Hot air rises over a heated stove element. The wall behind the stove appears to shimmer. Explain.
what do currents do?
they move like waves?
yes, true. there are many eddies in currents.
I don't get how currents relate to a wall shimmering...
The phenomenon you observe, where the wall behind a heated stove element appears to shimmer, is known as heat shimmer or heat waves. It occurs due to the differences in air temperature and density caused by the hot air rising.
When the stove element heats up, it releases a significant amount of heat into the surrounding air. Hot air is less dense than cold air, so it tends to rise. As the hot air from the stove element rises, it mixes with the cooler air surrounding the wall.
As the hot air rises and interacts with the cooler air, it creates turbulence and disturbances in the air around it. These disturbances cause the light passing through the air to bend in various directions, leading to a fluctuation in the refractive index of the air in that region.
When light passes through the air with varying refractive indices, it undergoes refraction, which is the bending of light as it passes from one medium to another. This bending of light rays gives rise to the visual effect of shimmering. It makes the wall behind the stove appear distorted, wavy, or shimmering.
It's worth noting that heat shimmer or heat waves are similar to the visual effect you see above a distant hot road surface on a sunny day, where the air near the road is heated, causing the light passing through it to bend and create a shimmering effect.