
Memes
Back-of-the-Envelope Calculation
It was from Kuiper that I first got a feeling for what is called a back-of-the-envelope calculation: a possible explanation to a problem occurs to you, you pull out an old envelope, appeal to your knowledge of fundamental physics, scribble a few approximate equations on the envelope, substitute in likely numerical values, and see if your answer comes anywhere near explaining your problem. If not, you look for a different explanation. It cut through nonsense like a knife through butter.A quick nonsense detection technique.
More Exciting Than the Supernatural
And yet there's so much in real science that's equally exciting, more mysterious, a greater intellectual challenge - as well as being a lot closer to the truth. Did he know about the molecular building blocks of life sitting out there in the cold, tenuous gas between the stars? Had he heard of the footprints of our ancestors found in 4-million-year-old volcanic ash? What about the raising of the Himalayas when India went crashing into Asia? Or how viruses, built like hypodermic syringes, slip...There are wonders in science far more amazing than the ideas presented in superstition.
Scientific Ignorance is Dangerous
I don't know to what extent ignorance of science and mathematics contributed to the decline of ancient Athens, but I know that the consequences of scientific illiteracy are far more dangerous in our time than in any that has come before. It's perilous and foolhardy for the average citizen to remain ignorant about global warming, say, or ozone depletion, air pollution, toxic and radioactive wastes, acid rain, topsoil erosion, tropical deforestation, exponential population growth. Jobs and wage...In a world filled with scientific workings, ignorance of science prevents us from success and misinforms the Democratic populous.
A Complex and Majestic Universe
To discover that the Universe is some 8 to 15 billion and not 6 to 12 thousand years old improves our appreciation of its sweep and grandeur; to entertain the notion that we are a particularly complex arrangement of atoms, and not some breath of divinity, at the very least enhances our respect for atoms; to discover, as now seems probable, that our planet is one of billions of other worlds in the Milky Way galaxy and that our galaxy is one of billions more, majestically expands the arena of w...The complexity of our Universe and our existence "majestically expands the arena of what is possible."
Science Appreciates Human Fallibility
Perhaps the sharpest distinction between science and pseudoscience is that science has a far keener appreciation of human imperfections and fallibility than does pseudoscience (or 'inerrant' revelation). If we resolutely refuse to acknowledge where we are liable to fall into error, then we can confidently expect that error - even serious error, profound mistakes - will be our companion forever. But if we are capable of a little courageous selfassessment, whatever rueful reflections they may e...Which distinguishes it from pseudoscience.
The Deleterious Effects of Pseudoscience
...science is more than a body of knowledge; it is a way of thinking. I have a foreboding of an America in my children's or grandchildren's time - when the United States is a service and information economy; when nearly all the key manufacturing industries have slipped away to other countries; when awesome technological powers are in the hands of a very few, and no one representing the public interest can even grasp the issues; when the people have lost the ability to set their own agendas or...Science is crucial to our civilization, but we live in a society that cannot grasp scientific issues.
Mistrust arguments from authority
One of the great commandments of science is, 'Mistrust arguments from authority'. (Scientists, being primates, and thus given to dominance hierarchies, of course do not always follow this commandment.) Too many such arguments have proved too painfully wrong. Authorities must prove their contentions like everybody else. This independence of science, its occasional unwillingness to accept conventional wisdom, makes it dangerous to doctrines less self-critical, or with pretensions to certitude.
...One of the "great commandments of science."
Science Saves Lives
Even at its best, pre-modern medical practice did not save many. Queen Anne was the last Stuart monarch of Great Britain. In the last seventeen years of the seventeenth century, she was pregnant eighteen times. Only five children were born alive. Only one of them survived infancy. He died before reaching adulthood, and before her coronation in 1702. There seems to be no evidence of some genetic disorder. She had the best medical care money could buy.
Diseases that once tragically carried off...You can pray over a sick person, or give them medicine. All the ways medical science has reduced mortality.
Discard Bad Ideas
the hard but just rule is that if the ideas don't work, you must throw them away. Don't waste neurons on what doesn't work. Devote those neurons to new ideas that better explain the data. The British physicist Michael Faraday warned of the powerful temptation
to seek for such evidence and appearances as are in the favour of our desires, and to disregard those which oppose them . . . We receive as friendly that which agrees with [us], we resist with dislike that which opposes us; whereas the...It is difficult to do, but we must put our ideas up for criticism.
Ronald Reagan's Memory Problems
President Ronald Reagan, who spent World War Two in Hollywood, vividly described his own role in liberating Nazi concentration camp victims. Living in the film world, he apparently confused a movie he had seen with a reality he had not. On many occasions in his Presidential campaigns, Mr Reagan told an epic story of World War Two courage and sacrifice, an inspiration for all of us. Only it never happened; it was the plot of the movie A Wing and a Prayer - that made quite an impression on me, ...Reagan recalled things as real that happened only in his movies, what does this mean for humans and major policy decisions?
Discovery of the First Pulsar
In 1967, British scientists found a much nearer intense radio source turning on and off with astonishing precision, its period constant to ten or more significant figures. What was it? Their first thought was that it was a message intended for us, or maybe an interstellar navigation and timing beacon for spacecraft that ply the space between the stars. They even gave it, among themselves at Cambridge University, the wry designation LGM-1 - LGM standing for Little Green Men.
However, they wer...Designated LGM-1 for "Little Green Men" because it gave off a repeating radio signal.
Commercial Culture is Full of Misdirections and Evasions
T.H. Huxley's formulation was
The foundation of morality is to . . . give up pretending to believe that for which there is no evidence, and repeating unintelligible propositions about things beyond the possibilities of knowledge.
Clement, Hume, Paine and Huxley were all talking about religion. But much of what they wrote has more general applications - for example to the pervasive background importunings of our commercial civilization: there is a class of aspirin commercials in which acto...Carl Sagan reviews the silly rhetoric in medicine commercials.
Chinese Women Stave Off Death to Perform their Ceremonial...
But there's something more: the Harvest Moon Festival is an important holiday in traditional Chinese communities in America. In the week preceding the festival, the death rate in the community is found to fall by 35 per cent. In the following week the death rate jumps by 35 per cent. Control groups of non-Chinese show no such effect. You might think that suicides are responsible, but only deaths from natural causes are counted. You might think that stress or overeating might account for it, b...Before the Harvest Moon festival, deaths drop off, but surge afterwards.
Logical Fallacies
In addition to teaching us what to do when evaluating a claim to knowledge, any good baloney detection kit must also teach us what not to do. It helps us recognize the most common and perilous fallacies of logic and rhetoric. Many good examples can be found in religion and politics, because their practitioners are so often obliged to justify two contradictory propositions. Among these fallacies are:
Ad hominem - Latin for 'to the man', attacking the arguer and not the argument (e.g., the Reve...A list of some logical fallacies which scientists must beware.
Humility is a Scientific Virtue
...science is part and parcel humility. Scientists do not seek to impose their needs and wants on Nature, but instead humbly interrogate Nature and take seriously what they find. We are aware that revered scientists have been wrong. We understand human imperfection. We insist on independent and - to the extent possible - quantitative verification of proposed tenets of belief. We are constantly prodding, challenging, seeking contradictions or small, persistent residual errors, proposing altern...Scientists must approach nature with open eyes and recognize human imperfection.
Herbal Remedies from Tribes Still Involve Science
Quinine comes from an infusion of the bark of a particular tree from the Amazon rain forest. How did pre-modern people ever discover that a tea made from this tree, of all the plants in the forest, would relieve the symptoms of malaria? They must have tried every tree and every plant - roots, stems, bark, leaves - tried chewing on them, mashing them up, making an infusion. This constitutes a massive set of scientific experiments continuing over generations, experiments that moreover could not...The experimental method was there, even if they did not know they were using it.
History VS Science
History generally is written by the victors to justify their actions, to arouse patriotic fervour, and to suppress the legitimate claims of the vanquished. When no overwhelming victory takes place, each side writes self-promotional accounts of what really happened. English histories castigated the French, and vice versa; US histories until very recently ignored the de facto policies of lebensraum and genocide toward Native Americans; Japanese histories of the events leading to World War II mi...History is written from a perspective, science tries to reconstruct events.
It's Okay for Scientists to Have Biases
...why does it matter what biases and emotional predispositions scientists bring to their studies, so long as they are scrupulously honest and other people with different proclivities check their results? Presumably no one would argue that the conservative view on the sum of fourteen and twenty-seven differs from the liberal view, or that the mathematical function that is its own derivative is the exponential in the northern hemisphere but some other function in the southern. Any regular peri...Because facts are the same despite our leanings.
Natural Laws are Universal
...the order of the Universe is not an
assumption; it's an observed fact. We detect the light from distant
quasars only because the laws of electromagnetism are the same
ten billion light years away as here. The spectra of those quasars
are recognizable only because the same chemical elements are
present there as here, and because the same laws of quantum
mechanics apply. The motion of galaxies around one another
follows familiar Newtonian gravity. Gravitational lenses and
binary pulsar spin-...The laws of nature are comprehensible and the same across the Universe.
Contradictory Aphorism and Biblical Texts
What realm of human endeavour is not morally ambiguous? Even
folk institutions that purport to give us advice on behaviour and
ethics seem fraught with contradictions. Consider aphorisms -
haste makes waste; yes, but a stitch in time saves nine. Better safe
than sorry; but nothing ventured, nothing gained. Where there's
smoke, there's fire; but you can't tell a book by its cover. A penny
saved is a penny earned; but you can't take it with you. He who
hesitates is lost; but fools rush in where...A strong argument for why we should do away with them.
We Must Apply the Scientific Method to Ourselves
If it is to be applied consistently, science imposes, in exchange for
its manifold gifts, a certain onerous burden: we are enjoined, no
matter how uncomfortable it might be, to consider ourselves and
our cultural institutions scientifically and not to accept uncritically
whatever we're told; to surmount as best we can our hopes,
conceits and unexamined beliefs; to view ourselves as we really
are. Can we conscientiously and courageously follow planetary
motion or bacterial genetics wherever th...Skepticism must extend to ourselves, our culture, and our institutions.
Scientific Scrutiny is Difficult to Bear
Even when it's applied sensitively,
scientific scepticism may come across as arrogant, dogmatic,
heartless and dismissive of the feelings and deeply held beliefs of
others. And, it must be said, some scientists and dedicated
sceptics apply this tool as a blunt instrument, with little finesse.
Sometimes it looks as if the sceptical conclusion came first, that
contentions were dismissed before, not after, the evidence was
examined. All of us cherish our beliefs. They are, to a degree,
self-defi...It comes across as arrogant and insensitive.
Supernatural Concepts Worthy of Further Inquiry
At
the time of writing there are three claims in the ESP field which, in
my opinion, deserve serious study: (1) that by thought alone
humans can (barely) affect random number generators in computers;
(2) that people under mild sensory deprivation can receive
thoughts or images 'projected' at them; and (3) that young
children sometimes report the details of a previous life, which
upon checking turn out to be accurate and which they could not
have known about in any other way than reincarnation...Carl Sagan lists three seemingly supernatural concepts worth investigation.
Skepticism and Wonder.
Both scepticism and wonder are skills that need honing and
practice. Their harmonious marriage within the mind of every
schoolchild ought to be a principal goal of public education. I'd
love to see such a domestic felicity portrayed in the media,
television especially: a community of people really working the
mix - full of wonder, generously open to every notion, dismissing
nothing except for good reason, but at the same time, and as
second nature, demanding stringent standards of evidence; a...We must cultivate both virtues.
We Must Interrogate Nature
Greek mathematics was a brilliant step forward. Greek science,
on the other hand - its first steps rudimentary and often uninformed
by experiment - was riddled with error. Despite the fact
that we cannot see in pitch darkness, they believed that vision
depends on a kind of radar that emanates from the eye, bounces
off what we're seeing, and returns to the eye. (Nevertheless, they
made substantial progress in optics.) Despite the obvious resemblance
of children to their mothers, they believed ...Being non-superstitious isn't enough.
A Novel Way to Teach the Constitution
Daniel Kunitz is a friend of mine from
college. He's spent his life as an innovative junior and senior high
school social sciences teacher. Want the students to understand
the Constitution of the United States? You could have them read
it, Article by Article, and then discuss it in class but, sadly, this
will put most of them to sleep. Or you could try the Kunitz
method: you forbid the students to read the Constitution. Instead,
you assign them, two for each state, to attend a Constitutional
...Have the children play delegates to the convention and have them produce their own Constitution.
The Hypocrisy of Elitism
At the same time, children with special abilities and skills need
to be nourished and encouraged. They are a national treasure.
Challenging programmes for the 'gifted' are sometimes decried as
'elitism'. Why aren't intensive practice sessions for varsity football,
baseball and basketball players and interschool competition
deemed elitism? After all, only the most gifted athletes participate.
There is a self-defeating double-standard at work here,
nationwide.Why aren't sports considered elitist?
Books Changed Everything
For 99 per cent of the tenure of humans on earth, nobody could
read or write. The great invention had not yet been made. Except
for first-hand experience, almost everything we knew was passed
on by word of mouth. As in the game of 'Chinese Whispers', over
tens and hundreds of generations, information would slowly be
distorted and lost.
Books changed all that. Books, purchasable at low cost, permit
us to interrogate the past with high accuracy; to tap the wisdom of
our species; to understand ...They made it possible to interrogate the past, see other view points, and communication across time.
Intelligence and Nutrition
Ann Druyan and I come from families that knew grinding
poverty. But our parents were passionate readers. One of our
grandmothers learned to read because her father, a subsistence
farmer, traded a sack of onions to an itinerant teacher. She read
for the next hundred years. Our parents had personal hygiene and
the germ theory of disease drummed into them by the New York
Public Schools. They followed prescriptions on childhood nutrition
recommended by the US Department of Agriculture as if they ...When confronted with malnutrition, the body deprives the brain of development.
Scooby Doo is a Show About Skeptics
A series called 'The X Files', which pays lip-service to sceptical
examination of the paranormal, is skewed heavily towards the
reality of alien abductions, strange powers and government complicity
in covering up just about everything interesting. Almost
never does the paranormal claim turn out to be a hoax or a
psychological aberration or a misunderstanding of the natural
world. Much closer to reality, as well as a much greater public
service, would be an adult series ('Scooby Doo' does it f...It is the exact opposite of the X-Files.
1939 New York World's Fair and a Future Through Science
The 1939 New York World's Fair - that so transfixed me as a
small visitor from darkest Brooklyn - was about 'The World
of Tomorrow'. Merely by adopting such a motif, it promised that
there would be a world of tomorrow, and the most casual glance
affirmed that it would be better than the world of 1939. Although
the nuance wholly passed me by, many people longed for such a
reassurance on the eve of the most brutal and calamitous war in
human history. I knew at least that I would be growing up i...Carl Sagan describes seeing the World's Fair as a youth.
Science is a Multi-National Culture
Ethnocentrism, xenophobia and nationalism are these days rife in
many parts of the world. Government repression of unpopular
views is still widespread. False or misleading memories are
inculcated. For the defenders of such attitudes, science is disturbing.
It claims access to truths that are largely independent of
ethnic or cultural biases. By its very nature, science transcends
national boundaries. Put scientists working in the same field of
study together in a room and even if they share no...Scientists will find a way to work together on a common subject of investigation despite their cultural differences.
The Founding Fathers were Scientists
Declaration of Independence puts it - 'the laws of nature and of
nature's GOD'. Dr Benjamin Franklin was revered in Europe and
America as the founder of the new field of electrical physics. At
the Constitutional Convention of 1789 John Adams repeatedly
appealed to the analogy of mechanical balance in machines;
others to William Harvey's discovery of the circulation of the
blood. Late in life Adams wrote, 'All mankind are chemists from
their cradles to their graves . . . The Material Universe ...Scholars of the enlightenment.
Thomas Jefferson was a Scientist
Thomas Jefferson was a scientist. That's how he described himself.
When you visit his home at Monticello, Virginia, the moment you enter its portals you find ample evidence of his scientific
interests - not just in his immense and varied library, but in
copying machines, automatic doors, telescopes and other instruments,
some at the cutting edge of early nineteenth-century technology.
Some he invented, some he copied, some he purchased. He
compared the plants and animals in America with Euro...He called himself such and took delight in technology.
Understanding Other Points of View
A few weeks before the debates, however, they are
informed that it is the task of each to present the point of view of
the opponent in a way that's satisfactory to the opponent - so the
opponent will say, 'Yes, that's a fair presentation of my views.' In
the joint written debate they explore their differences, but also
how the debate process has helped them better to understand the
opposing point of view.People in debates should be required to articulate the opposing viewpoint to their opponent's satisfaction.
William Tyndale Translates the New Testament into English
In the sixteenth century the scholar William Tyndale had the temerity to contemplate translating the New Testament into English. But if people could actually read the Bible in their own language instead of arcane Latin, they could form their own, independent religious views. They might conceive of their own private unintermediated line to God. This was a challenge to the job security of Roman Catholic priests. When Tyndale tried to publish his translation, he was hounded and pursued all over ......and was met with stiff resistance by the church.
Scientists Must Practice Communicating Science
Why should it be hard for scientists to get science across? Some
scientists, including some very good ones, tell me they'd love to
popularize, but feel they lack talent in this area. Knowing and
explaining, they say, are not the same thing. What's the secret?
There's only one, I think: don't talk to the general audience as
you would to your scientific colleagues. There are terms that
convey your meaning instantly and accurately to fellow experts.
You may parse these phrases every day in your...And apply the scientific method to their efforts to determine what works.
How Science is Different from Any Other Human Enterprise
Science is different from many another human enterprise - not, of course, in its practitioners' being influenced by the culture they grew up in, nor in sometimes being right and sometimes wrong (which are common to every human activity), but in its passion for framing testable hypotheses, in its search for definitive experiments that confirm or deny ideas, in the vigour of its substantive debate, and in its willingness to abandon ideas that have been found wanting. If we were not aware of our...For its need to form testable hypotheses.
The Good Science Does
• Despite plentiful opportunities for misuse, science can be the golden road out of poverty and backwardness for emerging nations. It makes national economies and the global civilization run. Many nations understand this. It is why so many graduate students in science and engineering at American graduate schools - still the best in the world - are from other countries. The corollary, one that the United States sometimes fails to grasp, is that abandoning science is the road back into pover...Science is a road out of poverty for nations, warns us of impending dangers, explains our origins, and encourages democracy.
Absolute Certainty Will Always Elude Us
There is much that science doesn't understand, many mysteries still to be resolved. In a Universe tens of billions of light years across and some ten or fifteen billion years old, this may be the case forever. We are constantly stumbling on surprises. Yet some New Age and religious writers assert that scientists believe that 'what they find is all there is'. Scientists may reject mystic revelations for which there is no evidence except somebody's say-so, but they hardly believe their knowledg...Science has a built-in error-detection mechanism.
Science is a Profound Source of Spirituality
In its encounter with Nature, science invariably elicits a sense of reverence and awe. The very act of understanding is a celebration of joining, merging, even if on a very modest scale, with the magnificence of the Cosmos. And the cumulative worldwide build-up of knowledge over time converts science into something only a littles short of a trans-national, trans-generational meta-mind.
[...]
Science is not only compatible with spirituality; it is a profound source of spirituality. When we r...Science instills a sense of awe and reverence, much like religion instills in its followers.
Skepticism is Not Enough
As I've tried to stress, at the heart of science is an essential
balance between two seemingly contradictory attitudes - an
openness to new ideas, no matter how bizarre or counterintuitive,
and the most ruthlessly sceptical scrutiny of all ideas, old and new.
This is how deep truths are winnowed from deep nonsense. The
collective enterprise of creative thinking and sceptical thinking,
working together, keeps the field on track. Those two seemingly
contradictory attitudes are, though, in some ...We must also be open to new and challenging ideas.
Wonder of the Natural World
Sun's nature as revealed by modern science
far more wonderful: no mere angels or gold coin, but an enormous
sphere into which a million Earths could be packed, in the core of
which the hidden nuclei of atoms are being jammed together,
hydrogen transfigured into helium, the energy latent in hydrogen
for billions of years released, the Earth and other planets warmed
and lit thereby, and the same process repeated four hundred
billion times elsewhere in the Milky Way galaxy?
The blueprints, deta...Scientific explanations are so much more enchanting than supernatural.
Science is an Equal-Opportunity Critic
Again, the reason science works so well is partly that built-in error-correcting machinery. There are no forbidden questions in science, no matters too sensitive or delicate to be probed, no sacred truths. That openness to new ideas, combined with the most rigorous, sceptical scrutiny of all ideas, sifts the wheat from the chaff. It makes no difference how smart, august or beloved you are. You must prove your case in the face of determined, expert criticism. Diversity and debate are valued. O...Science's error-correcting mechanisms hit everyone equally, but all ideas are welcome for scrutiny.
The Law Strives for an Impossible Standard of Accuracy
When we are asked to swear in courts of law that we will tell
'the truth, the whole truth, and nothing but the truth', we
are being asked the impossible. It is simply beyond our powers.
Our memories are fallible; even scientific truth is merely an
approximation; and we are ignorant about nearly all of the
Universe. Nevertheless, a life may depend on our testimony. To
swear to tell the truth, the whole truth, and nothing but the truth
to the limit of our abilities is a fair request. Without th...When it asks us to swear to tell the whole truth.
How Teenagers Lose Interest in Science
Every now and then, I'm lucky enough to teach a kindergarten
or first-grade class. Many of these children are natural-born
scientists - although heavy on the wonder side and light on
scepticism. They're curious, intellectually vigorous. Provocative
and insightful questions bubble out of them. They exhibit enormous
enthusiasm. I'm asked follow-up questions. They've never
heard of the notion of a 'dumb question'.
But when I talk to high school seniors, I find something
different. They memorize...Young children have an interest in science, but it is driven out of them by the time they enter high school.
The Baloney Detection Kit
In science we may start with experimental results, data, observations, measurements, 'facts'. We invent, if we can, a rich array of possible explanations and systematically confront each explanation with the facts. In the course of their training, scientists are equipped with a baloney detection kit. The kit is brought out as a matter of course whenever new ideas are offered for consideration. If the new idea survives examination by the tools in our kit, we grant it warm, although tentative, ...Bullet points for the baloney detection kit according to Carl Sagan.