Why Video files occupy more space than Audio files do?

[smith]

I have many video files in the form of AVI/RMVB/DVDRIP on the hard disk. I
found that these files really occupy much more space of disks than Audio
files like MP3/WMA/RM. Three video documentaries, each of which lasts for 1
hour, may make one DVD-R fully written, but 400 MP3 files that last for 30
minutes each won't take all the space of it. What is the reason?

 

[Bob I]

Simply because it takes a heck of of lot more data to encode a video
stream than audio for any given time frame.

 

[no_one]

video has more bandwidth (bit per second).

 

[Loren Pechtel]

I have many video files in the form of AVI/RMVB/DVDRIP on the hard disk. I
found that these files really occupy much more space of disks than Audio
files like MP3/WMA/RM. Three video documentaries, each of which lasts for 1
hour, may make one DVD-R fully written, but 400 MP3 files that last for 30
minutes each won't take all the space of it. What is the reason?

Because it takes more information to store a picture than a sound.

Think of the difference between a VHS tape and a casette tape.

 

[justincase]

Yes, but why does it take more information to store video than sound? Why does video need more bandwidth? Apologies for bumping a 14-year-old thread but it's the top result on Google when I try to find an answer.

What's the science behind why we need such little space for an audio file to sound pleasing to the ear, but our eyes demand so much more to produce a video that makes them happy. Are our eyes simply more sensitive to the frequency range of light particles/waves that they can pick up, while our ears are less sensitive to the frequency range of sounds they can pick up? Therefore you can get away with smaller audio files cause our ears are simply too blind to notice?