Video: A Physics Prof Bet Me $10,000 I'm Wrong

[lakeroadster]

Check this out...

"A UCLA Physics Professor bet me $10,000 that my video about going downwind faster than the wind was wrong."

 

[Funkworks]

FWIW, Derek is a PhD himself, who specialized in education. He makes a living with this by having a very successful channel. Not to be messed around with lightly!

https://en.m.wikipedia.org/wiki/Derek_Muller

 

[lakeroadster]

FWIW, Derek is a PhD himself, who specialized in education. He makes a living with this by having a very successful channel. Not to be messed around with lightly!

https://en.m.wikipedia.org/wiki/Derek_Muller

Sign of the times. A PhD making more money on You Tube videos... than in industry or traditional academics.

 

[neil_w]

Sign of the times. A PhD making more money on You Tube videos... than in industry or traditional academics.

Well... traditional academics was never a path to making a lot of money.

Having a Youtube channel with millions of subscribers, on the other hand... it's like being the star of a popular TV show.

 

[Funkworks]

Sign of the times. A PhD making more money on You Tube videos... than in industry or traditional academics.

On YouTube, it’s about how many views they get, not the degree. He clearly puts in a lot of work and it seems like he molded himself perfectly for that job (rather than research), just as YouTube was beginning.

 

[bjphoenix]

Some of that might be clickbait. I'm an engineer and a wanna-be engineer on youtube posted an open invitation for someone to prove him wrong for $10,000. I proved him wrong but never received a check.

 

[KenECoyote]

Logically it doesn't make sense to me that you can have an object go faster than the wind blowing it... especially given friction in the system, but there were bigger brains here than mine and probably some factor I'm missing.

Also the treadmill negates the need to gain momentum necessary to accelerate an object.

So this is actually better than perpetual motion?

 

[Sooner Boomer]

Logically it doesn't make sense to me that you can have an object go faster than the wind blowing it... especially given friction in the system, but there were bigger brains here than mine and probably some factor I'm missing.

Also the treadmill negates the need to gain momentum necessary to accelerate an object.

So this is actually better than perpetual motion?

The correct and accurate way to state this is that it can go faster across the ground/water faster than the speed of the wind. It's a matter of vector sums. If the wind is blowing from the north to the south, a sailboat can move from northeast to southwest at a higher velocity than the wind. If the sailboat was traveling from north to south (directly downwind), its velocity would be lower than that of the wind, even if it's running wing-and-wing.

 

[cls]

it doesn't make sense to me that you can have an object go faster than the wind blowing it...

Iceboats do it, land sailors do it, windsurfers do it, beach catamarans do it, hydrofoil sailboats do it... It's called lift and apparent wind.

My hydrofoil sailboat would easily do 25 to 30 in 12 mph wind; or over 40 if I had it just right angle to the wind.

I won't divulge the trick of the video, but once it gets going, the propeller on the buggy isn't doing what you think it is.

 

[KenECoyote]

Iceboats do it, land sailors do it, windsurfers do it, beach catamarans do it, hydrofoil sailboats do it... It's called lift and apparent wind.

My hydrofoil sailboat would easily do 25 to 30 in 12 mph wind; or over 40 if I had it just right angle to the wind.

I won't divulge the trick of the video, but once it gets going, the propeller on the buggy isn't doing what you think it is.

The correct and accurate way to state this is that it can go faster across the ground/water faster than the speed of the wind. It's a matter of vector sums. If the wind is blowing from the north to the south, a sailboat can move from northeast to southwest at a higher velocity than the wind. If the sailboat was traveling from north to south (directly downwind), its velocity would be lower than that of the wind, even if it's running wing-and-wing.

Ah, yes...I was assuming a 2D side view of things and forgetting about vectoring across the direction of the wind. Thanks both!
So the bet should've been made that it can't go faster in the same direction as the wind is blowing it. I'm surprised that professor didn't take that into account.

 

[neil_w]

Yeah, but the test was to go same direction of the wind... so all the side vector issues do not apply.

I watched the original video and the follow-ups and still don't really understand the phenomenon I'm seeing.

 

[jderimig]

Earlier post mentioning vectors had it. Sail craft can have a vector velocity component upwind. So yes you can go faster downwind than windspeed if you define the csys appropriately.

High performance boats, cataramans jibe downwind because velocity made good is higher than windspeed. (Also there maybe a current that can help further).

 

[boatgeek]

Sign of the times. A PhD making more money on You Tube videos... than in industry or traditional academics.

I mean, Hedy Lamarr had a patent on the technology that more or less became WiFi. Most people don't remember her for that. Also, there are very many fields in which a PhD can make more money than in academia. For many fields, welding is probably one of them.

Why is a math PhD like a medium pizza?
It can just about feed a family of four.

[told to me by a student whose nuclear family has more PhDs than members]

 

[Kelly]

Note that the craft/method described in this video is capable of going faster than the wind IN THE DIRECTION THE WIND IS BLOWING. So, if the wind is blowing due south, this vehicle can head due south, and go faster than the prevailing wind. There are no angles or cross-wind vectors involved here.

 

[davel]

This was all hashed over over 10 years ago. Yes, the 'Blackbird' (https://en.wikipedia.org/wiki/Blackbird_(wind-powered_vehicle))can go faster downwind than the speed of the wind itself. The power used by the vehicle is proportional to both the vehicle's current speed and the force on the vehicle in the same way that the HP of an motor/engine is proportional to the motor's speed and torque. The Blackbird trades off some of the force on the vehicle from the wind to gain greater speed. *Very* similar to the way a sailboat can move faster than the wind in a tack.

 

[jderimig]

.....

 

[bjphoenix]

Yeah, but the test was to go same direction of the wind... so all the side vector issues do not apply.

I watched the original video and the follow-ups and still don't really understand the phenomenon I'm seeing.

The propeller is driven by the wheels, so once it starts moving the wheels power the propeller, and if there is enough push from the propeller it can go faster. Before I knew better I wondered why someone didn't build an electric motor with a fan on it and point it at a generator with a fan on it so it could generate electricity to power the motor. Either mechanism seems to be what could be called a "perpetual motion machine" which we are told is impossible. But if you accept that the propeller car can generate more push than its drag, why doesn't it continue to go faster and faster? I cannot give an argument for why the device wouldn't go faster than the wind, other than the perpetual motion aspect of it.

 

[Sooner Boomer]

I confess, I hadn't watched the video until just now. I think all the explanations leave stuff out, they don't account for all of the forces involved.

My previous comments about sails are still true, they're just nor relevant in this example (sorry, next time I'll watch the video first)(no I won't)