What I mean is we will be accelerated and tossed to the other side of a very large black hole, in theory, so wouldn't the light that we see instantly be affected? I mean we orbit every 200 to 350 million years, but I would have to assume that would hugely affect our view of the cosmos.
@@numbersix8919 Technically they will recede away eventually, but it will take a really long time. Much longer than universe has existed so far. Scientists are now debating if the recession will eventually mean the Earth will be alone in dead, black space or its forces will overcome even that (big rip) and individual atoms will be all that is left...
@@GrandKai9 And to answer your question, thousands of LY is nothing on the scale of expansion. It is 'rapid' when measured on a scale of millions to billions of LY, trying to measure it to Orion's Belt would be like you checking if your cup of tea moved away from you by 0.0001 millimeter.
It’s crazy to think some stars you might see in the sky have long exploded and no longer exist but because of the distance and light still coming in we perceive it’s existence still.
It's been quite some time since an educational video literally blew my mind🤯 your explanation is sooo good I mean you clearly connected the dots by mentioning each point one after the other...
Doctor Lucid in the house!! Whoop whoop..this is beyond education brother..I always watch whether I understand or not...but this one is going to need several viewings...lol .. deep science!!!! 😆 this is the most counter intuitive thing I've ever seen...hopefully after a few more views, it'll sink in..great job brother
My mind is officially blown. You're dead right that no-one talks about this! I've been following science as a lay person for decades, and this is the first time I've heard of the phenomenon.
They doing some great math work to build that illusion into the Taj Mahal by making the minarets (the outside structures) at a angle so they appear to go straight up at a distance. I assume people had noticed the towers seaming to lean at a distance in other structures before this.
When you said it didn't look like a cone I was on the edge of my toilet seat waiting for what the real shape would be. The taj mahal tear drop was so satisfying.
Really nice video! It's amazing how much I learn from you. And now I'll wait for Veritasium to remake this with half as much understanding, some experiment gimmick and more arrogance without crediting you.
okay i knew about looking at distant stars means looking at past images of them because of light speed. but i did not consider the expanding universe thing causing those stars to have different distances to be in the same equation. now i feel REALLY melancholically nostalgic for a universe that i didnt even exist in.
Fantastic video, it made my Saturday! Your channel helped inspire me to peruse a physics degree, so thank you for all the incredible content and showing me to the subject which I enjoy more than any other
Angular Diameter Turnaround Point. That does blow my mind, literally. Why isn't this plastered all over cosmology discourse? I feel like I've been imagining the universe wrong until now where every object fades in optical diameter as it recedes into the distance. Everything starts to come closer, that is crazy,!! Thank you for sharing this and all the great new-to-me terms. I think it's a huge thing to know.
🤷♂️ I'm not sure why barely anyone talks about this. Maybe because the information can't be used to solve any problems cosmologists are facing, so they see it as unimportant? I don't know.
That teardrop shaped light cone reminds me of the shape of certain electron orbital diagrams. This jigsaw puzzle (physics) is infinitely large, with infinite shaped pieces. I predict that there will NEVER be an end to physics. Thank you Nick!
I like videos like this that explain how we solve problems that seem impossible to solve. Also, on the subject of judging distance, humans also use our binocular vision which can be tricked with things like magic eye pictures.
I used to always ponder about how energy is Mass and now I ponder about the role time plays and how wave-like matter can be, I saw an image of a rock that had been weathered by the wind over centuries or more and the image made it seem as if the Wind and The Rock where a still photo of fluid dynamics at play. I don't know what this means, but videos like yours help me pursue it even more and discover even more fun insights so thank you. I never went to college and this is what I've always wanted to check out 🙌🏿🙏🏿😄
Hi have a look at Jon Levi on YTUBE , there are two , this one shows pics of old rocks buildings etc m unmissable ,will have you questioning our give history timelines,
Wow, this is the most interesting thing I learnt that I have never ever seen or heard in any space documentary or even a youtube astrophysics channel video. Amazing.
Awesome video Nick, it reminds me more of your videos from earlier times. Please make a video on quantum locality and the Nobel prize for 2022. PBS made a video as well but maybe you can dumb it down for us a bit.
As I was editing this, I was feeling the same way. It felt a bit like the olden days. As for the Nobel, I made a video about entanglement earlier this year: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-hiyKxhETXd8.html I don't think I have any more to say about it at the moment.
Man, I had hard time imagining this during my post grad days and I moved on to different direction. Math of this apart, You nailed it in 15min. Thanks [Nasadiya Sukta] spoken 3000 years ago spoke about origins of the universe.(small part) नासदासीन्नो सदासीत्तदानीं नासीद्रजो नो व्योमा परो यत् | किमावरीवः कुह कस्य शर्मन्नम्भः किमासीद्गहनं गभीरम् ॥ १॥ Then even nothingness was not, nor existence, There was no air then, nor the heavens beyond it. What covered it? Where was it? In whose keeping? Was there then cosmic water, in depths unfathomed? न मृत्युरासीदमृतं न तर्हि न रात्र्या अह्न आसीत्प्रकेतः | आनीदवातं स्वधया तदेकं तस्माद्धान्यन्न परः किञ्चनास ॥२॥ Then there was neither death nor immortality nor was there then the shine of night and day. The One breathed windlessly and self-sustaining. There was that One then, and there was no other. तम आसीत्तमसा गूहळमग्रे प्रकेतं सलिलं सर्वाऽइदम् | तुच्छ्येनाभ्वपिहितं यदासीत्तपसस्तन्महिनाजायतैकम् ॥३॥ At first there was only darkness wrapped in darkness. All this was only unillumined cosmic field. That One which came to be, enclosed in nothing, arose at last, born of the power of energy. को अद्धा वेद क इह प्र वोचत्कुत आजाता कुत इयं विसृष्टिः | अर्वाग्देवा अस्य विसर्जनेनाथा को वेद यत आबभूव ॥६॥ But, after all, who knows, and who can say Whence it all came, and how creation happened? the devas (gods) themselves are later than creation, so who knows truly whence it has arisen? इयं विसृष्टिर्यत आबभूव यदि वा दधे यदि वा न | यो अस्याध्यक्षः परमे व्योमन्त्सो अङ्ग वेद यदि वा न वेद ॥७॥ Whence all creation had its origin, the creator, whether she/he fashioned it or whether she/he did not, the creator, who surveys it all from highest heaven, she/he knows - or maybe even she/he does not know.[11
Nice, didn't knew about that. I guess because indeed nobody talks about it: galaxies appearing to be bigger when further away. And because my eyes see comoving distances 😉👍. Nice video!
If we could see all the way to the Big Bang, there would be a single dot that fills the entire sky. That always freaked me out. Love this video. First time I've ever seen this unintuitive result addressed.
Super video - although I've attended some basic cosmology courses, I didn't actually know about the angular diameter turnaround. Makes sense though - especially from the clear way you explain it!
So from the Space-time diagram, it's like light and earth both started from singularity , then light and earth started moving away from each other in space while travelling equal distance in time and after turnaround point, distance between us and light keeps decreasing (while still we are moving equally in time) and at some point our space and time coordinates again meet each other...wow...great video Nick
"Images of the distant past filled with illusions of cosmic proportion." A beautiful summary for a great video, this one felt as profound to me as your circuit energy video (among others).
welcome back bro - happy to see your new video .. always a delight 😇😇😇 .. Love from India (BTW maybe second or third or fourth - missed by a Pico second 🤣 or it took a diagonal path for ur video to reach india -D~universal~delay)
I guess the real brainbreaker is realizing that any object (in the loosest sense, particles, waves, etc) can only move a lightspeed, while space is not limited by such constraints. I really love these seemingly ADHD fueled explanation, they just tickle my brain at the right buttons.
Space is also limited by those constraints... locally. It's the cummulative effect of many tiny and relatively slow stretchings of local space which causes the overall space/Universe to expand faster than light. That also happens with other peculiar situations like when you (theoretically) point a super laser at the moon and move it around: the (again theoretical) "object" (reflection) that your laser makes on the Moon's surface can perfectly move faster than light... but it's not any real object, it's just an effect.
"Would you call this shape a cone? I wouldn't. Thanks to our sponsor, I would call it Earth's Beautyblender!" But seriously, I love your videos Nick. Thanks for taking highly advanced topics and dumbing them down for me!
What I take from this is that most "common" things make sense, but when things get really big, or really small the universe just messes with us. That being said, really well explained, I even completely understood why one of the things I always thought to be an absolute, a light cone, can become a "not cone".
I think the common things make sense to us _because_ they're common. We're not built for the really big or really small. It's funny to think the universe could be messing with us though 😆. It would make for an interesting sci-fi story.
OR - the images of the very distant galaxies are not being delayed by the linear lengthwise expansion of space (directly between the Earth and the observed galaxies) but instead are enlarged by the widthwise stretching of space as the light of these images pass through regions which have more gravitational objects in every surrounding direction, therefore producing a simultaneous lensing effect in all 360 degrees of direction, thus making the images appear larger. That could easily be tested by estimating the difference between the expected size and observed size and the amount of gravitational masses at various distances required to produce this observed effect. Also would expect to see distortion present from widthwise lensing not expected from expansion of space linearly measured between any two objects.
One thing that continues to blow my mind is the conundrum of photons not experiencing time. If you follow the rabbit hole, you realize that, from the photon's perspective, it is simultaneously emitted at some time in the past and absorbed in the present some light-distance away. How is this even?!
@@ScienceAsylum Well, obviously it makes no sense for The Massless Boson to have perspective, bias, or orientation. Since emission and absorption are anti-states, I find it more useful to think of a photon as a pair of virtual force carriers separated by the speed of causality. About two fifths of me thinks that the maths here may lead to finding The ToE.
🤯 I thought that learning that the universe was expanding was the most mind blowing cosmic knowledge possible. This is the unexpected follow up after shock. 👽
Man, this was great! It brought together a lot of ideas I understand, or thought I did, in a way that puts all of the puzzle pieces together! Impressive!
Man Oh Man, figuring out how far those far away galaxies are from Earth is like trying to measure distance by only looking at the mirrors in a fun house!
Oh my god, this light cone is a COXINHA! It's a very popular street food here in Brasil. You even put a coxinha texture on the light cone like somehow you knew it! That's amazing. It needs to be officialy named The Coxinha of Light.
