Need expert advice on how to handle a seemingly legitimate objection

[Juma]

The notion that the speed of a massive body is somehow absolute seems to be a category error

Nah. Speed is relative. But that is maybe not what you ment...

That speed should be relative is fine with me. Re-reading my English it's clear that this is what my sentence sugested to begin with.

That being said, we don't really know what is speed anyway!

the way competent speakers use the word "speed", in the case of massive bodies, as the distance traveled divided by the time of travel.

Who are these "competent speakers"?

I knew you had no idea who they are!
Very simple. Tune to 198LW (not midday just now they are working on their broadcasting station or something! Try the evening.)

That's British English of course. It turns out competent speakers of English call themselves "the English".

Seems you speak of something else than speed at a specific time moment. Som sort of "mean speed over land" or something line that.

Why, I speak competent speaker's English! Look up English dictionaries. I'm talking about that sort of definitions. Sure, I mean mean speed. It's Hussain Bolt's kind of speed. Who would have a mind to disagree?

But how is distance measured if not relatively to other massive objects? Science says we don't measure the distance between two points of space but between objects.

Eh, again. Who says this?

Me.

But in competent speech, distance is the extent of space between two objects... or two places. So, the lexical meaning is clear and leaves room enough for the idea of absolute speed, which physicists say doesn't apply to the speed of massive objects.

What does these "physicist" really say? Cause what you say doesnt make sense.

It seems to make sense... Which part you don't like?

You can always talk about speed as the rate of change relative time of anything, really.

Sure but time itself is relative, right?

That real objects cannot have higher speed than c is a totally different matter.
I think your problem stems from the way we measure distance: in time units of light flight.

It's kinda out of the blue here.
Never mind.
EB

Check definition of distance: it is measured in the time it takes for light to travel that distance.

 

[fromderinside]

I'm not sure.

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

So? That Rex may be more than 1000kg is already assumed in the argument. That Rex may be more than 1000kg does not change the possible validity of the argument.
So?
EB

The so is relative to the relative. It's a logical argument and a specific question remains because the logic is not completely determinative, its relative.

 

[Speakpigeon]

Fast, relativity isn't just an idea that some one came up with and talked about. Relativity is not just a "description" of how someone thinks things work. I know that you understand this, but I'm going to reinforce it.

The theory of Relativity makes predictions that have actually been tested in many different ways. Relativity has also been monetized by industry. All of the GPS satellites factor in the effects of the theory of relativity to maintain their orbits and keep their clocks in perfect sync. Not only has relativity been tested and verified by scientists, people are actively using it to make money here in the real world.

Now keeping that in mind, suppose you are right for a moment. Suppose that an object can be described as moving even though there is nothing to compare it to. What does this supposition offer us? Are there any advantages to this new information independent of all other reference points? What can we predict if objects have an internal status of motion independent of everything else?

It offers us the TRUTH! Money is nothing, truth is all!
Sometimes we do wish we've known the truth and let go of the money...
EB

 

[Speakpigeon]

Check definition of distance: it is measured in the time it takes for light to travel that distance.

In topology, you define distance on a space as a relation between points of that space such that it complies with three properties:
D(a,a) = 0
D(a,b) = D(b,a)
D(a,b) + D(b,c) >= D(a,c)
That's all there is to it and the guy who was doing the teaching looked liked a competent speaker to me. That's what I learned a long time ago so may be things have changed since. Who knows? Everything goes so fast now!
EB

 

[Juma]

Check definition of distance: it is measured in the time it takes for light to travel that distance.

In topology, you define distance on a space as a relation between points of that space such that it complies with three properties:
D(a,a) = 0
D(a,b) = D(b,a)
D(a,b) + D(b,c) >= D(a,c)
That's all there is to it and the guy who was doing the teaching looked liked a competent speaker to me. That's what I learned a long time ago so may be things have changed since. Who knows? Everything goes so fast now!
EB

But we are talking real space-time here. Not any topological space.

 

[steve_bnk]

I think I may see the discontent.


Distance appears obsolete at firstglance. A meter is always meter, so speed must be absolute. I think train examples go back to Einstein. The problem with relative velectives predates Einstein.


A train is traveling past an observeron the ground. A man on a flatbed car drops a ball. Ignoring air resistance, to the person on the train dropping the ball the ball falls straight down. To the observer on the ground the ball falls in a parabolic arc.


Which view is correct?


You toss a football on a jet travelingat constant speed. To an observer on the ground the velocity of theball is the jet's velocity plus the football's velocity. To anobserver on the jet the ball is traveling at the thrown velocity.


Which view is correct? It all dependson what you arbitrarily pick as a reference frame. You could pick the ground, the jet, or a point on Mars.


We are conditioned to view the groundas a reference, but that is arbitrary. When you say you are sitting still on a jet it means relative to the inertial frame you are in. In a seat on the ground you are at rest to the inertial frame of the Earth.

Who is at rest, the ground or the jet? The Earth is spinning....


Two trains depart a station in the samedirection, one at 50 mph the other at 25 mph. An observer on theground and on the 25 mph train have RADAR speed guns. The man onthe ground measures the 50 mph train's velocity as 50 mph relative tothe ground. The man on the 25 mph train measures the 50 mph train'svelocity 25 mph.


Which measurement is correct and why.


The train observers at rest to the trains are moving relative to the ground. The ground observer is atrest to the Earth, but the Earth is moving relative to the rest ofthe universe. Trains going round the Earth, earth going round theSun, Sun goiung round the galaxiy, galaxies going round galleries.


For those who are arguing absolute velocity,....it is the same problem as the two train exmaple exceptyou do riot have the Earth surface reference.


Three space ships arrive at a spot areand comes to rest next to each other.


Space ships A, B, C are at rest nextto rest with each other.


Ship A changes velocity by 50 mph,followed by B at 25 mph in the same direction.


An observer on ship C measures A at 50mph and B at 25 mph.


An observer on B measures A at 25 mph.


Which observer is correct, B or C?


There are physical ramifications. Abowling bowl on the floor of a train has zero kinetic energy relative to anyone on the train. To an observer on the ground theball has kinetic energy = 0.5*mass* train_velocity^2.


.

 

[fast]

Because no matter how fast you are traveling compared to the speed of light the light would still be retreating from you at light speed.

But wouldn't that cause it to exceed the speed of itself?

 

[zorq]

Because no matter how fast you are traveling compared to the speed of light the light would still be retreating from you at light speed.

But wouldn't that cause it to exceed the speed of itself?

No. The speed of light isn't like a speed limit on the road. It isn't like a number on a number line. It is more like an asymptote on a hyperbolic graph.


No matter where we are on the hyperbola we are still an infinite amount of necessary acceleration away from the speed of light. Even though the asymptote may be .001 away from you it is un-reachable. The difference between your speed and the speed of light is always "infinity". As such, light always shines away from you at the same speed.

 

[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.

So? That Rex may be more than 1000kg is already assumed in the argument.

No it's not. The premises would be true even if all dogs weighed less than 1000kg.

That Rex may be more than 1000kg does not change the possible validity of the argument.
So?

Let's look at another argument in the same form:

P1: Almost all Americans are poorer than Bill Gates.
P2: Bill Gates is an American.
C: Therefore, Bill Gates is probably poorer than Bill Gates.

 

[Wiploc]

rex is a dog

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

what about the baby elephant hounds?

They are born right at 1001kg.

 

[Wiploc]

Because no matter how fast you are traveling compared to the speed of light the light would still be retreating from you at light speed.

But wouldn't that cause it to exceed the speed of itself?

No, it wouldn't, because motion is relative, not absolute. So that's a good question.

Here's another example:

For just a moment, Able, Baker, and Charlie are all next to each other on the Mason-Dixon line.

Able is traveling south at half of light speed.
Baker is standing still.
Charlie is traveling north at half light speed.

Somebody to the south of them turns on a bright light that hits them just at the very moment when they are together on the Mason-Dixon line.

Able, Baker, and Charlie all measure the speed of the beam of light. They each determine that it is going at exactly C --- relative to them! That is, the light hits Able at the same speed it hits Charlie, even though Able isn't going the same speed as Charlie.

It wouldn't work that way with a tennis ball.

Instead of hitting them at different speeds, it hits them as different colors.

This is a real phenomenon. We know it to be true in the real world. It wouldn't work at all in the world you imagine, the world with "real" speeds.

 

[zorq]

Let's look at another argument in the same form:

P1: Almost all Americans are poorer than Bill Gates.
P2: Bill Gates is an American.
C: Therefore, Bill Gates is probably poorer than Bill Gates.

First of all you did break the analogy to my original argument when you added extra information to it. The extra information you added was tying the measure to the sample with an identity.

My argument was a "statistical syllogism." It is meant to deal with uncounted masses. We already know how to compare individuals to themselves.

Still. I contend that your altered argument stands. *Absent any additional information* Bill Gates is probably poorer than Bill Gates.

 

[fast]

The difference between your speed and the speed of light is always "infinity".

It's no wonder I stay confused. Everytime I turn around, there is yet another surprise.

 

[fast]

I just watched an amazing video on you tube, and it's very much consistent with what I've been told in this thread. I now think i need to figure out how in the world things are in fact different when they merely appear different from the perspective of others. Hopefully, I have a faulty assumption in there somewhere.

 

[Wiploc]

The difference between your speed and the speed of light is always "infinity".

It's no wonder I stay confused. Everytime I turn around, there is yet another surprise.

Yeah, that one would have surprised Einstein too. Who knew that E = infinity squared?

 

[zorq]

The difference between your speed and the speed of light is always "infinity".

It's no wonder I stay confused. Everytime I turn around, there is yet another surprise.

Yeah, that one would have surprised Einstein too. Who knew that E = infinity squared?

That equation is for converting mass into energy.

I feel that you may be trying to characterize what I said. There is a reason I put the word "infinity" in quotation marks. I know that it's the wrong word but it is the word that I thought would help fast understand.

I still stand by the following statement though. It would take an infinite amount of energy to accelerate any piece of matter, including you, to the speed of light. Ergo it would take an infinite amount of "accelerating" to reach the speed of light. Ergo there is an infinite metaphorical chasm between you and reaching the speed of light.

If you want to Use Einstein's equation to convert all of yourself into a form of energy like light and then thereby make your "energy self" travel the speed of light. Please do that elsewhere. I don't care to be near you when you destroy a nearby country.

 

[Speakpigeon]

Check definition of distance: it is measured in the time it takes for light to travel that distance.

In topology, you define distance on a space as a relation between points of that space such that it complies with three properties:
D(a,a) = 0
D(a,b) = D(b,a)
D(a,b) + D(b,c) >= D(a,c)
That's all there is to it and the guy who was doing the teaching looked liked a competent speaker to me. That's what I learned a long time ago so may be things have changed since. Who knows? Everything goes so fast now!
EB

But we are talking real space-time here. Not any topological space.

What do you mean 'real'? Ordinary 'real' people who define speed as the ratio of the distance between what they think of as two points in 'real' space by the time taken to travel from one point to the other do mean to talk about 'real' speed. Yet, somehow, that doesn't satisfy scientists. Not only speed is relative (since Galilei at least I believe) but distances are also 'relative' to the observer, right?

My point is not that speed is not relative. Maybe it is. But the notion of speed too is relative (not the speed, the notion), so that what people mean by speed is relative... to them. People who think of speed as an absolute are unlikely to ever need to take a different perspective on that. They go to work by car or tram, not by rocket.

Further, speed is relative you say, but you don't really know. The notion of relative speed fits current observations but maybe scientists will observe something else tomorrow and decide that speed is absolute after all, i.e. that there is one, single, absolute, reference system. It's one thing to argue that we should abide by the one explanation that best fits observations so far, it's another to pretend that because we have such an explanation therefore we know that we know it's true to the 'real' world.
EB

 

[Speakpigeon]

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

I'm not sure.

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

So? That Rex may be more than 1000kg is already assumed in the argument.

No it's not. The premises would be true even if all dogs weighed less than 1000kg.

Sorry but to say that almost all dogs are less than 1000kg and that Rex is a dog is to assume that Rex may be more than 1000kg. So your suggestion that Rex may be an elephant hound and weighs more than 1000kg merely repeats the premises.

There is a point to be made but you are not making it.

That Rex may be more than 1000kg does not change the possible validity of the argument.
So?

Let's look at another argument in the same form:

P1: Almost all Americans are poorer than Bill Gates.
P2: Bill Gates is an American.
C: Therefore, Bill Gates is probably poorer than Bill Gates.

Precisely, it's not the same kind of argument. In other words, you jumped the gun.
EB

 

[Speakpigeon]

Let's look at another argument in the same form:

P1: Almost all Americans are poorer than Bill Gates.
P2: Bill Gates is an American.
C: Therefore, Bill Gates is probably poorer than Bill Gates.

First of all you did break the analogy to my original argument when you added extra information to it. The extra information you added was tying the measure to the sample with an identity.

My argument was a "statistical syllogism." It is meant to deal with uncounted masses. We already know how to compare individuals to themselves.

Yes, absent the information about how much Rex weighs, the initial argument stands:

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

As soon as you add the information that for example Rex is a grown-up Hound dog of 1010kg then the conclusion "3 Rex is probably less than 1000 kg" cannot be substained.

Clearly, this kind of logic doesn't work like deductive logic. The example argument provided by zorq is not deductively valid but it is clearly valid, notwithstanding fast's initial claim.

So, again, what's the real difference?
EB

 

[Speakpigeon]

Let's look at another argument in the same form:

P1: Almost all Americans are poorer than Bill Gates.
P2: Bill Gates is an American.
C: Therefore, Bill Gates is probably poorer than Bill Gates.

<snip>
Still. I contend that your altered argument stands. *Absent any additional information* Bill Gates is probably poorer than Bill Gates.

No. It sure is an interesting comingle but I can assure you that it's not true that Bill Gates is probably poorer than Bill Gates, whatever the premises might be.

P1 is Ok, obviously. P2 is good too. But C doesn't stand. It cannot be left to stand! I have my view why but maybe be you can recant on your acceptation of it? You already said you are used to change your mind, which if true is an indication of higher IQ than the average poster here... You even provided in your response to Wiploc what would be a good reason to change tack. So?
EB