Understanding Heat and Temperature

Our sense of touch tells us quite definitely that one body is hot and another cold. But this is a purely quali- tative criterion, not sufficient for a quantitative descrip- tion and sometimes even ambiguous. This is shown by a well-known experiment: we have three vessels con- taining, respectively, cold, warm and hot water. If we dip one hand into the cold water and the other into the hot, we receive a message from the first that it is cold and from the second that it is hot. If we th...

 Carbon VS Silicon Life

Though one might imagine "living" organisms such as intelligent computers produced from other elements, such as silicon, it is doubtful that life could have spontaneously evolved in the absence of carbon. The reasons for that are technical but have to do with the unique manner in which carbon bonds with other elements. Carbon dioxide, for example, is gaseous at room temperature, and biologically very useful. Since silicon is the element directly below carbon on the periodic table, it has simi...

 The Chance of Error in Atomic Sized Computers

The first thing that you would worry about when things get very small is Brownian motion--everything is shaking about and nothing stays in place. How can you control the circuits then? Furthermore, if a circuit does work, doesn't it now have a chance of accidentally jumping back? If we use two volts for the energy of this electric system, which is what we ordinarily use, that is eighty times the thermal energy at room temperature (kT=1/40 volt) and the chance that something jumps backward aga...