物理..功課..有2條!

我們看不到光線 = Correct. 光線是透明的

1)為何我們看不見光線?

A single 'light ray' actually doesn't exist. 'Light ray' is only a concept. It is the geometrical visulaization of a beam of light, just for the ease of interpretation and understanding in various physical phenomena in optics.

It is therefore you can see a beam of white. but never a single 'ray of light'.
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2)為什麼黑色的平面是黑色的呢?

You can see a surface because the surface reflects the light that falls on it into tour eyes.

Hence, a surface will appear black if the surface absorbs all the light that fall on it and reflects none.

我們看不到光線 = Incorrect. It is cutting a part off from the fact. We can see light but because of our limited ability to detect light, we can only see some frequencies of light. Some like gamma rays or X-rays are invisible for us.

我們看不到光粒子 = Correct. If you know that light is transfered as waves, then you will know that there are many frequencies of waves present. If our brain are made in a way that can read light immediately and do not have the effect of prolonged reading, then we could see flickery images. For example, assume that we can see ELF (Extremely low frequency) radio wave(it belongs together with light we see on a catergory, you will see 30 flinkering image each second. That is really annoying is it not?


為什麼黑色的平面是黑色的呢?? The colours of light we see are not the real colours. The colours we see are how we can identify colours. I think, if you switch your body with another person, you will see light in different colours. Generally, because our brain have the ability to read and tell different frequencies of light, therefore we can read and tell the difference by using different colours.