Thread: The earth is flat and we never went to the moon--Part II

1. Originally Posted by DFT_Dave
...We are talking about the theory of relativity in relation to velocity. I thought you understood that.

--Dave
Dave, you are talking about relative velocities, and getting two things wrong:
1. You do not need a 'fixed' point in order to measure velocity
2. This is basic classical physics, that was known centuries before Einstein's Theory of Relativity.

1. You do not need a 'fixed' point in order to measure velocity
2. This is basic classical physics, that was known centuries before Einstein's Theory of Relativity.

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JudgeRightly (April 14th, 2019)

3. Originally Posted by chair
Dave, you are talking about relative velocities, and getting two things wrong:
1. You do not need a 'fixed' point in order to measure velocity
2. This is basic classical physics, that was known centuries before Einstein's Theory of Relativity.

1. You do not need a 'fixed' point in order to measure velocity
2. This is basic classical physics, that was known centuries before Einstein's Theory of Relativity.
In the specific example we are dealing with we do need a fixed point to determine speed and distance.

The immovable earth is our fixed point from which we determine what is and is not moving over or on it.

The north star also acts as a fixed point of reference for navigation because it's the one star that doesn't move.

Even when a car is moving we "fix" an immovable point in time and location from which we calculate the velocity over a distance to another "fixed immovable" point in time and location. Even if the car continues to travel farther we can still determine velocity from immovable point A to immovable point B.

My main point from the start of this chain of commentary is that two cars starting at the same time from the same location--A, moving in opposite directions having the same speed of 60 mph will be 120 miles apart in one hour in there own location--B1 and B2. That they are 120 miles apart does not mean that they were traveling at 120 mph relative to each other.

--Dave

4. Originally Posted by DFT_Dave
...

Even when a car is moving we "fix" an immovable point in time and location from which we calculate the velocity over a distance to another "fixed immovable" point in time and location. Even if the car continues to travel farther we can still determine velocity from immovable point A to immovable point B.
"fix" is correct- but the choice of "fixed" point is arbitrary, there is nothing absolute about it. "Immovable" is false. There is no need for anything to be "immovable".

Originally Posted by DFT_Dave
My main point from the start of this chain of commentary is that two cars starting at the same time from the same location--A, moving in opposite directions having the same speed of 60 mph will be 120 miles apart in one hour in there own location--B. That they are 120 miles apart does not mean that they were traveling at 120 mph relative to each other.

--Dave
Dave, they have moved 120 miles relative to each other in 1 hour. That is what "120 miles per hour" means! they are travelling at 60 mph relative to the road, and 120 mph relative to each other.

It isn't that complicated.

The fact that we measure velocity always relative to something has no bearing on whether the earth is "immovable" or not. You are attacking basic classic physics for no reason. (Note that this is true for translational velocity, as in your automobile examples. Spinning objects are a bit different).

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JudgeRightly (April 14th, 2019)

6. Originally Posted by DFT_Dave
In the specific example we are dealing with we do need a fixed point to determine speed and distance.
Yes, in TWO different ways.

Originally Posted by DFT_Dave
The immovable earth is our fixed point from which we determine what is and is not moving over or on it.
The earth does not need to be "immovable" to be used as a reference point.

Originally Posted by DFT_Dave
The north star also acts as a fixed point of reference for navigation because it's the one star that doesn't move.
It does move, it is just used because it's "close enough". It's not "perfect".

Originally Posted by DFT_Dave
Even when a car is moving we "fix" an immovable point in time and location from which we calculate the velocity over a distance to another "fixed immovable" point in time and location. Even if the car continues to travel farther we can still determine velocity from immovable point A to immovable point B.
Neither point needs to be "immovable". It's simply a chosen reference.

Originally Posted by DFT_Dave
My main point from the start of this chain of commentary is that two cars starting at the same time from the same location--A, moving in opposite directions having the same speed of 60 mph will be 120 miles apart in one hour in there own location--B1 and B2. That they are 120 miles apart does not mean that they were traveling at 120 mph relative to each other.

--Dave

Dave, Dave, Dave.... you JUST said that they will be 120 MILES apart in ONE HOUR. That is 120 MILES PER (one) HOUR. Distance over time.... remember?

How you cannot understand this is beyond explanation. Even a high school student can understand these things.

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JudgeRightly (April 15th, 2019)

8. Originally Posted by chair
"fix" is correct- but the choice of "fixed" point is arbitrary, there is nothing absolute about it. "Immovable" is false. There is no need for anything to be "immovable".

Dave, they have moved 120 miles relative to each other in 1 hour. That is what "120 miles per hour" means! they are travelling at 60 mph relative to the road, and 120 mph relative to each other.

It isn't that complicated.

The fact that we measure velocity always relative to something has no bearing on whether the earth is "immovable" or not. You are attacking basic classic physics for no reason. (Note that this is true for translational velocity, as in your automobile examples. Spinning objects are a bit different).
I hope you understand that having studied theology and philosophy where logical propositions based on following the rules of logic vs irrational propositions based on fallacies helps us to know what is or is not true about the existence of God, morals, and meaning. I've not been a student of physics but that does not mean I now nothing about the subject.

I know I'm not dumb and you know I'm not dumb even though you say it enough. I know deep down you all love me because I provide great debate. I think you all know I'm absolutely sincere. I've admitted that there are some good arguments for spinning globe but then you get angry when I say there are also good arguments for flat earth. I think there are a lot of people in my shoes.

As I'm trying to learn and compare both views and see something that does not add up I say so. And I see a contradiction now in this equation V = V1 + V2 as per the illustration of the speed /velocity of cars. I know the laws of motion, as well as discovery of gravity, goes back to Newton, not Einstein.

Obviously I don't mind be called crazy or dumb, etc. but I think the name calling puts undo pressure on many who might think there are legitimate reasons for not accepting something that does not make sense to them.

If I'm wrong about an equation and how it's being applied then I simply want it to be explained so that it does make sense.

The illustration that two cars going in opposite directions at 60 mph after having traveled 60 miles in one hour have been moving at 120 mph relative to each other while actually traveling at a velocity of 60 mph makes no sense. Simply because they are 120 miles apart and it takes one hour to go 120 miles at 60 mph is not a rational answer.

I'm sorry, but I see fallacies in this equation and explanation. I'm not trying to be stubborn, I'm just being honest.

Obviously if we accept the formula and we add velocity of one car going in one direction at 60 mph with the other car also going 60 mph in the opposite direction we get 120 mph. My problem isn't math it's that the actual 60 mph is in relation to what is not moving which is the earth or ground beneath each car. The 120 mph removes the immovable ground but by doing that we have no bases for the 60 mph that 120 mph depends on.

I hope you get my point. Without "that which does not move" I can't get a speed/velocity for either car so I have no numbers to add up in order to get a velocity for a relative speed of two cars/things. All reference points must be "fixed" and that means "immovable".

Now, anyone please, even Clete if your're still at least reading these posts, explain to me where I'm wrong. Don't just say because we, or Newton says so. Give me articles to read, make arguments that are coherent, tell me videos to watch, what ever it takes to make me see I'm wrong about the arguments I have made on this specific point.

--Dave

9. Originally Posted by DFT_Dave
Obviously if we accept the formula and we add velocity of one car going in one direction at 60 mph with the other car also going 60 mph in the opposite direction we get 120 mph. My problem isn't math it's that the actual 60 mph is in relation to what is not moving which is the earth or ground beneath each car. The 120 mph removes the immovable ground but by doing that we have no bases for the 60 mph that 120 mph depends on.

I hope you get my point. Without "that which does not move" I can't get a speed/velocity for either car
Incorrect. You have a reference point that, relative to itself, is not moving. You don't need the ground to measure distance, just a way to measure distance.

so I have no numbers to add up in order to get a velocity for a relative speed of two cars/things.
SURE YOU DO! you have one car as your reference point, and the other car moving at 120 mph away from it. The ground has nothing to do with the relative velocities of two cars.

All reference points must be "fixed" and that means "immovable".
They ARE immovable, relative to themselves!

To the driver of one of the cars moving at 60mph relative to the earth, the earth is the object that's moving at 60 mph, while the car is stationary.

To an observer watching the car standing on the ground, the earth is motionless while the car moves.

If it were (and it's not) possible to stand on the poles of the sun, an observer at either would see the earth orbit the sun once every 365 days, while the sun wouldn't move.

Motion is relative, Dave.

The one observing, or the reference point he uses, is always considered motionless, even though it is moving.

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Right Divider (April 15th, 2019)

11. Originally Posted by Right Divider
Yes, in TWO different ways.

The earth does not need to be "immovable" to be used as a reference point.

It does move, it is just used because it's "close enough". It's not "perfect".

Neither point needs to be "immovable". It's simply a chosen reference.

Dave, Dave, Dave.... you JUST said that they will be 120 MILES apart in ONE HOUR. That is 120 MILES PER (one) HOUR. Distance over time.... remember?

How you cannot understand this is beyond explanation. Even a high school student can understand these things.
A = beginning point for both cars.

B1 = end point for car going west = 60 miles

B2 = end point for car going east = 60 miles

B1<----------A---------->B2

120 miles is the distance between point B1 and B2

It will take both cars one hour at 60 mph to get back to point A

B1---------->A<----------B2

It will take two hours at 60 miles an hour to go from point B1 to B2 or vise versa, or 120 mph in one hour.

B1------------------------->B2

The 120 mph from point B1 to point B2 in one hour is also calculated by the immovable ground beneath each car and is not derived from adding the speed of two cars each moving at 60 mph.

--Dave

12. Originally Posted by DFT_Dave
A = beginning point for both cars.

B1 = end point for car going west = 60 miles

B2 = end point for car going east = 60 miles

B1<----------A---------->B2

120 miles is the distance between point B1 and B2

It will take both cars one hour at 60 mph to get back to point A

B1---------->A<----------B2

It will take two hours at 60 miles an hour to go from point B1 to B2 or vise versa, or 120 mph in one hour.

B1------------------------->B2

The 120 mph from point B1 to point B2 in one hour is also calculated by the immovable ground beneath each car and is not derived from adding the speed of two cars each moving at 60 mph.

--Dave
Relative to B1... B2 is moving 120 MPH (in the opposite direction).
Relative to B2... B1 is moving 120 MPH (in the opposite direction).

Relative to A... BOTH B1 AND B2 are moving 60 MPH (in opposite directions).

It's just that simple.

Also, simply saying that the cars are 120 miles apart in one hour shows that THEY are moving 120 MPH relative to EACH OTHER.

I'm sure glad that you don't work on anything important that relies on understanding motion.

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JudgeRightly (April 15th, 2019)

14. Originally Posted by JudgeRightly
Incorrect. You have a reference point that, relative to itself, is not moving. You don't need the ground to measure distance, just a way to measure distance.

SURE YOU DO! you have one car as your reference point, and the other car moving at 120 mph away from it. The ground has nothing to do with the relative velocities of two cars.

They ARE immovable, relative to themselves!

To the driver of one of the cars moving at 60mph relative to the earth, the earth is the object that's moving at 60 mph, while the car is stationary.

To an observer watching the car standing on the ground, the earth is motionless while the car moves.

If it were (and it's not) possible to stand on the poles of the sun, an observer at either would see the earth orbit the sun once every 365 days, while the sun wouldn't move.

Motion is relative, Dave.

The one observing, or the reference point he uses, is always considered motionless, even though it is moving.
"You have a reference point that, relative to itself, is not moving."

A reference point by definition is what is not moving relative to what is moving.

Your definition is mere tautology, saying something twice by definition then by explanation as if the two were different things and not just saying the same thing twice in different words.

Let me explain. A reference point is defined by what is not moving. By saying it's in relationship to what is not moving relative to it's not moving self is redundant and meaningless.

Let me repeat, a reference or "fixed" point is immovable relative to what is moving.

The speed/velocity of a moving car cannot be the reference for the speed/velocity another moving car unless we can establish the speed/velocity from a reference point that is not moving for at least one of the cars.

I hope you see the contradiction when you say, "The one observing, or the reference point he uses, is always considered motionless, even though it is moving."

In other words, in order to determine the velocity for anything moving in a universe where everything is moving we must imagine or pretend something is not moving as a necessary reference point. Just how is a necessary thing a non existent thing?

I'm not the only one who thinks this is absurd, irrational, and not what we experience.

--Dave

15. Originally Posted by Right Divider
Relative to B1... B2 is moving 120 MPH (in the opposite direction).
Relative to B2... B1 is moving 120 MPH (in the opposite direction).

Relative to A... BOTH B1 AND B2 are moving 60 MPH (in opposite directions).

It's just that simple.

Also, simply saying that the cars are 120 miles apart in one hour shows that THEY are moving 120 MPH relative to EACH OTHER.

I'm sure glad that you don't work on anything important that relies on understanding motion.
The 120 mph is relative to the 120 miles to get from point B1 to point B2 and that is established by distance and time relative to the earth that is not moving not by another car that is.

I'm glad you're not driving a car telling me when your going to arrive based on the speed of the cars going in the opposite direction.

--Dave

16. Originally Posted by DFT_Dave
"You have a reference point that, relative to itself, is not moving."

A reference point by definition is what is not moving relative to what is moving.

It does not matter if the reference point is moving with regard to ANYTHING ELSE BUT the OTHER POINT involved.

Distance can be measured without the earth Dave. Ever hear of RADAR? Or SONAR?

Stunning that you cannot understand such simple things.

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18. Originally Posted by DFT_Dave
The 120 mph is relative to the 120 miles to get from point B1 to point B2 and that is established by distance and time relative to the earth that is not moving not by another car that is.

I'm glad you're not driving a car telling me when your going to arrive based on the speed of the cars going in the opposite direction.

--Dave

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20. Originally Posted by Right Divider

It does not matter if the reference point is moving with regard to ANYTHING ELSE BUT the OTHER POINT involved.

Distance can be measured without the earth Dave. Ever hear of RADAR? Or SONAR?

Stunning that you cannot understand such simple things.
We were talking about how we determine speed on the surface of the earth but if you want to go to sonar and radar make a point.

--Dave

21. Originally Posted by DFT_Dave
We were talking about how we determine speed on the surface of the earth but if you want to go to sonar and radar make a point.

--Dave
The surface of the earth is irrelevant to how far the cars travel. That's the point.

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23. Originally Posted by Right Divider
The surface of the earth is irrelevant to how far the cars travel. That's the point.
That's because the earth is not moving and the cars are.

So how do we determine how fast radar and sonar travels?

--Dave

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