Why can't humans fly?

Summary

In a discussion about the feasibility of genetically modifying humans to grow wings and fly, Dr. Sarah Thorn and Professor Jaime Carrera from MIT explain the challenges involved. While it’s theoretically possible to engineer wings, humans' heavy body structure and insufficient wing surface area compared to their weight prevent flight. They highlight that birds possess a greater wing-to-weight ratio and energy efficiency necessary for flying. The conversation also touches on the high energy demands of flight, suggesting that significant biological changes would be required for humans to achieve this capability.

Takeaways

• 😀 Humans cannot naturally fly due to their body structure and weight.
• 😀 The shape of the human body does not provide sufficient surface area for flight compared to birds.
• 😀 Birds have a much larger wing surface area relative to their weight, enabling them to fly.
• 😀 An example of a human-powered aircraft had a wingspan of about 15 meters and weighed around 30-40 kilograms.
• 😀 To achieve flight, humans would require wings significantly larger than what is possible with human anatomy.
• 😀 Energy consumption increases with flying speed; faster flying requires more energy.
• 😀 Birds can consume large amounts of food to fuel their energy needs for flight, unlike humans.
• 😀 The average bird may need to eat several times a day to maintain energy for flying.
• 😀 The human body is not designed to generate or sustain the energy levels needed for flight.
• 😀 While it is theoretically possible to engineer a human with wings, practical limitations make it unfeasible.

Q & A

What is the primary question posed by the students?

The students, Jade and Lauren, ask whether it is genetically possible for humans to grow wings and be able to fly.

Who are the experts responding to the students' question?

Dr. Sarah Thorn, a biologist at MIT, and Jaime Carrera, a faculty member in the Department of Aeronautics and Astronautics, respond to the students' question.

What is Dr. Thorn's perspective on genetically modifying humans to have wings?

Dr. Thorn encourages watching related videos on building a human with wings, indicating that while genetic modification is a possibility, there are numerous biological and engineering challenges involved.

Why do humans lack the ability to fly according to Jaime Carrera?

Carrera explains that humans cannot fly due to their heavy body weight relative to the small surface area that would be needed to generate lift.

How does Carrera compare the human body to birds regarding flight?

He notes that birds, such as the albatross, have a much higher wing-to-weight ratio, which is essential for flight, unlike humans who are significantly heavier.

What example does Carrera give to illustrate the wing size necessary for human flight?

Carrera mentions that a large bird like an albatross has a wingspan of about two meters and weighs around 20 kilograms, suggesting that a human would need a much larger wingspan to achieve flight.

What are the energy consumption differences between birds and humans regarding flight?

Birds consume energy efficiently and may eat several times a day to sustain their energy for flying, while humans typically do not intake enough energy to support the demands of flight.

What was the record set by a human-powered aircraft mentioned in the discussion?

Carrera refers to a human-powered aircraft that flew for about 100 kilometers, highlighting the need for significant additional surface area and structure to achieve flight.

What role does the ratio of wing surface area to weight play in flying?

A higher ratio of wing surface area to weight allows for better lift generation, which is crucial for the ability to fly.

In conclusion, what is the main takeaway from the experts' discussion on human flight?

The main takeaway is that while the idea of genetically modifying humans to fly is intriguing, both biological and engineering limitations make it an unlikely reality.