Like many words in common usage, “science” has come to mean different things. Its meaning also often depends on the context in which it is used. What are the distinguishing characteristics of science?
One of the most useful concepts in physics is a property of matter called entropy. It is useful for understanding topics as diverse as how steam engines work to the fate of structure in the universe. Just as one wouldn’t say an individual atom has a certain temperature or possesses a defined amount of heat, neither would one say it has a specified amount of entropy. Rather these parameters characterize the physical state of conglomerates of atoms and molecules, be they in the form of solids, liquids or gases. These are emergent macroscopic properties reflecting the collective behavior of all the constituents within a system. While temperature measures the average kinetic energy of all the system’s particles, heat specifies the total amount of kinetic energy possessed by all the particles in the system. Similarly, entropy quantitates disorder within a system. Saying the entropy of something increases is equivalent to saying the constituents making it up have become more random, chaotic or disordered; the system has lost structure. Solids are generally composed of parts arranged in a regular structure. This is especially the case with solid crystals where individual atoms are arranged in repeating patterns. Liquids and gases typically are more free-form. Consequently, the entropy of a solid increases as its warmer surroundings cause it to melt and then vaporize.
Is it possible computers and their software will become so robust in their capabilities we will think of them as being conscious? Might they one day pursue their own lines of thought without being directed by humans? Will their interactions with us be so sophisticated that, without visually seeing them, we wouldn’t be able to distinguish them from humans?
I have previously explained how complex eukaryotic cells, the cells that make up the tissues in our bodies, developed. They arose in an early stage of the evolution of life from simpler bacteria cells called prokaryotes.
Life’s history on Earth is punctuated by some important transitions. One of the more important ones was the development of symbiotic, interdependent relationships between simple prokaryotic cells, such as bacteria. This made possible a new kind of life form: the more complex eukaryotic cells that make up body tissues in complex organisms.
My wife and I recently returned from a vacation in Patagonia. One thing that struck me were the repeated reminders people in this southern South American region gave us to keep covered and apply sunscreen liberally.
The neural circuits and hormones that give rise to the functions of the human brain were optimized for the survival of our ancestors.
Charles Darwin’s theory of evolution by natural selection was a synthesis of ideas that had been brewing for centuries, indeed millennia, about the origins of and relationships between the organisms inhabiting the planet.
As all good theories should, the theory of evolution has grown to account for new discoveries.
The world’s ocean currents play a critical role in climate. Those currents are influenced by atmospheric conditions. These interactions between the oceans and atmosphere determine how vital rain and snow are distributed around the globe.