Science on This Day: November 15 | Johannes Kepler, William Herschel and the Microprocessor
November 15 offers three excellent ways to connect science history with the world students experience today. The date marks the death of Johannes Kepler, whose mathematical descriptions of planetary motion helped shape modern physics; the birth of William Herschel, who discovered a planet and revealed radiation beyond the limits of human vision; and the introduction of the Intel 4004, a microprocessor that helped change the development of modern computing.
These stories connect astronomy, mathematics, physics, engineering and computing. They also provide opportunities to explore how scientific knowledge develops, how experiments reveal things we cannot directly see, and how small technological components can have enormous effects.
For middle and high school science teachers, these events can become short lesson starters, discussion prompts, research tasks or links between subjects. Younger students can also explore the central ideas through simple models, observations and questions.
November 15: Johannes Kepler and the mathematics of planetary motion
Johannes Kepler died on 15 November 1630. Born in 1571, he was a mathematician and astronomer whose work helped transform our understanding of the Solar System. At a time when astronomers were still debating how planets moved, Kepler used mathematical analysis and astronomical observations to develop three laws describing planetary motion.
Kepler's work was particularly important because he recognised that planets travel in elliptical orbits rather than perfect circles. An ellipse is an oval-shaped path, and the Sun lies at one of its two focal points. His other laws describe how a planet's speed changes during its orbit and how its orbital period relates to its average distance from the Sun.
These ideas were not simply mathematical curiosities. Kepler used observations of Mars, including exceptionally accurate measurements collected by the astronomer Tycho Brahe, to test and improve his models. The differences between predicted and observed positions mattered. Rather than forcing the observations to fit a preferred circular orbit, Kepler developed a better explanation.
His work later became an important foundation for Isaac Newton's theory of gravity. Newton's laws explained why planets follow the patterns Kepler had described, connecting mathematical models of motion with a physical explanation of gravity.
This makes Kepler a useful example of how science develops through observation, mathematical reasoning and the willingness to revise an explanation when the evidence does not fit. His work also illustrates the relationship between mathematics and science: mathematics can describe a pattern, make predictions and help researchers test whether a model accurately represents the natural world.
Classroom connection: In middle school, students can compare circular and elliptical orbits using simple drawings or string-and-pencil models. High school students can investigate how orbital period changes with distance from the Sun, using Kepler's third law to explore the relationship mathematically. Ask students why a model that produces accurate predictions is useful, even before scientists fully understand the mechanism behind it.
November 15: William Herschel and the discovery of invisible radiation
William Herschel was born on 15 November 1738. Originally trained as a musician, Herschel became a skilled telescope maker and astronomer. His observations led to the discovery of Uranus in 1781, the first planet discovered in modern times rather than known since antiquity. The discovery expanded the known boundaries of the Solar System and demonstrated how improved observations could change humanity's understanding of its place in space.
Herschel's contributions were not limited to astronomy. In 1800, he investigated the different colours produced when sunlight passed through a prism. He wanted to compare the heating effects of different parts of the spectrum. By placing thermometers in different regions, he found that the temperature continued to rise beyond the red end of the visible spectrum.
This revealed the existence of infrared radiation, which human eyes cannot see. Infrared is part of the electromagnetic spectrum, alongside visible light, ultraviolet radiation, radio waves, microwaves, X-rays and gamma rays. These forms of radiation differ in wavelength and frequency, and they interact with matter in different ways.
Herschel's experiment offers a valuable lesson about scientific investigation. A thermometer can detect a change that our eyes cannot observe directly. The absence of visible light does not mean that energy is absent. Modern infrared cameras use related principles to detect thermal radiation, helping firefighters locate people through smoke, engineers identify overheating components and scientists study the temperatures of objects.
His discovery also creates a natural connection between astronomy and physics. Astronomers observe the universe using different wavelengths because visible light alone does not reveal everything about stars, planets, galaxies and other objects. Infrared observations can reveal relatively cool objects, penetrate some dusty regions of space and provide information that visible-light observations may miss.
Classroom connection: Ask students how they could investigate whether sunlight contains energy beyond the visible red end of a spectrum. They can design a method using thermometers, compare measurements and identify variables that need to be controlled.
For older students, extend the discussion to infrared astronomy and thermal imaging. For younger learners, use everyday examples such as remote controls or thermal cameras to explore how technology detects signals that human senses cannot.
November 15: The Intel 4004 and the rise of the microprocessor
On 15 November 1971, Intel introduced the 4004, widely recognised as the first commercially available single-chip microprocessor. This small electronic component brought computing functions that had previously required multiple components together on a single integrated circuit.
The 4004 contained approximately 2,300 transistors. Transistors are electronic components that can control electrical signals and act as switches or amplifiers. In digital computing, transistors can be arranged into circuits that represent and process binary information. Combining large numbers of these components allows a processor to perform calculations, follow instructions and control other parts of a device.
The idea of placing many electronic components on a single chip was important because it made computing systems smaller and more practical to manufacture. A microprocessor could serve as a central processing unit, carrying out instructions and performing operations that would otherwise require more complicated arrangements of electronic components.
The 4004 was originally developed for use in a calculator. It was not a modern personal-computer processor, and it did not contain everything needed to operate a computer by itself. Nevertheless, it demonstrated the potential of integrating processing functions into a compact device.
Modern processors are vastly more complex, containing billions of transistors in some designs. Microprocessors now help control smartphones, vehicles, medical equipment, household appliances, industrial machines and scientific instruments. Students can therefore connect this historical development with technology they use every day.
The 4004 also provides a way to discuss engineering progress without assuming that newer technology is automatically better in every situation. Engineers must consider performance, energy consumption, heat, manufacturing costs, reliability and the needs of the intended user. A processor designed for a simple calculator has different requirements from one used in a supercomputer or a spacecraft.
Classroom connection: In middle school, students can explore how binary information and simple logic operations allow digital devices to process information. High school students can investigate the role of transistors in digital circuits or compare the requirements of processors used in different devices. A useful discussion question is: how does putting more electronic components into a smaller space change what engineers can build, and what new challenges does it create?
Using Science on This Day in your classroom
These three November 15 events demonstrate why science history can be more than a collection of names and dates. Kepler connects mathematical models with observations, Herschel shows how experiments can reveal previously unknown phenomena, and the Intel 4004 illustrates how engineering can translate scientific principles into widely used technology.
A short science-history starter could begin with one question: How can mathematics predict the movement of a planet? How can a thermometer detect radiation our eyes cannot see? Or how can thousands of tiny electronic components work together to process information?
Give students a few minutes to consider the question independently or in small groups. They can then share their initial ideas, examine evidence and identify what they would like to investigate further. This approach can help students practise scientific reasoning while making connections across subjects.
For a ready-to-use collection, my November Science on This Day resource set contains 109 STEM stories spread across the 30 days of November. It includes an interactive HTML version with filters, an editable Google Slides version with classroom discussion questions, a filterable spreadsheet and a PDF version. Teachers can select a single event for a lesson starter or use several events to build a broader science-history activity.
You can also explore the free science teaching resources on The Teaching Astrophysicist to find additional materials for astronomy, physics, biology, chemistry and other STEM topics.
What else happened in November?
November's science history calendar provides plenty of opportunities to continue these connections throughout the month. On 16 November 1904, John Ambrose Fleming patented a thermionic valve, an important early component in the development of electronics. On the same date in 1974, the Arecibo message was transmitted towards the globular cluster M13, creating an opportunity to discuss binary information, radio astronomy and communication with hypothetical extraterrestrial intelligence.
On 17 November, the birth of mathematician August Möbius provides a memorable introduction to topology through the Möbius strip, while the 1966 Leonid meteor storm offers a way to discuss meteor showers and astronomical observation. Later in the month, students can explore the discovery of X-rays, the development of spaceflight, major advances in computing and the scientific questions raised by changing technology.
The value of these events is not just that they happened on particular dates. Each one provides a starting point for a question about how the world works, how evidence changes our understanding or how scientific knowledge influences everyday life. By bringing a short event from science history into a lesson, teachers can make links between past discoveries and the concepts students are learning today.
Thanks for reading
Cheers and stay curious
Oliver - The Teaching Astrophysicist
