Cloudscape

This entry is highly speculative even by my standards, and might be more of an interesting idea for science-fiction fans than a futuristic view. However, seeing how it is impossible to foresee the future, it is possible after all that we would find a means to realize the following.

If the axis of electron orbitals in an object could somehow be decreased, and this process would happen at a sufficiently slow speed, the atoms inside the object would steadily rearrange themselves as its electron orbitals steadily shrink.
Causing an electronic orbital to shrink would require a sophisticated insight into quantum mechanics, which we're still far from having. We know, however, that the distance of an electron from its nucleus depends on two important factors, much like with planets around the sun: the outward centrifugal force keeps the electron from colliding with the nucleus, while the Coulomb force keeps it from escaping from it. These can be mathematically equated as:

kZe2/r2 = mv2/r

where the first member of the equation is the Coulomb force and the second is the centrifugal force, and

k is the Coulomb constant
Z is the atomic number
e is the elementary charge
r is the atomic radius
m is the mass of the electron
v is the speed of the electron

Thus, the radius of an atom equals:

r = kZe2/mv2

k and e are universal constants, so unless we can locally manipulate the laws of the universe, these are impossible to change. However, recent evidence suggests that physical constants are perhaps not as constant as we believed: for instance, in a natural nuclear reactor in Gabon, the Sommerfeld constant was shown to have changed. However, changing physical constants might prove to involve such advanced quantum physics that this would perhaps not be the easiest way.
By increasing the momentum of the electron, however, its orbital radius would have to decrease too. However, increasing its momentum could instead cause the electron to escape its atom. Both increasing the momentum of the electron and keeping it in its orbital could theoretically be done by radiating it with energy from the right angle. This is simply the opposite of bremstrahlung ("braking radiation"), in which a charged particle (eg an electron) emits energy as it is slowed down by another charged particle (th emitted energy being its lost kinetic energy).
Now the real challenge would be: how can we know when to radiate the electron?
We can't. We can't even know where the electron is in the first place, not without knowing every interaction it has with other particles in its environment. At most, we can conceive of how this could hypothetically be done with even more hypothetical technology. That, in this case, would be picorobots, a subatomic version of nanorobots, which could collectively calculate where the electron would manifest macroscopically and based on this radiate it from exactly the right angle so as to slowly bring it closer to its nucleus as they increase its momentum - it would require astronomical computation power and technology we are today unable to clearly envisage.
Suppose, anyhow, that with science yet unknown to us today, somehow we could find a way of compressing atoms, be it by somehow manipulating the laws of physics or some other esoteric method, there could still be other problems involved. For instance, manipulating atoms would also manipulate the way they would interact with one another, so that if the process went too fast, the molecules they comprise would disintegrate; in addition, if the atoms would collide with one another, they could disrupt the process.
Supercooling the object may prevent atomic collisions from damaging its structure, although if the object were more complex, such as a person or even a single tissue, supercooling it may not be an option except with advanced cryonic technology; the necessity of this would depend on the speed at which the atoms would shrink.
If this would happen instantaneously, then certainly the chemical composition of the object would be profoundly damaged, and possibly all that would be left would be an amorphous heap of matter - this as well might be useful if the matter to be atomically compressed is already amorphous, such as a resource, in which case this might have other, indirect applications. Atomically compressing matter would NOT make it easier for transport because the atoms kinetic energy is retained, however, and therefore so is the outward pressure, but it might make it possible for it to permeate other material easier, even material which is normally very impermeable such as concrete; if the atomic compression were somehow temporary, this could also destroy the material in question, as the atoms' decompression throughout it would cause tremendous internal pressure in it. It might also allow it to pass through a pipeline faster, for instance, as more atoms could fit in it, or it could be easier absorbed by the body, perhaps even through the pores of the skin. This could also be used to create ultrasmall versions of nanorobots.
If the atomic compression could happen gradually so that it could be applied to a complex object despite the entropic force this process would involve, the result would be that the object would become a perfectly identical smaller version of its original. The possibilities such technology might involve would be endless, such as espionage, nano/picotechnology, and simply entertainment. Ironically, a human or object could safely be small without having to fear of be killed: being walked upon, for instance, would have the same effect as it would have if someone walked on you if you were of normal size, because you still have the same number of atoms and therefore the same energy holding them together as they would have if you were of normal size: in fact, because whatever force you would experience would be more diffuse, it would be less dangerous. Of course, unpleasant accidents such as being kicked against might be more frequent, but not any dangerous than at normal size.

Unlike nanorobots, which used atoms in their environment as building blocks, picorobots would produce particles as their building blocks. One way to do this is hadronization - a process in which hadrons duplicate. This process arises when the quarks which constitute hadrons (such as protons and neutrons) are taken at a sufficient distance from one another. Because the strong force is proportional to distance (unlike other forces), the farther quarks are taken from one another, the more energy it takes to keep them apart. At some point, this energy will create new quarks between the other quarks. So if one tries to separate the quarks in a meson (which has two quarks, one quark and one antiquark), all one manages to do as one splits them in two is to create two new mesons. In this way, with enough energy input, one can create new quarks indefinitely: the energy is materialized.
Picorobots could also concentrate light by adding up the energies of their photons. In this way, two photons could be combined to one photon with double energy, and therefore double frequency. In this way, the photons could eventually be made so energetic that upon colliding with each other they would create matter, which the picorobots could use to create atoms. In this way, light could, in essence, be converted into matter. We’d long learned to convert mass into energy, but it wasn’t too long ago we’d learned to do just the opposite.