This is a very simple experiment.
Each of them turned their heads. The sensation of this visual delay is very subtle, with a delay of less than 0.5 seconds. When I quickly turned my head, I already clearly felt that the head deflection angle had reached the limit, and the line of sight should stay on the right shoulder.
But what I saw in front of my eyes was the scene on the right front, and the imaging was delayed from the real scene. In the next instant, the line of sight moved to the right, and the real scene and the imaging coincide.
After repeating this experiment, both the original body and I were able to confirm that it was not a problem with the body commands, and that the body movements were still able to respond to the brain commands in a timely manner. The problem is our vision.
There are two possibilities for visual problems. One is that there is a problem with the light transmission. The special light and shadow effect formed by the purple light spider web causes the light transmission to be disturbed. Second, there is a problem with our eyes.
"Could it be our eyes?" I asked.
"Blink slowly, is there a delay?" Hara asked.
I tried it and shook my head. There was no delay, so there was no problem with my eyes.
Then there is only the problem of the speed of light propagation.
"But I really don't think it's the problem of light transmission." Hara stood up and patted the ashes on his body. "The light walks in the universe at a speed of 300,000 kilometers per second. The light we see now is in We set off from the sun eight minutes ago, venting billions of light-years before our eyes, and the sun at this moment came from eight minutes ago."
I naturally know what he wants to say. This is junior high school physics. "The eight-minute error comes from the vast distance between the sun and the earth. Even if it is light, it takes eight minutes to make up for the gap. "
But now, at a distance of about five meters, there is an error visible to the naked eye. We see diffuse reflected light from 0.5 seconds ago. The scene we saw was also the scene 0.5 seconds ago.
0.5 seconds, enough light to travel 150,000 kilometers.
"It's too difficult." I said, "I am a liberal arts student."
The original body said: "I know, so do I." He pinched his eyebrows, "I can't make up anymore."
If what I see is a scene about 5 meters in front of me, and the light travels 0.5 seconds at a distance of 5 meters, then the speed of light in this space is 10 meters per second. So the scene 20 meters away comes from 2 seconds ago, and the scene 40 meters away comes from 4 seconds ago. By analogy, if this space is infinitely vast and I can see infinitely far away, theoretically, I can see what happened in this space decades ago.
Of course, the premise is that the light propagation speed here is really only 10 meters per second.
If this conjecture is to be overturned at the end, it is very simple.
I and the original body looked at each other, "If you want to falsify, as long as I keep away from you, you can verify all this."
Only 20 meters is enough. At 20 meters, the normal light propagation is 30,000 kilometers per second, and the distance of 20 meters is like dripping water on the ocean, and if it is 10 meters per second, the situation will be different.
"Start?" he asked.
I don't want to split up for an absurd conjecture, but it doesn't seem to be a big deal, it's only 20 meters.
let's start.
The two faced each other and walked backward step by step. Because the speed is not slow, I see the original figure, there is actually some lagging.
When I reached about 20 meters, I said, "I raised my left hand."
As the word "I" was being uttered, I raised my left hand.
One second, two seconds.
"I see." Hara said.
The experiment ended and the falsification failed.
Two seconds later, he saw my movement. (End of this chapter)