Veritasium direct downwind video debunked

[Dacian]

Finally got around to setup my experiment to show how the direct downwind faster than wind cart actually works.
The Rigol 12bit oscilloscope was also very helpful for accurate force and current measurements.

I demonstrate that cart accelerates forward for 8 seconds and after that it decelerates as all the potential energy at the start was used up.
So direct downwind carts can only exceed wind speed for a limited amount of time proportional with the amount of stored energy in the form of pressure differential (below 2 Joule in my experimental setup) and after that energy is used up the cart decelerates (cart slows down).

Edit by gnif: Self promotion removed, this is the banned user `electrodacus`

[Andy Chee]

Here's a build video of Veritasium's model cart on treadmill providing continuous thrust:

[Dacian]

Here's a build video of Veritasium's model cart on treadmill providing continuous thrust:

It is not continuous thrust. They just did not measure that and made assumption of how and why it works.
That cart will work the same way as the one I build, meaning the cart speed after release increases as potential energy in the form of pressure differential is converted in to cart kinetic energy and heat  due to frictional losses.
When that energy is used up the cart will start to slow down as I demonstrated.

[Gregg]

If I were to bet money on this, I’d bet on Veritasium.

Just because you haven’t duplicated the experiment, doesn’t mean you have debunked it.

The principle is the same as a sail on a sailboat. Many sailboats can go considerably faster than the wind when sailing a broad reach maximizing the thrust by trimming the sails. 

In the Veritasium experiment the propeller acts as a sail, but it isn’t directly propelling the model but it is using its rotary motion to impart additional forward thrust via the wheels.  It is far from a practical vehicle but it is possible.  Getting the exact propeller design and gear ratios to the wheels only works for a narrow set of circumstances.  Note in the Xyla Foxlin video how they had to try a large variety of propellers and wheel diameters in order to achieve any success. In addition Xyla did an exemplary job of keeping things simple, lightweight and efficient.  Making a more complicated model would probably add mass, friction and inefficiency to the point of negatively affecting the experiment.

[Andy Chee]

In your video, you release your hand at steady state at ~17 seconds, then forward thrust, then fade to black cut the video at ~30 seconds.

If the potential energy is completely used up, then the treadmill should force the cart backwards.  Please show the cart moving backwards.

Also please note that Xyla's cart build is available for download (the bill of materials is in the video description):

https://www.thingiverse.com/thing:4897423

Please test her cart instead of your design.

[SiliconWizard]

Well, ok, but you made 469 views and Derek 27M views cumulated on both videos, and 1.5M for Xyla.
What can you say.

[Haenk]

Google "Racing Aeolus"

Debunking debunked. Next.

A local (to me) professor created the first "Gegenwindfahrrad" in 1992, so it is claimed.

[IanB]

Finally got around to setup my experiment to show how the direct downwind faster than wind cart actually works.
The Rigol 12bit oscilloscope was also very helpful for accurate force and current measurements.

I demonstrate that cart accelerates forward for 8 seconds and after that it decelerates as all the potential energy at the start was used up. So direct downwind carts can only exceed wind speed for a limited amount of time proportional with the amount of stored energy in the form of pressure differential (below 2 Joule in my experimental setup) and after that energy is used up the cart decelerates (cart slows down).

All you can demonstrate with that experiment is that you don't know how the cart works, and that you therefore failed to build a working model.

You cannot use your failure to build something that works to prove that nobody else can build one that works.

It would be like saying "I tried to build a powered aircraft, in order to show how such aircraft work. I demonstrate that my aircraft only flew for a few feet before coming back down, and was unable to sustain continuous flight. So I conclude that powered aircraft can only manage to fly for a short distance before having to land again."

Can you see the problem with this approach?

[gnif]

`Dacian` has been banned for ban-evasion, the account is an alt of the already banned user `electrodacus`

[SiliconWizard]

Was it the aether guy? Not sure anymore.

[Dan123456]

Now this thread is basically dead, just outta curiosity, why are alt accounts a no no?

I know it is pretty much a standard practice for forums to have rules against them and respect that you guys have the right to make and enforce whatever T’s and C’s you like  That said, I’ve never understood the reasoning behind that rule specifically it so figured I’d ask now it’s come up 

Is it just because most people with alt accounts are usually using one to be a dick or using them as a way to circumvent a ban etc.?

Obviously this case is pretty clear cut as their previous account was banned before but have always just wondered why the rule about alt accounts was there 

[Halcyon]

Now this thread is basically dead, just outta curiosity, why are alt accounts a no no?

Because 99.9% of the time, it's a spammer, troll etc... If you contacted one of the mods or Dave and had a genuine reason to have a second account, we'd consider it.

We don't ban users lightly. It usually take a lot for someone to be banned (if they aren't just a bot/spammer) and generally it's as a result of many reports from other users, telling moderators to get fucked* when they've been asked to pull their head in, or if they are just overtly causing trouble.

On the flip side, I've unbanned people if they come to be and genuinely apologise for being a dick. I completely understand that there are people who are neurodiverse and sometimes things can be taken the wrong way, or they are just having an "off week". We're humans too.

* If I'm faced with abuse when I'm genuinely trying to help and provide second, third or fourth chances, you'll lose that fight. I'm sure the other guys are the same. If I wouldn't accept a certain behaviour in-person, I won't accept it here. Hiding behind a keyboard isn't an excuse to be abusive.

[Dan123456]

Now this thread is basically dead, just outta curiosity, why are alt accounts a no no?

Because 99.9% of the time, it's a spammer, troll etc... If you contacted one of the mods or Dave and had a genuine reason to have a second account, we'd consider it.

We don't ban users lightly. It usually take a lot for someone to be banned (if they aren't just a bot/spammer) and generally it's as a result of many reports from other users, telling moderators to get fucked* when they've been asked to pull their head in, or if they are just overtly causing trouble.

On the flip side, I've unbanned people if they come to be and genuinely apologise for being a dick. I completely understand that there are people who are neurodiverse and sometimes things can be taken the wrong way, or they are just having an "off week". We're humans too.

* If I'm faced with abuse when I'm genuinely trying to help and provide second, third or fourth chances, you'll lose that fight. I'm sure the other guys are the same. If I wouldn't expect a certain behaviour in-person, I won't accept it here. Hiding behind a keyboard isn't an excuse to be abusive.

Ah awesome! That makes sense 

I had always seen that rule on pretty much every forum I’ve been on and was just a little confused as to why it was there 

Thank you so much for the reply 

[EEVblog]

Yes, forums have to have rules like ban evasion for obvious reasons, otherwise you might as well just have a free-for-all forum with no rules and no bans.

Electrodacus created this account to avoid the ban, and we eventually noticed. He's asked or his old electrodacus account back. I personally don't recall what he was banned for in the first place.
Obviously we don't just ban for talking about physics like we have here, we even let wacy free energy people discuss stuff on the forum if they are aren't otherwise creating trouble and generating user reports.

[EEVblog]

FYI, after discussion we have agreed to reinstate the Electrodacus account.
The Dacian account will remian banned as we generally don't allow multiple accounts as a rule.

[Brumby]

FYI, after discussion we have agreed to reinstate the Electrodacus account.

Your prerogative.

He'll remain on my "Don't waste your breath" list.

Why?

He's either:
 1. A troll who gets their kicks watching others run around trying to explain - where he couldn't care less about the facts.
 or
 2. A classic Dunning-Kruger candidate who just cannot see where their logic is flawed - and refuses to even concede that possibility.

As such, I warn any potential member with good intention to be mindful of the following saying:
"A man convinced against his will,
Is of his own opinion still."

[IanB]

FYI, after discussion we have agreed to reinstate the Electrodacus account.
The Dacian account will remian banned as we generally don't allow multiple accounts as a rule.

I would be good if this reinstatement could be conditional on not trying to discuss "direct downwind" or any related topics in any shape or form. It was relentless trolling in this area that provoked the original ban.

[5U4GB]

Obviously we don't just ban for talking about physics like we have here, we even let wacy free energy people discuss stuff on the forum if they are aren't otherwise creating trouble and generating user reports.

It's good to have a policy like this.  One of the major physics forums has an annoying policy of an absolute ban on free-energy discussions, including ones like "Can someone explain to me why this alleged free-energy device doesn't do what it claims?".  This is really annoying because it's one of the few forums that has people qualified to explain where the hole in the argument is, everywhere else it's just people guessing.

[electrodacus]

Thanks for reinstating my original account.
As I do not want to lose this I will no longer discus physics problems on this forum.
Gambling is illegal else I will bet Derek Veritasium that started all this and have someone like Kusenko be the judge.
For those that think this is some experimental flaw try and make measurements and you will get the same results using Xyla's design.
Do not replay to this as I will no longer read this post.

[spork]

If I were to bet money on this, I’d bet on Veritasium.

Boy do I have good news...
I'm here to offer the same $10K vote that Derek offered Professor Kusenko.  Anyone that wants to bet against Veritasium - this is your chance.


Just because you haven’t duplicated the experiment, doesn’t mean you have debunked it.

The principle is the same as a sail on a sailboat. Many sailboats can go considerably faster than the wind when sailing a broad reach maximizing the thrust by trimming the sails. 

Note in the Xyla Foxlin video how they had to try a large variety of propellers and wheel diameters in order to achieve any success.

That's only because Xyla didn't initially understand the principle of this thing.  When I spoke to her, she went out and bought the correct propeller and it worked fine.  Ultimately the important thing is simply that the propeller has to be trying to advance through the air more slowly than the wheels advance on the surface.  How much more will determine how efficient you need to make the cart.

[ridgerunner]

... Making a more complicated model would probably add mass, friction and inefficiency to the point of negatively affecting the experiment.

You mean like my Frankenkart?

[spork]

Gambling is illegal else I will bet Derek Veritasium that started all this and have someone like Kusenko be the judge.

This is a lie.  I've been trying for months to get e'dufus to take the same bet Derek gave Kusenko.  He simply won't do it.  He claims it would be unfair to take my money.

[NiHaoMike]

It's good to have a policy like this.  One of the major physics forums has an annoying policy of an absolute ban on free-energy discussions, including ones like "Can someone explain to me why this alleged free-energy device doesn't do what it claims?".  This is really annoying because it's one of the few forums that has people qualified to explain where the hole in the argument is, everywhere else it's just people guessing.

I think those free energy scam devices were invented by the fossil fuel industry as a distraction from free energy devices that do work. Some then say that solar panels aren't free energy since the panels aren't free, where do I get a free energy device (working or not) for truly free? Even if it turns out to be useless for making energy, I could at least try to make it useful for something.

[EEVblog]

NOTE: I have split the discussion of being WRONG into another thread:
https://www.eevblog.com/forum/chat/what-if-someone-is-wrong-on-this-forum/

[EPAIII]

I see too much hands_on of the cart. That probably includes downward force that keeps those rubber tired wheels in firm contact with the belt. So yes, the propeller and wheels both have stored energy when it is released. I have to wonder what it would do if it were allowed to run on the treadmill for a minute or two with NO force except to hold it in the fore-aft direction before it being very gently released to run on it's own with no outside forces/guidance. But for that it needs at least a steering mechanism to keep it centered. And that steering mechanism can not be mechanically tied to anything external to the cart. 

I fear this cart demonstration is inconclusive.

Here's a build video of Veritasium's model cart on treadmill providing continuous thrust:

It is not continuous thrust. They just did not measure that and made assumption of how and why it works.
That cart will work the same way as the one I build, meaning the cart speed after release increases as potential energy in the form of pressure differential is converted in to cart kinetic energy and heat  due to frictional losses.
When that energy is used up the cart will start to slow down as I demonstrated.