What science is and how and why it works

What science is and how and why it works

If you cherry-pick scientific truths to serve cultural, economic, religious or political objectives, you undermine the foundations of an informed democracy.

Science distinguishes itself from all other branches of human pursuit by its power to probe and understand the behavior of nature on a level that allows us to predict with accuracy, if not control, the outcomes of events in the natural world. Science especially enhances our health, wealth and security, which is greater today for more people on Earth than at any other time in human history.

читать дальше The scientific method, which underpins these achievements, can be summarized in one sentence, which is all about objectivity:

Do whatever it takes to avoid fooling yourself into thinking something is true that is not, or that something is not true that is.

This approach to knowing did not take root until early in the 17th century, shortly after the inventions of both the microscope and the telescope. The astronomer Galileo and philosopher Sir Francis Bacon agreed: conduct experiments to test your hypothesis and allocate your confidence in proportion to the strength of your evidence. Since then, we would further learn not to claim knowledge of a newly discovered truth until multiple researchers, and ultimately the majority of researchers, obtain results consistent with one another.

This code of conduct carries remarkable consequences. There’s no law against publishing wrong or biased results. But the cost to you for doing so is high. If your research is re-checked by colleagues, and nobody can duplicate your findings, the integrity of your future research will be held suspect. If you commit outright fraud, such as knowingly faking data, and subsequent researchers on the subject uncover this, the revelation will end your career.

It’s that simple.

This internal, self-regulating system within science may be unique among professions, and it does not require the public or the press or politicians to make it work. But watching the machinery operate may nonetheless fascinate you. Just observe the flow of research papers that grace the pages of peer reviewed scientific journals. This breeding ground of discovery is also, on occasion, a battlefield where scientific controversy is laid bare.

Once an objective truth is established by these methods, it is not later found to be false. We will not be revisiting the question of whether Earth is round; whether the sun is hot; whether humans and chimps share more than 98 percent identical DNA; or whether the air we breathe is 78 percent nitrogen.

Objective truths exist outside of your perception of reality, such as the value of pi; E= m c 2; Earth’s rate of rotation; and that carbon dioxide and methane are greenhouse gases. These statements can be verified by anybody, at any time, and at any place. And they are true, whether or not you believe in them.

Meanwhile, personal truths are what you may hold dear, but have no real way of convincing others who disagree, except by heated argument, coercion or by force. These are the foundations of most people’s opinions. Is Jesus your savior? Is Mohammad God’s last prophet on Earth? Should the government support poor people? Is Beyoncé a cultural queen? Kirk or Picard? Differences in opinion define the cultural diversity of a nation, and should be cherished in any free society. You don’t have to like gay marriage. Nobody will ever force you to gay-marry. But to create a law preventing fellow citizens from doing so is to force your personal truths on others. Political attempts to require that others share your personal truths are, in their limit, dictatorships.

Note further that in science, conformity is anathema to success. The persistent accusations that we are all trying to agree with one another is laughable to scientists attempting to advance their careers. The best way to get famous in your own lifetime is to pose an idea that is counter to prevailing research and which ultimately earns a consistency of observations and experiment. This ensures healthy disagreement at all times while working on the bleeding edge of discovery.

Today, other government agencies with scientific missions serve similar purpose, including NASA, which explores space and aeronautics; NIST, which explores standards of scientific measurement, on which all other measurements are based; DOE, which explores energy in all usable forms; and NOAA, which explores Earth’s weather and climate.

These centers of research, as well as other trusted sources of published science, can empower politicians in ways that lead to enlightened and informed governance. But this won’t happen until the people in charge, and the people who vote for them, come to understand how and why science works.

Neil deGrasse Tyson, author of Space Chronicles: Facing the Ultimate Frontier, is an astrophysicist with the American Museum of Natural History. His radio show StarTalk became the first ever science-based talk show on television, now in its second season with National Geographic Channel.

What is science?

As a physicist, I routinely receive (and try to answer) questions from friends, acquaintances, students, and other members of the general public that are indicative of a pandemic of confusion about science: Questions such as «why should we wear masks?»; questions pertaining to reading and interpreting COVID data, and of course questions pertaining to hydroxychlorquine’s effectiveness.

These questions (and many more) provoke deeper questions:

Endless poorly-designed Youtube videos also regularly sent to me which purport to «scientifically» «prove» or «disprove» something (e.g. lower oxygen levels when wearing mask and other nonsensical points) force me ask: «who taught this person physics?» or «have they ever taken a science course?» Such questions are merely symptomatic of widespread scientific illiteracy among the general public despite the fact that we live in a world dominated by science. And sadly, many people who don’t know better take these claims seriously and try to heed them (e.g. inhaling Lysol or using hair dryers to kill the virus in vivo) with dangerous, life-threatening consequences.

Despite, this desperate dearth of information and understanding of critical science-related issues in the general public, scientists (including doctors) are being censored. This is killing science which thrives on healthy debate and discussion to understand phenomena, weigh evidence and find solutions. Similar to public debate, you have the «right» to be «wrong» in scientific discussions. This is how scientists work out problems by not being afraid to try different approaches some of which may end up wrong. But we all learn from their missteps and ultimately find a solution as a result.

Unfortunately, as we hear less and less from real scientists/doctors but instead from nonscientists/college dropouts such as Bill Gates in the media, we are witnessing a tragic era in human history where we have ubiquitous unchecked and erroneous information propagating/circulating at the speed of light all over the world and no one believes or trusts anyone (including scientists) anymore. This has led to massive confusion amidst our leaders and the public during the most recent pandemic resulting in the unnecessary loss of lives, exacerbation of human suffering, and prolonging of the current crisis.

As a consequence of this misunderstanding of science and its critical role in our society, political leaders have dramatically curtailed scientific funding here in the US. These cuts come at a critical time where we need to rally and support scientists to solve the many pending and ongoing crises in the world such as climate change, pandemics, poisoning of our ecosphere and dwindling of our natural resources (e.g. fresh water) all of which threaten not only our way of life but much of life on this planet.

To better understand science, we must first recognize that we exist in a universe dominated by the Heisenberg uncertainty principle of quantum mechanics: error has been literally inextricably built into our universe. Quantum mechanics is based on this uncertainty: statistics/probability at the atomic and subatomic level. Though many expect that scientific theories are «exact,» there is in fact no such thing just as there is no such thing as a zero-dimensional point in our 4-dimensional universe. It is an abstract mathematical construct from geometry. All we can do is to try to reduce uncertainty/error but it will completely never go away.

Theories are only as good as the accuracy and precision of the measurements conducted to verify them. Scientific hypotheses are often hotly debated and require many years, decades and even centuries to fully «settle.» Only through many experiments reproduced in many different laboratories can hypotheses/theories be tested and accepted, improving our understand of this amazing world that we live.

In the case of medicine, there are many factors/variables that must be considered when doctors develop strategies for treating patients: weight, age, race, gender, blood type, use of other medications (that may interact with proposed medications and exacerbate certain conditions), general state of health, among many others. Thus, what may help one patient may hurt another or do nothing for a third. This is why it is absolutely critical for doctors to share their various experiences in treating patients to compare data and modify approaches (based on this shared information).

Unlike in «purer» scientific fields such as physics and chemistry where experiments can be designed, improved with high precision, accuracy and forethought, doctors have a more challenging task trying to help suffering patients in real time and «in the field» where time is critical, patients may suddenly die, and each patient may have different reactions to drugs/therapies. They must problem solve using the scientific method «on the fly.»

Though scientists try their best to minimize variables and interpolate their data with minimum uncertainty as much as humanly possible, there is always error in their data and often, mistakes are made either in the garnering or interpretation of data. This is how science grows as more experiments are conducted and, with improvements in technology (e.g. the MRI, X-ray, gamma-rays, fiber optics, PET scans, etc.), we can do more accurate and more deeply probing experiments to seek the underlying causes of natural phenomena (such as illness). As part of this growing process, scientists try to regularly publish their results and actively debate these results. Just because a study has been peer-reviewed doesn’t imply that it is flawless. It just means that another expert or experts examined the study and didn’t find any blatantly egregious errors either in the data collection or interpretation of the data.

Absolutely not! This is why censoring scientists is absolutely wrong. Let them speak out and discuss their opinions. The more the better. Science is our best hope to reduce our uncertainty (not completely abolish it) without which, we would still be in the Dark Ages. It is best suited to resolve critical problems associated with our existence in the natural world because science (natural philosophy) is predicated on studying the natural world as an unbiased observer and interpreting it; developing theories about how this world works. The key problem today is that science is not always being used for the public good but rather to enrich a small group of human «elites» at the expense of everyone else. This effort to control science and corral scientists into a «mainstream» group think is very dangerous.

One of my former professors (Nobel Laureate Kip Thorne from Caltech) made various bets with Stephen Hawking pertaining to black holes which ran for decades indicating that long standing issues may take decades to resolve.

Humanity is in deep crisis. We have never before had such an ability to destroy so much of life on this planet due to our tremendous advances in science. As Nikola Tesla once said:

«Science is useless unless it is in the service of all humanity.»

More than ever, we need scientists and the public jointly engaged in this discussion.

The Prairie Ecologist

Essays, photos, and discussion about prairie ecology, restoration, and management

How Science Works and Why It Matters

As a scientist and science writer, I’m concerned about the way science is perceived by the public. I think some big misunderstandings about how science works are creating distrust and dismissal of important scientific findings. That’s a huge problem, and I’d like to try to help fix it.

Let’s start with this: Science is a process that helps us understand and explain the world around us. That process relies on repeated observations and experiments that continuously change our understanding of how things work.

Scientists often come up with results that conflict with those of other scientists. That doesn’t indicate that something is wrong; it’s exactly how science is supposed to work. When scientists disagree about something, more scientists get involved and keep testing ideas until a consensus starts to emerge. Even at that point, ideas continue to be tested, and either gain more acceptance (because of more supporting evidence) or weaken (because conflicting results are found).

There is no endpoint in science. Instead, ideas move through various steps of acceptance, depending upon how much evidence is collected to support them. You can read much more about how the process works here.

We are lucky to have easy access to immense amounts of information today. However, it can be be very difficult to know which statements are supported by good science and which are just opinions amplified by people with an agenda and a prominent platform. Today’s world, for example, still includes people who earnestly believe the earth is flat, despite overwhelming evidence to the contrary.

Media coverage of science often increases confusion. How many times have you heard or read a media story about how a particular substance either cures or causes cancer? In most cases, the scientist being interviewed tries to explain that their work is just one step in a long process of evidence gathering and doesn’t prove anything by itself. That scientist might as well be talking to an empty void. The headline has already told the story and pundits are shaking their heads and complaining about how scientists can’t ever agree. (Please see paragraph three above.)

Unfortunately, confusion about how science works means the public often doesn’t pay attention when scientists actually do agree on things. Loud voices can easily sway public opinion on important topics because it’s hard to know who to believe. Often, we believe those who say things we want to be true.

Let me ask you three questions:

Do you believe that childhood immunizations are safe and effective?

Do you believe that rapid climate change is occurring as a result of human activity?

Do you believe that food derived from products containing Genetically Modified Organisms (GMOs) is safe for human consumption?

The scientific community has clearly and strongly stated that the answer to all three of these questions should be yes. Despite that, many people will answer yes to one or two of these questions, but not all three. If you’re one of those people, I have another question for you.

If you trust the scientific community and the scientific process on one or two of these topics, why not on all of them?

This post is not about vaccines, global warming or GMOs. I’m not trying to tell you what to think. Instead, I’m inviting you TO think.

If you’re a scientist, are you spending enough time thinking about how to talk to a public that is skeptical of science? Being right isn’t enough when there are louder voices shouting that you’re wrong. How do you expect the public to find the real story when your results are hidden in subscription-only journals and written in technical jargon-filled language? What can you, personally, do to help others understand what science is, why it’s important, and what it can tell us?

If you’re someone who believes the science on some topics, but not others, are you comfortable with the reasons behind that? Do you think science has been polluted by money and agendas, or do you think money and agendas are trying to discredit science? Have you spent enough time reading articles that contradict your position and evaluating the credentials of those on each side? Is it possible that long-held beliefs are preventing you from looking at evidence with clear eyes?

While individual scientists may have biases, the scientific process has no agenda other than discovery. Scientists are strongly incentivized to go against the grain – both employers and journal publishers get most excited by research that contradicts mainstream ideas. Because of that, ideas that gain overwhelming scientific consensus should be given extra credibility because they have withstood an onslaught of researchers trying to tear them down.

Can scientists be wrong? Yes, of course – scientists are wrong all the time, and they argue back and forth in pursuit of knowledge. That’s a good thing. Saying that science is untrustworthy because not all scientists agree is like saying that we shouldn’t eat fruit because some of it isn’t ripe.

We desperately need credible science in order to survive and thrive on this earth. Sustaining that credibility is the responsibility of both scientists and the public. Scientists must provide accessible and clear information about what they’re learning, but the public also needs to be a receptive and discerning audience.

There is a torrent of news and data coming at us every day. As you process that information, think like a scientist. Question everything, including your own assumptions. Form an opinion and then test it by looking for information that might disprove it. Most importantly, even when you’re confident in your viewpoint, keep your mind open to new evidence and alternate perspectives.

Finally, remember that science is a continual and cumulative process. Conflicting research results don’t indicate weakness, they drive scientists to keep looking for answers. Science shouldn’t lose your trust when scientists disagree. Instead, science should earn your trust when scientists reach consensus.

Special thanks to Anna Helzer for helpful feedback on this piece.

What is science—and why does it matter?

Q uestions, questions. Why this. Why that. How does this. How come that. If you’re the sort of person who’s always seeking answers, maybe you’re a scientist of sorts without knowing it? Knowing, in fact, is what science is all about: the term «science» is linked to Latin words like scire («to know») and scientia («knowledge»), so it’s the process of finding answers to how and why the world works as it does. From why the sky’s blue to how your nose smells, from why boats float on water to what makes us happy or sad, you can seek answers—and enlightenment— in all kinds of ways: you can ask your friends their opinion, pray to a god, paint pictures, write songs, or meditate on a mountain, scratching your head. What makes science so different from these other ways of thinking about things—and why does it matter?

Photo: Experiments are the «fuel» of science: they provide the evidence that confirms or disproves our ideas (hypotheses and theories) of how the world works. Photo courtesy of NASA Ames Research Center.

Contents

What is science?

What makes science different is that it’s a very systematic way of building up knowledge. It uses logical thinking to explain why things work or how things happen based on evidence gathered through observation and experiment. Slowly and surely, science comes up with coherent explanations called theories that mesh with bigger theories to make ever more comprehensive accounts of what’s going on around us. So, for example, Isaac Newton’s comprehensive, «universal» theory of gravity was built on smaller theories like Galileo’s observations of how falling objects hurtle toward Earth and Johannes Kepler’s ideas about the planets sweeping through space, themselves based on earlier science dating back to ancient times. Newton’s ideas, in turn, became part of a wider explanation of gravity, known as the general theory of relativity, which Albert Einstein put forward in the early 20th century. Science is a jigsaw puzzle, the theories are the pieces, and as different theories gradually lock together, they give us an ever-expanding picture of how our world works.

The scientific method

“ The important thing is not to stop questioning. ”

Why’s the sky blue? If you don’t know the actual explanation, you could probably guess at all sorts of answers—and so could everyone else. If we just asked people what they thought, we could easily end up with 50 or 500 possible accounts. How do we figure out which of these is the right one?

Scientists use an approach called the scientific method. First, they observe or measure something (the sky being blue, for example) very carefully and systematically, which is known as gathering data. (When is it blue? Precisely what shade of blue? Is it ever other colors? When?) From this, they come up with a tentative, logical explanation known as a hypothesis. (It could be something like: the sky is blue because there’s water in the air.) The hypothesis should suggest ways in which it can be tested, which are known as experiments. (Is the sky blue on cloudy days, when there’s apparently more water in the sky, or dry days, when it’s sunnier?) By carrying out experiments, a scientist can test a hypothesis to see if it’s a good explanation that accounts for all the evidence.

Photo: Which of Earth’s many lifeforms can survive on other planets or in space stations? It’s something we need to test with experiments like this one, which looks at how different genes are turned «on» or «off» in space. Photo courtesy of NASA.

Although experiments can be quick and simple, they can also be intricate and complex. Most experiments compare a situation where we’ve deliberately changed something (say, doing more exercise to see if we feel better) with another situation where we haven’t. That’s called a controlled experiment and it allows us to see whether the thing we change makes any difference. (We can do other experiments that change other things, one at a time, and see what difference that makes instead.) Experiments that come up with mathematical results also have to prove that those results couldn’t have happened purely by chance. There are ways of testing experimental data using math and if the data is better than a chance result, we say it’s statistically significant.

If a hypothesis can’t be tested by experiment, it’s usually rejected as bad science from the start. So if your idea of why the sky is blue is that Martians got out their paint pots when you weren’t looking, that’s essentially untestable: there’s no evidence and no obvious way of getting any, so the hypothesis is a non-starter. That doesn’t mean a hypothesis has to be tested immediately: sometimes it takes quite a while to devise just the right experiment. Albert Einstein first put forward his general theory of relativity in 1915. But he had to wait four years before another physicist, Sir Arthur Eddington, was able to confirm it, with the help of a famous solar eclipse.

“ Science is a method to keep yourself from kidding yourself. ”

Why is evidence so important to science? Medicine is probably the best example. If you’re sick, you want an effective treatment that makes you better; if you’re dying, you want a cure. It’s perfectly possible that quack cures will sometimes help people get better, either through pure chance or the very intriguing (and very real) placebo effect. But to come up with medical treatments that consistently improve people’s lives, we need to carry out experiments and build up evidence that those treatments really do work, consistently, and in all the different groups of people who might try them; we also need to be sure they don’t do more harm than good. Science stops us falling into the trap of gullibility—of believing specious ideas (things that sound right that are actually wrong). As Edwin Land, the physicist inventor of the Polaroid camera once said: «Science is a method to keep yourself from kidding yourself.»

What is a theory?

If there’s good evidence, a tentative and very fluid hypothesis starts to solidify into a more formal, generally accepted explanation of something, which is called a theory. In other words, a theory is a hypothesis confirmed by experimental evidence or other observations. The more and better the evidence, the stronger the theory—and the more things a theory can explain, the better it is. Importantly, evidence for a theory has to come from more than one person or group: in other words, the results of one team’s work has to be replicated (repeated) by others. Theories also have to be published and discussed by the wider scientific community (usually in reputable scientific journals) in a process known as peer review, which gives other people the opportunity to spot flaws in your theory or the methods you used to test it. If any evidence contradicts a theory, the theory is either wrong or incomplete, which means a better theory is needed. Sometimes wrong theories come from bad experiments that supply incorrect data or other kinds of misleading evidence. It’s important to try to disprove theories («If we see this happening, the theory must be wrong») and not just confirm them («If we see this happening, it agrees with our theory»), though it’s a sign of a good theory if it can be properly defended against criticism.

A good theory will also make predictions that go beyond things scientists have already seen or observed. A great example of this is the Periodic Table, Dmitri Mendeleev’s explanation of how different atoms relate to one another. When he drew up the table, there were various gaps in his diagram that predicted the existence of elements (such as gallium and germanium) that had not yet been discovered. When those elements were discovered later, it helped to confirm Mendeleev’s ideas. (It’s also important to note that Mendeleev’s theory predicted elements that were never found, so it wasn’t a perfect theory.)

Artwork: The Periodic Table is part of a brilliant theory that explains why different chemical elements have similar properties.

Some science is very complex and the process of rigorously testing theories can be even more challenging than devising them in the first place. There could be all kinds of alternative explanations for why certain people, living in a certain place at a certain time, suddenly develop a certain kind of sickness. Is it air pollution from a nearby industrial plant. something in the water. radioactive rocks underground. or just a statistical fluke? It can be very difficult to isolate the single most important variable when there are lots of factors could be responsible.

The best theories—things like the theory of evolution—have «evolved» (if you’ll excuse the pun) over decades or centuries, supported by many different kinds of evidence involving thousands of experiments and studies by many different scientists from all sorts of fields. It can take a long time for an excellent theory like this to be accepted. In much the same way, wrong-headed theories will sometimes take a long time to disappear. For example, it was originally believed that Earth was the center of the universe and the Sun and planets revolved around it. Known as the geocentric theory (literally, «Earth-centered» theory), that was widely accepted in ancient times, but evidence slowly emerged that it was wrong. To get around this, early scientists could simply have thrown that theory away and come up with a totally new one. Instead, what they did was come up with increasingly tortuous fudges to account for the discrepancies. Eventually, scientists like Kepler, Galileo, and Copernicus developed a rival heliocentric theory, in which the Sun sits at the center of things, which is what people believe today. Another commonly believed explanation that lasted a very long time was the miasma theory—the idea that diseases were passed on by bad air. It persisted as a plausible explanation of disease from ancient times right up until the late 19th century, when growing evidence led to a much better explanation known as the germ theory (the idea that bacteria and viruses cause diseases).

Photo: Albert Einstein’s theory of relativity wasn’t just his throwaway «opinion»: it was a explanation designed to account for all the facts Einstein knew about things like light, gravity, and motion. Photo courtesy of US Library of Congress.

It’s important to realize that calling something «a theory» doesn’t mean it’s flaky, speculative, or just an opinion. The theory of evolution is supported by a huge mass of very different evidence and, though there are still gaps in our understanding of how it works, it’s generally accepted as the best explanation of how the modern pattern of humans and other living creatures came to arrive on Earth. In other words, it’s the best explanation for all the facts that we have. Einstein’s original, «special» theory of relativity was also supported by evidence, but there were various things it couldn’t explain. That was why Einstein soon developed a deeper, more comprehensive explanation in the shape of his «general» theory of relativity. This, too, has gaps and is by no means a perfect theory (for example, it’s an ongoing challenge to reconcile Einstein’s ideas with quantum theory, the currently favored explanation of how the atomic world works). Crucially, no scientific theory can ever be proved completely correct: someone could always come up with new evidence tomorrow that disproves it. But that doesn’t mean every theory is automatically suspect. If a theory has been around a long time and it’s supported by a huge body of different evidence (like the theory of evolution), we can be reasonably confident that it’s right. Even so, as the heliocentric theory shows, we can never be complacent: as scientists, our minds should always be open. The key point is that science is a work in progress; it’s like a vast jigsaw puzzle that will never be complete.

“ Some claim that evolution is just a theory, as if it were merely an opinion. The theory of evolution—like the theory of gravity—is a scientific fact. ”

Types of science

If science is a method—a way of building knowledge about the world—that suggests it’s a kind of tool we can apply to all kinds of things. From physics and chemistry to medicine and sociology, scientific methods have been used to study every aspect of our world. Different sciences are very different from one another and range from the highly abstract, mathematical ideas of theoretical physics to the very concrete ideas of medical science, which are firmly grounded in biological observations of how our bodies work.

Photo: Much of space science is applied physics—ordinary physics theories applied to the problems of space travel or living in microgravity. Here, three of NASA’s women scientists are practicing weightlessness in a flotation tank at Marshall Space Flight Center. Photo courtesy of NASA.

There’s no hard distinction between pure and applied science, however. A scientific discovery might seem rather abstract and «pure» initially—like the idea that two different metals can make a frog’s leg twitch. What possible use is that? Sooner or later, however, a finding like that could lead to a highly practical bit of science (a way of making electricity whenever you need it for laboratory experiments)—namely, the invention of the battery. And that, in turn, could lead to all kinds of interesting technological applications. In the same way, applied scientific work designed to develop very practical inventions can often lead to new, «pure» scientific discoveries. Often, pure and applied science weave in and out of one another. Heinrich Hertz’s demonstration of waves in his laboratory led to the very practical science of radio, but it also led to pure research into things like the ionosphere (a part of Earth’s atmosphere that helps to bounce radio signals around our planet).

Science and its rivals

The scientific method—and the fundamental importance of evidence—is the big difference between science and other ways of thinking about our place in the world, including myths, superstitions, art, religion, and things like astrology. You might be a superstitious kind of person who doesn’t walk on the cracks in the pavement, but there’s no evidence that walking on cracks is either bad or good for you in any way—and no obvious mechanism by which it ever might be. Myths and superstitions may be fascinating and fun, but they’re not credible explanations that can compete with science.

Photo: Science tells us plants are green because of the chloroplasts inside them, which capture the Sun’s energy a bit like miniature solar cells. Can religion, art, or myth explain things like this? Osiris, the ancient Egyptian god of agriculture and fertility, had green skin, hinting at a connection with vegetation, but that’s hardly an explanation! Photograph courtesy of NASA.

Science versus religion?

What about religion? It’s perfectly fine to have religious beliefs about why we see colors in the sky or to paint a picture that shows a rainbow forming, but art and religion are a world away from scientific explanations. They might even be based on meticulous observations, but they still lack the logical rigor of scientific theories. You might say «Well, a religious miracle is evidence for [such and such],» but that’s hardly a scientific explanation. Miracles aren’t testable, they’re not repeatable, and they generally have other, more scientific explanations behind them. That’s not to say that religion has no value; the value it has as a coherent belief system, which helps people to live morally good, spiritually enriched, happy and fulfilled lives, is very different from the value of science. You can pray, if you have lung cancer, and it could help you in all kinds of ways—but medical treatments, based on years of evidence-based research, are much more likely to cure you.

Science and art

“ To develop a complete mind: Study the science of art; Study the art of science. Learn how to see. Realize that everything connects to everything else. ”

When people are studying in schools and colleges, they often think of themselves as «arty» or «sciencey,» as though there’s a sharp line between the two. Arts subjects are meant to be more human, creative, poetic, emotional, and romantic; sciences are considered more logical, rational, methodical, prosaic, and perhaps even a bit plodding and boring. Of course, that’s all a matter of opinion: it’s hard to think of anything more human than medicine, for example, which is quintessentially scientific.

It’s never really clear why people want to build high walls between the arts and sciences. A genius like Leonardo da Vinci obviously straddled the divide; modern artists and scientists also work on similar or overlapping problems. You could argue, for example, that, with their pursuit of cubism, artists like Cezanne, Braque, and Picasso were studying very similar problems to scientists like Einstein. Bridget Riley’s op-art clearly has much in common with a branch of psychology called psychophysics (which studies how the eyes and brain perceive light, colors, and patterns). Artist Josef Albers was just as much a scientist of color as Isaac Newton or Thomas Young. Less obviously, a sculptor like Rodin was arguably just as preoccupied with gravity (in his own way) as a scientist like Galileo or Newton.

The very short story of science

How did humans come up with the idea of science? What was wrong with myths, superstitions. and all those earlier, older, and often more magically enchanting ways of explaining? Science, ultimately, turned out to be a more successful intellectual engine for powering civilization. It had better answers and more useful explanations; it soon pulled ahead of the pack.

It’s easy to see why with an example. In hindsight, it’s clear how a growing scientific understanding of electricity and magnetism in the 18th and 19th centuries enabled the development of a superb new way of harnessing, storing, and using energy that’s been revolutionizing our world ever science. By contrast, it’s hard to see how mystical, mythical, religious, or superstitious ways of explaining things like static electricity, lightning, or sparks could ever have spawned such fabulously useful technologies as electric cars or computers. They might be very comforting to people, as self-contained explanations of a kind, but they offer no real value going forward.

Before science

Early civilizations had systematic knowledge—astronomy and math were their strongest suits—but they didn’t have what we now regard as science. People certainly made discoveries—fire, for example—and they came up with world-beating inventions like the wheel and axle. They could see those things were effective, but they didn’t understand how or why (how a fire burst to life or exactly why a wheel made it easier to push a cart). Nor did they appreciate how one discovery could couple with another to make a third that was even more useful (how a fire could be used to drive a wheel—which was the thinking behind steam engines). Early people knew how to extract metals like gold and silver from the Earth and how to refine them, but they didn’t understand the relationship between different elements or the chemistry of how they combine, which is why they got sidetracked by absurd ideas like alchemy. Knowledge, such as it existed, tended to be practical rather than theoretical and very much more fragmented.

Ancient science

Photo: Thales: the ancient Greek father of modern electrical science. Credit: Photographs in the Carol M. Highsmith Archive, courtesy of Library of Congress, Prints and Photographs Division.

Science was really born in ancient times, with the Sumerians, Egyptians, and Greeks like Thales, Pythagoras, Anaximander, Aristotle, Archimedes, and Eratosthenes. Infatuated with logical reasoning and mathematics, they had both qualitative («wordy») and quantitative («numbery») explanations for things. The scientific foundations of physics, botany, zoology, anatomy, physiology, engineering, and medicine were all laid down in ancient times. The Romans who followed the Greeks were, by contrast, more practical and applied scientists, making huge leaps in architecture and engineering.

Dark and Golden science

“ Arabic science throughout its golden age was inextricably linked to religion; indeed, it was driven by the need of early scholars to interpret the Qur’an. ”

Following the collapse of the Roman Empire, scientific progress stalled in the west, in a time known as the Dark Ages, while the baton of progress passed to the Islamic world in a glorious period of science history now known as the Islamic Golden Age. Al-Khwarizmi (who gave his name to algorithms) developed algebra, Avicenna advanced medicine, Alhazen pioneered modern optics, and Al-Jazari developed ingenious machines. In the Arabic world, the best ideas from Egypt, Greece, China, India, and elsewhere fused and burned like the fuel in a modern-day rocket, before drifting back to Europe at the end of the Middle Ages. Science, in the Golden Age, helped to illuminate religion. And from then on, religious and philosophical ideas slowly started to merge with scientific ones thanks to the enlightened open minds of scholars like Peter Abelard, Thomas Aquinas, Hildegard of Bingen, and Roger Bacon.

The science revolution

True science probably began at the point where the world’s best thinkers started to toss aside ancient ideas. Leonardo da Vinci blurred the boundaries between art and science, as never before or science. Another defining figure was Nicolaus Copernicus, who, as we’ve already seen, challenged the long-held (and religiously defended) idea that God’s Earth anchored a «geocentric» Universe. Meanwhile, Belgian Andreas Vesalius published a detailed anatomical textbook superseding the ancient, out-of-date medical ideas of Galen and Avicenna. And Francis Bacon helped to formalize the scientific method.

Copernicus paved the way for Kepler and Galileo, who, in turn, opened the door for Isaac Newton and his insightful theories of gravity, motion, light, and a superb mathematical tool known as calculus (developed in parallel by German polymath Gottfried Leibniz). Meanwhile, Robert Hooke studied plants, animals, and living cells under the microscope, while William Harvey built on Vesalius’s work with a pioneering theory of how blood circulates around our bodies and hugely influential ideas about magnetism. Another Robert, Robert Boyle, kick-started the systematic, experimental study of chemistry.

Artwork: Galileo Galilei—student of motion and gravity, and pioneer of telescopes. Photo courtesy of US Library of Congress.

Modern science

In physics, thanks to a steady stream of pioneers from Benjamin Franklin to Michael Faraday, the 18th and 19th centuries were the age of electricity and energy, a fusion of practical and applied ideas, science spawning technology. Over in chemistry, magical ideas like alchemy (which even Newton had toyed with) gave way to more realistic, systematic explanations based on a gradual understanding of the chemical elements as fundamental building blocks of our world. Two key figures here were Frenchman Antoine Laurent Lavoisier, who figured out the logic of how elements fused together in reactions, and Englishman John Dalton, who sketched out the beginnings of our modern atomic theory (the idea that everything is ultimately made of atoms). Their ideas would help Dmitri Mendeleev to figure out how elements related to one another in a theoretical diagram he drew up known as the Periodic Table.

Meanwhile in biology, a Swedish botanist named Carl Linnaeus studied the similarities and differences between plants and animals and worked out a neat, hierarchical system of classifying species that we still use to this day. A little later, Gregor Mendel pioneered genetics (the idea that plants and animals inherit important characteristics from their parents). The work of Linnaeus and Mendel held the door wide for Charles Darwin and his life-explaining theory of evolution by «natural selection.»

These seeds of modern biology spawned amazing new advances in the 20th century, most notably with Francis Crick and James Watson’s discovery of the structure of DNA in 1953, and Frederick Sanger’s pioneering work on DNA sequencing. But the 20th century saw many other huge advances, from Einstein’s world-bending theory of relativity to Edwin Hubble’s idea of the ever-expanding universe. The biggest, most revolutionary advances arguably came with a much deeper understanding of the atomic theory, with discovery piled upon discovery by such brilliant physicists as Ernest Rutherford, Niels Bohr, Lise Meitner, Enrico Fermi, Richard Feynman, and many others. Practical spin-offs of this work included everything from nuclear power plants to superconductors and supercomputers.

The power of science

Photo: Not all famous scientists are «dead white guys.» African-American scientist George Washington Carver (1864?–1943) was a pioneer of 20th-century biotechnology. Born to parents who were slaves in Missouri, he discovered that he loved learning and worked hard to educate himself. Photo courtesy of US Library of Congress.

How does science work?

Science is a system of knowledge: knowledge about the physical and natural world, knowledge gained through observation and experimentation, knowledge organised systematically. It is knowledge gained using the scientific method, commonly involving a hypothesis that can be proved or disproved, or a question that can be answered. Science-based knowledge is usually subjected to discussion, debate and further examination and review over time, especially as new information becomes available.

This process of testing, contesting and reviewing is what gives scientists confidence in the state of knowledge at a particular time; it is what they use to explain the physical world. The knowledge that we retain and build on (‘systematised knowledge’ ) can explain phenomena robustly.

The scientific method is often thought of as a straightforward process: form a hypothesis, test or try to disprove the hypothesis through experimentation, and then revise the hypothesis. But this view can discount the role of purely observational research and pattern recognition—so-called ‘discovery science’ —and understate the role of analysis and synthesis of concepts.

Scientists do not often use the word ‘proven’ to describe a current level of understanding. This is reserved for the well-tested laws of nature. Science works on the basis that in many areas there will be always more to know. Even an overwhelming body of evidence may be expanded, or modified, as further work is completed and evidence compiled. That body of evidence usually becomes more complete with more work, but is rarely overturned. This is science at work.

The processes of science

Different scientific disciplines approach the task of gathering knowledge in different ways. For example, an astronomer does not have the same opportunity to experiment that a chemist or physicist might have. A neuroscientist has a different approach to medical knowledge from an epidemiologist. There are, however, three main and mutually compatible approaches to gathering scientific knowledge. These are often combined and most scientists will use all three approaches in their research. The knowledge gained is then tested against established understandings, reviewed and contested, all in order to ensure that the new knowledge is robust.

Observation and gathering data are critical for building scientific knowledge. Here, a diver surveys Middleton Reef in Lord Howe Marine Park. Credit: Antonia Cooper / RLS; CC-BY-2.0

Observation

Scientific observation involves the close examination of phenomena. Historically, natural philosophers watched, learned and recorded their observations using only their senses, sometimes assisted by simple instruments. Over time, devices that assist observation have become increasingly sophisticated, ranging, for example, from simple magnifying lenses to scanning electron microscopes that can detect and examine objects at finer resolutions than the human eye, through to radio telescopes that can observe space objects well beyond the limit of visible light and well beyond the visible light spectrum.

Observations are no longer limited to human senses. Technology allows us to gather and record data on any number of physical properties. Such technology ranges from the simple and everyday—such as a thermometer or a rain gauge—to the highly advanced—such as the IceCube neutrino observatory in Antarctica, which detects subatomic particles (neutrinos) that barely interact with other matter. Scientific observation might include identifying gene sequences and comparing them across species, or measuring radio bursts from distant stars, lasers or crystallography to identify the structures of molecules, or large scale observatories to identify subatomic particles.

Image of the IceCube neutrino observatory. Credit: Felipe Pedreros, IceCube/NSF.

Observations need to be meticulously recorded and reported so that they can be compared across time periods, with or against the observations of others, or against benchmarks and standards. Knowledge is drawn from these comparisons.

Scientific disciplines that rely heavily on observations include astronomy, genetics, taxonomy, anatomy and medical science, and subatomic physics.

Experimentation

Experimentation is the deliberate, procedural testing of the physical world. It can be thought of as extending observations by changing aspects of a system to see what effects those changes have. Experiments are carefully designed to ensure that the conclusions drawn are derived directly from the changes made and the observed results. An experimental system is usually designed to retain as much control of the system as possible, so that deliberate changes are under the control of the experimenter and the resulting observations can be assumed to result from those changes.

Again, the methods and results of experiments must be meticulously recorded and reported. Experiments need to be reproducible by others so that their veracity can be tested and results examined.

In experimental disciplines, knowledge is gained by testing hypotheses and exploring different aspects of a system. As the understanding of the various interactions grows, predictions can be made with greater confidence. Systems can then be harnessed in reproducible, reliable ways. In this way, an experimental system becomes an applied technology, as in a medical or engineering device.

Examples of experimental disciplines include chemistry, biochemistry and molecular biology, agricultural science, physics and medical science.

Students building an electronic windmill as part of the Science and Technology Education Leveraging Relevance (STELR) program. Credit: Eamon Gallagher for ATSE

Analysis

The data gathered and recorded from observational and experimental sciences provide insights beyond their immediate context. Scientists can gather and synthesise data from different sources and conduct analyses on the aggregated dataset. Using the greater statistical power of more massive datasets, we can be more confident of the patterns and relationships that we find within them.

The starting dataset does not necessarily need to be a scientific one. For example, medical records used in hospital administration might reveal patterns of disease prevalence, which could lead to knowledge about how those diseases are caused and transmitted.

Analytical disciplines include statistics, epidemiology, atmospheric science, data science, genomics and proteomics.

Conceptualising and testing

All knowledge gained through scientific processes must be contextualised within the current understanding. Science means testing: testing assumptions, testing knowledge, testing boundaries, testing evidence. Regardless of the approach taken or the methods used, a scientist must maintain an essential scepticism, constantly examining their work to ensure it is robust.

Publishing and communication

Scientists usually publish their work as research papers in specialised journals. These provide a record of a discrete piece of work: a set of observations, a series of experiments or a full analysis.

Academic journals have always had an essential role in the quality control of research. Journals do not publish material without analysis and comment by people skilled in the field of the research to be published, a process known as peer review. Reviewers usually remain publicly anonymous to allow comments to be made without fear of repercussion. Based on advice from the reviewers, a paper can be published or not published, or the author can make changes based on the reviewers’ concerns and resubmit to the journal.

Many scientists also archive their work in data and research repositories, to make it available to other researchers. This is mandatory for much of publicly funded research. Such repositories—including preprint servers, for papers that have been submitted but not peer reviewed—are beyond the scope of this article, but provide other opportunities to disseminate work beyond formal journal publication.

Once a paper is published, it is subject to scrutiny by anyone working in the field. Research results can be integrated into other scientists’ research and may be reproduced, analysed and challenged. It is common to publish research that contradicts (or appears to contradict) another paper. By recording and analysing these differences and discrepancies, scientists can identify flaws and errors that need to be corrected. A paper found to have major flaws will be withdrawn, either by the authors or by the journal, with the reasons being outlined. Withdrawal of a paper is seen as a correction of the scientific record—a necessary and appropriate action in certain circumstances, but it is a rare occurrence. Expert peer review usually exposes flaws and misinterpretations prior to publication.

As knowledge grows, newer papers with additional evidence generally take the place of older papers. Older papers remain in the scientific record so that the lines of reasoning that led to the current knowledge can still be traced and understood.

Any given paper is open to challenge. Peer review provides only a certain minimum quality standard and does not raise the research above criticism. Once published, the paper and the data on which it rests can be scrutinised by the wider international scientific community. There is, however, something of a hierarchy of trust: a peer-reviewed paper is considered more reliable than a description of research which has not been reviewed, and a heavily scrutinised and cited paper may be regarded as more reliable (unless the citations point to flawed work) than a less-cited paper.

Other methods can be used to communicate scientific results. Communication papers are short peer-reviewed summaries of research that generally provide results in advance of a full paper. Review articles collect the results of several papers on a particular subject, providing a detailed summary of the available knowledge while citing the original papers. Monographs (books) do the same on a larger scale, addressing a broader branch of knowledge. And models are shared, synthesised collections of data that describe a particular system in detail.

In some fields, it is normal to release papers on preprint servers ahead of peer review and formal publishing. Papers on preprint servers conform to the standards of their discipline and meet academic publishing and format standards, but are not peer reviewed. Publication on these servers allows early community scrutiny and rapid dissemination of results ahead of publication, and provides a record of active research. Papers on preprint servers are often cited, but are treated with the caution owed to research that has not been peer reviewed.

News articles, essays, videos, magazines, websites, social media and other forms of public communication help communicate scientific knowledge to non-specialists. The Australian Academy of Science produces videos and articles for this purpose. Importantly, these are not research publications and are not afforded the same status as peer reviewed research. However, they can provide valuable opportunities for scientists to share their knowledge widely and to encourage an interest in science.

Scientific knowledge is an aggregate: it is not based on any single publication or work, but rather on continual conversation that publishing represents. A scientist can only communicate what they know and understand; the scientific system ensures that knowledge will continue to expand and mature, and that new knowledge will be created.

This article has been produced by the Australian Academy of Science to stimulate discussion. Official position statements of the Academy can be found here.

This feature article from the Australian Academy of Science is part of the ‘Science for Australians’ series where experts are asked to shed light on how science benefits all Australians and how it can be used to inform policy.

The production of ‘Science for Australians’ features are supported by the Academy’s Ian Ross Bequest.