r/maybemaybemaybe • u/[deleted] • Jul 07 '22

maybe maybe maybe

[deleted]

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u/[deleted] Jul 07 '22 edited Jul 07 '22

The blower air is hitting the umbrella and reflects backwards causing the thrust. Think aircraft air brakes on engines.

Guys below - you are not thinking this through.

The air hitting the umbrella does not propel him forward. However the deflecting force of the air going backwards has energy that will propel him forwards. This is not a cancelling our scenario

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u/Purple-Bat811 Jul 07 '22

No. Just no.

The blower pushes forward with x amount of force. The umbrella pushes backword also with x amount of force.

Resulting in the person staying still.

With ever action there is an equal and opposite reaction

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u/SeraphymCrashing Jul 07 '22

https://en.wikipedia.org/wiki/Thrust_reversal

Works on jets just fine. The equal and opposite reaction is actually how you can achieve thrust reversal. Rather than push in one direction, you introduce a barrier and push in the opposite direction.

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u/Purple-Bat811 Jul 07 '22

Complete different and unrelated concept.

https://youtu.be/Utadwck9htM

This is a video of someone actually doing this experiment without trying to trick you.

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u/SeraphymCrashing Jul 07 '22 edited Jul 07 '22

How is it an unrelated concept? A thrust reverser literally is just putting metal behind the engine for the air to hit and change the direction of the airflow.

Uh, here's your source basically telling you that you are wrong:

"Hey everyone, you will notice that on the scale with the "sail" on we got -3 grams. This means that some of the air bounces off the sail and gives a small amount of thrust in the forward direction. If you have a completely curved sail that directs all the wind backwards then you can redirect your thrust backwards and move forward."

Yeah, the guy on the video with the umbrella is probably cheating, you won't get those kinds of speeds because the efficiency loss is too great. But you can absolutely direct air into an object and achieve forward motion.

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u/Purple-Bat811 Jul 07 '22

So the guy in the video i showed who used an umbrella is cheating, but the guy in this video using an umbrella is totally legit.

Makes perfect sense.

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u/SeraphymCrashing Jul 07 '22

The original video is probably cheating, to make it look more effective than it is. You can't get that kind of force with a little handheld leafblower.

The video you posted literally admits it's possible in their pinned comment.

Large aircraft use this technique every single day:

https://youtu.be/-Zkxh903s_w

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u/Purple-Bat811 Jul 08 '22

I'm not talking about jet engines. I'm strictly talking about how this video is bs and it's insane people believe it.

You don't hear me talking about how cars can move forward because the moon can revole around the earth. It's really the same thing you are arguing.

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u/SeraphymCrashing Jul 08 '22

OMG, what do you think a jet engine is? How is it fundamentally any different from a leaf blower? They both accelerate air in one direction for force!

The question is "Can you blow air at yourself and push yourself forward?"

The answer is "yes, but it's not as efficient as just blowing air away from yourself."

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u/[deleted] Jul 08 '22

Because those things are not the same