What is the speed of visible light per second in air?

The speed of visible light in air is approximately 186,000 miles per second. This value is widely recognized as a fundamental constant in physics, representing how fast light travels in a vacuum. While light does travel slightly slower in air due to the presence of molecules, the speed in air is still very close to this value.

When considering how light behaves in various mediums, it's important to note that the speed of light can change depending on the substance it is moving through, such as glass or water, where it slows down more significantly. However, for the purpose of this question, the commonly accepted value for the speed of light when discussing broad scenarios, particularly in air, is 186,000 miles per second.

The other provided options represent speeds that are either below or above the officially recognized speed of light, making them inaccurate in this context. Therefore, 186,000 miles per second remains the standard answer for the speed of visible light in air.