Just to add here that it is the apparent speed of light through a medium which is less than that in vacuum. However, it is not true that light slows down - rather there are interactions with the medium it travels through. Although this is too simplistic, it is as if it bounces around in many directions so that it takes longer to progress in the original direction of travel (modified by the refraction angle). In reality there are absorptions and re-emissions going on. But in between interactions, light does still travel at the speed c in vacuum, within any medium.pogmoor wrote:The speed of light in a vacuum is a constant such that the speed it arrives remains the same even if you are moving away from the source. However the speed of light through transparent solids, liquids and gases is less than its speed in a vacuum.
Sound travels at different speeds through different mediums, but its speed through air is influenced only by temperature, not by density. Sound travels more slowly through colder air because molecules move more slowly as their temperature drops. Sound travels more slowly higher in the atmosphere because the air is colder, not because it is thinner.Andrew Fryer wrote:Both very easily. Glass slows down light. Thin air slows down sound.
I tested your theory with my Dyson but it was too dark and dusty inside for any meaningful results, although I did find a pound coin.pogmoor wrote:The speed of light in a vacuum is a constant.
Granary Guitars wrote:I tested your theory with my Dyson but it was too dark and dusty inside for any meaningful results, although I did find a pound coin.
Not so, pressure counts, because air is not an ideal gas. So sound would travel more slowly in higher levels of the atmosphere even if there were no temperature difference.gitgeezer wrote:its speed through air is influenced only by temperature, not by density.