During the daytime, you can’t see stars primarily because of the overwhelming brightness of the Sun and the scattering of sunlight by Earth’s atmosphere.

1. Sunlight Intensity: The Sun is the brightest celestial object in our sky and emits a vast amount of light. During the day, when the Sun is above the horizon, its direct and reflected light is so intense that it outshines all other celestial objects, including stars. Stars, even though they are massive and emit light themselves, appear relatively faint compared to the Sun.
2. Atmospheric Scattering: Our atmosphere scatters sunlight, especially at shorter (blue) wavelengths, which is why the sky appears blue during the day. This process, known as Rayleigh scattering, makes it difficult to see stars because it diffuses the incoming light and spreads it across the sky. The scattered sunlight competes with and obscures the much fainter starlight.
3. Background Light: Even when the Sun is below the horizon (twilight), there’s still a considerable amount of indirect light scattered by the atmosphere, as well as light from the Earth’s surface, which can overpower the visibility of stars until it becomes dark enough.

However, under exceptional circumstances like during a total solar eclipse or when observing from a very high altitude (where atmospheric scattering is reduced), it is possible to see some of the brighter stars and planets close to the Sun. But for the majority of the time and locations, stars remain invisible to the naked eye during daylight hours.

However, it is possible to see stars during the day if you look through a telescope that can collect a large amount of light and block out the sunlight. This allows the faint light from stars to be seen, even in the daylight.