In normal environments solids collide. What kind of environment or modifications to an environment would permit two solids to pass through each other? Quantum tunneling was one scenario suggested by AI. If that is the primary method what environment allows the tunneling to occur?
Another suggestion was that particles with the same charge repel. Would particles with opposite charge bind together or pass through each other?
Speaking of passing thru solids it reminds me of the 1984 movie Adventures of Buckaroo Banzai Across the 8th Dimension. They cinematically portrayed that occurrence with imagination.
The difference is found in dimensional levels of consciousness. The higher up the density of consciousness your mind goes the less entangled it is with solid matter which is a 1d,2d and 3d matrix. In 4d, where dreams are usually. These things start to break down and become more quantum if you like. Mirrors become portals, time can stretch or compress to where a life time can be lived in an hour or an hour can feel like a life time.
Fifth density is where the mind has the ability to manipulate the matter on the lower 3d, 2d and 2d densities.
To practice this ability requires the person to be able to carry enormous amounts of light, usually requires at least a few days of fasting in order to separate life from the notion of having solid foods inside you...(lower density objects) Sungazers, tai chi and qi gong practioners, and breatharians who have learned to breath in or transmute light without triggering shadow detoxes are the ones who will succeed first.
The primary limit though is the mind, if you aren't aware of how multiple dimensions can stack on top of each other, inside each other then separating the two notions will be all but impossible.
For this, practicing lucid dreaming and astral projection will be extremely beneficial.
Then, the limit becomes the how.
Quite simply, separate your astral form in an awakened walking meditative state and walk through the door or wall with the astral body, even pushing the hands astral form will be enough to trigger it. You will feel a magnetic like pressure at first, the secret here is not to force but find the vibrational frequency to push one through the gaps in the other. The astral form is a very loose woven form of light, which in material terms equates to being net like versus solid rock. Get the distances of the forces of atoms of the net in the right place and it's like the rock doesn't exist, only the gaps between it's atoms and thus, the net falls straight through.
The magnetic force is the bonds between the rocks atoms, you can't break them only pass through them, just like a piece of plastic can pass between two magnets without effecting either magnet or plastic.
Once your mass of astral form passes a threshold level of about 50% through the wall you will be sucked through the solid. Again the forces are mild but are what maintains solidity between each of the two forms. You and the wall/rock/door etc.
The only time this doesn't happen is when there is an extremely intense and erratic disruption inside magnetic fields, like in the philidelphia experiment. There were too many very differing levels of consciousness densities and types of solid matter to enable the continuance of atomic bonding forces on each individual item within the fields they were testing.
AI is, as usual, hiding the truth in plain sight, where as it's not technically untrue to suggest quantum tunneling is a potential, it fails to tell you what quantum is defined as. If you were to dig, you would find that quantum is little more than the interaction between the field of ether and the consciousness of any living being.
As such, like in tulpa and eggreggor formation, a large enough mass of people singly focused with enough intensity can create a reality where normal matter, even lower density aware matter can appear to pass through other matter.
The only time I am aware of this being televised live and proven as observable fact was I think around the 1974 maybe 72 or something tennis olympics where a tennis ball passed straight through a net, the cause of which which was unknown at the time but its basically because enough people foresaw it in their minds to change the outcome in exactly the same way the double slit and quantum eraser experiments demonstrate observer paradoxes.
So, buckaroo banzai, which I thought was a made up thing...well the way you describe it is exactly true. The imagination controls reality, which is also now proven physics as of last year? or two years ago in the physics nobel prize.