Need expert advice on how to handle a seemingly legitimate objection

[steve_bnk]

http://en.wikipedia.org/wiki/Inertial_navigation_system




Submarines use inertial navigation. Given a known initial point such as a port location the sub departsfrom, by measuring acceleration continuously change in speed anddistanced can be calculated. Acceleration is integrated twice yielding change in distance.


A simple accelerometer is a small masson a spring. You are in a closed car on a train at rest in a ation.The spring is horizontal to the floor of the car and pointed in thedirection of travel. As the train accelerates out of the station in astraight line the mass compresses the spring. Knowing the spring constant and the mass, acceleration can be determined from Force =Mass * Acceleration. From acceleration distance from the station cane calculated without seeing outside the train. if the train slowsdown the spring is stretched instead of compressed. Using three accelerometers distance traveled in 3D can be determined.




Amazing what you can do with a littlecalculus. No need to quibble over meaning of words. Speed and velocity are interchangeable. unambiguously defined as meters per second.

http://physics.nist.gov/cuu/Units/units.html

'...speed, velocity

meter per second

m/s...'

 

[Wiploc]

A true speed would probably be extremely fast, like 2 1/2 million mph. I could be way off, but shoot, I can't measure it, but my best guess at this time would be somewhere around the speed in which galaxies are moving.

ETA: correction ... The speed in which our galaxy is moving...um, or the galaxy cluster to which we belong.

I'm confused. What is our galaxy (or cluster) moving 2.5 million mph relative to?

Well, the thing is, I'm denying that it must necessarily be relative to something at whatever speed we are moving.

Why? What would be the point of claiming we're moving at a given speed if that speed isn't relative to anything?

I'm not saying we aren't moving relative to other things, however. If we could magically place two imaginary and stationary points one mile apart in front of our trajectory, we could measure the speed in which we're moving.

Stationary relative to what?

Our inability to do such a thing makes it necessary to calculate relative speeds if we want to know how fast we are going.

Just so you know how weird that sounds, I'm going to use a different illustration. I'll talk about location rather than speed.

I can say I'm seven feet north north west of the kitchen door, or that I'm nine miles north of Topeka, or that I'm outside my car, or that I'm just ahead of the tornado. Any location I give must be relative to something. Otherwise, it makes no sense.

Now suppose you say that those locations are all true enough, but they are only relative. My real location, you say, is two miles north. I say, "North of what?" And you say that you are denying that it is north of anything. You aren't offering a comparison, but an absolute: I'm not two miles north of something; I'm just absolutely two miles north.

Do you see how weird that sounds? Do you see how similar it is to what you're doing?

It's apparently recognized that we can calculate a variety of relative speeds; in fact, because we can't determine if there is in fact a truly motionless object, we are without the tools necessary to calculate a true speed. It's the very recognition that we can't do such a thing and the commonplace acceptance that we can only calculate speeds relative to other objects that gives rise to the faulty notion there is no true (or actual) non-relative speed. We are simply lacking a basis for calculation, but given that we know that, shouldn't we recognize that that is simply a barrier to doing the math?

Bertrand Russell said something like, "Where the experts are agreed, the layman does well not to hold a contrary position. Where the experts are disagreed, the layman does well not to hold any opinion at all."

 

[fast]

A true speed would probably be extremely fast, like 2 1/2 million mph. I could be way off, but shoot, I can't measure it, but my best guess at this time would be somewhere around the speed in which galaxies are moving.

ETA: correction ... The speed in which our galaxy is moving...um, or the galaxy cluster to which we belong.

I'm confused. What is our galaxy (or cluster) moving 2.5 million mph relative to?

Well, the thing is, I'm denying that it must necessarily be relative to something at whatever speed we are moving.

Why? What would be the point of claiming we're moving at a given speed if that speed isn't relative to anything?

I'm not saying we aren't moving relative to other things, however. If we could magically place two imaginary and stationary points one mile apart in front of our trajectory, we could measure the speed in which we're moving.

Stationary relative to what?

Our inability to do such a thing makes it necessary to calculate relative speeds if we want to know how fast we are going.

Just so you know how weird that sounds, I'm going to use a different illustration. I'll talk about location rather than speed.

I can say I'm seven feet north north west of the kitchen door, or that I'm nine miles north of Topeka, or that I'm outside my car, or that I'm just ahead of the tornado. Any location I give must be relative to something. Otherwise, it makes no sense.

Now suppose you say that those locations are all true enough, but they are only relative. My real location, you say, is two miles north. I say, "North of what?" And you say that you are denying that it is north of anything. You aren't offering a comparison, but an absolute: I'm not two miles north of something; I'm just absolutely two miles north.

Do you see how weird that sounds? Do you see how similar it is to what you're doing?

It's apparently recognized that we can calculate a variety of relative speeds; in fact, because we can't determine if there is in fact a truly motionless object, we are without the tools necessary to calculate a true speed. It's the very recognition that we can't do such a thing and the commonplace acceptance that we can only calculate speeds relative to other objects that gives rise to the faulty notion there is no true (or actual) non-relative speed. We are simply lacking a basis for calculation, but given that we know that, shouldn't we recognize that that is simply a barrier to doing the math?

Bertrand Russell said something like, "Where the experts are agreed, the layman does well not to hold a contrary position. Where the experts are disagreed, the layman does well not to hold any opinion at all."

Relative to an imaginary and immobile backdrop grid maybe?

Let's say all objects in motion ceased. We would not be moving. If you could step outside of this magical impossibility and mark that specific co-ordinate, then couldn't you then measure your speed in miles per hour should all objects resumed motion? The point you're at one hour later would give you an exact average speed traveled through the universe eliminating the need to approximate one's speed by adding and subtracting the relative speeds and direction of the galaxy, solar system, planet, and dune buggy you're jumping a sand hill in.

 

[none]

I am not by any means of the word expert but I thought I would contribute a little
http://en.wikipedia.org/wiki/Metric_expansion_of_space

The metric expansion of space is the increase of the distance between two distant parts of the universe with time. It is an intrinsic expansion whereby the scale of space itself changes. This is different from other examples of expansions and explosions in that, as far as observations can ascertain, it is a property of the entirety of the universe rather than a phenomenon that can be contained and observed from the outside.

 

[fast]

I am not by any means of the word expert but I thought I would contribute a little
http://en.wikipedia.org/wiki/Metric_expansion_of_space

The metric expansion of space is the increase of the distance between two distant parts of the universe with time. It is an intrinsic expansion whereby the scale of space itself changes. This is different from other examples of expansions and explosions in that, as far as observations can ascertain, it is a property of the entirety of the universe rather than a phenomenon that can be contained and observed from the outside.

which gave rise to my earlier mention to also consider that speed (if it can be described as such) as well

- - - Updated - - -

What is an example of a valid non-deductive argument?

1 Almost all dogs are less than 1000 kg
2 Rex is a dog.
3 Rex is probably less than 1000 kg

If 1 and 2 are true, then 3 MUST be true?

Yep

are you sure?

 

[fast]

http://en.wikipedia.org/wiki/Spacetime

Interesting

 

[Wiploc]

What is an example of a valid non-deductive argument?

1 Almost all dogs are less than 1000 kg
2 Rex is a dog.
3 Rex is probably less than 1000 kg

If 1 and 2 are true, then 3 MUST be true?

Yep

are you sure?

I'm not sure.

Rex may be an elephant hound, and no elephant hound ways less than 1000kg.

 

[Wiploc]

Stationary relative to what?

Relative to an imaginary and immobile backdrop grid maybe?

Immobile relative to what?

Let's say all objects in motion ceased.

To make sense of that, I'm going to imagine that everything goes the same speed. Everything matches speed with, say, Pee Wee Herman. So every tardyon is stopped, relative to every other tardyon.

We would not be moving.

I guess you can think of it like that. But you could equally well think we're all going 42 miles an hour. In fact, that's probably a better way to think about it, given that 42 is the answer to the question of life, the universe, and everything.

If you could step outside of this magical impossibility and mark that specific co-ordinate, then couldn't you then measure your speed in miles per hour should all objects resumed motion?

It gives you your exact motion relative to Pee Wee Herman. I just don't know what that's worth.

The point you're at one hour later would give you an exact average speed traveled through the universe eliminating the need to approximate one's speed by adding and subtracting the relative speeds and direction of the galaxy, solar system, planet, and dune buggy you're jumping a sand hill in.

That's not a simplification. It's a complicated irrelevancy. Most things in the universe don't give a fig for their speed relative to Pee Wee Herman.

That's like declaring Swahili to be the "real" language, and requiring everyone to learn Swahili so they'll know what they've been saying all this time.

 

[steve_bnk]

If we detected no relative motion we still have no way to know if all objects are traveling at the same speed or were at rest relative to a common point.

Two trains with closed cars are traveling in the same direction at the same speed. there is a window in each train that allows one to see inside the other train. There is no way for people o the trains to know if they are moving relative to the ground.

 

[fast]

What is an example of a valid non-deductive argument?

1 Almost all dogs are less than 1000 kg
2 Rex is a dog.
3 Rex is probably less than 1000 kg

If 1 and 2 are true, then 3 MUST be true?

Yep

are you sure?

I'm not sure.

Rex may be an elephant hound, and no elephant hound ways less than 1000kg.

rex is a dog

 

[fast]

Let's say all objects in motion ceased.

To make sense of that, I'm going to imagine that everything goes the same speed. Everything matches speed with, say, Pee Wee Herman. So every tardyon is stopped, relative to every other tardyon.

Seriously? The same speed, yeah--exactly zero miles per hour; hence, not moving at any speed at all. Nothing is moving! What's the relevance of the fact that it can be put in terms of being relative? That's not a necessary quality to bring up. You make it sound like a universe with only a single object can't be moving unless there's another object to compare it to or for it to be relative with. Sure, it may appear to not move, but if it's getting closer to the outer reaches of the galaxy, it's moving. We talk in terms of objects in motion being in motion relative to other objects, yes, but motion, movement, and velocity doesn't require that fact. It may be a fact, but it's not necessary. What I'm saying isn't contradicting relativity. Objects do move in speeds relative to other moving objects. So what? If the only single object in a one-object universe is moving, then that is so whether we can tell it's moving or not, and if the only single object in a one-object universe is not moving, then that is so whether we can tell it's stopped or not. Truth, as philosophy has taught us is independent of our knowledge of the truth. If the cat is in the other room, then that is so whether we know the cat is in the room or not.

 

[Wiploc]

rex is a dog

Yes, all elephant hounds are dogs. And they all weigh over 1000kg.

 

[none]

rex is a dog

Yes, all elephant hounds are dogs. And they all weigh over 1000kg.

what about the baby elephant hounds?

 

[Kharakov]

What is an example of a valid non-deductive argument?

1 Almost all dogs are less than 1000 kg
2 Rex is a dog.
3 Rex is probably less than 1000 kg

If 1 and 2 are true, then 3 MUST be true?

Yep

are you sure?

I'm not sure.

Rex may be an elephant hound, and no elephant hound ways less than 1000kg.

rex is a dog

Moving at what percentage of c?

 

[fast]

rex is a dog

Yes, all elephant hounds are dogs. And they all weigh over 1000kg.

He used the word, "probably" in the conclusion, and he used the term, "almost all" in the first premise. I don't know how to handle that.

- - - Updated - - -

What is an example of a valid non-deductive argument?

1 Almost all dogs are less than 1000 kg
2 Rex is a dog.
3 Rex is probably less than 1000 kg

If 1 and 2 are true, then 3 MUST be true?

Yep

are you sure?

I'm not sure.

Rex may be an elephant hound, and no elephant hound ways less than 1000kg.

rex is a dog

Moving at what percentage of c?

Less than 100%

 

[Kharakov]

How about 99.9999999%? The dog would be about 22,361 times as heavy.

 

[Juma]

If the only single object in a one-object universe is moving, then that is so whether we can tell it's moving or not, and if the only single object in a one-object universe is not moving, then that is so whether we can tell it's stopped or not.

If there is only one object in an infinite featureless universe then the "constant velocity" is meaningless and simply will not exist: how much you accelerate you still wont be moving.

 

[steve_bnk]

If the only single object in a one-object universe is moving, then that is so whether we can tell it's moving or not, and if the only single object in a one-object universe is not moving, then that is so whether we can tell it's stopped or not.

If there is only one object in an infinite featureless universe then the "constant velocity" is meaningless and simply will not exist: how much you accelerate you still wont be moving.

Not exactly true. Read what I posted on inertial navigation and measuring acceleration. You can determine achange in velocity by measuring acceleration.

You are on the single object. If acceleration has always been zero then you are ether at rest to some universal unchanging reference point or you are at a constant speed.

You fire a rocket attached to the object,and measure acceleration. Change in velocity is calculated. When the rocket stops firing and acceleration goes to zero, you knowyou are traveling at a constant speed.

You are in a square object withexternal rockets on each outer surface and you want to know if the object is moving. Fire one rocket and measure acceleration. If it isnegative you are decelerating from one velocity to another. If acceleration is positive fire the opposite rocket to return to iitial conditions and test the other directions.

 

[Juma]

If the only single object in a one-object universe is moving, then that is so whether we can tell it's moving or not, and if the only single object in a one-object universe is not moving, then that is so whether we can tell it's stopped or not.

If there is only one object in an infinite featureless universe then the "constant velocity" is meaningless and simply will not exist: how much you accelerate you still wont be moving.

Not exactly true. Read what I posted oninertial navigation and measuring acceleration. You can determine achange in velocity by measuring acceleration.

You are on the single object. Ifacceleration has always been zero then you are ether at rest to someuniversal unchanging reference point or you are at a constant speed.

You fire a rocket attached to theobject,and measure acceleration. Change in velocity is calculated. When the rocket stops firing and acceleration goes to zero, you knowyou are traveling at a constant speed.

You are in a rectangular object withexternal rockets on each outer surface and you want to know if theobject is moving. Fire one rocket and measure acceleration. If it isnegative you are decelerating from one velocity to another.

But if there is no other object your position and speed is meaningless.

 

[steve_bnk]

If the only single object in a one-object universe is moving, then that is so whether we can tell it's moving or not, and if the only single object in a one-object universe is not moving, then that is so whether we can tell it's stopped or not.

If there is only one object in an infinite featureless universe then the "constant velocity" is meaningless and simply will not exist: how much you accelerate you still wont be moving.

Not exactly true. Read what I posted oninertial navigation and measuring acceleration. You can determine achange in velocity by measuring acceleration.

You are on the single object. Ifacceleration has always been zero then you are ether at rest to someuniversal unchanging reference point or you are at a constant speed.

You fire a rocket attached to theobject,and measure acceleration. Change in velocity is calculated. When the rocket stops firing and acceleration goes to zero, you knowyou are traveling at a constant speed.

You are in a rectangular object withexternal rockets on each outer surface and you want to know if theobject is moving. Fire one rocket and measure acceleration. If it isnegative you are decelerating from one velocity to another.

But if there is no other object your position and speed is meaningless.

Maybe philosophically meaningless, but scientifically you can chart the change in position and speed from an arbitrary starting point.

One object or many objects in our observable universe it is still the same problem.. Relativity and the lack of a universal reference frame.

With a coordinate system centered at the Sun the Earth goes around the Sun. From a coordinate system centered on the Earth that is not so. From relativity neither view is right or wrong.