Down wind faster than the wind

[John Freestone]

I'm just doing some catching up and wanted to say that I agree with you and Marcus on this, spork (sorry I lost track)...

Ta-daaaa! No flywheels, no rags, no sticks in place of props. Seriously, spork or JB - have you not yet replaced the prop with a flywheel and put it on the treamill so that humber can dismiss the result as irrelevant?

Nope, but if humber defines the test and tells us what result he predicts I will do it.

...later...

There was the test that had you replacing the prop with a flywheel, but Humber backed out of that one, too, saying that the cart could go backwards, just not as fast as the belt. Thus making his prediction unfalsifiable, as any wheeled object would do this.

Yes, I remember that, and then forgot again. It's quite right, spork, for you not to test that once he didn't stick to his first prediction.

That's the repeated pattern - make a ridiculous prediction off the cuff, then, when people are amazed and ask for confirmation of it, wheedle out, backtrack, begin dismantling sentences so that nothing specific is said, or finally end up saying virtually the opposite and hoping no-one noticed. JB, yes, he's a liar. Christian, yes, like a kid caught chocolate-handed.

 

[CyCrow]

I keep being amazed by the sheer amount of WRONG being spouted by humber. Parachute drag force at maximum at terminal velocity? WTF? 70 pages and still thinks KE is absolute?

And no, parachutes do not behave like that. They can be designed to be like a 'constant' force or 'constant' velocity.

That's just ... wrong on so many levels. Constant force parachutes? Independent of relative air velocity? THAT's a over-unity device that would easily of DDWFTTW!

The gyroscope is also a complete red herring. Yes, on earth a gyroscope can detect the rotation of the earth and provide a latitude and true-north reference. That's because the earth rotates. It also means that a earth-surface reference frame is not strictly an inertial reference frame, but for all practical purposes the coriolis forces do not affect the cart, either on or off a treadmill.

// CyCrow

 

[John Freestone]

Funny how the JREF is doing database work 25-26 December. Reminds me of a public holiday, can't quite think what it is. Have a very merry forum downtime everyone...and a happy new database. I hear Santa's bringing me four casters and a cardboard box. I'm sure I can make a generic windcart with that.

 

[humber]

Tell me what a gyro registers other than change? With the gyro in steady state, tell me which output you would read from the gyro to determine velocity and what it would read?

Look it up. Gyrocompass.

Yes, to sense and to output *changes*. Not applicable in a steady state test.

No, it runs all the time. Try denying that is not steady state. Show me a gyro that is not a gyro. I need not accept you restrictions.

You can tell the entire world what you wish -- the gyro agrees with me and that is all that matters.

The gyro does not agree with you, but only what agrees with you, matters.

Tell me which output you would read from your timepiece to determine velocity and what it would read?

Ask a ship's captain.

You're still sensing change -- not relevant to a steady state test.

No, the earth is already here. You cannot have a new steady state upon demand. You cannot accomplish your goal. Unless you want to tell me the treadmill is magical.

I'm not saying my belt is moving -- I'm asking you to tell me if it is. You're saying that you can tell. You're failing however.

Your claim is trivial. Remove all means of measurement, and you can't tell anything. Go to the top of the class. You are building a sensory deprivation chamber, not to meet your "though experiment", but merely your "thought".
You are also faced with the problem that you can never prove your claim. All means denied me to detect the belt, will not allow any local measurements that you may use to support your claim. Like you, I can simply assert the opposite of your claim. Your argument is a nonsense.

Anyway, you cannot enforce your rules upon a real treadmill. I can do what I like, and certainly detect difference between that and your claimed frame of reference.
I can turn the tables upon you. You would need to demonstrate that the treadmill is equivalent. That you cannot do. It is loaded with contradictions, and internally inconsistent. On the other hand, I can conclude without any contradiction whatsoever, or reliance upon metaphor, that what is been shown to me, is a toy on a treadmill, spinning its propeller, as a result of being loosely coupled to the belt. A misappropriated exercise machine.

Now you're just a simple liar -- post #2217 written ~10 days ago: (excerpts)

While you are just...

Me:
>There is absolutely no experiment which can be
>performed without external reference

>the treadmill is turned on steady state.

Both "external reference" and "steady state" are covered clearly.

>A classic retreat.

A classic humberism -- lie and hope to get away with it.

JB

You can't enforce those conditions, that was the point

 

[humber]

I keep being amazed by the sheer amount of WRONG being spouted by humber. Parachute drag force at maximum at terminal velocity? WTF? 70 pages and still thinks KE is absolute?

I think that I said it could be controlled in such away, or built, but that doesn't matter. I will simply use a long spring. They model constant force quite well.

That's just ... wrong on so many levels. Constant force parachutes? Independent of relative air velocity? THAT's a over-unity device that would easily of DDWFTTW!

I should point out that my skater lives in the Newtonian world. If you want to impute yours on top of that, and that raises questions about your world, should answer them yourself.

The gyroscope is also a complete red herring. Yes, on earth a gyroscope can detect the rotation of the earth and provide a latitude and true-north reference. That's because the earth rotates. It also means that a earth-surface reference frame is not strictly an inertial reference frame, but for all practical purposes the coriolis forces do not affect the cart, either on or off a treadmill.
// CyCrow

Yes, they do spin. Their axis are aligned, so the rest should be obvious. A gyro is an inertial reference. I wonder how the treadmill stack up, if I introduce an independent reference like a gryro?

OK You say that KE is 'relative'. You say in the case of the treadmill, you can make that zero, because it is relative to that frame? No, I would like to see you do that, and show me that KE is not fixed to the moving object. I say it is not negotiable, or transferable between frames.

 

[spork]

It looks like humber is going to ignore my challenge to find anyone, anywhere, on or off this forum that agrees with him. I'd like to meet that person.

 

[spacediver]

Then it is accelerating. That will happen until opposing forces equal that of the parachute. That's its maximum velocity. If there is no significant opposing force, then why does it not continue to accelerate?
The skater can't be pulled by the parachutes 'velocity' alone.

It does not continue to accelerate because it is no longer experiencing a unbalanced force due to the tailwind.

Let me break it down in a bit more detail.

For the following, forget the skates - just imagine a small parachute hovering in the air.

In the above scenario, the parachute is simply hovering.

In this second figure, the wind suddenly picks up, and the air molecules impinge their kinetic energy upon the concave portion of the parachute. The parachute is motionless until these molecules hit it. These molecules carry a certain amount of kinetic energy, which is transferred to the parachute.

The parachute experiences a force due to the wind.

The critical thing to note here is that the force of the wind on the parachute is a function of the velocity of the wind relative to the velocity of the parachute.

If you do not understand this, or disagree, please state so clearly in your reply.

At this point in time, since the parachute is at 0 m/s and the wind is at 50 m/s, there is a difference of 50 m/s. Suppose this translates to 20 newtons.

The force of the wind on the parachute is 20 newtons.

Let's say the mass of the parachute is 1 kg.

F = MA; A = F/M; therefore the acceleration of the parachute at this moment in time is 20 Newtons/ 1 Kg = 20 m/s/s

Now another key thing to understand is that once the parachute starts moving, the velocity of the wind relative to the parachute starts changing.

As the parachute picks up speed, the relative difference between its speed and the windspeed becomes smaller and smaller.

And therefore, the force of the wind upon the concave portion of the parachute becomes smaller and smaller.

Now I know what you're thinking, when the parachute reaches maximum velocity, what about the resistance from the air molecules impinging upon the convex portion of the parachute (i.e. on the left edge of the parachute).

Yes there will be a little bit of air resistance, but the key thing to note is that since the parachute is no longer accelerating, it is no longer experiencing an unbalanced force (f=ma, and a = 0, therefore f = 0). That means that the force of air resistance upon the convex portion must equal the force of the air molecules hitting the concave portion. Now here's the key point: Since the velocity of the wind, relative to the parachute, is at a minumum (50-35 = 15 m/s), the force is also at a minimum.

 

[Christian Klippel]

OK You say that KE is 'relative'. You say in the case of the treadmill, you can make that zero, because it is relative to that frame? No, I would like to see you do that, and show me that KE is not fixed to the moving object. I say it is not negotiable, or transferable between frames.

Let's take the "bullet example" from some previous post here.....

If you fire a bullet from a gun, it has some KE relative to the ground. That is, relative to anyone that is "moving" at the same speed and direction as the ground.

Now, if i would move at the same speed and direction as the bullet, that bullet has 0 KE relative to me. That means that i can pick it up like a pencil on my table. So, the "KE" is negotiable, simply by choosing the frame i want.

Do you agree that in that example the bullet has zero KE relative to me, while i'm moving with the same speed and same direction as the bullet?

If not, you have some serious issues for that you should really consult some expert (read: doctor) to help you with.

 

[ThinAirDesigns]

Look it up. Gyrocompass.

Been there, done that -- the "gyro" portion only reacts to change and the "compass" portion violates the "no external referrence" clause of the test.

I need not accept you restrictions.

Of course you do, there the laws of the universe -- laws that you claimed you would beat. So far -- failure.

Ask a ship's captain.

I did, and he gave me the correct answer. I'm interested in your answer.

Your claim is trivial. Remove all means of measurement, and you can't tell anything.

I've said you can have any form of measurement you wish as long as it isn't using an "external reference". There's a reason for this -- the cart doesn't use any external reference. You are allowed only to know what the cart knows.

Go to the top of the class. You are building a sensory deprivation chamber, not to meet your "though experiment", but merely your "thought".
You are also faced with the problem that you can never prove your claim. All means denied me to detect the belt, will not allow any local measurements that you may use to support your claim. Like you, I can simply assert the opposite of your claim. Your argument is a nonsense.

I claim that neither you nor I can tell treadmill or not. You have said you can -- but you have been unable to respond to the challenge so now you lie and squirm.

Anyway, you cannot enforce your rules upon a real treadmill.

They are not my rules -- they are the laws of physics that the cart (and you) must abide by.

I can do what I like, and certainly detect difference between that and your claimed frame of reference.

You *can't* do as you like because without external reference, it's impossible. Not my rules.

You can't enforce those conditions, that was the point

More lies -- that *wasn't* your point. Your point was clear -- that I was changing the rules as I went along, and that was simply a lie. The "steady state" and "no external reference" requirements were included in the original challenge.

No go and lie no more -- just tell us what test you will use which does not include an external reference and will work within the steady state requirement of the test.

JB

 

[Christian Klippel]

No go and lie no more -- just tell us what test you will use which does not include an external reference and will work within the steady state requirement of the test.

JB

Hello JB,

i am waiting for that as well. After all, he said that any known measurement system can be used to determine velocity. Which, uhm, would include things like a beaker, a level, a ruler ... well, you know, any measurement system. I'd really like to see him judge his velocity by using a digital multimeter alone. Or a beaker, or ....

Not that i expect him to come up with any sensible answer, but it's fun to try anyways. After all, with every "answer" he gives all he does is to give a really great example of how to not behave on a public forum if you want people to take you serious. He really fails big time at that.

Greetings and happy holidays,

Chris

 

[Dan O.]

humber apparently knows some big words but doesn't really understand them. For instance, A GPS calculates its position and motion from signals it receives from the GPS satellites. We can block these signals with simple shielding and even introduce a fake signal to make the GPS read anything we want (equipment to do this is available specifically for testing GPS systems).

(side note: If you were involved with GPS in the early days, there was a fake signal incorporated in the GPS signals called Selective Availability that caused public GPS receivers to give inaccurate position and velocity reports. This was purportedly done so that our enemies could not use the GPS system against us in a time of war. However, the first tome we got into a major conflict where GPS was used (the first Gulf war), SA was turned off because the military did not have enough of their special receivers and equipped the troops with commercial receivers like any hiker would have.)​

That humber wants to use gyros and accelerometers to measure absolute velocities and position indicates that humber doesn't know about the problem of "Integration Drift" associated with inertial navigation systems. The very concept that we are trying to teach humber is the reason that INS fails and GPS was developed.

 

[Christian Klippel]

humber apparently knows some big words but doesn't really understand them. For instance, A GPS calculates its position and motion from signals it receives from the GPS satellites. We can block these signals with simple shielding and even introduce a fake signal to make the GPS read anything we want (equipment to do this is available specifically for testing GPS systems).

(side note: If you were involved with GPS in the early days, there was a fake signal incorporated in the GPS signals called Selective Availability that caused public GPS receivers to give inaccurate position and velocity reports. This was purportedly done so that our enemies could not use the GPS system against us in a time of war. However, the first tome we got into a major conflict where GPS was used (the first Gulf war), SA was turned off because the military did not have enough of their special receivers and equipped the troops with commercial receivers like any hiker would have.)​

That humber wants to use gyros and accelerometers to measure absolute velocities and position indicates that humber doesn't know about the problem of "Integration Drift" associated with inertial navigation systems. The very concept that we are trying to teach humber is the reason that INS fails and GPS was developed.

Hello Dan,

even more, if we receive a GPS signal, one assumes that the satelites are "steady" with respect to out position. That means that they are always "on the same spot" if we look up to them. If they would "move around", the GPS receiver would tell us that we are moving on the earth's surface, even if that is not true. Talk about reference frames. Not to mention that their clocks get set up while on earth to compensate for the relativistic effects that occur when they are shot into space.

Oh, and still the regular GPS signal has much less "resolution" compared to what the military can get out of them. But that is not a problem of the satelites, but of the receiver's softwares which limits the usable resolution. But of course the "nowdays" resolution is much better than some years ago.

But the, as we all have learned, there are no relative frames in the humberverse, only absolute stuff bound to the earth.

Happy xmas to you as well,

Chris

 

[spacediver]

Another way for the skater to move faster than the wind is to have a pulley attached to the parachute with the skater holding both ends of the rope with a loop on one end of the rope. When the skater reaches maximum speed in the wind, they throw the loop over a stake pounded into the ice and hold on to the other end of the rope! Crack The Whip with a parachute!

lol I had a wonderful time visualizing that. Thanks for the gem.

 

[spork]

I guess we can assume humber is off on his search for anyone anywhere that will agree with him on anything. Personally, I can hardly wait.

 

[Dan O.]

Hello Dan,

even more, if we receive a GPS signal, one assumes that the satelites are "steady" with respect to our position.

The individual GPS satellites are assumed to all be moving at different velocities relative to the receiver. Every satellite is transmitting a similar signal on precisely the same frequency. If they weren't moving, there would not be a Doppler shift to separate the signals.

The ephemeris for the satellite orbits are updated by ground based tracking stations so the satellite signals are referenced to the ground.

ETA: The last statement is somewhat misleading, The ephemeris is a set of numbers describing the satellites orbit in a non rotating earth centered reference frame aligned to the fixed stars.

 

[humber]

Originally Posted by Dan O. View Post

humber apparently knows some big words but doesn't really understand them. For instance, A GPS calculates its position and motion from signals it receives from the GPS satellites. We can block these signals with simple shielding and even introduce a fake signal to make the GPS read anything we want (equipment to do this is available specifically for testing GPS systems).

Some small words escape you there, Dan_O.

(side note: If you were involved with GPS in the early days, there was a fake signal incorporated in the GPS signals called Selective Availability that caused public GPS receivers to give inaccurate position and velocity reports. This was purportedly done so that our enemies could not use the GPS system against us in a time of war.

Cats like fish, particularity red herrings. You try too hard, again.
No, I was not involved in the early days of GPS. I do know that PBRS sequences were (are) restricted so to that the resolution was dependent upon the knowledge of the receiver. ( e.g. enemies or not)
PBRS sequences are also useful in a number of applications, perhaps you'd like to try tour luck against me with one of those, where you have to think without Wikki.

However, the first tome we got into a major conflict where GPS was used (the first Gulf war), SA was turned off because the military did not have enough of their special receivers and equipped the troops with commercial receivers like any hiker would have.)

Did you get fries with that last information? Do you think that information may have been a "fake signal" of another sort? Ha!

The remainder only confirms that I can indeed take that measurement unless you stop me. Furthermore, I can argue that all the would be technical inaccuracies are moot. If you can have an infinite belt, I can have an infinity accurate GPS or gyroscope.

That humber wants to use gyros and accelerometers to measure absolute velocities and position indicates that humber doesn't know about the problem of "Integration Drift" associated with inertial navigation systems.

The accelerometer will be adequate to detect the belt's acceleration whenever necessary. If there is no change in wind, that will alert me to the fact that my environment is artificial.
But you cannot deny that these tools work. You are equivocating over accuracy to save face.
Same rules apply to gyros. No need for pinpoint precision. The gyro compass has a "steady state" history that is incorporated in its compensation mechanism. More than good enough.

Hello Dan,
even more, if we receive a GPS signal, one assumes that the satelites are "steady" with respect to out position. That means that they are always "on the same spot" if we look up to them. If they would "move around", the GPS receiver would tell us that we are moving on the earth's surface, even if that is not true. Talk about reference frames. Not to mention that their clocks get set up while on earth to compensate for the relativistic effects that occur when they are shot into space.

Yes, Geostationary orbit. The system's designers seem to be more than a match for you, as they have solved all those problems.
Actually not. The compensation process is continuous, and more complicated than you may expect.
I see the genesis if of a new excuse. "Sorry I am late; stuck in traffic" becomes "I lost my frame of reference".

Oh, and still the regular GPS signal has much less "resolution" compared to what the military can get out of them. But that is not a problem of the satelites, but of the receiver's softwares which limits the usable resolution. But of course the "nowdays" resolution is much better than some years ago.
But the, as we all have learned, there are no relative frames in the humberverse, only absolute stuff bound to the earth.
Happy xmas to you as well,
Chris

"Nowadays", all of the above are locker room excuses.

 

[humber]

The individual GPS satellites are assumed to all be moving at different velocities relative to the receiver. Every satellite is transmitting a similar signal on precisely the same frequency. If they weren't moving, there would not be a Doppler shift to separate the signals.

The ephemeris for the satellite orbits are updated by ground based tracking stations so the satellite signals are referenced to the ground.

ETA: The last statement is somewhat misleading, The ephemeris is a set of numbers describing the satellites orbit in a non rotating earth centered reference frame aligned to the fixed stars.

And there was I thinking that I could use a GPS from Walmart.

 

[humber]

I guess we can assume humber is off on his search for anyone anywhere that will agree with him on anything. Personally, I can hardly wait.

Ahhh, go one. New Year soon. See if you can find a professor who will agree with you.

 

[humber]

Hello JB,

i am waiting for that as well. After all, he said that any known measurement system can be used to determine velocity. Which, uhm, would include things like a beaker, a level, a ruler ... well, you know, any measurement system. I'd really like to see him judge his velocity by using a digital multimeter alone. Or a beaker, or ....

Not that i expect him to come up with any sensible answer, but it's fun to try anyways. After all, with every "answer" he gives all he does is to give a really great example of how to not behave on a public forum if you want people to take you serious. He really fails big time at that.

Greetings and happy holidays,

Chris

I see your problem! An oscillikcope doesn't just measure oscillies. No, with some imagination, it can measure all sorts of things.

 

[humber]

Let's take the "bullet example" from some previous post here.....

If you fire a bullet from a gun, it has some KE relative to the ground. That is, relative to anyone that is "moving" at the same speed and direction as the ground.

Now, if i would move at the same speed and direction as the bullet, that bullet has 0 KE relative to me. That means that i can pick it up like a pencil on my table. So, the "KE" is negotiable, simply by choosing the frame i want.

Do you agree that in that example the bullet has zero KE relative to me, while i'm moving with the same speed and same direction as the bullet?

If not, you have some serious issues for that you should really consult some expert (read: doctor) to help you with.

No, it does not have zero KE relative to you. It has zero velocity relative to you.
What you have done is given another example of how you achieve the same result.
Your challenge is to show that KE or momentum are relative. How does that work? Where does it go?

Two objects in the air:
Object A: 7J wrt ground
Object B: 3J wrt ground
Total 10J
A relative to B 4J
B relative to A 4J (-4J??)
Total 8J
That's what I get, if I use your methods. Please explain.

If I have 3 objects, does the KE circulate with the observer? What if there are 10E6 objects? How is the information conveyed over distance as the viewer moves about?