So, technically, 5000 Joules should, by the standards of how we usually calculate feats, be capable of fragmenting (5000/8 =) 625 cubic centimeters of solid stone. To put this in perspective, that would be equivalent to cracking a hole, roughly a little over 4 inches tall and wide, into and through a 2 inch thick wall... yet, clearly, in real life this is not quite what happens.
I'm not a physics expert, or anything of the sort, but I know about the existence of Inelastic Collisions and the Law of Conservation of Energy. I also know sections of solid stone tend to not fragment when shot by stray bullets, despite theoretically doing so on paper (some higher-powered bullets approach our current threshold for "Wall level")... we had ought to take that into account when considering "Wall" level, and how we intend for Wall level to actually function in practice.
My recommendation for now, I suppose? Well, here's the section for
Muzzle Velocity on Wikipedia... "heavy" weapons, like the
.50 BMG and
14.5 x 114 mm, which by our current standards are well above the baseline for Wall level... the .50 BMG, while still often used against other personnel, is one of the lightest weapons I could find with kinetic energy that classified it as a
"Anti-Materiel" rifle, i.e. designed to break solid objects. If we were to use it's 15,037 Joules (rounded to 15000 for simplicity's sake) for our low-end, it would probably line up at least to some degree with how people tend to imagine Wall level without being too dramatic a shift (only thrice the value we currently use.)
(Note: This would also allow an absolute Peak Human, such as
Bren Foster, to garner Street level+, rather than a generic Street level, to distinguish between Peak Human and a "normal" Exceptional Human if this appeals to anyone.)
I guess if that's still too low, there's the 14.5 x 114 mm, which, as an explicit Anti-Tank weapon designed for use against tanks (metal-walled war machines) yields 32000 Joules or so with its shots. Something in the realm of 30000 - 32000 Joules will surely suffice. I think I personally recommend the 15000 Joules value over this, though.
The unfortunate side effect, of course, of this is that one might on occasion find "wall-busting" feats that
technically don't qualify for Wall level by our site's conventional standards... either the calculation may have to account for real-world laws of Physics, or such (very rare) occasions are a necessary cost of a more accurate Attack Potency chart.
On a side note? I personally recommend improving the low-end for Street level, as well... there are many documented cases of athletes in sports yielding over 200 Joules of energy (especially in sports like hockey), and as we have it now
a large contingent of "average" athletes would be Athlete level+, rather than standard Athlete level... perhaps the low-end threshold of Street level should be adjusted to 300 Joules?
Again, I'm not a Physics expert of any kind, just offering suggestions based on what I can find on the web.
