Physics without time The structure of physical law as we generally recognize it today is firmly held together by the existence of time. Although physical laws can both predict and retrodict (reversible time does not break the laws but entropy seems to police the direction in real life), are we able to go further and in some manner entirely divorce time from physical law?
Have there been attempts to do this, and if so what are the main roadblocks that prevented a reformulation?
Is it just that a time-free physics is not compatible nor useful with beings that depend on memory?
 A: I once read of a science fiction scenario where  on a planet the distance from a specific center was time. Life in that format progressed in height  from the center, grew contours of certain height  and became flat at death. The consciousness of those entities had time defined by their changes but humans just saw a completed contoured landscape unchanging in human terms.
We, humans, define time by changes  .  The three dimensional contours in our environment, described by dx/dy, dy/dz,dz/dx etc  change values . These changes force us to define time. The sun motion,  day and night these are geometrical changes in contours that would be invariant if t=constant. In contrast to the hypothetical planet above our fourth dimension, time, has more complicated algebra but the concept is the same.
Physics without time would just be three dimensional geometry, invariant, and it is evident that just three dimensional geometry does not describe even the simplest phenomena we observe, a falling apple for example.
A: No complete formulation of physics without time is possible. To be physical, a formulation must explain and predict the observable universe, of which time is a fundamental feature. In a timeless formulation, no quantities can change and no events can cause or be caused. Since we overwhelmingly find that quantities do change and events have causal relations to each other, a purely timeless formulation is unphysical.
A: We know particles that exists outside of time: Photons, travelling at the speed of light, see their path (and their lifetime) relativistically contracted to a point (and an instant of no duration). It must obviously be mathematically possible to describe what happens to a photon in its own rest frame.
We just do not know how: Just changing our frame of reference leads to the problem that everything on the photon's path appears at the same point, the only one ever seen by the photon (in its rest frame). We cannot squeeze enough information into a singular point for this to work the way relativity suggest should work, with the known laws of physics.
If we could discover how the known laws of physics (or perhaps our Lorentz transform, or perhaps our notion of spacetime) need to be extended to describe known physics from the point of view of a photon, we would have a description outside time, and hence at least superficially free of time.
