Science on This Day: November 26 | Air Conditioning, Ancient Egypt and Exploring Mars
November 26 brings together three stories that show how science and technology help us understand and shape our surroundings. Willis Carrier helped develop modern air-conditioning systems, changing how people control temperature and humidity indoors. Howard Carter and his team reached a view into Tutankhamun’s tomb in 1922, creating one of the best-known moments in the history of archaeology. And November 26 marks two major milestones in Mars exploration: NASA’s Curiosity rover launched in 2011, and the InSight lander arrived on Mars in 2018.
These events connect engineering, archaeology, planetary science and the challenge of collecting reliable evidence. They also make useful classroom starters because students can relate them to familiar questions: how do we stay comfortable in hot weather, how do we learn about the past, and how can a robot investigate a planet millions of kilometres away?
November 26, 1876: Willis Carrier and the science of air conditioning
American engineer Willis Haviland Carrier was born on November 26, 1876. His engineering work helped make modern air conditioning practical, particularly systems that control both temperature and humidity. Carrier’s work grew from an industrial problem: a printing company needed to manage the conditions inside its factory because changes in temperature and moisture affected the paper and printing process. His engineering solution helped establish principles used in modern climate-control systems.
Air conditioning is often described simply as cooling the air, but controlling indoor conditions involves several linked processes. A typical system moves heat from one place to another using a refrigerant that circulates through components such as an evaporator, compressor, condenser and expansion device. The refrigerant absorbs heat in one part of the system and releases it elsewhere. The compressor uses energy to drive the cycle.
Humidity matters too. Air contains water vapour, and the amount it can hold depends on temperature. When warm, moist air passes over a sufficiently cold surface, some of the water vapour can condense into liquid water. This is why an air-conditioning unit may drain water as it operates. Removing moisture can make a room more comfortable and can also help protect materials and equipment that are sensitive to damp conditions.
Carrier’s work was important because it treated temperature and humidity as conditions that could be measured and controlled. That idea transformed more than domestic comfort. Reliable climate control became useful in manufacturing, printing, laboratories, hospitals, food storage and other settings where environmental conditions matter.
The history provided by Carrier explains how Carrier’s engineering work contributed to the development of air conditioning.
Bring this into the classroom
This story links naturally to heat transfer, changes of state, energy transfer and the water cycle. Ask students why a cold drink can collect droplets on its outside, or why a bathroom mirror fogs after a hot shower. These everyday examples show that water vapour in the air can condense when it encounters a cooler surface.
Students can also compare a fan with an air conditioner. A fan moves air and can help sweat evaporate from skin, making a person feel cooler, but it does not generally remove heat from the room. An air conditioner uses energy to transfer heat from indoors to outdoors. This distinction helps students separate the movement of air from the transfer of thermal energy.
A useful discussion question is: Why does controlling humidity matter as well as controlling temperature?
For older students, investigate how a refrigeration cycle works and where energy enters the system. They can also consider the environmental trade-offs of cooling buildings, including electricity use, refrigerant leakage and the importance of designing efficient systems.
November 26, 1922: Howard Carter and Tutankhamun’s tomb
On November 26, 1922, British archaeologist Howard Carter and his team opened a small view into the tomb of the ancient Egyptian pharaoh Tutankhamun. Carter reportedly used a candle to look inside and was asked whether he could see anything. His famous response was that he could see wonderful things.
The moment followed the discovery of a staircase leading to the tomb earlier in November. Carter had been searching for Tutankhamun’s burial place in the Valley of the Kings, supported by Lord Carnarvon. The tomb contained an extraordinary collection of objects, many of which helped researchers investigate royal life, craftsmanship, burial practices and material culture in ancient Egypt.
The discovery is often remembered as a dramatic moment of exploration, but the scientific and historical value came from the careful recording and study of what was found. Objects, their materials, their locations and their relationships to one another can all provide evidence. If an object is removed without documenting where it was found, important information about its context may be lost.
Archaeology therefore has much in common with other evidence-based disciplines. Researchers make observations, record measurements, compare findings and develop explanations that can be revised as new evidence appears. Scientific methods can help identify materials, examine pigments, study organic remains and investigate how objects were made or used.
Tutankhamun’s tomb is also a useful reminder that discovery is not the same as understanding. Finding an artefact may create new questions rather than answer every question about the people who made it.
Bring this into the classroom
Students can explore archaeology as a process of evidence collection and interpretation. Give them an image or description of an artefact and ask what they can observe directly, what they can reasonably infer, and what they cannot know without further evidence.
For example, a decorated cup might reveal something about the materials and techniques available to its makers. Its decoration may suggest a cultural or symbolic meaning, but that interpretation would need to be supported by other evidence. Students can compare several possible explanations and identify what additional information would help distinguish between them.
A useful discussion question is: Why is it important to record where an artefact is found, rather than simply collecting it?
This activity can also connect to chemistry and materials science. Researchers may examine the composition of metal objects, identify pigments, or investigate how materials have changed over time. It shows students that the study of the past often draws on scientific techniques as well as historical knowledge.
November 26, 2011 and 2018: Curiosity and InSight investigate Mars
Two major NASA Mars missions are associated with November 26. In 2011, NASA launched the Mars Science Laboratory spacecraft carrying the Curiosity rover. Seven years later, on November 26, 2018, NASA’s InSight lander touched down on Mars. Although both missions travelled to the same planet, they were designed to investigate different scientific questions.
Curiosity was built to examine the geology and chemistry of Mars and to investigate whether ancient environments there could have supported microbial life. It carries instruments that analyse rocks and soil, take images, measure environmental conditions and investigate the planet’s chemical composition. By studying sedimentary rocks and other geological evidence, scientists can reconstruct aspects of Mars’s ancient environment.
The key question is not whether Curiosity can simply find life by looking at a rock. Instead, it investigates whether the conditions needed to support life may once have existed. Evidence such as minerals formed in water, certain chemical compounds and geological features can help scientists determine what ancient Mars was like. Evidence that an environment could have supported life is not the same as proof that life actually existed there.
InSight had a different purpose. Rather than travelling across the surface, it studied Mars’s internal structure. Its instruments included a seismometer designed to detect marsquakes and other vibrations. Seismic waves travel through a planet differently depending on the materials they pass through, so recording these waves can help scientists investigate the structure of the crust, mantle and core.
InSight’s observations helped researchers improve their understanding of Mars’s interior. The mission also showed the value of studying a planet with instruments that can detect processes happening beneath the surface, rather than relying only on photographs or surface samples.
Bring this into the classroom
Curiosity and InSight provide a clear way to compare scientific instruments and the questions they are designed to answer. Ask students why a rover that can travel between rocks is useful for geology, while a stationary lander with a seismometer is better suited to investigating a planet’s interior.
Students can create a table comparing each mission’s location, instruments, measurements and scientific questions. They could then design a hypothetical mission to another planet or moon, choosing the instruments they would need to investigate a specific question.
A useful discussion question is: What kinds of evidence could show that an ancient Martian environment might have supported microbial life?
For older students, the missions also provide an opportunity to discuss how scientists interpret indirect evidence. A seismometer does not photograph a planet’s core, but measurements of seismic waves can reveal information about internal structure. Similarly, chemical and geological measurements can help reconstruct past environmental conditions even when researchers cannot observe those ancient environments directly.
These missions also highlight the importance of engineering. Spacecraft must survive launch, travel through space, enter an atmosphere or descend to the surface, and operate in a challenging environment. The instruments must be designed to collect useful data despite limits on mass, energy, communications and the possibility of repair.
Using Science on This Day as a classroom activity
November 26 is a useful date for connecting classroom topics with practical problems. Carrier’s work links temperature, humidity and energy transfer. Carter’s discovery provides an introduction to evidence, materials and archaeological interpretation. Curiosity and InSight show how different scientific instruments can investigate different parts of a planet.
One approach is to begin with an image and a question. Show students an air-conditioning unit, an artefact from an archaeological site or a Mars lander, then ask what they would need to know to explain how it works or what it reveals. Give them a few minutes to generate questions before introducing the historical story.
My November Science on This Day activity set includes 109 STEM stories across the month. It comes in several classroom-friendly formats: an interactive HTML version, editable Google Slides, a filterable spreadsheet and a PDF version. The events can be selected by date or subject, and discussion questions make it easy to use a story as a warm-up, retrieval prompt or short evidence-based discussion.
You can also browse The Teaching Astrophysicist store for free and paid resources across physics, chemistry, biology, Earth science and space.
What else happened in science history?
On November 27, Anders Celsius was born in 1701. His name is now attached to the temperature scale used in science and everyday life. The original Celsius scale was defined in the opposite direction from the familiar modern version, with the scale later reversed. This makes a useful starter for discussing how measurement systems are developed and standardised.
November 28 brings a milestone in the history of scientific collaboration: the Royal Society was founded in London in 1660. Its emphasis on observation, experiment and the sharing of findings offers a connection to how science works as a community. The same date in 1964 saw NASA launch Mariner 4, whose later flyby returned the first close-up images of Mars, revealing a cratered surface that challenged some expectations about the planet.
On November 29, Christian Doppler, born in 1803, is remembered for the effect that explains how the observed frequency of a wave changes when its source and observer move relative to each other. The Doppler effect is relevant to sound, medical ultrasound and astronomy. The date also includes the story of Enos, a chimpanzee who orbited Earth in 1961 as part of the preparations for human spaceflight, and the release of the video game Pong in 1972, a useful link to computing and the development of interactive technology.
As November draws to a close, the December Science on This Day activity set provides 132 STEM stories across all 31 days of December, in multiple formats for classroom use. It offers another way to introduce a topic, encourage discussion or connect a curriculum concept with a real scientific event.
The stories of Carrier, Carter, Curiosity and InSight show how science can improve our control of the environment, help us interpret evidence from the past and reveal details of worlds beyond Earth. November 26 is a reminder that progress often depends on asking a clear question, choosing the right tools and understanding what the evidence can genuinely tell us.
Thanks for reading
Cheers and stay curious
Oliver - The Teaching Astrophysicist
