The Motor Boat

[Neddy Bate]

In 22.5 seconds the cruise ship traveled 20.4375 meters in the harbor.

That is the same thing Pete told you here, and look how you replied:

So, in the 22.5 seconds it takes the boat to go the length of the pool, the whole pool moves 20.4 metres.
So, the little boat actually moves 70.4 metres if it's moving in the same direction as the ship (downstream), but only 4.6 metres if it's moving in the other direction (upstream).

Pete, you can't be serious??

Why is it okay for you to do arithmetic, but when Pete does it you object?

In 22.5 seconds the boat traveled 70.4375 meters in the preferred frame [harbour frame].

That is the same thing Pete told you here, and look how you replied:

So, in the 22.5 seconds it takes the boat to go the length of the pool, the whole pool moves 20.4 metres.
So, the little boat actually moves 70.4 metres if it's moving in the same direction as the ship (downstream), but only 4.6 metres if it's moving in the other direction (upstream).

Pete, you can't be serious??

Again, why is it okay for you to do arithmetic, but when Pete does it you object?

Now all you have to do is calculate the distance the model boat traveled "upstream" (in the opposite direction as the cruise ship) to be 4.6 meters, and you will have duplicated Pete's results.

By the way, what is the speed of the model boat in the preferred frame?

 

[Pete]

In 22.5 seconds the boat traveled 50 meters in the pool.
In 22.5 seconds the pool traveled 0 meters in the cruise ship.
In 22.5 seconds the cruise ship traveled 20.4375 meters in the harbor.
In 22.5 seconds the harbor traveled 0 meters in the preferred frame.
In 22.5 seconds the boat traveled 70.4375 meters in the preferred frame.
In 22.5 seconds the cruise ship traveled 20.4375 meters in the preferred frame.
In 22.5 seconds the pool traveled 20.4375 meters in the preferred frame.

So are we agreed that for the little boat in the moving pool, the velocities add linearly?
I.e. the little boat's total speed is its still-water speed plus the speed of the water.

What's your point?? The motion of the cruise ship doesn't equate to a current in the pool. The water is at rest in the pool. The water is not moving relative to the pool. In comparison, the water in a still body of water is not moving, it is still water. NO CURRENT.

Well, I'm not so sure. After all, the water in the pool is actually moving at 3.27km/h, right?

Let's try this:
Would it make a difference to the little boat if the pool was not on a ship, but was floating along in a current at the same speed?
Now, what if the walls of the pool were a very thin sheet of plastic?
Now what would happen if that thin sheet of plastic was slipped away? Would it make any difference to the little boat?

 

[Motor Daddy]

That is the same thing Pete told you here, and look how you replied:

Why is it okay for you to do arithmetic, but when Pete does it you object?

That is the same thing Pete told you here, and look how you replied:

Again, why is it okay for you to do arithmetic, but when Pete does it you object?

Now all you have to do is calculate the distance the model boat traveled "upstream" (in the opposite direction as the cruise ship) to be 4.6 meters, and you will have duplicated Pete's results.

Pete was claiming the boat traveled 70.4 meters in WATER because he has no preferred frame, remember? I can draw up this exercise and it will look almost exactly like 1452-1456. Can Pete draw it up showing his numbers add up with light? I'd like to see it!

By the way, what is the speed of the model boat in the preferred frame?

In the preferred frame the boat travel 70.4375 meters in 22.5 seconds, so in the preferred frame the the boat's speed is 3.13 m/s.

Do not try saying that the boat traveled 70.4375 meters of water, because it didn't. The boat traversed 50 meters of water in 22.5 seconds.

 

[Neddy Bate]

Pete was claiming the boat traveled 70.4 meters in WATER because he has no preferred frame, remember?

I understood what Pete meant, and I think most reasonable people would also. He meant that the harbor frame would measured the distance traveled by the model boat to be 70.4 meters.

In the preferred frame the boat travel 70.4375 meters in 22.5 seconds, so in the preferred frame the the boat's speed is 3.13 m/s.

You still have not told me the model boat's distance or speed through the preferred frame when it travels in the opposite direction, but that's alright, I know the answer.

 

[Motor Daddy]

So are we agreed that for the little boat in the moving pool, the velocities add linearly?

If you have a preferred frame like I do, but you don't, do you?

I.e. the little boat's total speed is its still-water speed plus the speed of the water.

The little boat travel 70.4375 meters in 22.5 seconds in the preferred frame. The preferred frame is not made of water.

Well, I'm not so sure. After all, the water in the pool is actually moving at 3.27km/h, right?

Right. The water is at rest in the pool and the pool is at rest on the cruise ship, and the cruise ship is traveling at the speed of 3.27km/hr in the preferred frame so the pool and the water each travel 3.27km/hr along with the cruise ship in the preferred frame.

Let's try this:

Would it make a difference to the little boat if the pool was not on a ship, but was floating along in a current at the same speed?

Yes, because the boat has to travel 70.4375 meters in the preferred frame and 50 meters in the water, so how does the little boat accomplish traveling two different speeds in the same body of water?

Now, what if the walls of the pool were a very thin sheet of plastic?

Then the plastic is also traveling along in the preferred frame.

Now what would happen if that thin sheet of plastic was slipped away? Would it make any difference to the little boat?

No, because all that time the boat was traveling in water for 70.4375 meters, which is quite different than the little boat traveling only 50 meters in water, wouldn't you say so too?

 

[Motor Daddy]

I understood what Pete meant, and I think most reasonable people would also. He meant that the harbor frame would measured the distance traveled by the model boat to be 70.4 meters.

Right, and the harbor frame knows that the pool traveled 20.4375 meters and the boat traveled 50 meters in the pool. Clearly! The harbor frame knows that the boat did not traverse 70.4375 meters of water, it only traversed 50 meters of water in 22.5 seconds

You still have not told me the model boat's distance or speed through the preferred frame when it travels in the opposite direction, but that's alright, I know the answer.

What opposite direction? A toy boat traveled in the x direction from one end of the pool to the other in 22.5 seconds. That's it. Do you want to lay out the details of the round trip times and velocities for us all, Neddy Bate? I'd like to see that as well. Maybe Pete can draw it up so we can all see how it looks in Einstein's world.

 

[Pete]

If you have a preferred frame like I do, but you don't, do you?

I call it the embankment frame.

The little boat travel 70.4375 meters in 22.5 seconds in the preferred frame. The preferred frame is not made of water.

Right, in the embankment frame, the little boat moves at 8+3.27 km/h.
The embankment frame is not made of anything. It's a reference frame.

Yes, because the boat has to travel 70.4375 meters in the preferred frame and 50 meters in the water, so how does the little boat accomplish traveling two different speeds in the same body of water?

It doesn't, unless you consider different reference frames, which you seem to be reluctantly doing.
If you want to just consider the preferred reference frame, (which I've been doing from the start of this exercise), then the little boat moves 70.4375 meters, no question.

No, because all that time the boat was traveling in water for 70.4375 meters, which is quite different than the little boat traveling only 50 meters in water, wouldn't you say so too?

Yes, I would agree.
So we've at last agreed that the little boat (which can motor at 8km/h in still water), will move at 11.27km/h when motoring downstream in a 3.27 km/h current.

 

[Neddy Bate]

What opposite direction? A toy boat traveled in the x direction from one end of the pool to the other in 22.5 seconds. That's it. Do you want to lay out the details of the round trip times and velocities for us all, Neddy Bate? I'd like to see that as well, Maybe Pete can draw it up so we can all see how it looks in Einstein's world.

Oh, sorry, did you forget to read all of post #90?

So, in the 22.5 seconds it takes the boat to go the length of the pool, the whole pool moves 20.4 metres.
So, the little boat actually moves 70.4 metres if it's moving in the same direction as the ship (downstream), but only 4.6 metres if it's moving in the other direction (upstream).

Is this really that difficult of an exercise for you? And yet you can probably rebuild a transmission with one hand tied behind your back. Just goes to show that different people have very different skill sets.

 

[Motor Daddy]

I call it the embankment frame.

Call it whatever you want, if it includes time dilation, length contraction, and ROS, then you are SOL!

Right, in the embankment frame, the little boat moves at 8+3.27 km/h.

I didn't say that. I said the little boat travels 70.4375 meters in the preferred frame in 22.5 seconds.

If you want to just consider the preferred reference frame, (which I've been doing from the start of this exercise), then the little boat moves 70.4375 meters, no question.

Right, that's 50 meters in the pool while the pool traveled 20.4375 meters, which of course doesn't count towards how far the boat traveled IN THE POOL!

Yes, I would agree.
So we've at last agreed that the little boat (which can motor at 8km/h in still water), will move at 11.27km/h when motoring downstream in a 3.27 km/h current.

Nobody said anything about "downstream" or "current." The boat traveled 50 meters in still water in 22.5 seconds. There is no current.

 

[Motor Daddy]

Oh, sorry, did you forget to read all of post #90?

Sorry, I must have missed it, how much time does it take to travel "IN THE OTHER DIRECTION?"

Is this really that difficult of an exercise for you?.

No, but it clearly is for you.

And yet you can probably rebuild a transmission with one hand tied behind your back. Just goes to show that different people have very different skill sets.

Just goes to show you that you don't know what you're talking about. I don't rebuild transmissions, two hands or one.

 

[Neddy Bate]

Sorry, I must have missed it, how much time does it take to travel "IN THE OTHER DIRECTION?"

Well the problem is based on the idea that the model boat has a "still water" speed of 8 km/hr. The pool is still water, and 50m long, so, 22.5 seconds. I would have thought that was obvious, but I guess not.

 

[Pete]

I didn't say that. I said the little boat travels 70.4375 meters in the preferred frame in 22.5 seconds.

70.4375 meters in 22.5 seconds is 11.27 km/hr. Right?
So the little boat is moving at 8+3.27 = 11.27 km/h. Right?
And your preferred frame is the embankment frame. Right?

Nobody said anything about "downstream" or "current." The boat traveled 50 meters in still water in 22.5 seconds. There is no current.

OK, let's just reach an agreement regarding the little boat in the pool, then we'll consider the current later.

Are we agreed that the little boat actually moves at 11.27km/h?

 

[Motor Daddy]

70.4375 meters in 22.5 seconds is 11.27 km/hr. Right?

3.13 m/s, so yes, in one hour the boat would have traveled 11.27 kilometers in SPACE, which is the preferred frame. ALL objects travel in the preferred frame and the objects each have a closing speed to all other objects at all times.

So the little boat is moving at 8+3.27 = 11.27 km/h. Right?

No. Where do you now get the "8" from when the only thing we are discussing at the moment is 3.13 m/s?? There is no "8" in 3.13 m/s.

And your preferred frame is the embankment frame. Right?

Wrong. The embankment is made of rock, and dirt, and there are pedestrians that are moving about, and some are watching the boats in the water. However, the preferred frame is literately nothing. No pedestrians, no rocks or dirt, just literally NOTHING. I call that nothing "space" and that space is INCAPABLE of motion. The space has 3 dimensions, x,y, and z, and that space is measured as volume. So space is volume that has three dimensions (x,y,z). LIGHT TRAVEL TIME determines distance in the volume, and I'll call that distance the "meter." Objects are literally something, and the preferred frame is literally nothing. The two of them are not the same, they are different, therefore the embankment and the preferred frame are DIFFERENT. Clear now?

OK, let's just reach an agreement regarding the little boat in the pool, then we'll consider the current later.
Are we agreed that the little boat actually moves at 11.27km/h?

In the pool the little boat moves 50 meters in 22.5 seconds, which is 2.22 m/s, which is 8,000 meters per hour, or 8 km/hr. So I guess my answer to your question is a NO, we are not agreed that the boat moves 11.27 km/hr in the pool.

 

[Pete]

3.13 m/s, so yes, in one hour the the boat would have traveled 11.27 kilometers in SPACE, which is the preferred frame. ALL objects travel in the preferred frame and the objects each have a closing speed to all other objects at all times.

It seems you're assuming the Earth is at rest in SPACE, which is too woo for this thread.
We're just interested in the speed of the boat along the surface of the Earth (the embankment), We're not concerned with how the Earth is moving through space.

No. Where do you now get the "8" from when the only thing we are discussing at the moment is 3.13 m/s?? There is no "8" in 3.13 m/s.

You agreed that the boat moves at 11.27km/hr.
You surely agree that 8 + 3.27 = 11.27 ?

In the pool the little boat moves 50 meters in 22.5 seconds, which is 2.22 m/s, which is 8,000 meters per hour, or 8 km/hr. So I guess my answer to your question is a NO, we are not agreed that the boat moves 11.27 km/hr in the pool.

Not what I asked, MD.
We agree that the boat moves at 8km/h relative to the water.
What does the boat moves at 11.27km/h relative to? The ground/embankment, right?

 

[eram]

This thread has grown pretty fast. What's MD arguing about this time?

 

[Motor Daddy]

It seems you're assuming the Earth is at rest in SPACE, which is too woo for this thread.

Actually it's YOU who's assuming that the EMBANKMENT (Earth) is at rest in space, which is the worst WOO ever.

We're just interested in the speed of the boat along the surface of the Earth (the embankment), We're not concerned with how the Earth is moving through space.

So in your hypothetical world we can assume that the embankment is made of rock and dirt, like the moon, but in your world the moon can move and the embankment can't? How is it possible that you see every other object as capable of motion in space, but your object (the embankment) is INCAPABLE of motion in space? I ask you to remove yourself from your reality just for a brief moment and consider a possibility that the embankment too might, JUST MIGHT be in motion in space, just like the moon and every other object is. Wow, if only!!

You agreed that the boat moves at 11.27km/hr.

I agreed that the boat traveled 11.27km/hr in space. That was the boat traveling in the pool 50 meters, and the pool traveling in space 20.4375 meters, all in the elapsed time of 22.5 seconds.

You surely agree that 8 + 3.27 = 11.27 ?

There are two different measures of distance, there is the distance the boat travels in the pool, and there is the distance the pool travels in space. Do you understand the difference, or do you need me to explain that to you?

Not what I asked, MD.

You mean to say that's not the answer you were looking for, right?

We agree that the boat moves at 8km/h relative to the water.

Correct!

What does the boat moves at 11.27km/h relative to? The ground/embankment, right?

Wrong, the 11.27 km/hr is a calculation of the distance of 70.4375 meters in 22.5 seconds. The embankment is irrelevant to that distance and time.

 

[Pete]

Take a breath, MD. Let's leave this for a while and return after a break.
Let's find where we agree, instead of looking for things to argue about.

 

[Motor Daddy]

Take a breath, MD. Let's leave this for a while and return after a break.
Let's find where we agree, instead of looking for things to argue about.

K. Please don't get me wrong, you're still my buddy like James R is. I understand people get a little confused every now and then about how to measure distance and time correctly. I used to get a kick out of how James R. (like Einstein) got confused over the issue.

 

[eram]

K. Please don't get me wrong, you're still my buddy like James R is. I understand people get a little confused every now and then about how to measure distance and time correctly. I used to get a kick out of how James R. (like Einstein) got confused over the issue.

Ha ha very funny.

Anyway, I'm gonna ask you again: Can you please restate the problem you are trying to solve?

 

[Neddy Bate]

Ha ha very funny.

Anyway, I'm gonna ask you again: Can you please restate the problem you are trying to solve?

Post #90 has all of the information. A swimming pool is 50m long, a model boat takes 22.5 seconds to go from one end of the pool to the other at a fixed "still water speed" of 8 km/hr. But the pool is actually on a cruise ship which is being tugged through a harbour at 3.27 km/h. Solve for the speed and distance of the model boat as measured in the harbour frame, (for both the case where the model boat travels in the same direction as the cruise ship, and in the opposite direction).

When stated this way, Motor Daddy does not like the idea at all. He insists the model boat only travels 50m, because that is the given length of the pool. He also insists the speed of the boat is only 8 km/hr, because that is the given speed.

But if you ask him to assume the harbour is at rest in the absolute rest frame of MD Theory, then suddenly Motor Daddy understands the problem. I guess it makes sense that he would understand his own theory better than other approaches.