Jim G There is no such line,as a straight line. Have you ever
heard a pitcher throwing a straight ball.? Bert

PD wrote:

PD wrote:

PD wrote:

Starbles@Earthlink.net wrote:

Which infinity? Positive or negative infinity?

Let's say that 1/0 = 1/x, and infinity is lnx. If 1/0 = infinity, then
1 = 0 times infinity. But x * lnx as x approaches infinity is zero.

How does your notion of infinity square with that?

There is *nothing* "less than" zero. There is NO physical entity which
is less than zero. Such a description (read name) for less than zero,
is never a reality- always just a human invention of the mind. When a
situation arises that calculation has produced a net negative, then a
mistake has been made in the math (it may be faulty), or the assumption
upon which the calculations depended (position of the zero coordinate),
was wrong/mistaken.

Jim G
c'=c+v

I can think of two quantities, both of which have nonzero (and
opposite) effect in nature, but the sum of which is zero effect in
nature. How would *you* characterize those quantities?

Don't be coy! What are they? After all, I have promised to do a thread
featuring my bare arse, if one is ACTUALLY a "less than zero physical
entity"

Before I give a couple of examples, the question was how you would
characterize those quantities. The way I see it, there are two ways to
characterize them:
1. As 1-D vector quantities, both with nonzero magnitude, but pointing
in the opposite direction.
2. As scalars on the real number line, one positive and one negative.

Note that I am asking for a *mathematical* characterization of the
*quantities*, so that we can have an operational definition.

The next question I would ask you is whether you think there is a
clear, fundamental distinction between those two characterizations. If
there is, what is it?

Wising up? at least you haven't mentioned money, electrons et al......

The "math characterisation" is the root of the problem. Addition is
accepted when it suits, but seen to be lacking when a positional
description, rather than a "less than" is involved. eg distance from A
(-1) to B (+1) is NOT zero.
Yet (-1)+(+1)=0 otherwise.
Similarly, the vectors cancelling look fine, until they represent
SOMETHING eg
forces (the rope gets broken- the forces didn't cancel).

Well, then I'd say one has to be a bit more precise in defining terms.
Position is not the same thing as, say, displacement. The
*displacement* from A to B in your example above is indeed 2, and the
displacement is given consistently by (final position) - (initial
position) = 1 - (-1) = 2.

Now, suppose I say that I want to know the displacement from the origin
O (position=0) to A. Following the above prescription, then we might
say the displacement is (-1) - (0) = -1. No, no, no, you might say, the
distance gone is obviously 1, not -1! So true, I might say, but I am
referring to displacement, not distance.

The problem clarifies if I ask what is the displacement from O to B if
I first go from O to A and then A to B. I need to be able to combine
the displacements in such a way that it's clear that if I go from O to
B or from O to A to B, I still end up at the same place. But if I go
from O to A and say that is 1 and from A to B and say that's 2, then if
I combine those to get 3, then I'm obviously not getting what I'm
looking for, because if I go from O to B directly, I get 1. In this
way, combining displacements does a much better job than combining
distances.

No problem, you might say, we'll just use + sometimes for combining
distances and - sometimes, depending on the direction. And I say then,
why? Why, when displacements contain the same information and the rule
for combination is then always +?

The difference, you might say, is that there is physics content in
using positive distances, and keeping track of + and - in the
combinations is just the work we have to do in the math to keep it all
straight, and putting the signs in the distances to make them
displacements confuses math and physics. And in response, I would
politely disagree and say that it's *all* mathematical convention, a
model we use to accurately predict nature, and I like how my model
works better.

PD

I learned this stuff way back- George D has given me a reefresher
lately, very similar to your explanation. The FACT remains, that as
handy as it may be to use "displacement" as exampled above, REAL
physics would see you run out of fuel 1/3 of the trip--
anywhere from point 0 is positive, when considering distance, time
taken, fuel required, or any other real-world exercise. The "where I
am" may be important, but the "what I need to get there" is not to be
ignored.

So I say use (-) to describe a position or direction; use it to show
reduction (less than an equal or greater positive).
When a net result of a calculation yields "less than zero", either a
mistake has been made by using both systems in the same
derivation/calculation, or a WRONGFUL assumption has been used (eg
Schwartz claimed -300K; if such a temperature was found, I suggest that
it was NOT less than zero temp, but that -273K needs to be revised as
being zero temp/heat.

I know of no physical state with a temperature of -273K (aside from the
fake temperature associated with the inversion present in lasing).

It wouldn't be the first fake pulled by Al S.
Now what about the fake reversal of direction of the train in the LT's,
which is necessary to "show" the contraction??

Jim G
c'=c+v

NB: "less than zero physical entity"- not matheramagics
(...anything in energy? force? distance? time? mass? )
(and the point being that the LT's, by reversing the direction of the
train/light during the "proof" of the postulate of length contraction
are faulty/fraudulent)

PD wrote:

PD wrote:

PD wrote:

Starbles@Earthlink.net wrote:

Which infinity? Positive or negative infinity?

Let's say that 1/0 = 1/x, and infinity is lnx. If 1/0 = infinity, then
1 = 0 times infinity. But x * lnx as x approaches infinity is zero.

How does your notion of infinity square with that?

There is *nothing* "less than" zero. There is NO physical entity which
is less than zero. Such a description (read name) for less than zero,
is never a reality- always just a human invention of the mind. When a
situation arises that calculation has produced a net negative, then a
mistake has been made in the math (it may be faulty), or the assumption
upon which the calculations depended (position of the zero coordinate),
was wrong/mistaken.

Jim G
c'=c+v

I can think of two quantities, both of which have nonzero (and
opposite) effect in nature, but the sum of which is zero effect in
nature. How would *you* characterize those quantities?

Don't be coy! What are they? After all, I have promised to do a thread
featuring my bare arse, if one is ACTUALLY a "less than zero physical
entity"

Before I give a couple of examples, the question was how you would
characterize those quantities. The way I see it, there are two ways to
characterize them:
1. As 1-D vector quantities, both with nonzero magnitude, but pointing
in the opposite direction.
2. As scalars on the real number line, one positive and one negative.

Note that I am asking for a *mathematical* characterization of the
*quantities*, so that we can have an operational definition.

The next question I would ask you is whether you think there is a
clear, fundamental distinction between those two characterizations. If
there is, what is it?

Wising up? at least you haven't mentioned money, electrons et al......

The "math characterisation" is the root of the problem. Addition is
accepted when it suits, but seen to be lacking when a positional
description, rather than a "less than" is involved. eg distance from A
(-1) to B (+1) is NOT zero.
Yet (-1)+(+1)=0 otherwise.
Similarly, the vectors cancelling look fine, until they represent
SOMETHING eg
forces (the rope gets broken- the forces didn't cancel).

Well, then I'd say one has to be a bit more precise in defining terms.
Position is not the same thing as, say, displacement. The
*displacement* from A to B in your example above is indeed 2, and the
displacement is given consistently by (final position) - (initial
position) = 1 - (-1) = 2.

Now, suppose I say that I want to know the displacement from the origin
O (position=0) to A. Following the above prescription, then we might
say the displacement is (-1) - (0) = -1. No, no, no, you might say, the
distance gone is obviously 1, not -1! So true, I might say, but I am
referring to displacement, not distance.

The problem clarifies if I ask what is the displacement from O to B if
I first go from O to A and then A to B. I need to be able to combine
the displacements in such a way that it's clear that if I go from O to
B or from O to A to B, I still end up at the same place. But if I go
from O to A and say that is 1 and from A to B and say that's 2, then if
I combine those to get 3, then I'm obviously not getting what I'm
looking for, because if I go from O to B directly, I get 1. In this
way, combining displacements does a much better job than combining
distances.

No problem, you might say, we'll just use + sometimes for combining
distances and - sometimes, depending on the direction. And I say then,
why? Why, when displacements contain the same information and the rule
for combination is then always +?

The difference, you might say, is that there is physics content in
using positive distances, and keeping track of + and - in the
combinations is just the work we have to do in the math to keep it all
straight, and putting the signs in the distances to make them
displacements confuses math and physics. And in response, I would
politely disagree and say that it's *all* mathematical convention, a
model we use to accurately predict nature, and I like how my model
works better.

PD

I learned this stuff way back- George D has given me a reefresher
lately, very similar to your explanation. The FACT remains, that as
handy as it may be to use "displacement" as exampled above, REAL
physics would see you run out of fuel 1/3 of the trip--
anywhere from point 0 is positive, when considering distance, time
taken, fuel required, or any other real-world exercise. The "where I
am" may be important, but the "what I need to get there" is not to be
ignored.

So I say use (-) to describe a position or direction; use it to show
reduction (less than an equal or greater positive).
When a net result of a calculation yields "less than zero", either a
mistake has been made by using both systems in the same
derivation/calculation, or a WRONGFUL assumption has been used (eg
Schwartz claimed -300K; if such a temperature was found, I suggest that
it was NOT less than zero temp, but that -273K needs to be revised as
being zero temp/heat.

I know of no physical state with a temperature of -273K (aside from the
fake temperature associated with the inversion present in lasing).

It wouldn't be the first fake pulled by Al S.
Now what about the fake reversal of direction of the train in the LT's,
which is necessary to "show" the contraction??

Jim G
c'=c+v

NB: "less than zero physical entity"- not matheramagics
(...anything in energy? force? distance? time? mass? )
(and the point being that the LT's, by reversing the direction of the
train/light during the "proof" of the postulate of length contraction
are faulty/fraudulent)