The winter sun hits the ice on the back deck railing and causes it to vaporize without liquefaction. I can see the light aberrations indicating the vapors rising from the ice sheets without puddles. The same energy is required from the sun to sublimate the ice as to melt then evaporate it, but here the conditions are right and the water is skipped. This is sublimation.
In Freudian psychology, sublimation refers to the process of redirecting undesirable urges toward productive activities. From immovable personality traits, the solidity of the hard-wired psyche, we could push the sloppy fluidity of our own destructive desires and transcend to the sublime. Effervesce even to the ethereal potential of the Ego directed by the Superego, instead of the Id. A defensive mechanism, sculpted by the slow winds of evolutionary change to impart a fitness due to the suppression and redirection of mental momentum, that doesn't stop the desires but redirects them to purpose.
When I made sublimation a word for 2010, I was thinking of physical chemistry, sublimating my own energies of anxiety over lack of control over the news, the weather, whatever, and focusing trying to understand the world around me rather than the world brought to me by the noisy electromagnetic waves of technology. It takes as much energy to convert from solid to vapor, whether a fluid phase is involved or not. You cannot avoid the input of energy and there is no free transformational process. While a liquid phase is common in most instance, there are special conditions that sublimation is enhanced. The temperature, that is the energy level, must be correct. It must be present in sufficient quantity, yet not be excessive, (at least in the case of water and many organics). But it is mostly a function of pressure. Lower atmospheric pressure lowers the energy required for phase change. Lower pressure just means a reduced molecular crowding in the same volume of space, a lower particle population per cubic centimeter. More space into which to sublime. In the case of the ice in the sun, the lower relative humidity of the January air helps too. Again, the sky is less crowded with other vapors. The more space to move, the more likely the movement. A cold day with a bright sun, a dry breeze and a potential for a storm in a couple of days helps ice disappear invisibly, vaporizing from crystal sheets. Change under the right conditions, an invisible phase change noticeable only by how the old form fragments, craters, pits and crumbles away, on a beautiful day, becoming the sublime.