Mizukawa pointed to the turned on light and said, "I'm just thinking about a question." Lights are man-made, so is the speed of light the speed of light?

Liuzi Fenglai immediately asked: Isn't it the speed of light?

Mizukawa smiled, and then said: If it is the speed of light, why is the range of the light not even one mile? What are your thoughts on this?

Duenas looked at the lamp and said, "Don't say it, it's true." The range of light illumination is indeed very small, which is very inconsistent with the high speed of light. I think the speed of the light is not reaching the speed of light, so the range of the light is small.

Margarita retorted: "Light is light, and its speed should be the speed of light." As for why the irradiation range is small, I think the irradiation limit is the reason. The irradiation limit is produced by the luminous body, and the light cannot break through the irradiation limit. Why is there an irradiation limit? The speed of a photon is the speed of light, very fast. A lot of energy is required to maintain such a high speed. With a finite luminaire, the energy that can be supplied to a photon is limited. I guess there is a limit to any luminaire, no exceptions. It is a mistake to assume that only one year has appeared, and one light year has gone.

Liuzi Fenglai immediately retorted to Margarita: Geckos are tigers? Is a whale a fish? Is a seahorse a horse? Of course not. Why, then, do you think that a light is light? If the light is not light, then the speed of the light is not the speed of light. So, everything is taken for granted.

Mizukawa said: No. The speed of light refers to the speed of a photon, not the speed of a beam. There is no doubt that the light is light, and its speed is the speed of light is also certain. We know that photons form beams of light, and the speed of the beam cannot reach the speed of light. In an ideal environment, the speed of the beam is equal to the speed of light. In real life, a beam of light cannot reach the speed of light. Since the light needs to form a beam before it can travel outward, the light cannot reach a place of 30,000 miles.

Liuzi Feng immediately asked: The beam is composed of photons, how can their velocities not be equal? If so, wouldn't the beam and the photon be at odds?

Mizukawa explains: Actually, most photons rely on the beam for movement. However, a small number of photons can move independently from the beam, and more and more photons will be separated from the beam over time. Since the speed of a photon is the speed of light, the energy consumption is significant. Therefore, the range of light exposure is limited.

Margarita said: But you can't seem to deny that there is a limit to irradiation.

Mizukawa nodded: That's true, there is a possibility. However, I think the difference between photons and light beams is the most fundamental reason.

"Light travels in a straight line, that's what we know," Duenas said. But does light here refer to a beam or a photon? As long as we look closely, we will find that the beam of light is emitted in all directions around the luminous part of the luminous body, which means that the straight line propagation here does not refer to the beam. And photons are. Can photons go far? No, because the photons are absorbed by the objects they touch. I think that the kind of luminous object that says that light can travel more than a light year must be a very massive celestial body. In fact, Margarita said that the irradiation limit exists, but it decreases as the mass of the luminous body increases.

Mizukawa said: Today's discussion was very fruitful. Let's go back and think about it, and try to come up with a better point of view on a cloudy day.