Timing the sunset to calculate where space begins

Рет қаралды 21,834

Күн бұрын

I put a 1,000 year old theory to the test. Thanks to Nebula for supporting this video: go.nebula.tv/simonclark
Buy my book on the history of atmospheric science, Firmament: geni.us/firmament
You can support the channel by becoming a patron at / simonoxfphys
My video on where the atmosphere stops: • Where does the atmosph...
According to a scholar living 1,000 years ago in Andalusia, by taking two simple measurements of Twilight and applying some trigonometry you can estimate the height of the atmosphere. In this video I test out the theory, and come up with a height for where space begins.
REFERENCES
This video was inspired by this paper: B. Goldstein, ‘Ibn Muʿādh’s Treatise on Twilight and the Height of the Atmosphere’, Archive for History of Exact Sciences, vol. 17, no. 2 (1977), pp. 97-118.
--------- II ---------
More about me www.simonoxfphys.com/
My second channel - / simonclarkerrata
Threads - www.threads.net/@simonoxfphys
Instagram - / simonoxfphys
Twitch - / drsimonclark
--------- II ---------
Music by Epidemic Sound: nebula.tv/epidemic
Some stock footage courtesy of Getty.
Edited by Luke Negus.
Where does space begin? How did ancient people know about space? What is Twilight? How can you use twilight to estimate the height of the atmosphere? Is all atmospheric science western? In this science experiment video I answer these questions and more.
Huge thanks to my supporters on Patreon: Piet Braat, Artem, Sylvus , Florian Thie, Daniel Chen, Gary Stark, Martina Alini, Vernon Swanepoel, Adam Scott, Felix Winkler, CC, Ivari Tölp, Thomas Charbonnel, Mark Moore, Philipp Legner, Zoey O'Neill, Heijde, Paul H and Linda L, Marcus Bosshard, Dan Sherman, Matthew Powell, Adrian Sand, Dan Nelson, The Cairene on Caffeine, Cody VanZandt, Igor Francetic, Daniel Irwin, bitreign33 , Thusto , Andy Hartley, Lachlan Woods, Dan Hanvey, Andrea De Mezzo.
Ilan Henzler, Mark Thomlinson, Dan Lilley, Tristan Schefke, Theo coz 1-letter-name invites ridicule, Gunnstein Lye, Trevor Scheuing, Andy Giesen, Tingus Pingus from Lativia, Mathias Hüttenmüller, RomanConsul, Ave Jonathan Cahyadi, John Bate, Cifer, Chris Conrey, Christian Weckner, Quinn Sinclair, Frida Sørensen, Ned Funnell, Aleksa Stankovic, Meagan, Indira Pranabudi, Sekhalis, Chaotic Brain Person, Simon H., Ben Cooper, Mark Injerd, dryfrog, Justin Warren, Angela Flierman, Alipasha Sadri, Calum Storey, Mattophobia, Riz, The Confusled, Simon Stelling, Gabriele Siino, Bjorn Bakker, Ieuan Williams, Tom Malcolm, GordonV47, Leonard Neamtu, Brady Johnston, Louise K., Rapssack, Kevin O'Connor, Timo Kerremans, Thomas Rintoul, Lars Hubacher, Ashley Wilkins, Samuel Baumgartner, ST0RMW1NG 1, Morten Engsvang, Cio Cio San, Farsight101, Haris Karimjee, K.L, fourthdwarf, Stormchaser007 , Sam Ryan, Felix Freiberger, Chris Field, Kolbrandr, Vinni, Shane O'Brien, Alex, Jesper Koed, Jonathan Craske, Albrecht Striffler, Jack Troup, Sven Ebel, Sean Richards, Peter Reid, Kedar , Alastair Fortune, Mat Allen, Krisztián Török, Colin J. Brown, Mach_D, Keegan Amrine, Simon Donkers, Kodzo , James Bridges, Liam , Wendover Productions, Kendra Johnson.

Пікірлер: 163

@UniverseMeetMiranda 4 ай бұрын

"Professional wrong opinion-haver Aristotle" took me right out

@vigilantcosmicpenguin8721 4 ай бұрын

That's the heart of philosophy.

@SarastistheSerpent 4 ай бұрын

I truly cannot think of a better descriptor for Aristotle lol

@peterfireflylund 4 ай бұрын

His ideas about “points of locomotion” (Google it!) are truly fascinating… not only are they are wrong, but they are wrong in such an eccentric way :) Also, women apparently have fewer teeth than men - according to Aristotle. He didn’t believe that insects had 4 legs… he was referring to a species that really only had 4 (and 2 that didn’t look like legs).

@alexandredesouza3692 3 ай бұрын

I love Aristotle so much. Everything he said makes logical sense, especially when you don't have the technology to prove otherwise. But it's all wrong.

@Ratgibbon 4 ай бұрын

What we learned about Simon in this episode: - He probably lives in or near Bath - He likes Metallica - He's got a copy of Twilight I've also got to give props for the sponsor intro, couldn't tell if it's going to be Brilliant or Nebula. And the video was Interesting as usual, keep it up, Simon! 👍

@Ryno_YT 4 ай бұрын

And the fact that even a doctor needs to say "SOH CAH TOA" out loud

@latheofheaven1017 4 ай бұрын

I just watched your 'I Don't Think I Can Do This Anymore' video, Simon. I checked and found that despite being subscribed to you for at least a year, you had released two videos I hadn't noticed in recent weeks. So here I am, watching and enjoying.

@andyr9220 4 ай бұрын

Likewise! Now also commenting to up engagement, if that a thing the algorithm deity takes into account...

@EB-fc2mp 4 ай бұрын

I will third this statement. I may be one person, but there are evidently more like me who were simply never recommended these videos we want to see.

@woufff_ 4 ай бұрын

Same here !

@beverleybarnes5656 4 ай бұрын

And here 😊

@Harreso 4 ай бұрын

Yeah same here!!

@spelunkerd 4 ай бұрын

I came here after realizing that KZfaq has not been sending me notifications. This is another great video. It is so sad to see how an algorithm is punishing high quality channels, some to extinction, in favor of short cat videos.

@ButzPunk 4 ай бұрын

The number of little easter egg gags in this video is nuts! Simon, you've outdone yourself

@vinni40k 4 ай бұрын

The sheer subtlety of the ruler at pi minutes is **chef kiss**

@vinni40k 4 ай бұрын

And a Metallica reference on top? Good sir you are a national treasure

@bikalimark 4 ай бұрын

"pi minutes" oooh mmy

@ChristopherCurtis 4 ай бұрын

I also appreciate that proof of the geocentric flat earth model.

@reidflemingworldstoughestm1394 4 ай бұрын

But pi in base 10 is 3-08.496 in minutes and seconds.

@vinni40k 4 ай бұрын

@reidflemingworldstoughestm1394 meh, for engineering purposes '3 and a bit' usually suffices

@xWood4000 4 ай бұрын

It is quite the flex to use your own book as a ruler

@bertilhatt 3 ай бұрын

Immediately rendered moot by using _Twilight_…

@ScottAtwood 4 ай бұрын

OK, this video was WAY cooler than I expected! I didn’t click on it the first time, because the title and thumbnail didn’t draw me in, but after your recent video about doing things differently, I clicked on it from the end of that video, and I’m glad I did! I learned something new and interesting! And it was entertaining!

@hglundahl 4 ай бұрын

5:45 Let's put it like this, the method becomes a bit less precise when done in cold weather!

@SimonClark 4 ай бұрын

Presumably less of a problem for the original experiment in Spain!

@hglundahl 4 ай бұрын

@@SimonClark ah, especially if he did it in Summer (was it on the Meseta or in Granada)?

@Kualinar 4 ай бұрын

@@hglundahl But, in the Summer, if you are far North enough, the twilight never end. ANYWHERE if the UK, from May to July, there is no true night. Same here in Québec.

@hglundahl 4 ай бұрын

Wait, I think this is false, I could be wrong. In Malmö, same latitude as Gretna / Newcastle, or a bit further North, there is 4 hours night in Summer. True, somehow a Summer Night is kind of twilightish ... Probably best to do it at equinox, if you get that far north.

@michaelhiggins9188 4 ай бұрын

This is a really fun exercise. I think it would be good to teach it to schoolkids because it is simple enough to do and understand. Also, I have to compliment your introduction to Nebula - the sponsor. That was a clever transition.

@AB-fh9zh 4 ай бұрын

Yes, that was one smooth segway.

@Dantyx1 4 ай бұрын

This must have taken literally hours to do since you had to wait for the sunset! We in the audience always undervalue how much work goes into these videos!

@sebgillman5841 4 ай бұрын

The dayman and nightman on the monitor is brilliant around 3:30

@ScopeofScience 4 ай бұрын

This is such a simple and elegant experiment and I love that you did it. Great video, as usual, Simon!

@jiangkuailv4047 4 ай бұрын

I know this is not meant to be a accurate measurement, but it would make sense that you account for the fact that the sun is not moving perpendicular to the horizon. The 19.5 degree you calculate is the great circle distance the sun travels. It is not however how many degrees it is below horizon, which is the angle that actually controls which part of the atmosphere is illuminated.

@Mortonimo 4 ай бұрын

Thank you for keeping in you doing S(O/H) C(A/H) T(O/A) in your head from a STEM student that still has to do silly trick to remember trig identities. Great Video also, very interesting!

@OldShatterham 4 ай бұрын

Great video! I think it's incredible how close even the original estimate was considering the additional uncertainty of the radius of the earth etc.

@kendrajohnson6535 4 ай бұрын

I absolutely loved everything about this video. The patron constellations were fabulous! Thank you Simon for another wonderful watch :)

@bog123 4 ай бұрын

I really liked this new style of video format and presentation, although I imagine it was a lot more work, but despite having watched your channel for years I often find it difficult to get through your videos as I lose interest or the thumbnail isn't very engaging but this was superb and fun and just excellent, would like to see more like this!

@RS-jq4oc 4 ай бұрын

Simon, if you are seeing this, this video is one of your best in terms of the presentation method. It doesn't feel too long or drawn out unlike some of your other videos. You nailed the concise presentation and it feels engaging. I don't know if yt will bless your videos with more views, all i know is that you're on the right path.

@jabberwockytdi8901 4 ай бұрын

Well according to those who were(n't) paying attention in school what you do is keep going in any direction till you come to the ice wall then climb over said wall and bingo you're in space....(unless you think there is a magic dome above you as well in which case bring a hammer and be prepared for a lot of blow back from your fellow inhabitants....)

@Tsudico 4 ай бұрын

Think of how much money someone could get by going to the ice wall and chipping off pieces of the dome and then selling them online!

@flamencoprof 4 ай бұрын

I like this stuff. I once did a blog post titled "How far apart are the sunset points at solstices by angle around the horizon at my latitude?" kicked off by noticing the sunset direction moving as Autumn progressed and wondering. The answer was 49.3 degrees. Where do I live? (Clue: - Not Spain)

@chrisconnors7418 4 ай бұрын

I do the same thing when having to work with trig equations---I first mutter the correct formula to myself, and then rearrange if needed. :)

@Strawberryearthquake2 4 ай бұрын

I have core memories from maths class. SUCK A TOE A, Some Old Hag cracked all her teeth on apple. Some Old Hippy Caught Another Hippy Tripping On Acid. I think 3 years into an engineering degree i've just memoriesed them as little triangles. with the numerator on top of each. but I sure do miss the days when equation triangles were a totally valid way of remembering equations! too many variables these days :')

@miguel5785 4 ай бұрын

Sir, Gavin Schmidt of the NASA Goddard Institute is saying to Neil DeGrasse that their models did not expect such uptick in temperatures and that they might have underestimated aerosol effect.

@th3d3wd3r 4 ай бұрын

Taaaaake myy hand, we're off to never never land

@msaditu 4 ай бұрын

Great video, Simon! It is very engaging and clear. Loved it so much. You are a very good science communicator.

@hglundahl 4 ай бұрын

8:47 Yeah, twilights do last longer the further North you get on the Northern hemisphere, dito four Southern, the further South.

@merseyviking 4 ай бұрын

4:56 Thanks Bob!

@jimmurphy7296 4 ай бұрын

Great video, I don’t often encounter new-to-me methods such as this. And the patron star field earned a legit LOL. Nice work, thanks.

@patrickavis5475 4 ай бұрын

Another really interesting and top notch video :-)

@sapientiapotestasest3073 4 ай бұрын

3:11, perfect product placement. Well done😀

@EiBeiDieMau 4 ай бұрын

The sandman reference was nice, dry delivery, perfect

@B1bthinkin 4 ай бұрын

Really fascinating video. I must admit that when you got into the maths my brain slipped into rhubarb, rhubarb, rhubarb ... 93 km! And gotta love the subtlety of the book plug!

@entropyobserved 4 ай бұрын

Your videos are always fun to watch!

@markosterman4974 4 ай бұрын

Simon, one of your best videos! Given the existence of the modern flat earth movement and the young earth creationists, one wonders if science has progressed at all. But then we are reminded that the diameter of the earth was calculated more than two thousand years ago and the height of the atmosphere, a thousand years ago. All without laptops, iPhones or any technology at all. If we could all just park our technology, observe our surroundings, and reflect on what we see, we will discover the marvels of the universe. Thank you!

@djinghiskhan9199 4 ай бұрын

Love the product placement 😃

@benhowcroft9971 4 ай бұрын

Exit light enter night 🎸😊

@firekid631122 4 ай бұрын

Thanks for sparking my scientific curiosity - love your videos!

@raymondsmit344 3 ай бұрын

I really enjoy your educational content. To me, your content pushes through the noise of the environmental ‘grief’ that hinders people from being an active participant in understanding the subject. Your videos is exactly what I needed to get a non- biased source of information on the topic of climate change and the broad spectrum of knowledge on the subject. You are more important than you realise. For me at least, you are fundamental to my intellectual growth on Earth/Space science. This is the beauty of KZfaq and Nebula, never before could the average-joe get this breadth of passionate education.

@tvuser9529 4 ай бұрын

The way your love for science comes through in this visual story > Twilight.

@SarastistheSerpent 4 ай бұрын

Truly a better love story than Twilight

@anmold5676 3 ай бұрын

"Professional wrong opinion-haver Aristotle" caught me of guard.

@jenniferlevine5406 4 ай бұрын

Wonderful video. I am going to share this with my son, he will like it too! I really appreciate your approach and the interesting topics you discuss. Thank you!

@jakethefakejake69 4 ай бұрын

Love your channel! Keep up the great work. #Hyped

@BC-xu8yq 4 ай бұрын

Love the style of this video

@whophd 4 ай бұрын

I really enjoy “making” sunsets on Microsoft Flight Simulator 2020 - it’s a game with a misleading name, since it’s an earth simulator that just happens to have a physics model for aircraft built in

@g0dzilla5 4 ай бұрын

How the actual hell is this not getting pushed by yt this video is hysterical

@lewismassie 4 ай бұрын

I mean the US military gave pilot wings to anyone who flew over 50 miles, him getting 52 miles is impressively good

@LemonCurry. 3 ай бұрын

the segues in this video are seamless in a very satisfactory way

@VernonSwanepoel 4 ай бұрын

I really enjoy getting a look into the history of our understanding of climate.

@woufff_ 4 ай бұрын

Great video, us usual :)

@limouna 4 ай бұрын

absolutely amazed 🤯

@TotalJustinGaming 4 ай бұрын

Great video

@stephenmkahler 4 ай бұрын

Yay! Fun Simon is back!

@kotor1357 Ай бұрын

This is a great video It's a shame that the topic/thumbnail/title doesn't bring in the views

@Jorge_Pronto 4 ай бұрын

Nice video, Simon. The audio is a bit off, sounds like there is a new source of reverb in your room?

@matt123miller 4 ай бұрын

Another fantastic video 🔥 keep my engagement flowing

@JimBob4233 4 ай бұрын

Does it count as a signed copy if it's got -Sharpie- _own-brand_ _marker_ smudges up the spine and covers?

@616ShadowFox 4 ай бұрын

cool and interesting!

@forthrightgambitia1032 4 ай бұрын

I actually came here from your 'I can't do this any more' video... this is actually a pretty interesting topic, shame it wasn't recommended.

@rickylovenuts7466 4 ай бұрын

damn watched your video after a very long time

@meb3369 4 ай бұрын

Need to get your book for my dad. He's a pilot and an aerospace engineer, I think he'd find it interesting!

@michaelday6870 4 ай бұрын

I'm so sorry that you had to finnish Twilight, Simon. Your heroism and comitment knows no bounds! 🤣

@g0dzilla5 4 ай бұрын

Everyone else is commenting it too but DAMN the Aristotle gag is an all time quote

@jonathandevries2828 4 ай бұрын

What is that you're using as a straightedge?

@SimonClark 4 ай бұрын

Why that would be Firmament, a history of and introduction to atmospheric physics, perfect reading material for a student or curious adult!

@RonJohn63 4 ай бұрын

2:47 Intellectually, I _know_ that the sun sets earlier as you go north, but it always shocks me _how much_ earlier.

@muvdetta 4 ай бұрын

This was super fun! Accessible to my 11 year old

@ThijsSchrijnemakers 3 ай бұрын

thanks

@vsevolodburavchenko8400 19 күн бұрын

An interesting idea, but you need to consider the angle in vertical plane, but not in equatorial plane (19,5 which you measured). Your measurement would be useable if you were at equator. The higher is the latitude you're at, the lower's the equator plane to the local horizon, the larger angle you get. Considering you do the measurement in England and al-Jayyani did it in Cordoba, it's natural you get the larger angle (19,5>18). So considering the latitude your measurement gives about 12 degrees below horizon plane on 51st parallel, and al-Jayyani gets 14 degrees below horizon on 37th parallel. I believe he was a bit more persistent in his measurements))

@BernardtheBrave 4 ай бұрын

How would latitude influence this answer?

@MrStoyan5 4 ай бұрын

"I'm gonna call this the end of Twilight" Oh I see what you did there!

@JeremyNasmith 4 ай бұрын

The precision of timekeeping also affects the precision of the result: I wonder what method of timekeeping was used in antiquity as the sundial has a very specific downside for use in this experiment ;)

@Kualinar 4 ай бұрын

The actual height of the Karman line ois about 84 Km, and, yes, it had been rounded up to a nice 100Km.

@SisterSunny 4 ай бұрын

omg i loved this video wth

@edgeeffect 4 ай бұрын

Bringing up the fact that Jeff Bezos' rocket looks like a willie (again), describing Aristotle as a "Professional wrong opinion-haver" and trying to break our misconceptions about how "tidy" the history of science is... yeah, I think this is going to be good.

@altejoh 4 ай бұрын

0:50 for the nerds out there, this is apparently where the concept of the "phlogiston" in Spelljammer comes from - the idea that all the elemental fire on earth "evapourates" and rises up past the atmosphere, and thus collects in outer space; and thus instantly ignites if you so much as look at it wrong xD

@JimBob4233 4 ай бұрын

Phlogiston was how they explained flammability - if something could burn, it contained phlogiston, and the flames were the phlogiston escaping. That combining things with atmospheric oxygen made them more massive was handily explained by phlogiston having a negative mass, which is also why it flows upwards towards the Sphere of Fire.

@Buckets41369 4 ай бұрын

Where can I buy that ruler for drawing crisp straight lines?

@hglundahl 4 ай бұрын

10:13 How do you verify that a new star actually _has_ been made?

@italktoomuch6442 4 ай бұрын

I laughed at the SOH CAH TOA pause.

@tootumeke 4 ай бұрын

I caught that sneaky Enter Sandman lyric 😆

@rchas1023 4 ай бұрын

Does refraction no longer take place?

@stephanb.6015 4 ай бұрын

4:19 _„Eggs and light, end all nights“_ 😂 famous Metallica quote

@rubberduck3y6 4 ай бұрын

2:57 the reason this video was made in the winter, so you didn't have to wait until evening for the sun to set.

@ThePrimevalVoid 4 ай бұрын

That nebula segue lol

@perplexingpantheon 4 ай бұрын

I'm shocked i didn't see this despite being subbed.

@rgraph 4 ай бұрын

"Exit light, enter night" ... are you a Metallica fan per chance...? :-)

@AB-fh9zh 4 ай бұрын

I knew this comment had to be here.

@rgraph 4 ай бұрын

@@AB-fh9zh Those lyrics are burned into my memory after listening to it over and over again (30 years ago!)

@karldubhe8619 4 ай бұрын

The ancients used the stars as part of their evening's entertainment. :) It must have inspired some science as well as some bizarre stories that were mostly myth.

@altejoh 4 ай бұрын

Also find it hilarious that the exaggeration of the atmosphere is noted, but not the size of the sun, the distance from earth, or the fact that Simon has the power to move the constellations to spell out the names of his supporters xD Edit: though this also makes me curious as to when exactly people knew/suspected that the earth's axis was tilted, because I imagine having seasonally longer days/nights would also throw a wrench into this calculation.

@SimonClark 4 ай бұрын

I don't know what you mean, due to a Pratchett level coincidence my patrons names are absolutely spelled out in the night sky

@JimBob4233 4 ай бұрын

It's not like the stars come with little numbers next to each of them to make a cosmic dot-to-dot; the constellations can be whatever

@ryan-cole 4 ай бұрын

People since ancient times figured out the path of the sun in the sky (the ecliptic) was not in the same plane as the equator. They could measure the angle between them (the inclination) by comparing the length of shadows at noon throughout the year. The difference between the shortest and longest shadow would determine the angle; this was first interpreted as a tilt of the earth's axis by Copernicus.

@vigilantcosmicpenguin8721 4 ай бұрын

I wonder what people are going to know about Simon Clark a millennium from now. He could be the next Ibn Mu'adh.

@thes7754 4 ай бұрын

nice

@Need4Needle 4 ай бұрын

soo is the aurora a matter for astrophysicists or atmosphere scientists?

@jsoderba 4 ай бұрын

Aurora's are caused by the interaction of charged particles (electrons, mainly) from the solar wind, Earth's magnetic field and gas molecules in the top of Earth's atmosphere. So the answer is both.

@Need4Needle 4 ай бұрын

@@jsoderba i can't believe they're not fighting to determine whom auroras belong to

@mickleblade 4 ай бұрын

And at the equator that 78minutes is about 5...

@g0dzilla5 4 ай бұрын

“Professional wrong opinion haver” I’m dead and I’m not even a minute in

@nuclearnyanboi 4 ай бұрын

"professional wrong opinion haver" 😂

@KatharineOsborne 4 ай бұрын

Like this comment if you are here after Simon's latest video about the sustainability of his channel. Let's show him our support!

@LeoStaley 4 ай бұрын

I hate the yt algorithm. It should have shown this to me.

@harveytheparaglidingchaser7039 4 ай бұрын

Cool

@veaxvoid 4 ай бұрын

me observing It's Always Sunny in Philadelphia, top hat

@alphamikeomega5728 4 ай бұрын

But how do you know the radius of the Earth (as someone in the Islamic Golden Age)? In fairness, there were accurate estimates from this time and before, but there were also inaccurate ones, and it was hard to tell which was which.