Born into the world of space travel and atomic energy it would have been easy to have not noticed two inventions that provide the foundation of our modern world: the laser and the transistor. Eagle and Trinity were spectacular then but now out of reach. Whereas fiber optics and integrated circuits manufactured in phenomenal volume every day touch us far more directly.
Both lasers and transistors depend on the properties of atoms and especially interacting ensembles of atoms in crystalline structures and resonant cavities. These exquisite properties of order have proven more useful if less dramatic than the explosive disorder of a rocket engine or chain reaction.
# Transistor
Imperfections in a crystal allows for current to flow through a process similar to the way the empty square allows the remaining 15 puzzle pieces to move in the popular toy. Highly engineered silicon has just the right number of "holes" to variably conduct, to be a semiconductor, under the influence of weaker applied electrical forces. A signal is thus amplified even though power is consumed.
The information processing capacity of a transistor circuit improves as dimensions are made smaller and signals weaker for the simple reason that there is less material to be moved in each operation. By lithographically printing fantastically small transistor networks onto atomically smooth crystal surfaces we now construct computational giants: the integrated circuits we call chips.
Amplifiers erase the small losses in signal quality that come from any handling. When a signal arrives at 15% or 85% percent of the designed range an amplifier will restore that to 0% or 100%. Other transistor configurations will invert the amplified output to 100% or 0%, providing a logical signal negation. These and similar circuits are arranged to do math and remember results to be guided by more decisions made by more amplifiers.
A circuit becomes a computer when its logical behavior is guided by instructions represented as more signals arranged in a code for what to do when. My career as a programmer began about the time lithography squeezed all of the circuits required of a computer onto a single chip of silicon crystal. The transistor, discovered about the time I was born, had matured to become the microprocessor while I matured to become its master.
# Laser
Atoms can absorb and release energy as they adjust the orbits of their own electrons which need not travel themselves to carry information as they do in semiconductors. Atoms are big and bulky, electrons small and fleet, but their interactions, the stuff of light, that transcends time itself. pdf 
Einstein predicted that emission of energy from one atom could stimulate the emission from another. This was realized first with microwaves and then with light around the time I was born. First treated as a useless curiosity the laser produced light from coordinated emissions. This light had orderly properties not unlike crystals that would give it precision for rapid, long distance signaling.
A resonance purifies the laser's signal by a different mechanism but to a similar effect as amplifiers in digital logic. Because designers know more about their signals they can do more with their signals. They can reduce a message to femtosecond pulses and guide them around corners and over kilometers with a glass fiber's total internal reflection. Thus engineered materials conquer communication as they have computation.
# Internetworking
I will add to these physical properties of matter another truly exceptional property of humans: the will to cooperate. The silent hand of which industrialists are so proud guided the development of integrated circuits and fiber optics such that computer networks became practical. But the vision that the world would be better with one network connecting everyone, a network of networks, this came not from nature, but from my peers.
We should be grateful that science and engineering has understood and exploited such marvelous properties of nature to make amplifiers and resonators for us. But we must add to that the political will to turn them to everyone's advantage. Our internet is among the most fragile of civilization's creations. Please be careful.
See Quantum Physics for a deeper view into the collective behavior of forces.
See Life with Transistors for the social impact of miniaturization and mass production.