Risking My Life To Settle A Physics Debate

Can any wind-powered vehicle go directly downwind faster than the wind itself?

• A sailboat accelerates when wind pushes its sail • Once it reaches wind speed, there is no relative wind motion • Without drag, a sailboat can only match wind speed going straight downwind • Sailboats can exceed wind speed only when traveling at an angle to the wind

Blackbird, a special propeller craft, claims to go straight downwind faster than the wind itself.

• Physics professors and internet users dismissed the idea as impossible • Critics questioned whether the concept violates conservation of energy • Some suggested hidden mechanisms like magnets or fans out of view

Derek travels to El Mirage, a dry lakebed a couple hours from Los Angeles, to test the Blackbird propeller craft.

• Rick is the inventor of Blackbird • Neil is the current owner • Gene operates the Potato Jet YouTube channel and provides drone footage

After hours in the hot desert, wind conditions remain inadequate to conduct the test.

• Blackbird has a recumbent design with feet positioned far down • Steering: push right hand to go left, pull to go right • Pitch control for propeller blades operated with left hand • A telltale string on the front indicates wind direction

• The propeller does not operate like a windmill that requires air flow • Instead, wheels are geared to turn the propeller opposite to wind direction • The propeller functions as a fan, pushing air backwards

Rick developed this idea by imagining two sailboats tacking downwind on opposite sides of a cylinder, their sails combined making an effective propeller.

• Rick posted on two forums expecting people to say it would never work • People dismissed it as fake, claiming it violated physics laws • Physics professors argued that treadmill models were not good analogs of the real world

• A treadmill model successfully demonstrated the concept • Video demonstrations addressed conspiracy theories about hidden magnets or fans • Building the full-scale vehicle became necessary to convince skeptics

Derek reaches seven to eight miles per hour, approaching wind speed, when the chain comes off the propeller.

• Derek felt the vehicle picking up speed as the propeller spun • Speed reached approximately eight to nine miles per hour before mechanical failure • The chain disengagement prevented reaching beyond wind speed

The propeller chain failure requires immediate repair before another attempt.

Rick indicates that wind speed of at least 8 mph is the absolute minimum, with 10 mph considered healthy for a successful run.

• The propeller shows significant imbalance during high wind conditions • Excessive vibration and wobbling develop when wind intensifies • The structure risks shaking itself apart under extreme conditions

Rick decides to pilot the vehicle first to assess whether it is safe enough for Derek to drive given the stronger winds and structural wobbling.

The team determines that wind speeds around 15 mph represent the upper threshold for safe operation.

• Derek expresses fear but remains determined to attempt the test • He acknowledges higher stakes but commits to the challenge • The final run will be the last chance before sunset

As the sun sets, Derek positions Blackbird for a straight run downwind toward the windsock with stronger wind conditions.

• Blackbird accelerates gradually, approaching wind speed • Derek urges the vehicle to push past wind speed threshold • The vehicle successfully exceeds wind speed

• The telltale string points straight backward, indicating apparent headwind • The windsock shows true wind direction opposite to apparent wind • Derek is traveling faster than the wind blowing from behind

• Derek's heart rate spikes during the high-speed run • The team expresses that the performance looked scary • Derek confirms the vehicle felt stable despite the intense experience

• The propeller operates as a fan, not a windmill requiring air flow • A fan can push air backwards even in still air • This allows the vehicle to continue accelerating beyond wind speed

• Energy powering the fan comes from the wheels via gearing • The wheels extract energy from the tailwind as the vehicle moves through air • The vehicle moves at different speeds relative to ground versus air due to the tailwind

• The propeller pushes air backwards, slowing the tailwind behind it • Wind behind the propeller moves more slowly than ambient wind • The energy difference accelerates the cart forwards

• Blackbird's creators achieved a record speed of 2.8 times wind speed • The demonstrations prove this is physically possible • The concept does not violate conservation of energy

Kiwico creates hands-on STEAM projects for kids, combining science, technology, engineering, art, and math through fun learning activities.

• All materials needed are included in each crate, no shopping required • Children learn by doing projects themselves • Projects include supplemental magazines with additional educational content

A featured Kiwico project teaches aerodynamics concepts including lift and drag through hands-on experimentation.

Viewers can get 50% off their first month of any Kiwico subscription by visiting Kiwico.com/veritasium50.