
YouTuber and science communicator Steve Mould, famed for his excellent and interesting demonstrations of physics and engineering (check out this life-sized pop pop boat, for example) has turned his attention to an old idea about treadmills. Rather than getting the result he had expected, he ended up feeling a little more empathy for flat-Earthers when faced with uncomfortable experiment results.
According to various sources, running uphill on a treadmill is easier than running on an actual hill. This seems to make a bit of intuitive sense, as on a treadmill you might think that you don’t have to keep pushing your body up in Earth’s gravitational field, whereas on a hill you certainly do. On top of that, outside there are factors like wind resistance to add to your running pain.
But physically, as Mould goes through in the video, they should be pretty equivalent (ignoring factors like air resistance for ease). According to Galilean relativity, a person sealed inside a sealed box moving at a constant speed would not be able to tell whether they were moving at all, nor do any experiment to figure out how fast they were moving. The laws of physics look the same whether you are in a sealed train moving at a constant 100 kilometers (62 miles) an hour, or just sat in a sealed train standing at the platform for an hour due to leaves on the line.
So, if you took a treadmill and placed it outside of the train, but set it to turn at the same speed as the train, you and another runner inside of the train could match that speed and remain stationary with respect to each other. Until, that is, the runner on the train runs out of train to run down and smacks into a wall. Yet another advantage of the gym.
Factoring out wind resistance, there should be no difference between the experience of running on the train, and running on the treadmill. But what about the incline? For this, Mould explains another thought experiment, before testing it a little.
In this scenario, you should imagine climbing a ladder. Pretty easy. And then imagine you are climbing a ladder which is being moved downwards as you climb it, matching the same rate as your climbing speed. While the ladder is moving at a constant speed (i.e. not accelerating) these two tasks should also be equivalent, other than the fact you do not have to move your body further upwards in a gravitational field. Mould tested this, though not very scientifically, using a climbing wall, with both him and his producer saying they were roughly equivalent in terms of exertion.
In the last portion of the video, Mould attempted to measure the difference using a remote-controlled car, a treadmill, and a ramp, and a way of monitoring power consumption in both scenarios. He and his team ran many experiments, but did not get the results he was expecting.
“Yeah, so it’s harder to go up the ramp by about 1 watt. And that’s really consistent over like loads and loads of tests that we did. It’s always about 9 watts on the treadmill and about 10 watts on the ramp,” Mould explains in the video. “It’s really annoying.”
Mould, who took part in a parody of a documentary about flat-Earthers, explained that after the result he felt more empathy for flat-Earthers getting experimental results which they don’t like, either.
“My first thought was how can I explain this away how can I explain away this result that disagrees with what I believe, and that’s exactly what the flat Earth people did in this documentary,” Mould said.
“I guess my point is I have empathy now for these people. And I I want to be very clear that I don’t have any sympathy for their point of view. Like I don’t think there’s any credibility in the idea that the Earth is flat. What I’m saying is I understand that feeling, and it’s very natural for even you know for scientists to feel like ‘okay I got this result that I didn’t want, what did I do wrong, because I must I must be right.”
Mould, though, is not a conspiracy theorist, and instead thought about other factors which might be affecting the experiment. Wind resistance, according to his calculations, could account for about 0.3 watts of power, which isn’t enough to explain the full difference. However, on the treadmill the wheels were occasionally slipping, meaning that the car had to do less work as it was out of contact with the treadmill.
Assuming (and Mould stresses it is an assumption) that the car was not slipping on the ramp, this could account for almost all of the difference, in combination with air resistance. In short, he concludes, “We need to improve the experiment to figure out if that’s actually what’s going on.”
Source Link: YouTuber Tests Whether It Really Is Easier To Run Uphill On A Treadmill, Gets Unexpected Result