0:01 Have you ever looked up at the night sky
0:04 and wondered, "How did ancient people
0:06 with no telescopes, no satellites, and
0:09 no modern math measure the stars with
0:11 such mind-blowing accuracy? How did
0:14 Egyptians align pyramids to true north
0:15 with a precision we struggle to match
0:18 today? How did the Maya predict solar
0:20 eclipses centuries before they happen?
0:21 And how did the Babylonians track
0:23 planets so accurately that NASA still
0:25 uses their data as reference? Today,
0:27 we're traveling thousands of years back
0:30 in time into the deserts, temples, and
0:31 mountains of the ancient world to
0:33 uncover the true story of how our
0:35 ancestors measured the heavens. Welcome
0:37 to the sky before time, before
0:40 electricity, before cities, before
0:42 screens. The night sky was the brightest
0:44 show on earth. To ancient people, the
0:47 sky wasn't just decoration. It was a
0:49 calendar, a clock, a map, and even a
0:52 guide for survival. when to plant crops,
0:53 when rivers would flood, when winter
0:56 would strike, when kings should rule.
0:58 All of this could be read in the stars.
1:00 And the first people to truly master
1:03 this celestial language were the ancient
1:06 Mesopotamians. Over 4,000 years ago, the
1:07 people of Babylon didn't just watch the
1:10 sky, they recorded it night after night.
1:12 Scribes sat on rooftops pressing tiny
1:14 wedge-shaped symbols into wet clay
1:16 tablets. They track the position of
1:19 Venus, Jupiter, Mars, not for a science
1:21 project, but because they believe the
1:22 gods used the heavens to send messages
1:25 to humankind. But their fortunetelling
1:27 created something unexpected. The
1:29 world's first astronomical database.
1:31 Those clay tablets, some still intact
1:33 today, contain precise measurements of
1:36 planetary motion. The Babylonians
1:38 discovered the moon has an 18-year
1:40 cycle. Planets move in predictable
1:42 loops. Eclipses follow mathematical
1:44 patterns. They even calculated the path
1:45 of planet Jupiter using geometry
1:49 geometry in 800 B.CE. This wasn't luck.
1:51 This was the birth of astronomy. While
1:53 the Babylonians mapped the movements,
1:55 the ancient Egyptians built their entire
1:57 civilization around the stars. And the
2:00 star that mattered most was Sirius.
2:02 Every year, Sirius rose in the same spot
2:04 on the horizon. And when it did, the
2:06 Nile River would flood, bringing rich
2:09 soil that allowed Egypt to thrive. So
2:11 Egyptians used Sirius to create one of
2:13 the world's first calendars. But their
2:15 real masterpiece was the skyaligned
2:17 architecture. Look at the great pyramid
2:19 of Giza. It's aligned almost perfectly
2:22 with true north, off by only a fraction
2:24 of a degree. Modern engineers tested
2:26 this alignment. Even with lasers and
2:30 GPS, it's hard to replicate. So how did
2:32 they do it? Egyptians noticed that
2:34 certain stars in the night sky rotated
2:36 around a fixed point, the pole. By
2:38 watching two stars cross the meridian,
2:40 they could mark perfect north. No
2:43 compasses, no metal tools, just the sky
2:46 and thousands of years of observation.
2:48 Even the pyramid shafts point directly
2:50 to the stars they worshiped. Orion
2:52 Sirius, the north star of the ancient
2:55 world, Thuban. These monuments weren't
2:57 just tombs. They were cosmic
3:00 instruments. Across the sea, another
3:02 ancient civilization carved the heavens
3:04 into Stone Stonehenge. Everyone knows
3:07 it's old, but what many don't know is
3:09 that it might be one of Earth's oldest
3:11 astronomical observatories. When the sun
3:13 rises on the summer solstice, its light
3:16 shines perfectly through the heelstone,
3:18 landing in the center of the circle.
3:19 This isn't coincidence. This is
3:21 engineering. The builders tracked the
3:23 sun for years, marking the horizon,
3:26 moving stones, adjusting the angles
3:27 until it aligned with celestial
3:30 perfection. Some archaeologists believe
3:33 Stonehenge was used to predict seasons,
3:35 track eclipses, mark lunar cycles, even
3:38 time ceremonial events. Think about it.
3:40 No writing, no metal tools, just stone
3:43 and sky. While temples and pyramids
3:45 captured the stars in stone, the ancient
3:47 Greeks tried something different. They
3:49 tried to measure the universe with math.
3:53 In 240 B.CE, a man named Aeritosines
3:56 used sunlight and a stick, yes, a stick,
3:57 to calculate the size of the Earth, and
4:00 he was only off by a few miles. A
4:01 century later, Hipparus created the
4:03 first star catalog, mapping more than
4:06 800 stars with astonishing precision. He
4:08 even discovered the procession of the
4:10 Earth, the slow wobble of our planet
4:11 that changes the position of stars over
4:13 thousands of years. And then came the
4:16 masterpiece, the anti
4:19 the shoe box
4:21 of years that
