On Aug. 21st,
the moon’s shadow will shoot across North America
going more than a thousand miles per hour. Everyone in this area
will get the chance to see the sun at least partially covered by the moon. And along the “path of totality,” birds will go silent, the temperature will drop, the wind will shift direction,
and the stars will come out as the sun’s light is momentarily extinguished. But eclipses are more than just natural marvels. Over the centuries, they’ve spurred major
discoveries about the universe. The oldest surviving record of an eclipse
comes from Yin, an ancient capital city in China.
It was carved on a tortoiseshell. A lot of ancient stories — from the Americas
to Scandinavia to India — refer to the sun being eaten. People thought some deity was angry or these were omens that meant a king would
die. And some of those kings were nervous enough [that],
they appointed people to study the sky and take lots of notes
What started out as fearful fascination turned into something more … scientific.
Freaking out about eclipses kick-started astronomy. One of these early astronomers — Hipparchus —
used an eclipse to calculate the distance to the moon.
There was a total eclipse in his hometown but he heard that 600 miles due south
only four -fifths of the sun was obscured. That was all he needed.
See, Hipparchus was all about this new kind of math involving lots of angles and triangles. He calculated that the moon was between this
far away and this far away. This was hundreds of years before telescopes, and we’d already started to measure the solar system. By the 17th century, the moon’s size and distance
were well-known — but no one knew why the moon orbited Earth. Then a real oddball named Isaac Newton figured
out … The law of gravity! But some people needed convincing. Newton’s hype man — Edmund Halley (that guy
they named a comet after) —said, “OK, Newton’s law of gravity determines
the moon’s orbit. So I should be able to use that law to predict
exactly when the moon will go in front of the sun.” He calculated that an eclipse would hit Britain at 9:05 a.m. on May 3, 1715,
and he printed up these handy posters that reassured everyone – no, the king isn’t
going to die. Haley got impressively close — the sun went
dark at 9 sharp. And that eclipse proved Newton wasn’t crazy — he
was a genius! People went on to use Newton’s ideas to accurately
predict the orbits of most of the known planets. But two planets had unexpected wobbles — Uranus
and Mercury. In France, tireless mathemetician Urbain Le
Verrier used lots of equations to show that it must be the gravity of unknown planets
pulling Uranus and Mercury off track. He calculated exactly where the planet pulling
on Uranus would have to be, and when astronomers went to look — there it was. They named it Neptune. Le Verrier was psyched — and he was so sure
they’d find a planet pulling on Mercury, too, he pre-emptively named it Vulcan. But here’s the problem — Vulcan was supposed
to be right here, just hidden by the sun’s glare.
Vulcan hunters would need an eclipse! Every time one rolled around, scientists — including Thomas Edison — scoured the sky.
But those eclipses never revealed Vulcan. It just wasn’t there. Mercury’s wobbly orbit remained a mystery … until .. Albert Einstein came along. Einstein had this radical new theory and it made Vulcan unnecessary. According to the theory, Mercury was thrown off course because the sun’s bulk was warping
the very fabric of space time. Einstein’s equations predicted the wobbly
orbit perfectly. But — as always — some people demanded more
proof. And once again, an eclipse came in useful. In 1919, the darkened skies
allowed scientists to see stars near the sun and just as Einstein predicted, the sun’s huge
mass nudged the starlight off course. Those results made him an instant celebrity. During a solar eclipse you can see the sun’s fiery
atmosphere. Here’s the reddish chromosphere. In 1868, scientists studying the light of
the chromosphere found evidence of an unknown element. They named it helium, after the Greek sun god Helios. It took another 27 years before someone discovered
helium on Earth. Where the chromosphere ends, the feathery
corona begins. It sends blasts of charged particles into
the solar system, and these space storms can take out electronics
on Earth. They could even potentially kill interplanetary
astronauts. So how does the corona work? Well, there’s a lot we still don’t know —partly
because we can really only investigate it when something blocks the overpowering brilliance
of the sun’s disk. We’ve built advanced instruments to try and
do that, but the moon still does the job, much much
better. That’s why, even after all these years, scientists
still flock to eclipses, point their gadgets at the sky,
and make the most of that brief moment in the moon’s shadow to shed new light on
the sun. Thanks for watching. Check out our other videos, submit a question
to Skunk Bear and please subscribe to our channel.

Author Since: Mar 11, 2019

  1. The fact that y'all don't have hundreds of thousands of subscribers at least is a tragedy. I really appreciate all the work you do on these videos, and I hope they keep coming for years to come!

  2. Your videos have such a nice aesthetic, and are really interesting and informative. Thanks for all of the work you put into making these.

  3. this is your first video i watched & it was mind blowing…Continue to inspire the next generation astronomers…Thank you

  4. 2:12
    I always thought it was pronounced "Hailey's Comet" not "Halley." ??

    Edit: forgot to mention, this was a very well made video! great job!!

  5. you are pronouncing Uranus wrong. Its not pronounced like a 2nd grader would say it, its pronounced /ˈjʊərənəs/ ….Ur A Nus

  6. Does anyone know how I can see it if I can't get the special glasses? My library don't have any. Please any ideas how to make something? I don't want to miss it.

  7. You forgot to mention the historic invasion of the Fire Nation during an eclipse

    If you understand that reference, you may like my channel.

  8. This was great. I have one question that I never see addressed anywhere. I get the warning that you need eye protection to avoid burning your retina.Why is this so??? It seems one would have a more chances to burn their eyes all year long when the sun is largely exposed. So if during an eclipse when the sun is mostly blocked, why is it problematic then? Is it because we spend more time watching than otherwise?I don't get it. Please explain.

  9. 1:59 the voice over, did you mean 18th century instead of 17th century? You show a graphic reading 1715 and then referred to the 17th century, 1715 is the 18th century.
    Excellent video good content, thanks for sharing.

  10. Yay fun! But I hate it when a planet pulls on my… nevermind.

    So how about going over the equations that are used to determine when an eclipse will occur?

  11. For the people asking why your retina can burn during an eclipse…Think about what happens when you are in a dark room- your pupils expand to compensate for that lack of light. That's why it's okay to take the glasses off DURING totality (not before or after). So you've got big expanded pupils as the sun in losing light exposing your eye to sunburn. The moon begins to move exposing your pupils with your doe eyed stare letting in light to the retina.

  12. tornados, hurricanes and earthquakes will happen all over the world and the end of the world is near…maybe.  by my book and learn how to survive the eclipse…I will be selling water and toilet paper also.

  13. You have used the helocentric model of the universe which is only based on theoretical observation and assumed measurements which scientist formulated using their invented quantum physics theories. Theories are not facts. We still have a lot to learn yet, but I find that if you use the geocentric model of the universe these things describe themselves a whole lot better. Even a lot of the flat earth models show that the solar eclipses work perfectly yet many questions arise from using the helocentric model. Could it be that modern science be wrong? I think so based on what God tells us in the Bible where, "thoughts of men are foolishness to God". Could it be that we have all been deceived?

  14. THIS ALIGNMENT CAUSES EARTHQUAKES. TRY TO STOP IT. American Indians were hired to work at Cheyenne mountain. They try to convince the hollow mountain that it's sold so it doesn't collapse in on itself. It works. BELIEVE.

  15. In 1999 ring it is distinct diamond ring sharp clean edges, no Fuzzy edges like I've seen in all the pictures, on the Internet something doesn't look right, now can't my finger on what it is, everything is fuzzy edging, I think

  16. I made a video about the exact same topic. It appears we have different information. The Chinese started to document eclipses and tried to predict them as early as 2500 BC.

  17. Do more these types of vids so you'll soon get a lot of subs…the vid was great , the animation and the speaker were just perfect for the vid

  18. We don't live on a rotating ball earth with 1000 miles per hour, the earth is 100% proven flat. The solar eclipse was the face of the black sun

  19. I live in the best spot in America to see the Total Solar Eclipse on August 21th 2017!!! Southern Illinois is the BEST!

  20. I managed to see the eclipse in totality on the Kentucky/Tennessee border. I live in Indianapolis and we had a ninety percent totality but I wouldn't settle for anything less than a total eclipse so I took the three hours to drive there and back. It was such an amazing moment for me I actually started crying. It's a shame I won't be able to see it again for a couple decades, but I look forward to it

  21. Dude you are so underrated :/
    Please do colabs with vsauce scishow itsokaytobe….. etc.
    Serriouly ou need much more veiws than this.

  22. Probably one of the most brilliant videos I've ever seen.
    And seriously…this channel deserves more acknowledgement.

  23. Wait if you see the eclipse doesnt it make you go blind or hurt your eyes? How did this people watch the eclipse?

  24. On a serious note, can anyone describe what, just before and after totality, causes: a) "Solar snakes"/shadow bands, and b) Crescent light patterns though small openings (for instance, when little bits of sunlight shine through the tiny openings between leaves in the trees, creating several crescent-shaped light patterns on the ground, or a nearby building? I actually find these phenomena even more fascinating than the eclipse, itself!
    …then again, being in Chicago, I've never been in the "path of totality" before, in my nearly 42 years of life (though, had I stayed in southern NC, for a few more years, I would have been driving distance from the 2017 "path of totality." Here in Chicago , the skies were so darn cloudy, I barely noticed the partial eclipse, aside from a very slight drop in temperature, but that's about it. Fortunately I was 16 when we had a partial eclipse, and the skies were clear, so I actually got to witness the crescent light patterns, which totally blew my mind! Out teachers let us all go outside (plus some people were on lunch period already, anyway…we had 3 lunch periods, as it was a HUGE school!).
    If anyone knows what causes these phenomena, I would be very interested to hear!

  25. Today was the 2 year anniversary of when this video was uploaded. 🤓

    EDIT- 11:13 P.M.: finishes video 6 minutes later
    I never realized how important that eclipses were to science.

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