We don't see it Enrique. Lift it way above your head. The sponsor is KiwiCo: https://www.kiwico.com/stevemould

12:10 "I broke my fibula" 13:15 Steve running on a treadmill precariously propped up on a plastic bin.... Stares suspiciously

In the train experiment Steve can tell the train is moving because the conductor yells at him to "STOP RUNNING ON A MOVING TRAIN SIR!"

"Can you lift the graph? ...Interesting" Pure genius. The beanie was the icing on the cake.

The "raise the graph" had me laughing without the explainer 😂

One of my biggest fears when helping Steve with the video was that I had made some rookie mistake when designing and building the rover that meant it would not deliver the needed result. I am feeling some relief that no one has called out a huge error hahahah.

19:18 Good news! The man featured in that clip, Jeran (Jeranism on YT) is now a believer in the globe earth. He went on the trip to Antarctica for "The Final Experiment" and observed the 24 hour sun during the summer in the southern hemisphere and concluded that the globe earth must be real. Unfortunately many other flat earthers weren't convinced and are now calling him a paid-off shill/government plant lmao.

Idea for next time: Do the experiments as you did them here. Then repeat them but with the car going down the ramp and the treadmill inclined down. If it's the change in potential energy that explains the 1 watt difference going up, you should find that going down the slope is easier for the car than driving on a downward-sloped treadmill. If it's the air resistance and slippage that explains the 1watt difference, you should find that it is still harder to go down the slope than to drive on the downward-sloped treadmill.

I think it would be more productive to start with the question "Why is going uphill harder than going on flat surface?" I am pretty sure that missing watt will get solved. "Passive"/"Internal resistances" energy losses were, as measured in flat movement, ~6w. That adds perfectly well with 4w of potential energy in the case of going uphill to ~10w. So the question is "Why we have to spend 3w when not accelerating?". The core realization that car staying on the fixed elevation IS accelerating by 1G. "No acceleration" path is essentially free fall, like in space. We are all accelerating all the time by being pushed by the earth that gets on our way when our bodies try to freefall down the gravity well. In your scenario accelerating car by 1G through time of experiment costs 4W of energy. On flat treadmill earth pushed for that energy on the ramp car had to pay it itself. Try to look at it not through Newtonian lenses but through general relativity point of view. Then next question should be "Why slanted treadmill car had to pay only 3W?". Well.. being completely unsupported we need to accelerate in 1G but with treadmill being only partially slanted we still get partial support and partial force from the ground - the closer to 90 deg angle the less of it. I guess it amounted to 1W in your case :) By the way it also explains why ladder feels exactly the same in both scenarios. It is 90 degrees incline after all Edit: I even measured angle from the video and it is about 13.35 degrees. sin(13.35deg) * 4W = ~0.93W.

The material of the ramp and treadmill also appear to be different; not only will that lead to slippage, it may also yield different rotational friciton to the car wheels.

Wow. Admitting when the data didn't match your expectations is just great to see. We need more of this kind of work around the internet.

I really appreciated that you were transparent with the results. It seems to me that the biggest difference may be the surfaces, and my suggestion is that you cover the ramp with the same material as the treadmill - ie. that you cut a treadmill belt and put it on the surface of the ramp. In terms of scale, I would guess that the second difference is the vibration that occurs with the treadmill (though I would for that expect the inverse result). Thanks for the video !

One possible explanation: even though it's the same motor, the wheels were spinning at different RPMs in each experiment. Motors have power curves that vary with RPM — they only deliver peak power at certain speeds. If the wheel RPM pushes the motor outside its optimal range, efficiency drops and less mechanical work is produced. That could easily account for the performance difference you're seeing.

The way I think about it is that the treadmill/elevator/whatever is subtracting potential energy by lowering you down. In order to stay in the same spot, you must add that potentially energy back in.

I had a fantastic time helping you with this project, Steve. Peoples comments are really interesting!! Thanks for the shoutout and for the fun!

Sources at the end: Super cool video! This idea has been studied a lot in the Kinesiology and Sport Science literature, and it gets a lot more complicated than the typical physics simplifications that we often try and boil things down to. The big concepts that are missing with the car are human gait/running kinetics and kinematics. Most of your assumptions were right about the angle of the treadmill being the same as the ground, gravity being the same, and the extensors of the body having to work to propel the person's body upwards. But the big difference about human movement than the car movement is the flight and landing phases in our locomotion. When breaking it down, there are changes to landing/push off mechanics and how it effects the angle of the ankle (plantar/dorsiflexion, inversion/eversion). Additionally, there is less total force the extensors have to produce, and the time they have to produce it are reduced, due to the movement of the surface under the body (this is the secret). You had it bang on when you said, "gravity wants to pull you down" and human gait is often categorized as "controlled falling" - so even if our centre of mass is travelling at a constant velocity, our limbs are constantly accelerating and decelerating to produce motion. Ground contact time is highly variable depending on the individual, the speed of the run, and previous training history. But it typically ranges from 100-200ms for sprinting, and 200-300ms for jogging. That means you can see measurable differences with even small changes in ground contact time, and similarly ground reaction forces. These concepts are evidenced by assessing the average normal loading rate, normal impulse, propulsive impulse, and vertical centre of mass excursion, which are greater running on the ground. This effectively boils down to a decreased demand on the hip, knee, and ankle extensors, which can be why treadmill running can be perceived as easier. That being said, it also means a greater relative contribution of the hip flexor:hip extensor ratio, and greater perceived ankle instability which can make treadmill running be perceived as more difficult. Ultimately, do the modality of exercise that allows you to stay active and consistent! Three-dimensional kinematic comparison of treadmill and overground running Jonathan Sinclair, JIM Richards, Paul J Taylor, Christopher J Edmundson, Darrell Brooks, Sarah J Hobbs Sports biomechanics 12 (3), 272-282, 2013 A kinematic comparison of overground and treadmill running Benno M Nigg, RUUD W De Boer, Veronica Fisher Medicine and science in sports and exercise 27, 98-98, 1995 Joint kinematics and ground reaction forces in overground versus treadmill graded running Colin R Firminger, Gianluca Vernillo, Aldo Savoldelli, Darren J Stefanyshyn, Guillaume Y Millet, W Brent Edwards Gait & posture 63, 109-113, 2018

A thought: If the wheels are slipping on the threadmill, but not on the ramp; and you controlled for the length of a rotation of the threadmill (instead of wheel speed); then the cart is moving further on the threadmill than the length of a whole rotation. So it should use more energy, not less. Climbing up a mountain twice because you fell down along the way takes more energy than climbing it once, even if falling gives you a short pause of relief. :D And it would be hard to argue "man, you should really make your car tires slip because you could just turn up the RPM of your tires and need less energy for the same hills!".

The jeranism reference was gold. As soon as you started talking I was like "that's almost exactly what jeranism said" and then I got it with the "bring up the graph"

"Power consumption" - he said it... I heard him! I'm calling the Technology Connections guy right now. OMG He said it again! (In John Cleese voice)

A story to contribute to the argument. My wife and I did a transatlantic trip on the Queen Mary 2 several years back, and hit rough weather halfway through. There was a 10m swell (yes, over 30 feet) so the ship was really pitching up and down. I had an accelerometer app on my phone and measured peak accelerations of +/- 0.3g, which meant I was gaining or losing over 25kg/50lb while riding the swells! There are both elevators and stairs on the ship, and there are many decks.We had been taking the stairs to stay active, but discovered something really interesting while taking the stairs during the worst of the storm. If I paused on the landing while the ship rose (positive Gs) and then ascended the stairs as it fell (negative Gs) going up the stairs felt effortless, more like walking across a floor than going up a flight of stairs. I would pause on the next landing as the ship rose, and then "ascend" the next flight as it dropped. I chalked this up to the ship dropping below us so I wasn't actually going "up" the stairs, but I will say that there was a VERY noticable difference between doing this and going up the stairs in calm seas. Definitely not scientific analysis but an interesting anecdote to add to the discussion. I don't remember if I tried going up the stairs while the ship was rising - I probably did to experience it being harder, but I can't remember.