Science on This Day: 11 November | Tycho Brahe’s Supernova, the Einstein-Szilard Refrigerator and Gemini 12
Science history gives students a way to explore how scientific ideas change, how engineering responds to practical problems, and how people prepare for challenges beyond Earth. The events associated with 11 November offer three useful examples: Tycho Brahe’s observations of a new star in 1572, a refrigerator design developed by Albert Einstein and Leo Szilard, and the launch of Gemini 12 in 1966.
These stories connect astronomy, physics, engineering and space exploration. They also raise questions that work well in middle and high school classrooms. How can careful measurements challenge accepted ideas? How can a safety problem inspire a different design? And why do astronauts need to practise working outside a spacecraft before attempting a spacewalk?
Each event can serve as a short lesson starter, a reading activity or the beginning of a deeper investigation.
1. Tycho Brahe and the new star in Cassiopeia
In November 1572, Danish astronomer Tycho Brahe observed a new star in the constellation Cassiopeia. He measured its position carefully, and his observations provided evidence that the heavens could change.
At the time, many traditional views of the cosmos treated the heavens as a realm that was fundamentally unchanging. The appearance of a new object challenged this assumption. Brahe's careful observations helped make the event important in the history of astronomy, showing how measurements could be used to question established ideas.
The object is now known as SN 1572, or Tycho's Supernova. It was a supernova, an enormous stellar explosion whose light reached Earth and was visible to observers. Although people could not study such events with modern telescopes or instruments in the sixteenth century, careful records of the object still provide a valuable example of how observations can influence scientific understanding.
Brahe's work also illustrates the importance of measuring rather than simply describing what someone sees. A record of an object's position can be compared with later observations and used to investigate whether it has moved, changed or lies at a different distance.
Classroom connection: How can measurements challenge accepted ideas?
Ask students to imagine that they observe something in the night sky that does not fit what they have been taught. What should they do next? They might record its position, compare observations on different nights, ask other observers to check their results and look for explanations that fit the evidence.
For middle school classes, this can introduce observation, measurement and the difference between evidence and assumption. High school students can explore how astronomers use measurements of position and motion to investigate celestial objects, including the role of parallax in estimating distance.
A useful discussion question is: How can measuring parallax tell us whether an object is nearby or distant? Students can consider why an object's apparent position may change when viewed from different locations and how this can provide evidence about distance.
For further reading, visit Encyclopaedia Britannica's biography of Tycho Brahe.
2. The Einstein-Szilard refrigerator: solving a safety problem through engineering
In 1930, Albert Einstein and Leo Szilard developed refrigerator designs without moving parts. Their work was motivated in part by concerns about the safety risks associated with refrigerant leaks.
Refrigeration is a useful example of physics applied to an everyday need. A refrigerator transfers thermal energy from a cooler interior to its warmer surroundings, allowing food and other materials to be kept at lower temperatures. Different refrigeration systems achieve this using different physical processes and designs.
Einstein and Szilard's work provides a way to discuss how engineers approach problems. Rather than simply improving an existing machine, designers may reconsider how the system works when they identify a safety concern. A problem can therefore become the starting point for a new design.
The story is also a reminder that a clever design is not automatically a successful product. Engineers must consider whether a design works reliably, whether it can be manufactured, how efficiently it operates, what materials it requires and whether it solves the original problem in practice.
Classroom connection: How can a safety problem inspire a new design?
Ask students to identify a familiar device that could be made safer. It might be a bicycle helmet, a kitchen appliance, a phone charger or a heating system. What risks does the current design present, and how could those risks be reduced?
Middle school students can sketch an improved design and explain how it addresses the problem. High school students can go further by identifying trade-offs. A change that improves safety might increase cost, reduce efficiency or make the device more difficult to maintain.
To connect the activity to physics, students could investigate how a refrigerator moves thermal energy and why maintaining a temperature difference requires energy transfer. They can then consider how a different system design might affect safety, reliability and performance.
A useful discussion question is: How can a safety problem inspire a new engineering design?
You can explore the historical record through Google Patents' search for patents involving Albert Einstein and Leo Szilard.
3. Gemini 12: practising for work in space
On 11 November 1966, NASA's Gemini 12 mission launched with astronauts Jim Lovell and Buzz Aldrin. Aldrin's successful spacewalks helped develop procedures for working outside a spacecraft.
Working in space is much more complicated than simply putting on a spacesuit and stepping outside. Astronauts must manage their movement, handle tools, remain connected to the spacecraft and complete tasks while wearing equipment that restricts their actions. The environment also presents hazards that are very different from those encountered on Earth.
Practising tasks underwater can help astronauts prepare for spacewalks because the buoyancy of water can create a form of simulated weightlessness. Underwater training is not identical to working in space, but it allows astronauts to rehearse movements and procedures while engineers and trainers observe how they perform.
Gemini 12 is therefore a useful example of how practice, careful preparation and improvements to procedures can make difficult tasks more manageable. Space exploration depends not only on powerful rockets and sophisticated spacecraft, but also on understanding how people will work within those systems.
Classroom connection: Why practise a spacewalk underwater?
Ask students to think about the skills needed to repair equipment outside a spacecraft. How might a spacesuit affect their ability to bend, grip tools or move their arms? Why might it be useful to practise the sequence of actions before attempting the task in space?
Middle school students can identify the differences between working on Earth and working in microgravity. High school students can investigate how training environments help engineers and astronauts identify problems, refine procedures and reduce risks.
For a practical extension, give students a simple assembly task to complete while wearing thick gloves or using limited movement. Afterwards, ask them to identify which parts were difficult, what instructions would help, and how they would change the task to make it safer and more reliable. This is not a direct simulation of a spacewalk, but it helps students think about how equipment and working conditions affect performance.
A useful discussion question is: Why is practising a task underwater useful when preparing for a spacewalk?
For further information, visit NASA's Gemini XII mission page.
Using science history to develop scientific thinking
These three events offer different ways to help students think like scientists and engineers. Tycho Brahe's observations connect measurement with changing scientific ideas. The Einstein-Szilard refrigerator demonstrates how a practical safety problem can inspire a different engineering approach. Gemini 12 highlights the role of testing, practice and human factors in complex missions.
A straightforward way to use these stories is to give students a short introduction to an event and ask them to answer one question using evidence from the account. They can write independently, discuss their ideas in pairs or compare their explanations as a class.
You can also turn an event into a question-generation activity. Show students an image related to a supernova, refrigerator or spacewalk and give small groups three to five minutes to generate as many questions as possible. Afterwards, students can sort their questions into those that can be answered with existing knowledge, those requiring research and those that might lead to an investigation.
This routine is adaptable across age groups. Middle school students can focus on describing observations, explaining basic processes and identifying problems. High school students can evaluate evidence, explore physical principles and consider the trade-offs involved in engineering decisions.
More science history to explore in November
On 12 November, Voyager 1 made its closest approach to Saturn in 1980. The encounter revealed details of Saturn's rings and moons, as well as information about Titan's thick atmosphere. This is an opportunity to discuss how a single spacecraft encounter can change scientific understanding of an entire planetary system.
The same date also marks the launch of Space Shuttle Columbia on STS-2 in 1981. It was the second Space Shuttle mission and the first time a crewed spacecraft designed for reuse returned to space after a previous orbital flight. The mission provides a connection to engineering, testing and the challenges of designing reusable spacecraft.
As the month continues, you can select events that connect with the topics you are teaching or use a historical example to introduce something new. Science history stories can become short starters, reading comprehension tasks, retrieval questions or discussions about the ways evidence and technology influence our understanding of the world.
Find more Science on This Day classroom resources
If you would like a ready-to-use collection of science history stories for the whole month, my November Science on This Day resource set contains 109 items across the 30 days of November.
The set includes an interactive HTML version with filters, editable Google Slides with discussion questions, a filterable spreadsheet and a simpler PDF version. You can select individual events to suit your lesson, whether you want a quick starter, a short reading, a discussion prompt or a recurring classroom routine.
You can also explore the wider Teaching Astrophysicist store for other free and paid science teaching materials.
A few minutes spent on a historical event can give students a concrete way to explore bigger ideas: how scientists use observations, how engineers respond to problems, and how people prepare to work in unfamiliar environments. The key is to pair the story with a question that encourages students to explain their thinking rather than simply remember a date.
Thanks for reading Cheers and stay curious
Oliver - The Teaching Astrophysicist
