The Fermi Paradox: Are We The First?

This is a possible consequence of the “too rare” solution, that we may be the first ones to emerge in our galaxy, or even all of the Universe that we can observe. However, this solution only requires rarity before our emergence, and not after.

But considering when we emerged, it is hard to point to what might make our emergence rare before when we emerged and common afterward. An obvious possible limiting factor is metallicity, the abundance of elements heavier than hydrogen and helium, what astrophysicists call metals. Old and exploding stars have gradually been enriching the interstellar medium with metals, giving later-forming stars more and more of metals. However, Earth-sized exoplanets have been detected orbiting stars with a wide range of metallicities, sometimes much less than the Sun’s (An abundance of small exoplanets around stars with a wide range of metallicities | Nature). This makes it unlikely that the Solar System was the first planetary system with habitable planets.

Continue reading
Advertisements

Fuzzy logic

Fuzzy logic is the addition of other sorts of values to true and false, like adding a “maybe true or false” value, and using a continuum of values between true and false. Traditional mathematical logic, with only true and false, is sometimes called crisp logic by comparison. It is also known as Boolean algebra, from 19th cy. mathematician George Boole, who found analogies between logic and arithmetic.

Fuzzy logic has turned out to be very useful for device control, because it is a good way of handling real-world conditions. For instance, when does gray stop being black and start being white? For crisp logic, one can say black – medium gray is dark and medium gray to white is light. That is not very informative, so we subdivide these ranges: black to dark gray is dark-dark, dark gray to medium gray is dark-light, medium gray to light gray is light-dark, and light gray to white is light-light. One can continue with these subdivisions, reinventing binary representations of numbers. But once one does that, one can use the numbers directly. Black is 100% dark and 0% light, dark gray 75% dark 25% light, medium gray 50% dark 50% light, light gray 25% dark 75% light, and white 0% dark 100% light. Once one has such numbers, one can then use them in fuzzy analogs of crisp-logic operations like “not”, “and” and “or”.

Below the fold, I will construct some a simple system of fuzzy logic using “maybe true or false”.

Continue reading

WFF ‘N Proof, a mathematical-logic game

“WFF ‘N Proof, the Game of Modern Logic”, is a game that I had had in my childhood, though I now only have its rulebook. A WFF (“woof”) is a well-formed formula, one that is syntactically correct, and in the game, one creates proofs with inference rules. The game has dice with operation and variable names on them, and one tries to find WFF’s and proofs that fit what is on the dice. The game also includes an hourglass for timed play.

It was created by Layman Allen in 1962, and he has also created On-Sets, on set theory, and Equations, on arithmetic, both played much like WFF ‘N Proof.

I wish that I could recommend WFF ‘N Proof, but it has several deficiencies.

  • It uses a prefix representation for its binary operators, (and) p q, with no attempt to relate it to the more usual infix form, p (and) q.
  • It does not use the logical constants (true) and (false), and it does not have truth tables, tables of output values for input values (arguments).
  • It does not name the operator properties that it has proofs of, like (and) and (or) being commutative and associative.

After the fold, I will describe the formalism in WFF ‘N Proof in more detail.

Continue reading

Transcendental Future Orientation

Psychologist Philip Zimbardo has proposed that much of our attitudes can be explained by our time orientation. Are we oriented to the past? The present? The future? Is our orientation positive? Or negative? That is, do we think about good things or bad things? He explains what he means at his site, The Time Paradox.

That site has an odd time orientation: Transcendental Future. He even has a quiz about it: Transcendental-future Time Perspective Inventory (TTPI). Continue reading

Time Orientation by Philip Zimbardo

Philip Zimbardo is a psychologist who has worked on what can make “normal” people turn bad (the Stanford Prison Experiment and his book “The Lucifer Effect”), and he has an interesting proposal of how much of our attitudes can be explained as time orientation. I first found out about it from his talk at the 2008 Beyond Belief conference; he shows some slides that give correlations of his time orientations with various personality factors.

Continue reading

Abraham Maslow’s Hierarchy of Needs

Around World War II, psychologist Abraham Maslow decided to consider mentally healthy people, to balance out study of mental pathologies. In 1943, he published his conclusions in “A Theory of Human Motivation” in Psychological Review. He proposed that we have a hierarchy of needs, from the physiological to the transcendent: Maslow’s hierarchy of needs – Wikipedia, Maslow’s Hierarchy of Needs | Simply Psychology, Abraham Maslow and Happiness, What Is Maslow’s Needs Hierarchy?

This hierarchy is often depicted as layers of a pyramid. From bottom to top:

  1. Physiological: breathing, food, water, sex, sleep, homeostasis, excretion
  2. Safety: security of body, employment, resources, morality, family, health, property
  3. Love and Belonging: friendship, family, sexual intimacy
  4. Esteem: self-esteem, confidence, achievement, respect of others, respect by others
  5. Self-actualization: morality, creativity, spontaneity, problem solving, lack of prejudice, acceptance of facts

Continue reading

Isaac Asimov on Searching for Information

In my earlier post, “Books: The Ancient and Ultimate Document Viewer?”, I had commented on Isaac Asimov’s belief that that’s what physical books are, and I had pointed out some important deficiencies of them. One of them is searchability. But IA himself had written on this problem.

n 1955, he wrote “The Sound of Panting” (in “Only a Trillion”). The panting that he described was for him as he tried to keep up with the biochemistry literature.

In 1964, he wrote Asimov Suggests Science of Data | News | The Harvard Crimson

Science’s rapid accumulation of data, Asimov said, has created the need for a new branch of science, information retrieval. The new field, he said, should attempt to make the data scientists need available to them simply “by pushing the right button.”

Regaling his audience with a Jackie Masonesque style, Asimov then launched into a lengthy example of how Mendel’s theories of heredity were overlooked for a generation, the delay producing misconceptions that may ultimately have led to two world wars.

He also wrote about that in one of his science essays.

Continue reading