Well first, there’s no such thing as a perfect vacuum. Even the most perfect vacuum has some amount of particles floating around, and on the quantum level, quantum vacuum fluctuations.
But none of that natters because light doesn’t need a medium to travel through the way sound does. Light is oscillations in the electric and magnetic fields, which permeate all of space, so there’s no need for any physical matter for light to propagate through.
I’m probably wrong about this, but just because a vacuum lacks anything inside of it, doesn’t mean that something can’t go inside of it, right? You can fill nothingness with something and then it just isn’t a vacuum anymore, like you’d say “it’s a vacuum full of light,” implying that’s all that’s in it, right?
Space being (mostly) devoid of matter makes things travel better. If there were more atoms in space, they would create friction with moving objects that have mass, slowing them down more quickly.
Light is energy- it doesn’t require matter to travel. If it hits matter, it is absorbed or reflected, so it, too, is impeded by matter to some extent.
Are you thinking of sound and how it requires a medium to be heard? Sound is made up of waves of compressed matter- air usually for humans, but water or other things, occasionally. The sound traveling is a function of the matter being there and compressing. Light isn’t like like that and requires no medium to travel.
Light is Electromagnetism, Electromagnetic particles. Light is emitted by the star, the Electromagnetic particles travel unopposed through space, until they hit something hard, like a building, where Infra red radiation (Which is Electromagnetic) generates heat, or the particles interact with the atmosphere, generating the blue sky and daylight.
In short, light can move through space the same way stuff moves through space. Light is stuff.
Are you confusing light for sound? Sound is the effect of stuff vibrating in waves. Light has a waveform, but is also its own stuff. It coasts in space until it hits something, getting absorbed.
If you mean, “how can light be transmitted through nothing?”, the answer is: the same way as anything else. Generally particles are equally good at existing either on their own or in groups, so not only can groups of particles like atoms or planets move through a vacuum, single ones like photons can too. It’s only things that are created through the action of groups of particles, such as sound waves, that need a group of particles in order to exist and move.
If you mean, “how can space be called a vacuum if it contains light?”, space isn’t a perfect vacuum anyway and nobody with any real knowledge of the subject would say it is. But also, we don’t consider light when we determine if an area is in vacuum or to what degree. Something would still be a perfect vacuum if it was in pitch blackness or if it was in bright light.
You are actually asking a VERY good question. This very same question led people to assume space must be filled with some sort of medium, the ‘aether’.
However attempts to detect this aether constantly failed, very careful experiments were devised to look for the aether – and they came up empty. now these experiments were failures but they taught us a lot about light.
We now know light behaves like both a particle and a wave – and as a wave it propagates through the electromagnetic field. Fields aren’t physical objects like water or air, but they are a very very real part of how our universe works. Light as an electromagnetic wave does not need any matter to propagate through.
Light can also be thought of as particles of photons – and particles do not need any medium to travel through. how both of these are true is a bit beyond the scope of the question, but is another great question.
Comments
Well first, there’s no such thing as a perfect vacuum. Even the most perfect vacuum has some amount of particles floating around, and on the quantum level, quantum vacuum fluctuations.
But none of that natters because light doesn’t need a medium to travel through the way sound does. Light is oscillations in the electric and magnetic fields, which permeate all of space, so there’s no need for any physical matter for light to propagate through.
where did you get the idea that light needed something to travel through?
It doesnt. Throw a rock through space, it flies, its a rock. Big woop.
Same for light.
basically only sound needs a medium to move through.
I’m probably wrong about this, but just because a vacuum lacks anything inside of it, doesn’t mean that something can’t go inside of it, right? You can fill nothingness with something and then it just isn’t a vacuum anymore, like you’d say “it’s a vacuum full of light,” implying that’s all that’s in it, right?
Space being (mostly) devoid of matter makes things travel better. If there were more atoms in space, they would create friction with moving objects that have mass, slowing them down more quickly.
Light is energy- it doesn’t require matter to travel. If it hits matter, it is absorbed or reflected, so it, too, is impeded by matter to some extent.
Are you thinking of sound and how it requires a medium to be heard? Sound is made up of waves of compressed matter- air usually for humans, but water or other things, occasionally. The sound traveling is a function of the matter being there and compressing. Light isn’t like like that and requires no medium to travel.
Light is Electromagnetism, Electromagnetic particles. Light is emitted by the star, the Electromagnetic particles travel unopposed through space, until they hit something hard, like a building, where Infra red radiation (Which is Electromagnetic) generates heat, or the particles interact with the atmosphere, generating the blue sky and daylight.
You can travel through a vacuum too, it just wouldn’t be very pleasant
In short, light can move through space the same way stuff moves through space. Light is stuff.
Are you confusing light for sound? Sound is the effect of stuff vibrating in waves. Light has a waveform, but is also its own stuff. It coasts in space until it hits something, getting absorbed.
If you mean, “how can light be transmitted through nothing?”, the answer is: the same way as anything else. Generally particles are equally good at existing either on their own or in groups, so not only can groups of particles like atoms or planets move through a vacuum, single ones like photons can too. It’s only things that are created through the action of groups of particles, such as sound waves, that need a group of particles in order to exist and move.
If you mean, “how can space be called a vacuum if it contains light?”, space isn’t a perfect vacuum anyway and nobody with any real knowledge of the subject would say it is. But also, we don’t consider light when we determine if an area is in vacuum or to what degree. Something would still be a perfect vacuum if it was in pitch blackness or if it was in bright light.
You are actually asking a VERY good question. This very same question led people to assume space must be filled with some sort of medium, the ‘aether’.
However attempts to detect this aether constantly failed, very careful experiments were devised to look for the aether – and they came up empty. now these experiments were failures but they taught us a lot about light.
We now know light behaves like both a particle and a wave – and as a wave it propagates through the electromagnetic field. Fields aren’t physical objects like water or air, but they are a very very real part of how our universe works. Light as an electromagnetic wave does not need any matter to propagate through.
Light can also be thought of as particles of photons – and particles do not need any medium to travel through. how both of these are true is a bit beyond the scope of the question, but is another great question.