Few scientists now dispute that today's soaring levels of carbon dioxide and other gases in the atmosphere will cause global temperature averages to rise by as much as nine degrees Fahrenheit sometime after the year 2000.
Eratosthenes's only tools were sticks, eyes, feet, and brains; plus a zest for experiment. With those tools he correctly deduced the circumference of the Earth, to high precision, with an error of only a few percent. That's pretty good figuring for 2200 years ago.
Demon mean knowledge in Greek, especially about the material world. Science means knowledge in Latin. A jurisdictional dispute is exposed, even if we look no further
I promise to question everything my leaders tell me. I promise to use my critical faculties. I promise to develop my independence of thought. I promise to educate myself so I can make my own judgments.
The way to find out about our place in the universe is by examining the universe and by examining ourselves - without preconceptions, with as unbiased a mind as we can muster.
What does it mean for a civilisation to be a million years old? We have had radio telescopes and spaceships for a few decades; our technical civilisation is a few hundred years old ... an advanced civilisation millions of years old is as much beyond us as we are beyond a bushbaby or a macaque
We are the product of 4.5 billion years of fortuitous, slow biological evolution. There is no reason to think that the evolutionary process has stopped. Man is a transitional animal. He is not the climax of creation.
One of the reasons for its success is that science has a built-in, error-correcting machinery at its very heart. Some may consider this an overbroad characterization, but to me every time we exercise self-criticism, every time we test our ideas against the outside world, we are doing science. When we are self-indulgent and uncritical, when we confuse hopes and facts, we slide into pseudoscience and superstition.
Discussing the possibilities of extraterrestrial life: I would love it even if they were short, sullen, grumpy and sexually obsessed. But there just isn't any good evidence.
Once we overcome our fear of being tiny, we find ourselves on the threshold of a vast and awesome Universe that utterly dwarfs — in time, in space, and in potential — the tidy anthropocentric proscenium of our ancestors.
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% of Americans are "scientifically illiterate." That's...the same fraction...of slaves who were illiterate before the Civil War.
Science is an attempt, largely successful, to understand the world, to get a grip on things, to get hold of ourselves, to steer a safe course. Microbiology and meteorology now explain what only a few centuries ago was considered sufficient cause to burn women to death.
The secrets of evolution are death and time-the deaths of enormous numbers of lifeforms that were imperfectly adapted to the environment; and time for a long succession of small mutations.
There are in fact 100 billion galaxies, each of which contain something like a 100 billion stars. Think of how many stars, and planets, and kinds of life there may be in this vast and awesome universe.
Widespread intellectual and moral docility may be convenient for leaders in the short term, but it is suicidal for nations in the long term. One of the criteria for national leadership should therefore be a talent for understanding, encouraging, and making constructive use of vigorous criticism.