10 Scientific Terms You Might Be Misunderstanding

Main Points

Humans are naturally inquisitive. It's part of who we are to seek patterns and come up with explanations to better understand our surroundings. However, unless we're regularly engaged in scientific research, many of us tend to bend the meanings of scientific terms in our everyday conversations.

Do you have a theory that your car somehow senses when you have extra cash and then requires repairs that are just enough to use it all up? Do you think you have a genetic tendency to get lost because your mother was the same way?

While it may seem harmless to use scientific terms loosely in casual talk, understanding their true meaning in science can really help us make sense of research and articles about important topics like health, the environment, and even the economy.

Have you been boasting about your company's remarkable growth? Do you think your past four summer vacations prove that it always rains when you go to the beach?

You might want to check out our list of 10 scientific terms you're most likely using incorrectly.

10: Evidence

On any given day, we might show a receipt as evidence of a purchase or provide ID as proof of our age or identity. But ask a climate scientist or evolutionary biologist to 'prove' that humans cause global warming or that Darwin's theories are correct, and you're likely to get an eye roll. While the evidence supporting these well-accepted scientific ideas is compelling, most scientists would tell you they aren't in the business of 'proving' anything.

Here's why: Proofs are final. Evolutionary psychologist Satoshi Kanazawa asserts that 'proofs exist only in mathematics and logic' (some might even add whiskey to that list), but not in science. In mathematics, once a proposition is proven, it becomes a theorem. (For instance, the square of the hypotenuse of a right triangle will always equal the sum of the squares of the other two sides. There’s no ambiguity, and no need for Pythagoras to prove it again.)

Science, in contrast, aims to constantly broaden our understanding of the world, operating under the idea that 'any idea, no matter how widely accepted today, could be overturned tomorrow if the evidence justified it' [source: University of California Museum of Paleontology]. With this in mind, nothing in science is ever truly proven.

So where does all that scientific evidence come from? Keep reading to discover the answer.

9: Hypothesis

If you've ever participated in — or assisted your kids with — a science fair project, you likely recall being taught that your hypothesis should be a statement that can be tested and either supported or disproven through experiments. However, in daily conversations, we often use the word 'hypothesis' to mean an educated guess. While not exactly the same, a hypothesis, much like an educated guess, relies on logic, observation, and sometimes intuition. The key difference is that a hypothesis must be testable, and its testing can be repeated.

A hypothesis is essentially a scientist's effort to propose a solution or explanation for an unexplained phenomenon [source: Zimmerman]. As you learned from the first term on our list, in science, a hypothesis is never definitively 'proven' correct; instead, it is supported or contradicted through repeated experiments and observations — which may take decades to confirm.

In the scientific method, a hypothesis represents the very initial step in the process of developing the next term on our list.

8: Theory

If you want to make a scientist's blood boil (figuratively, of course), tell them that evolution (or gravity, for that matter) is "only a theory." In everyday speech, a theory may seem like just a thought, but in science, it's a well-supported system of ideas that holds up against repeated challenges.

Some may attempt to dismiss widely accepted theories of global warming and evolution as mere speculation. However, while a theory can never be "proven" (since we're dealing with science!), it's far beyond mere conjecture. A scientific theory often combines multiple related hypotheses, gaining acceptance only after being rigorously tested and supported through consistent observation and experimentation [source: Zimmerman].

A concept closely tied to a theory is a scientific law. One simple way to distinguish the two is that a law tells us what will happen, while theories aim to explain why it happens. Laws are often framed as mathematical formulas. For instance, Newton's law of gravity predicts what occurs when an object is dropped, but it doesn't explain why. For that, we turn to Einstein's theory of general relativity [source: Krampf].

The next term on our list is a valuable tool for testing a theory — though you probably use it to mean something entirely different.

7: Model

When people talk about a model in everyday life, they’re likely referring to things like fashion, a toy plane, or someone who exemplifies good behavior (like a "model student"). You might even hear the term 'business model' to discuss how a company plans to make money ("Sounds interesting, but what’s their business model?"). But in the world of science, a model is a tool that helps researchers predict how a system is expected to behave.

The term 'model' can take on various meanings depending on the scientific field. In the behavioral sciences, for instance, a model could refer to a set of conditions necessary for behavioral changes to occur. A physical model of the solar system is a basic way to show how the planets revolve around the sun, while a mathematical model is a collection of equations that represent a system. Both economic models and climate models fall under mathematical models, though they aim to predict very different outcomes. In scientific contexts, models are used to test a hypothesis by generating expected outcomes. To focus on specific variables, real-life factors are sometimes excluded [source: University of California Museum of Paleontology].

6: Natural/Organic

Our grocery store shelves are filled with products boasting labels like 'all-natural' and 'organic,' from food and beauty products to cleaning supplies. But what do these terms truly signify? Poison ivy is 'natural,' but you wouldn't want it in your salad — or in your hand lotion, for that matter.

In the U.S., the term 'natural' on food packaging lacks a clear, regulated definition. According to the Food and Drug Administration (FDA), 'It is difficult to define a food product as 'natural' because it has likely been processed and is no longer a direct product of the earth.' That said, the FDA hasn't developed a definition for 'natural' or its variations. Nevertheless, they don't oppose the term's use as long as the product doesn't contain added colors, artificial flavors, or synthetic substances. So, the 'natural' peanut butter you buy might not be any healthier than the 'regular' version.

The term 'organic' is more clearly defined compared to 'natural.' The U.S. Department of Agriculture (USDA) organic label signifies that a product meets a set of specific standards, including being grown without pesticides or synthetic fertilizers [source: Organic.org]. Of course, from a chemical standpoint, all food is organic since 'organic' refers to carbon-based compounds.

The next frequently misused term on our list shifts us from the realms of natural and organic to the debate between nature vs. nurture.

5: Genetic

Have you ever heard of a rare form of cancer or some other uncommon illness and wondered if it was 'genetic'? Most likely, you were asking whether it was inherited from a parent, rather than occurring randomly.

The term genetic simply refers to 'of or relating to genes' [source: Merriam-Webster]. All cancers are, in fact, genetic because they arise from gene mutations, but only 5 to 10 percent are hereditary, meaning they are caused by genetic alterations passed down through generations. The majority—70-80 percent—are classified as sporadic cancers, which result from genetic changes that occur during an individual's lifetime [source: MD AndersonCooper].

4: Exponential

This term is often used, but not always correctly. We frequently hear that a new trend is 'growing exponentially,' or that a booming industry is experiencing 'exponential growth,' or even that one thing is 'exponentially better' than another.

In common usage, exponential has come to signify something extremely large or rapid, but in mathematical terms, exponential growth refers simply to growth that occurs at a rate proportional to the size of what is growing. The rate of growth could be large or small. For example, if our economy grows by 0.1 percent annually, that’s exponential growth, although not particularly striking [source: Safire].

Another misconception is that exponential growth must involve increases by powers of 2, 3, and so on. If we hear that Earth's population is growing exponentially, we might be alarmed by the idea of 49 quintillion people competing for resources. However, exponential growth simply means that the population's growth over a certain period is proportional to its current size. Right now, the estimated growth rate is about 1 percent per year, which translates to an additional 70 million people [source: Annenberg].

The next term on our list also has to do with size.

3: Quantum

A car company may advertise its latest model as representing a 'quantum leap' beyond anything else in its class. However, while the company likely intends to highlight how much better their new sedan is compared to others, the term 'quantum' has an entirely different meaning in physics.

In scientific terms, a quantum is the smallest indivisible unit of energy [source: Rohrer]. Albert Einstein referred to photons as 'quanta of light,' describing them as tiny, discrete particles, and in 1900, physicist Max Planck introduced the concept of quantum in his theory explaining the behavior of subatomic particles like photons and electrons [sources: Quanta Magazine, Rohrer]. In this context, a quantum leap doesn’t appear as a giant leap forward. In fact, a quantum leap would represent the smallest possible change in an electron's energy level.

Car commercials aren't the only places where the word quantum is misused. One key principle of quantum mechanics is that subatomic particles can behave both as waves and as particles. However, once an observer measures something like a particle's exact position, its wave properties can no longer be observed [source: Swanson]. Self-help figures such as Deepak Chopra and Rhonda Byrne, author of "The Secret," have oversimplified and misinterpreted this concept, wrongfully using quantum physics as 'proof' that merely observing something can bring it into existence — suggesting that we can manifest our desires simply by visualizing them [source: Swanson].

2: Percent

We all understand that a percent is one out of 100, but things get tricky when we talk about percentages without giving them proper context. For instance, a news report warned that "white women who experience five or more severe sunburns before age 20 have an 80 percent higher risk for melanoma." While 80 percent sounds alarming, since the American Cancer Society estimates the chance of developing melanoma at approximately 2 percent for women, an 80 percent rise results in a new risk of around 3.6 percent. So, the absolute risk rises by just 1.6 percentage points (or 1.6 cases per 100 people), but the 80 percent relative risk increase (i.e., compared to others in the study) grabs all the attention.

Marketers excel at using percentages to promote products and ideas ("30 percent fewer calories!" "10% whiter!"). However, presenting percentages without understanding their source can lead to confusion. For example, you've likely encountered the myth that 50 percent of U.S. marriages end in divorce. The National Center for Health Statistics derived that statistic by comparing the annual marriage rate per 1,000 people to the annual divorce rate [source: Hurley]. However, since those getting divorced in any given year aren't the same as those who married that year, examining statistics from a single year doesn't provide a meaningful insight.

1: Cause

I had an oceanography professor who would always mention that every year, a rise in ice cream sales happens to coincide with an uptick in shark attacks. Should we therefore assume that eating ice cream attracts sharks, or that shark attacks trigger ice cream cravings? The true cause is, of course, that both ice cream sales and shark attacks increase with warmer weather. Beyond this shared factor, there's no real connection between the two.

Just as any credible scientist would refrain from claiming that the outcome of an experiment "proves" a hypothesis, responsible researchers take care not to confuse correlation with causation, even if preliminary findings or casual observations suggest a connection between two events. For instance, if you were studying alcoholics and found they were more depressed than non-alcoholics, you'd need to conduct more research before concluding that excessive drinking causes depression. It could be that the subjects were already depressed and drank alcohol in an attempt to feel better. What were their jobs like? Did depression run in their families? By answering such questions, you'd be able to make the leap (not quantum!) from coincidence to causal relationship in your study.