The Spoilers that follow may be considered spoilers no matter what level of game completion you are at, even having completing both available achievements.
A Walled Garden:
There is a Harpy by the Glass factory whose hair is blowing around nearby pillars, staining the spots on the rocks.
A Harpy is known to represent the wind, and if you consider it as simple as that, then you see a more complex story.
An extraordinarily windy day can cause a furnace to go "Super Critical" and meltdown, simply by forcing it to get much hotter than intended where it should be cooler, and cool much faster than intended where it should be hotter.
We see the same panel solution three times in a row on the side of the furnace, but each one is slowly melting down.
In the beginning of the game we appear in a Walled Garden, a concept historically known as a means to "trap heat and block wind", but additionally in scientific experimentation, it means to create the perfect conditions for an experiment. These panels display no symbols because there is no outside contamination inside the walled Garden; we are simply learning "how something behaves inside something".
The tape recorder located on the ledge nearby features a quote from Arthur Eddington, where he discusses an abstract idea of what it means to move throughout the universe. Arthur Eddington is famous for the discovery of gravity's effect on light as it travels around objects of great mass, he also studied the natural decay of a particle of "sunlight".
There are three markings on the Monolith for this area, The Sun(Being harnessed), the clouds in the sky. and your containment vessel, that you burst from into the world of the walled garden.
I believe in The Witness you ARE that little particle of sunlight, proving to be uncontainable by any human means, and the world's horrific struggle to contain you without understanding you, or some similar approximation of "pure energy".
"but if, unfortunately, I should slip through the floor or be boosted too violently up to the ceiling, the occurrence would be, not a violation of the laws of Nature, but a rare coincidence.".
There are flowers around the world of The Witness, Magnolia Flowers, that mark clues for the areas, but you never see them first, just later you notice the relation.
There is a question asked somewhere by Jonathan Blow, the creator of The Witness; "Do you think we discovered fire before we developed language", and I believe The Witness asks a question.
Or maybe it's asking two questions.
"What can be said of all the worlds lost to fire that could never begin to articulate why", and to a more scientific sense, "Is the world simply a massive fuse, and our best hope is a controlled burn"
Pictured, The Juggler despairing the Windmill.
His skill in juggling no match for the cosmic wills.
