Why is the red dot on the wall clock of 24 solar terms Golden Bell bright?

The reason is that hands and figures are coated with fluorescent powder. The night hand of the alarm clock glows because the hands and characters are coated with fluorescent powder. Phosphor contains substances such as zinc sulfide or calcium sulfide, which has the ability to absorb light energy when it is irradiated by light, and then slowly releases light energy when the external light darkens. However, if you want it to shine for a long time, you should add a little radioactive material coated with light-storing fluorescent material while making fluorescent powder, and slowly release it after absorbing enough light energy. This is the fluorescence phenomenon you see. This is because the hands and figures are coated with fluorescent powder. Phosphor contains substances such as zinc sulfide or calcium sulfide, which has the ability to absorb light energy when it is irradiated by light, and then slowly releases light energy when the external light darkens. But in order to make it glow for a long time, a little radioactive material should be added when making phosphor. These radioactive substances can continuously emit invisible light for absorption by substances such as zinc sulfide and calcium sulfide. In this way, the night light needle can continue to shine.