Astronomy - Ch. 2: Understanding the Night Sky (5 of 23) Understanding the Celestial Sphere

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In this video I will explain what is the celestial sphere (a sort of GPS of the universe).

[@tkar66]

One of the best (videos, teacher) of YT University. A GOOGOL Thanks

[@lucassantos3476]

Thanks very much for all your videos, they are great!!

[@wolfamri]

Very well explained. I am going to photograph the milky way (if the weather is good) somewhere 5° south of the equator. And I was looking for info how to point my star tracker to the south celestial pole, so that I can take longer exposures. This video helped me understand tremendously - thanks for the good work!

[@bipasanabhattacharya9882]

Your explanations are easy to understand as well as informative. Great video!

[@MichelvanBiezen]

Glad you are enjoying the videos

[@deanemilne6275]

Great that you explain 'why' this happens and not just 'what'. Excellent teaching style

[@MichelvanBiezen]

The "why" is usually the hardest part to answer, but it does offer a better understanding. 🙂

[@rishikhettry]

Appreciate your effort. Sir, you seem very fluent with your content. Great work. Thanks

[@ramblingsofateenager3323]

ah asaidai ramro xa

[@1bobini]

Very good information. Thanks for the closed captioning.

[@philwesom8784]

thank you so much....u finally made me understand....ur content is awesome...hats off

[@adisakpirom]

Thank you for very good lecture, good explanation. You made difficult subject to be easy thing. My son and I like it.

[@Gabriel-ev6qg]

Excelent video series! Thanks for sharing.

[@georgenachkebia9986]

Excelent series! thank you very much

[@pujaghimire1074]

Thank you very much sir . I am preparing for astronomy olympaid and taking all the knowledges i can from these videos . They are simple to understand as short in length making the content engaging and entertaining

[@MichelvanBiezen]

Thank you. We have received many comments over the years that these videos helped students prepare for the astronomy olympiad. Good luck on your competition. 🙂

[@caseyv.6679]

Thanks so much, I'm taking Astronomy this year and was having some trouble wrapping my head around the concept of imaginary celestial poles and what that meant for star positions. This was super helpful! I subscribed and I'll be sure to come back here if I need any more help. Thank you!!

[@emanperez28]

You made this so easy to digest!

[@katherinegeorge8103]

Your drawings and explanations are SO GOOD!!!

[@MichelvanBiezen]

Thank you.

[@panduprasad1841]

Thank you so much Sir for the wonderful lectures

[@nama5257]

Brilliant. Thanks for a clear lecture.

[@jonathanstaley3883]

Very informative! Thanks!

[@nickrobinson1648]

Great video, thanks!

[@shavuklia7731]

Very clear, thank you!

[@ASHWINHARMALKAR]

michel you are the best......thanks alot

[@s4eyes61]

Thanks for these videos Michel. Clearly presented and as a Brit I love your pronunciation of Greenwich.

[@MichelvanBiezen]

Haha that was funny. Welcome to the channel!

[@KarimKhan-im5lg]

thanks u very much to enlighten geographical science

[@PokeABrain]

Finally I get this! thank you for posting!

[@MichelvanBiezen]

Glad I could help!

[@tomasgrimm3086]

great explanations, greetings from the southern hemisphere Argentina

[@MichelvanBiezen]

Welcome to the channel! (Are you ready for winter?)

[@tomasgrimm3086]

totally ready, love the warmth of home and the long nights, thanks for the videos!

[@harnesbortford5538]

great video very informative

[@22nuwan]

Thank You Very much. You explain the subject very simple

[@MichelvanBiezen]

Thank you. Glad you found our videos. 🙂

[@esther9032]

Thank you~ teacher☆

[@pravinchandar]

brilliant. thanks!

[@abettermousetrap]

I just happened on these videos . they are so cool. I am a surprised they have only been watched 85 thousand times since 2014. that seems sad that so few people would want to watch.

[@MichelvanBiezen]

We are glad you are enjoying the videos. Yes, astronomy is a fascinating science.

[@vasilicacaia4721]

😊thank you.all informations are amazing.

[@MichelvanBiezen]

Thank you. Glad you enjoy our videos. 🙂

[@Ali-fh9ix]

You have explained it very nicely.. Thanks a lot

[@MichelvanBiezen]

You are most welcome

[@tamannatabassum4348]

I really enjoy your classes 😊 Thank you sir

[@MichelvanBiezen]

Glad to hear that

[@heavenaboveearthbelow6237]

I appreciate your taking the time to explain this system, my only criticism is how you bring up how this system came to be, "we decided that it should be . . ." makes it sound as if last year a world conference was held to make a universal universe coordinate system, but wasn't this decided before we even have a written history?

[@arlz11]

Excellent videos and explaining,

[@MichelvanBiezen]

Thank you. Glad you found our videos. 🙂

[@luweiyuan210]

great video

[@geovibes7919]

Wao sir. You are an amazing teacher.

[@MichelvanBiezen]

Thank you. Glad you found our videos! 🙂

[@thewritingculture6750]

Great explanation sir..so easy to understand..

[@MichelvanBiezen]

Glad to hear that 🙂

[@suomynona7261]

So if you stand on the equator can you see both the south and north celestial areas? Or better yet, would one always be able to see at least three celestial areas no matter their position?

[@MichelvanBiezen]

If you stand at the equator you can see most of the north and south celestial regions, but it becomes difficult to see stars near the horizon, so it would be difficult to see the stars near the celestial poles due to atmospheric interference.

[@suomynona7261]

Michel van Biezen Wow thanks for taking time to reply! :)

[@thaissabolzanmoreira8527]

Nice video helped a lot

[@MichelvanBiezen]

Glad it helped

[@profeluisegarcia]

WHAT about longitude distance in the celestial sphere? Where does is located the "celestial Greenwhich?

[@MichelvanBiezen]

Essentially it is the location of the Sun on March 21

[@legobuilding0]

Great ! video .

[@MichelvanBiezen]

Thank you. Glad you liked it.

[@lyingcat9022]

Wait… so the Earth isn’t flat? Huh, you learn something new every day;)

[@MichelvanBiezen]

shocking indeed.

[@Jay2012jan02]

Very nice guide

[@MichelvanBiezen]

Glad you think so!

[@kalyanimehta1153]

excellent ..

[@rakshavyas7713]

आप हिंदी मे बता सकते हैं मूझे

[@cybellemarie]

Is there a well known South Star like Polaris in the southern hemisphere? I have never herd of one. I really enjoy and appreciate your classes!

[@MichelvanBiezen]

There is no bright star near the south celestial pole, so they don't have a south Polaris star.

[@eMBO_Gaming]

The closest you would get to that is Polaris Australis (Sigma Octantis).

[@GiffysChannel]

Is there a coordinate system for the sky that doesn't change? I've been looking around for the last hour and it looks like the constellations are mapped using a system like that but it looks very complicated.

[@MichelvanBiezen]

The problem is that we as observers are on the surface of an object (the Earth) that is constantly moving in different ways.

[@GiffysChannel]

@@MichelvanBiezen yes but the view sky and the constellations don't move from their positions in relation to each other no matter where they are. The sky is mapped in a grid but that grid is rarely talked about.

[@eMBO_Gaming]

@@GiffysChannel actually they do, it's called proper motion.

[@GiffysChannel]

@@eMBO_Gaming well ya but I don't think it's noticeable to the naked eye. Maybe to enthusiast level telescopes

[@eMBO_Gaming]

@@GiffysChannel Indeed.

[@eleneavlog9321]

Thank you

[@MichelvanBiezen]

You're welcome

[@marissacubias8408]

So the celestial equator is basically the earths equator but and infinite line ?

[@MichelvanBiezen]

That is correct.

[@rahulranjansah3724]

Should we measure angles from horizon or from the zenith? Love from 🇳🇵NEPAL

[@ronen124]

AFAIK, from the North Pole to where you are

[@MrBlazingup420]

​@@ronen124Polaris (North Star) is 0.7 degrees of Earth's axis, the Sun is tilted 7 degrees, the Sun rotates once on its axis every 25 Earth days (2+5=7). The Sun spins slower at it's poles, 35 days each, 35+35=70, which is the number of minutes in the Twilight hour, the time between both Day and Night. September 6th is 16 days from the fall equinox, 106 days from the winter solstice, 169 days from the spring equinox, they all reduce to 7, go back 7 days, August 31st is 70 days from the summer solstice, August 31st is 183 days either way to February 29th, Leap Day, on a Leap Year, September 6th is the 250 day of the year, 115 days left, in Latin, 'septem' means Seven. A Mercury year is 88 days, 8+8=16, Venus retrogrades 43 days )4+3=7) every 77 weeks, 7 week hidden behind the Sun, thats tilted 7 degrees, a point on the tilt takes 79 year to complete one rotation, and a 79 year cycle is seen between Mars and Mercury, they show up together every 79 years on the same day, in the same zodiac sign. Mars retrogrades 70 to 79 days, loops around the Sun in 707 days, conjuncts with Venus 3 times in 9 months, on a 77 month cycle. in Hebrew, Shiva means 7, the Dancing Shiva has a cycle too, 2,160,000,000 years, it takes the Sun 2,160 years to cross a zodiac sign, or 30 degrees, 2160÷4=540 added Leap Days, 540÷7=77.14, if you add 7+7 to the 77, there are 91 days in a season 77+14=91. Take 3 sevens (777), join them together, long end to short, they create a 60 degree triangle, 3x60=3 hours, 3x7=21 hours, the 60 degree triangle equals 24 hours, 7 hours to sleep, 7 hours to work, and 7 hours to play, at the end of 7 is 60x7=420, Ha Ha Ha The Dogon tribe knows that cycle, they wait for Sirius the Dog Star to show up between to mountain peaks every 60 years, then they celebrate for 7 years, going village to village getting Stoned. If you play the words "He Knows Dope" in reverse, it echoes "420", if you play Seven in reverse, it echoes "Novus", Latin meaning "New", play "Novus Universe" in reverse "77", the gematria value for Christ, the son of Mari, "Gift from God" the meaning of Juana. Hee-Haw Hee-Haw 420

[@Fancyhudibaba]

This was easy ty

[@MichelvanBiezen]

You are welcome. 🙂

[@xandrap.5649]

What is the difference between the north and south celestial pole?

[@MichelvanBiezen]

The north celestial pole is the point in the sky directly above the Earth's North Pole, where stars do not appear to move during the night, because from every point on the Earth (in the Northern Hemisphere) the celestial north pole appears in the same place. The south celestial pole is the point directly above the South Pole.

[@Jacob-yg7lz]

The north celestial pole is the one that you can see from the northern hemisphere, and it's where the north star is. The southern celestial pole can only be seen in the southern hemisphere, and doesn't have a star. Most people find it by using the Southern Cross, aka the constellation on the Australian flag.

[@clsharma4538]

I appreciate all your efforts! The videos are really Amazing. But you mixed up latitude and longitude in this one! Other than that, GREAT! 🖤

[@MichelvanBiezen]

Yes, I did

[@surendrakverma555]

Very Good 👍👍👍👍

[@MichelvanBiezen]

Thanks for the visit

[@rakshavyas7713]

Nice

[@delynnaddams8774]

Can someone mention some more notable area? Like 11, 19, 21, 101, or 321? Biblical is good too.

[@MichelvanBiezen]

Sorry. I didn't understand the question.

[@nigelmarshall5891]

Who is the Green Witch?

[@MichelvanBiezen]

Haha, that is funny! 😂😂😂 Yes my pronounciation is a bit off.

[@RAOROCKSTAR1990]

I live at latitude 21.19 degrees. Yet I am able to see the north star (or Polaris). By your explanation, it shouldn't be visible to me as it is beyond my horizon. Could you please explain how that happens? Thanks in advance!

[@MichelvanBiezen]

If you live north of the equator, you should be able to see it, (at an angle of 21.19 degrees above the horizon).

[@bowrudder899]

I was sure comments would say Greenwich is pronounced "Grennich".

[@MichelvanBiezen]

Yes, we had a few comments like that already. Thank you.

[@achingaster1199]

Thank you. I’m taking Astronomy, but the class explanations go too fast for me to follow.

[@MichelvanBiezen]

Glad you found our videos. We have most of astronomy on video, so you can follow along.

[@thomasarthurmaj]

Greenwich is pronounced “Grenitch” and today it’s very much an area of central London.

[@MichelvanBiezen]

Jolly Good!

[@johnhall5478]

no one care

[@jayhaddan7927]

So ur saying everything is not relative then

[@SirFluffyFluffton]

Any chance I can have a brain transplant, you have my brain and I have yours.. I'm free on Wednesday.

[@MichelvanBiezen]

Unfortunately, I am busy on Wednesday. :)

[@TheEnigmaticDeenTruth]

Math is everything. PEACE.

[@sunny9161able]

💞💞a💞💞

[@markmaguire3830]

I was going to show this to my kids until mid-video you said the wintertime solstice is when sun rises and falls farthest north. I'm not understanding that. In the northern hemisphere, my observation is that the sun goes across the sky in a position that is much farther south.

[@MichelvanBiezen]

Can you tell me where in the video you heard this? I listened to it and couldn't find it. You are correct that in the winter the Sun will rise and set at a point along the horizon farther south, than compared during the summer.

[@markmaguire3830]

@@MichelvanBiezen Hello! Thank you for fast reply. I was looking at several of your videos, and posted my comment on the wrong video. I apologize for my carelessness. Perhaps I can delete this one. The comment applies to kzbin.info/www/bejne/boaTZmuOr7mIe5o

[@markmaguire3830]

minute 1:55 approx

[@MichelvanBiezen]

Yes indeed I misspoke. That happens once in a while as we are human and mistakes are bound to happen. After more than 7300 videos I have made a number of mistakes. Viewers do point them out and we appreciate it. :)

[@markmaguire3830]

@@MichelvanBiezen . 7300, that is so amazing! If you said 73 videos, that's impressive enough! I'm going to start watching this series

[@sreeshab4093]

The very definition of Latitude and Longitude at 0:20 seconds is incorrect. Its exactly the opposite: lines going from North to South are actually Longitudes and East to west the Latitudes.

[@fernandoaldekoa2436]

You are wrong. Professor is right.

[@samanthasr7798]

You're mistaken bro. Latitude is distance north or south of the equator. Think of it like a ladder- Latitude. Longitude is how far east or west you are from the Royal Observatory in Greenwich. Might want to Google again to make sure you're aware of what you're talking about!

[@redabdab]

The prof is correct “latitude is the height above and below the equator”. But you are also correct to say north-south lines are longitudes and east-west lines are latitudes. For example, the equator is simply the 0 degree latitude line and it goes east-west. You and the prof are saying the same thing, not opposite things.

[@redabdab]

@@fernandoaldekoa2436 they are both right

[@harshannn]

😀 👕🤘 👖

[@redabdab]

0:29 Green Witch?! It’s pronounced GRENN-itch. Great video though. Thanks

[@MichelvanBiezen]

You are correct. I butchered that name. Thanks for the input.

[@LoveMeSomePhysics]

@@MichelvanBiezen We pronounce it as Green Witch in South America as well :)

[@Colmarnock]

You confused latitude and longitude. Latitude is parallel and goes around. Meridians of longitude go up and down and form the time zones.

[@Logarius_]

Nope, he said it right. Latitudes are the horizontal lines and longitude is vertical

[@IrishPhysicist]

Yes longitude lines run up and down and latitude run parallel to the equator. However, when the coordinate system of earth is defined in spherical coordinates, the longitude angle isn’t the angle that runs along the longitude line it’s the angle at which how far must we turn east to west from the prime meridian to reach a fixed line of longitude. The longitude angle runs along the direction of a latitude line if that makes sense. Essentially when we say lines of longitude what we really mean is how far must I got east or west to reach a fixed line of longitude running from that point pole to pole.

[@michaelbyrne5535]

Can you confirm we have polar vortexed 90deg? Our moon cartwheels every night, rises wax ,sets wane

[@highlyambitious]

Main defination is wrong abt latitude n longitude...Highly dissapointing video...

[@Renegadesoul33]

Everyone knows the Earth is hotdog shaped and floats through space like it's in a pot of boiling water 🙄

[@stevenwilliams1915]

"Green-witch". ??? It's "Grinitch" you dolt...

[@MichelvanBiezen]

Yes, I have been pronouncing it that way my whole life. You are not the first one to catch me on that. 🙂

[@mosesnacorie9681]

..earth..."going around the sun"! oh come on professor, give us surrender please

[@MichelvanBiezen]

Are you suggesting that the "Sun goes around the Earth"?

[@mosesnacorie9681]

@@MichelvanBiezen yes professor.

[@RossCampbell1992]

How about we split the difference and say they both go around a point relative to their masses/density, the barycenter, which in this case in not in the direct centre of the sun (though this still means things revolve around the sun) but being more specific the earth-sun barycenter is somewhat off-centre. Better? ​@The Mist Moses Jarn www.wikiwand.com/en/Barycenter

[@SirFluffyFluffton]

@@RossCampbell1992 you'll be telling me next Princess Diana really died. And Adolf Hitler doesn't live on the moon.🌙🌜 please gents just Grow up .

[@ravirasalkar9196]

Use a darker pen , u r drawings not legible

[@MichelvanBiezen]

Yes, our older videos did not get the proper lighting. The newer videos are better.

[@mosesnacorie9681]

constellation, the zenith, the 365 days.... and we always see the same stars rising setting whole life. no make sense we dont understand professor, please.. for the same way about to say that distant stars go around the sun a year.. ruin the pyramids. ... but amazing explanation

[@mikeredd2608]

its literally pseudoscience, all you're learning here is a hypothesis; just a waste of time

[@bcbc8649]

Flat earther?

[@barukyahuah7056]

lying the earth doesnt revolve