Not really sure how to phrase this question. If I were small enough to stand on the nucleus of an atom would I feel the effects of what was going on in the real size world around me, for instance I was a hydrogen atom in boiling water, would I be aware of the change in temperature? Or if atoms are not the best analogy here are their any smaller particles that would be oblivious to what might be happening on the full size earth?
If you can feel movement/acceleration, then you’ll know if your particle is part of something moving.
Heat is represented at the atomic level by random motion of particles. Higher heat means a higher average velocity. You’ll have to run some statistics on your motion to arrive at a temperature and to eliminate general motion.
Pressure shows up in increased collisions in a gas, so presumably you could measure that. Maybe you could measure the strain on intermolecular bonds in a solid under pressure, but we start reaching a point here where we have to ask exactly what measuring tools the mini-you has.
Electromagnetic fields would affect charged particles. You’d clearly know this in some cases (like deflection of a free electron), but I’m not sure if the mini-you would be able to detect/measure the field in every case.
You could detect radiation (light) if you could measure changes in energy of surrounding particles. (To illustrate: A photon hits an electron, raises it to a higher energy level. When it returns to its “rest” state, it releases another photon to dissipate the excess energy. For the electron, this is clearly measurable.)
The world we experience on the everyday scale, heretofore referred to as the “macro[scopic]” scale, is an amalgam of stochastic (non-deterministic) phenomena that is sufficiently distributed to the point that we view phenomena as being smoothly continuous. In other words, the behavior of individual particles is average to a result that can be consistently be predicted by gross state-based mechanics such as Newton’s Laws, classical electrodynamics, and classical thermodynamics. For instance, what we experience as we experience as temperature on a macro scale is actually an average of the randomized momentum of particles hitting each other and transferring energy back and forth. We consider temperature as being a measurement of a particular system along a continuum, whereas the actual events of momentum transfer experienced at the individual particle level will vary wildly although over a long enough time (or number of events) you could average the interactions to obtain an estimate of system temperature, similar to how you can repeatedly sample a random event, like a roll of dice, to obtain an estimate of the relative probability, and this would tell you that you are in a boiling pot.
The other thing to consider is the relative strength of forces as the level of individual particles as cogently elucidated in Richard Feynman’s classic 1959 lecture entitled “Plenty of Room at the Bottom”. At the macro level, gravity largely dominates the other forces in terms of mechanics, which is why it is so hard for us to fly through the air. Technically speaking, the electrostatic forces that hold material objects together are even stronger, but the interactions between large objects mediated by electromagnetic fields beyond the tribological (surface-to-surface or surface-to-boundary-layer) contact are generally small. However, a small insect finds it much easier to fly or float, because the fluid dynamic forces of the atmosphere are more significant on their scale (due to having low density and therefore high buoyancy), and individual molecules of diatomic oxygen and nitrogen bounce around like beach balls at a rock concert due to intermolecular (electrostatic) forces. When you get down at the scale of electrons and nucleons, the electromagnetic and internuclear forces, respectively, are comparatively so large that gravity can actually be neglected in calculating the interactions, which is the inverse of what we experience on the macro scale where electromagnetic forces (aside from direct contact) are typically small and internuclear forces are invisible (though a result of their interactions and decay can produce massive electromagnetic and thermofluid effects).
So, the simple answer to the question of the o.p. is that at very small scales on the order of atoms or molecules one would not experience the effects that are part of our everyday experience such as temperature. However, we could sample the discrete reactions sufficiently to estimate what the global temperature state of the overall system is.
Stranger