'Science progresses best when observations force us to alter our preconceptions.' - Astronomer Vera Rubin (1928 - 2016)

Particularly at the frontiers, investigations conducted based on established knowledge can provide unexpected results. This opens the door to revising existing models, inspiring new lines of research, and ultimately leading to better future comprehension. For instance, experiments on the speed of light and the expansion of the universe yielded then-confusing data that led to revolutionary insights.

Through the acquisition of scientific knowledge, scientists construct explanations of the world, which are rigorously tested and verified until they narrow down to a leading theory of the natural world. However, because of how science works, these ideas will never become factual, as they must always remain open to be iteratively revision based on new data.

From Galileo’s crude spyglass to the James Webb Space Telescope, each technological leap has expanded our observational reach and redefined philosophical and moral conceptions of our place in the universe. Identifying signs of life through the study of exoplanet atmospheres would represent the next great revolution.

- Astronaut Buzz Aldrin (1930-present)

- Marine biologist and environmentalist Rachel Carson (1907-1964)

- Albert Einstein

"The scientific man does not aim at an immediate result ... His duty is to lay the foundation for those who are to come, and point the way."

When Thomas Kuhn published "The Structure of Scientific Revolutions" in 1962, he described the history of science as comprising periods of "normal science" where these accepted frameworks—paradigms—gradually accumulate anomalies until they cannot describe nature. Revolutionary science, such as the development of a new theory, results in a paradigm shift, another term Kuhn helped popularize.

In the 1920s, the Hooker Telescope helped Edwin Hubble make a discovery that forever changed how we see the universe. Building on the work of astronomers like Henrietta Leavitt and Harlow Shapley, Hubble used the telescope to prove that galaxies exist beyond the Milky Way—revealing a vast and expanding universe.

-Alexander Graham Bell (1847-1922)

- Mae Jemison (1956-present), the first Black woman in space

- Author Malcolm Gladwell (1963 - present)

Nobel Prize winner Jacques Monod proposed, “Ideas have retained some of the properties of organisms. Like them, they tend to perpetuate their structure and to breed; they too can fuse, recombine, segregate their content; indeed they too can evolve, and in this evolution selection must surely play an important role.”

- Radio inventor Guglielmo Marconi

- US President James Madison (1751-1836)

She discovered that stars on the outer edges of galaxies were orbiting much faster than expected based on visible matter alone, implying the presence of unseen mass exerting gravitational force. Without dark matter, the outer stars in galaxies would fly off into space instead of staying in orbit.

When you close your eyes, do you see static or colorful patterns or an "intrinsic grey" known as Eigengrau in German? This variation of our internal experiences is just the tip of the iceberg, one that scientists are increasingly studying and...

- Science fiction writer Ray Bradbury

-Frances Perkins (1880-1965), first female member of US Cabinet

- "Star Trek" actor George Takei (1937-present)

On its own, no study serves as a source of truth or solves an existing problem indefinitely, though many can be analyzed collectively in a systematic review to build more confidence—the result of more data—in a conclusion. Studies can explore knowledge gaps or test an existing theory, which is always subject to refinement and improvement.

- Poet Walt Whitman (1819-1892)

Acknowledging that most people have "an enormous tendency to resist change," Hopper's clock served as a reminder for the computer scientist that just because things have been done a certain way does not mean they should forever remain that way: "They love to say, 'We've always done it this way.' I try to fight that."

Facts are observations of the world, and they can be pooled together for a given phenomenon to develop a hypothesis—a proposed explanation consistent with observations that requires further investigation. Experiments and additional data can rule out many hypotheses or graduate a proposed explanation into a widely accepted and validated theory.

After confirming that the accuracy of some laws of physics is limited to certain domains, science became more hesitant to categorize identified mathematical relationships, such as quantum mechanics, as unchanging laws. Instead, these recent, complex frameworks are designated as theories to acknowledge that they are conditional and may be part of a larger, more complete future framework.

- Astronaut John Glenn (1921–2016)

He states that conducting research online cannot replace consulting with scientific experts who have spent their entire lives intimately studying a field. The former science education show host argues that deepening cynicism towards scientific institutions has been fueled by leaders embracing debunked and unsupported claims.

"Change, by its very nature, is threatening but it is also often productive."

“Three Secrets to Success: Be willing to learn new things. Be able to assimilate new information quickly. Be able to get along with and work with other people.”

The winners of Nature's 2025 photo competition capture the essence of scientific fieldwork in diverse and challenging environments. From a biologist battling waves for whale research to ice core drilling in polar night conditions, this gallery details the research being each winning photo.

- Teacher and astronaut Christa McAuliffe (1948-1986)

- Artist Salvador Dalí (1904-1989)

Introduced by philosopher Karl Popper, falsifiability holds that a scientific theory must make predictions that could be proven inaccurate by future observations. Explanations that cannot make such predictions are not scientific theories. It is scientists' jobs to seek out data to poke holes in scientific theories, thereby potentially strengthening them if they hold up to scrutiny.

Scientific laws describe outcomes of specific conditions, and scientific theories explain why those outcomes occur. Both are supported by observational and experimental data and can each inform one another, but neither can become the other. Instead, additional data can improve each towards more accurate descriptions and explanations of reality.

- Actress Betty White (1922-2021)

Since quantum systems exist as a superposition of states before producing a definitive outcome, some quantum pioneers wondered if the act of conscious observation was what collapsed the wave function of possibilities into one state.

Change and uncertainty induce stress, but reframing the unknown into an opportunity for discovery has tangible benefits. Approaching change with curiosity enhances activity in the hippocampus and promotes neuroplasticity, promoting learning and serving as a barrier against anxiety. A neuroscientist explains how embracing the unknown, trying small experiments, and other techniques build curiosity.

- Billionaire John D. Rockefeller (1839-1937)

- Activist Dorothy Height (1912-2010)

- Author James Baldwin (1924–1987)

Einstein's theory of general relativity—that mass literally bends space and time—can be difficult for the human brain to imagine. This interactive resource lets you create celestial objects, imagine their effect on space-time, and see how they interact with each other (best viewed on desktop).