Comments by "Mikko Rantalainen" (@MikkoRantalainen) on "Risking My Life To Settle A Physics Debate" video.

@fullaccess2645 The problem with flag is that it will the influenced by the fan but you still cannot pass the flag though the fan to see the turbulence after the fan. A good demonstration would be using some kind of RC plane to draw horizontal smoke lines orthogonal to direction of the vehicle movement and the fan would then run through those smoke lines while another drone high enough (and maybe somewhat aside not to cause vertical air movement towards the smoke) would shoot the lines. If Derek's explanation is the correct one, this vehicle should be able to run through the smoke lines and the part of the smoke line that is hit by the vehicle will be delayed next to all the other areas. The only question is, will the smoke stay in visible clusters long enough when released into the wind?
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Autorotation is more like using the rotor as wings with really poor connection to the plane body. It's closer to airplane with a broken engine.
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Yes, this wouldn't work for plane because that cannot use the friction between the vehicle and the ground.
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@timoord1611 Supposedly this vehicle can do faster than wind so any smoke in front of the vehicle should go through the fan because the vehicle wouldn't run faster than wind. As such, a good demonstration would be to have the smoke quite a lot in front of the vehicle and when the vehicle catches the smoke (which is moving with the wind!) it's both obvious that this is indeed faster than wind movement and we would be able to see the wind movement near the fan.
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If I understand this correctly, basically the wheel breaking force is used to rotate the fan which then moves air faster than wind through the fan. As a result, the forward speed can be up to wind speed + the speed of air moved by the fan. The video failed to explain what the left side control actually did; was it similar to helicopter collective control?
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@Nabeelco The fact that rotor spins during the autorotation simply increases the wing speed and therefore causes more lift. Of course, if the rotor stops spinning, the wing speed is so low (the wings being the blades of helicopter rotor) that the helicopter is going to fall.
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Moving into headwind is obviously possible but not with this exact same design because this design requires that the vehicle can move slower than wind into downwind even if the propeller is anchored in place. Here's a very simple setup for moving directly into headwind: imagine a wind power station mounted on top of a tank where the tank has an electric motor. The wind is used to generate electricity which is then used to move tank. It's obvious that the tank can move (slowly) to any direction as long as the windmill is rotating. In this case, too, the tank is hold by the friction and the windmill extracts the power from wind movement relative to ground.
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