287: Chapter 287: How did the ancients know the speed of light?

Hearing Jiang Zhe say this instantly piqued the interest of countless viewers in the live stream.

Kyoto, Qingfeng Temple.

Zheng Ming stared at the screen, his brows furrowed, and he couldn't help but sneer, "He's starting to build hype again. I don't believe he can come up with anything new."

Jin Xianmeng wore a thoughtful expression. He didn't speak, just stared intently at the large screen, not wanting to miss any details.

On the large screen, Xiao Yu felt a bit uneasy due to Jiang Zhe's smile and couldn't help but ask, "Brother, what's the next point?"

Jiang Zhe looked up at the lights, then fixed his gaze on Xiao Yu, "Xiao Yu, do you know the speed of light?"

Xiao Yu nodded slightly, "I do, that's too simple; the speed of light is 299,792,458 meters per second, approximately equal to 300,000 kilometers per second."

Jiang Zhe asked again, "Then do you know who first calculated the speed of light, and under what conditions it was calculated?"

Xiao Yu furrowed her brows. Although it was written in textbooks, she didn't seem to have learned any more specific details.

"I've forgotten that; it seems it was calculated by a modern physicist, but what instrument did they use..."

"I really don't think I've ever learned about this."

At this moment, in the live chat, names of relevant scholars began to appear one after another.

"I remember it was measured by Michelson?"

"No, it was even earlier, it seems it was Rømer from Denmark!"

"Rømer used Jupiter's satellites to measure it in 1676, but it didn't seem very accurate."

"There were also Fizeau, Foucault, and others. I remember it being a hot topic a few hundred years ago; it seemed like people all over the world were measuring it back then."

As for the specific reasons, no one could explain them clearly.

Gusu High School, in the Principal's office.

Ren Xiaoyao looked at Principal Fu and the others, and began to explain, "The measurement of the speed of light can actually be traced back to 1676, initially by the Danish astronomer Rømer."

"When observing Jupiter's satellites, he discovered that when the Earth moved away from Jupiter, the satellite eclipses would be delayed."

"Io revolves around Jupiter regularly. Every so often, it rotates behind Jupiter and its light is blocked by Jupiter. This is called a satellite eclipse, similar to a lunar eclipse on our Earth."

Hearing this, Principal Fu and the others nodded, indicating they understood.

"When the Earth orbits to a position closer to Jupiter, the eclipse of Io appears earlier than calculated. He realized this was because it takes a certain amount of time for light to travel from Jupiter to Earth, rather than arriving instantaneously."

"He then used the distance difference and time difference to estimate the speed of light at approximately 220,000 kilometers per second; although this value was not very accurate, it was humanity's first attempt to measure the speed of light, marking the beginning of light speed measurement."

"So he estimated the speed of light at approximately 220,000 kilometers per second."

Principal Fu nodded, "And then?"

"Later, in 1849, the French physicist Fizeau used the rotating gear method on the ground to measure the speed of light, obtaining about 315,000 kilometers per second."

"In 1862, Foucault used the rotating mirror method to obtain 298,000 kilometers per second."

"In 1926, Michelson used the rotating prism method to accurately measure the speed of light at 299,796 kilometers per second."

"Finally, in the 1970s, after global laser technology emerged, the speed of light was defined as 299,792,458 meters per second, marking the moment it became a fundamental physical constant."

Ren Xiaoyao finished speaking in one breath, and Xiao Wang and Wang Shulin were listening intently.

It was clear that to measure the distance of the speed of light, one needed precision instruments, and lasers were required.

At this time, in the live chat, some knowledgeable viewers began to explain.

"History of light speed measurement: Rømer in 1676 used Jupiter's satellites, Fizeau in 1849 used gears, Foucault in 1862 used rotating mirrors, Michelson in 1976 accurately to 299,796, later defined by lasers."

"So our modern speed of light value is measured using lasers?"

"That's right, if you don't use lasers to measure it, it's completely inaccurate!"

"By the way, why is Brother talking about this? Isn't it just the speed of light?"

"..."

Inside the large screen.

Jiang Zhe listened to Xiao Yu's answer and began to explain, "Actually, the precise measurement of the speed of light has undergone over three hundred years of scientific accumulation, utilizing astronomical observation, precision machinery, electronic technology, and laser technology, until the end of the twentieth century to obtain the precise value of the speed of light we have now."

Speaking of this, the corners of his mouth curled up slightly, and suddenly he changed the subject, "Xiao Yu, do you think the Ancient Egyptians must have had very good mathematics and astronomy?"

Xiao Yu said without hesitation, "Of course, if their mathematics and astronomy weren't good, they wouldn't have been able to build the Pyramids. I still remember that the two Pyramids next to the Pyramid of Khufu correspond to the stars in the sky."

"Not just Ancient Egypt, the astronomy of the Sumerian Civilization was also very good—"

"They could observe Neptune with the naked eye. You've said before that some cuneiform texts recorded Neptune's orbital data. That requires very precise observation, which is enough to show that mathematics and astronomy were very common in ancient civilizations long ago!"

Jiang Zhe grinned, then picked up the tablet on the table, opened a map application, and handed it to Xiao Yu,

"Xiao Yu, search for the Pyramid of Khufu, and then tell me the coordinates you see."

Xiao Yu was a bit confused, took the tablet, and entered 'Pyramid of Khufu'.

The map quickly located Giza, Egypt, and a small square icon appeared on the screen.

Xiao Yu zoomed in with two fingers and read out the numbers on the screen,

"North Latitude 29.979250..."

When these words fell, the barrage in the live chat suddenly decreased significantly; clearly, some people realized something.

But most people stared at that latitude coordinate, unable to react for a moment.

At this moment, in the office, after Ren Xiaoyao saw this number, his pupils suddenly constricted, and he was completely stunned.

Xiao Yu hadn't realized anything yet and looked curious, "Brother, this latitude coordinate, why are you showing me this?"

Jiang Zhe asked back with an amused expression, "Xiao Yu, what is the specific value of the speed of light?"

Xiao Yu blurted out, "299,792,458 meters per second."

"And what about the coordinates you see now?"

"29.979250..."

When Xiao Yu read out this line of numbers again, her voice stopped abruptly.

29.979250.

299,792,458.

She suddenly raised her head, her pupils constricted sharply, and a chill rushed from her back straight to her scalp.

"How is it possible? How is this possible?"

Jiang Zhe watched her with a calm expression.

Xiao Yu stared fixedly at the numbers on the tablet, her lips trembling continuously, "29.979250 multiplied by 10 to the 7th power is 299,792,500, which is almost exactly the same as the speed of light, 299,792,458!"

Reading this, her nose suddenly felt sore, and her eyes turned red with terror, "Ancient Egyptians, thousands of years ago, how did they know the speed of light was this value, and so specifically?"

As she finished speaking, her body couldn't stop trembling.

Even Wang Shulin, who was monitoring the data in the background, stopped and looked at the large screen in horror.

Not only that, even the junior operators nearby couldn't help but tremble after checking the specific latitude of the Pyramid of Khufu.

At this moment, the live chat completely exploded.

"Holy crap, holy crap, holy crap!"

"The pyramid's latitude coordinate and the speed of light value are almost the same?"

"Holy crap, is this a coincidence?"

"Damn, how did the Ancient Egyptians thousands of years ago know the speed of light?"

"They probably didn't even know what the speed of light was, right?"

"Damn it, the speed of light is a product of modern physics. Measuring it requires very precise laser instruments to be accurate. Even with ordinary mathematics or any other means, it's impossible to measure this value. How could it be possible thousands of years ago?"

"My scalp is tingling."

"Could it really be technology left behind by Atlantis or... aliens?"

"..."