The American system of jurisprudence recognizes a wide range of factors, predispositions, prejudices, and experiences that might cloud our judgment, … - Carl Sagan

Science arouses a soaring sense of wonder. But so does pseudoscience. Sparse and poor popularizations of science abandon ecological niches that pseudoscience promptly fills. If it were widely understood that claims to knowledge require adequate evidence before they can be accepted, there would be no room for pseudoscience. But a kind of Gresham’s Law prevails in popular culture by which bad science drives out good. All over the world there are enormous numbers of smart, even gifted, people who harbor a passion for science. But that passion is unrequited. Surveys suggest that some 95 percent of Americans are “scientifically illiterate.” That’s just the same fraction as those African Americans, almost all of them slaves, who were illiterate just before the Civil War — when severe penalties were in force for anyone who taught a slave to read. Of course there’s a degree of arbitrariness about any determination of illiteracy, whether it applies to language or to science. But anything like 95 percent illiteracy is extremely serious.

If the world is to be understood, if we are to avoid such logical paradoxes when traveling at high speeds, there are some rules, commandments of Nature, that must be obeyed. Einstein codified these rules in the special theory of relativity. Light (reflected or emitted) from an object travels at the same velocity whether the object is moving or stationary: Thou shalt not add thy speed to the speed of light. Also, no material object may move faster than light: Thou shalt not travel at or beyond the speed of light. Nothing in physics prevents you from traveling as close to the speed of light as you like; 99.9 percent of the speed of light would be just fine. But no matter how hard you try, you can never gain that last decimal point. For the world to be logically consistent, there must be a cosmic speed limit. Otherwise, you could get to any speed you wanted by adding velocities on a moving platform.

Pero los humanos tenemos talento para engañarnos a nosotros mismos. El escepticismo debe ser un componente de la caja de herramientas del explorador, en otro caso nos perderemos en el camino. El espacio tiene maravillas suficientes sin tener que inventarlas.