(to Roald Hoffmann, great colleage and friend, on his 75th birthday):
Anniversaries are great. They make us to think about the time and to remember the good -and not so good- moments. Today is your birthday. So, let me share with you this:
It's a new day. The alarm clock rings. Wave sounds travel at 331 m/s, from the small clock's gear mechanical mechanism, without major changes since Leonardo da Vinci designed it almost 400 years ago to the date, until they reach your ear. The waves resonate and transmit vibrations to the nervous terminals almost instantaneously, moving at the very high speed to the brain and the "sound" has sense for you. In seconds, your brain reacts and a synaptic cascade of neurons take control of the muscles of your right arm to turn-off the device. You are awake. Your brain pass from a low activity state to other very busy; millions of rhodopsin molecules are hit almost simultaneously by the same number of photons, generating an illusionary image of the real world. You can see. Then, you move slowly toward the bathroom, ready to have a shower. Around 80 liters of water (maybe 2.67 x 10 27 water molecules) fall on you, and they make you awake completely. After you dry and dress, a breakfast is waiting for: orange juice (25% organic pulp, 70% water, 5% carbohydrates, minerals and vitamins), scrambled eggs (produced by the thermal denaturalization of proteins that were before protected by a porous inorganic membrane based in calcium carbonate). After you finish it, you drive yourself toward your office; in the meantime, your digestive system is busy using enzymes, gastric juices and absorbing nutrients, from the components of your meal. You decided to use your car, so after the engine start, gas is injected into the combustion chamber, along some additives to prevent friction and mechanical damage. The car moves, and at the same time a milliard of tiny carbon and metal particles are emitted in a clear fume, plus carbon dioxide, carbon monoxide, nitrogen and sulphur oxides, and water. You park in front of the Sciences building, and after you descend, a spark of static electricity moves from your body to the floor. You walk to your office now, and move through the gardens; smells and colors are result of thousands of molecules, some of the volatile enough to diffuse into your nose; others have chemical structures capable of capture light and selectively absorb only a fraction of the electromagnetic spectrum. Upstairs (and your potential energy changes with each step), you enter and take your seat. Happy, you see a big note of congratulations from your friends on your desk, printed in a paper which visibly shows the fibrous structure of cellulose which is composed. I think about than in the final point, at the last paragraph of that note, in a space no larger than 100 micrometers, three mites could move comfortably; they are so small, that I would never notice them, as usually, I never perceive most of the science going on around me.