Imagine a car that can travel faster than the wind pushing it, without using any motor or batteries. Sounds impossible, right? This is exactly what a vehicle called Blackbird claims to do. This bold claim led to a $10,000 bet between the creator of a video about Blackbird and a UCLA physics professor named Alex Kusenko. Let’s dive into the details of this fascinating story, the science behind it, and the outcome of the bet.
The main idea is that Blackbird can move faster than the wind using only the wind itself as its energy source. This surprising claim caught the attention of Professor Kusenko, who was skeptical and wanted to understand how this could be possible.
After much discussion, the two parties agreed to a public bet of $10,000. The challenge was simple: if the creator could prove that Blackbird could indeed go faster than the wind, the professor would pay up. To ensure fairness, famous science figures like Neil deGrasse Tyson, Bill Nye, and Sean Carroll were invited to witness the signing of the bet.
Professor Kusenko had several doubts about the claim:
1. **Wind Speed Variability**: He thought the wind speed might change during the test, making it seem like the car was faster than it actually was.
2. **Wind Gradient**: The wind speed was measured at a lower height than where the car’s propeller was, which might create an illusion of the car moving faster due to differences in wind speed at different heights.
3. **Treadmill Tests**: He questioned the accuracy of treadmill experiments that simulated a steady wind, suggesting that human error could affect the results.
4. **Theoretical Analyses**: Kusenko referred to theories suggesting the car couldn’t maintain a speed equal to or greater than the wind without slowing down.
Derek Muller, the creator of the video, explained how Blackbird works. Unlike a regular windmill, the propeller on Blackbird pushes air backward, creating forward thrust powered by the wheels. This allows the car to keep accelerating even when it reaches wind speed.
Muller provided several pieces of evidence to support his claim:
– **Tell-Tale Measurements**: Devices called tell-tales were placed at different heights on the car. They consistently showed that every part of the vehicle was moving faster than the wind.
– **Acceleration Data**: Video analysis showed that Blackbird kept accelerating even after the tell-tales indicated it was faster than the wind.
– **Historical Context**: Muller mentioned previous successful downwind carts, including one from 1969, to show that this concept had been proven before.
After reviewing the evidence, Professor Kusenko was convinced that Blackbird could indeed travel faster than the wind. He conceded the bet and transferred $10,000 to Muller, acknowledging the validity of the claims.
This story highlights the importance of scientific debate and being open to changing one’s mind when presented with new evidence. Muller plans to use the winnings to promote science communication, showing that disagreements in science can lead to learning opportunities. The Blackbird experiment not only demonstrates fascinating physics principles but also reminds us of the value of curiosity and open-mindedness in the pursuit of knowledge.
Design and build a small model car that can move using only wind power. Use materials like paper, cardboard, and small wheels. Test your car by blowing on it or using a fan. Discuss how the design could be improved to make the car move faster than the wind.
Divide into two groups. One group will argue that a car can go faster than the wind using only wind power, while the other group will argue against it. Use scientific principles and evidence from the Blackbird story to support your arguments. Present your case to the class.
Use an anemometer to measure wind speed at different heights. Compare your findings and discuss how wind speed variability and wind gradient might affect the performance of a wind-powered vehicle like Blackbird.
Watch a video of Blackbird in action. Use video analysis software to track its speed over time. Discuss how the data supports or contradicts the claim that Blackbird can move faster than the wind.
Research previous attempts to create vehicles that can move faster than the wind. Present your findings to the class, highlighting any successful designs and the principles that made them work.
Car – A vehicle with wheels that is powered by an engine or motor, used for transporting people or goods. – In physics class, we calculated the force needed to accelerate a car from rest to $60 , text{km/h}$ in $10$ seconds.
Wind – The natural movement of air, particularly in the form of a current blowing from a particular direction. – Engineers designed the wind turbine to convert wind energy into electrical energy efficiently.
Speed – The rate at which an object covers distance, usually measured in meters per second (m/s) or kilometers per hour (km/h). – The speed of the car was measured to be $20 , text{m/s}$ as it traveled down the highway.
Energy – The capacity to do work or produce change, often measured in joules (J). – The kinetic energy of a moving object is given by the equation $E_k = frac{1}{2}mv^2$, where $m$ is mass and $v$ is velocity.
Thrust – The force applied on an object to move it in a specific direction, commonly used in the context of propulsion systems. – The rocket’s engines produced a thrust of $5000 , text{N}$ to lift it off the ground.
Evidence – Information or data that supports a conclusion or hypothesis. – The experiment provided strong evidence that increasing the temperature of a gas increases its pressure.
Physics – The branch of science concerned with the nature and properties of matter and energy. – In physics, we study the laws that govern the motion of objects and the forces that act upon them.
Experiment – A scientific procedure undertaken to test a hypothesis by collecting data under controlled conditions. – The students conducted an experiment to measure the acceleration due to gravity using a pendulum.
Acceleration – The rate of change of velocity of an object, usually measured in meters per second squared (m/s²). – The acceleration of the car was calculated to be $3 , text{m/s}^2$ as it increased its speed on the track.
Debate – A formal discussion or argument on a particular topic, often involving opposing viewpoints. – There was a debate in class about whether renewable energy sources can fully replace fossil fuels in the future.
