text: can somebody explain to me how the "mirage" works in the desert scientifically?   the heated sands warms up their overhead air, causing the reflection factor of it to be different from upper layers which is much colder. therefore, the low-angle light rays (e.g. 10 to 20 degrees to horizon) may reflect horizontally or with a slight up-angle and reaches the eyes. now, what our brain may imagine by this signal is a decisive image: human used to see the sky in the water, therefore if he/she sees these light rays then thinks that there is a water next to horizon which reflects back the sky light-rays.