Cofty,
Five elements are the part of the intuitive explanations of the physical structure of the world! It’s more of philosophical than physical.
Look at our bodies! We find in them solids, liquids, body-heat, air-circulation and space (or ether) they all occupy. Human body is exact representation of the physical world we find outside. Hence the ancient people taught physical world—including our physical bodies—are made of panchabhoothas (five basic or primordial elements): Land, Water, Fire, Air and Ether (or space—for example atoms are 99.999999999999 % empty space; and universe too is more of space than objects floating in it) and is called prapancha (meaning the play and interaction of the five elements) in Sanskrit.
The point I wanted to highlight was not the division into 5 elements, but their relationship with each other. These five elements are individually inimical to each other. For example, water of oceans can swallow earth, fire can evaporate the water, air can suck fire … etc. Yet they are collectively supportive, working for the sustenance of all inanimate and animate beings. Thus they make our lives enjoyable! This is a silent lesson the five elements teach the intelligent humans that they should be more and more supportive to each other despite the diverse variety in their geography, race, religion, nationality, thinking, attitude, likes and dislikes!
These five physical elements have their emergent properties or corresponding sensations: Smell, Taste, Light, Sound and Pressure (or touch). And there are five corresponding sense-organs in living beings to experience them: Nose, Tongue, Eyes, Ears and Skin. We can list living beings into five general categories: ONE-SENSED Plants able to feel pressure through their skin; TWO-SENSED Worms able to feel pressure through their skin and taste through their tongue; THREE-SENSED Insects able to feel pressure, taste, and smell through their skin, tongue and nose respectively; FOUR-SENSED Reptiles able to feel pressure, taste, smell and sight through their skin, tongue, nose and eyes respectively; and FIVE-SENSED Birds & Animals able to feel pressure, taste, smell, sight and sound through their skin, tongue, nose, eyes and ears respectively.
Hence, better not to get struck with the word. Neither ether nor space is a correct translation of the Sanskrit word akash! Interestingly, no one has coined a correct word so far! In sanskrit, akash means much more than space!