# How is time defined in newtonian physics?

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i suppose i could define it from the equation s=vt taking v as the velocity of an object under no external forces

so next would be define whats space

a space is defined as the distance between two objects but lets imagine there are just two objects alone in the whole universe

distance is relative to ones size and how can i define distance if i dont define size

for example if i slowly double the size of both objects APPARENT distance will be half than before

i hope you see where im going how can i define the distance dimention if i dont define the size dimention?

we are just assuming as theres no RELATIVE change in size theres no change in size at all in space but we can not not is theres a change that relativily doesnt change

so there wouldnt actually be 5 dimentions to acount for?

x,y,z, time and SIZE

edit:

what is more what if parmenides, zenos teacher was righ and motion was illusory?

could you explain APPARENT motion as a symultaneous change of size between two separated objects?

of course if two objects grow symultaneously they wont notice theyre growing because relatively they dont change size with respect to each other but their apparent distance is decreasing

you may argue then how is it posible an object goes past other as we know it happens in the real world because however big this objects grow their centers never cross

but this is where zenos dichotomoy enters the game

so the objects doubles size so apparent distance halves, they double size again and apparent distance halfs again

but lets suppose that as they double their size to keep conservation of momentum true they half theyr time rate

then they would apparently be separated 1 meter in one second half meter in half second quarter of meter in quarter of second and at second 2 they will have cross and at second 3 they have gone past by the opposite ways but how is this posible?

imagine a cuadriculated space with 5 dimensions:

x rotation y rotation z rotation change in size and time

youre on the coordinates (0,0,0) and go past an object in the coordinates (0,2,0)

what happens exactly with time and space?

theres a light clock at those coordenates you want to go to

we assume the light clock doesnt move but just change size

when it doubles its size the light beam has double distance to run but the period remains constant which means the beam is twice as faster than before so its time rate has halved

the light clock keeps doubling size as its time rate halves and as i explained before on this way at second two you reach it, but what happens next?

if after crossing the clock you look back accounting before crossing it the light beam was going to the right what sense is it going after you cross it, the opposite sense to the left,so time has reversed

so whats going on here? that time is relative to size, the bigger the size the slower the time but relativily the time period is always the same

if the time is going negative means that instead of growing you are shrinking and if you multiply -1*(-1) you get the same than if you multiply 1*1

and this is actually whats going on, you advance towards and object and it grows you walk away from an object and it shrinks

so wouldnt relativity of space time allow us to consider space motionless?

Edited by farolero

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I don't see how size is relevant. The distance between two objects that are a fixed distance apart is the same however large they are.

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If s = vt then you are measuring one object in motion? its size is irrelevant regarding distance travelled

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not if theyre groing simultaneously

if theyre growing simultaneously they wont notice theyre growing but the metric tape they have in their pocket to measure distance has grown as well so APPARENT distance has decreased

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Your mixing space-time and Newtonian physics up.

The mathematics is different, it depends on the relative equation but for a single object moving in Newtonian physics s=vt is true because vt will give you the distance travelled relative to time, if you reach your position the total distance is calculated regardless of whether the other object has exponentially increased in size.

it will only tell you at any given moment how far you have travelled, not how far you have left.

If you have two objects moving towards each other the same holds true, if both are increasing in size the equation s = vt will still only tell you how far either object has travelled.

ETA unknown.

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but newton assumed a 4 dimentional spacetime when there are five relevant dimentions:

x,y,z,time and size

newton and einstein ASSUMED size is constant and hence completely ignore this dimention

but what if size was constant just relatively to each other.

imagine a 2 m plane where theres one inhabitant and as he halves distance from the end of the plane he halves his size

from his perception this 2 m plane would be infinite, size is a very relevant dimention

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No size is a dimension within x,y,z.

space-time is used in Eisenstein theories

time is used in newtons

You want to add size as function of time in a differential, but that doesn't make size a dimension, it makes it variable.

Also if the plane is getting bigger and he is getting smaller your missing the fact that one or both of these objects are moving, which still makes the basic equation true.

Edited by DevilSolution
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No size is a dimension within x,y,z.

im not saying there are other axes of space than those

im saying than newton and einstein considered the size dimention along the xyz axe as universally CONSTANT and hence just neglect it and ignore completely all along

i claim its posible things could be just relatively constant in size to each other

i dont know if you understand this:

if 2 guys both double their size the metric tape they have in their pocket will have grown as well, their eyes have grown the measure instrument has grown, so universally they have grown but of course RELATIVILY to each other or to the measure instrument or to their eyes size remains constant and they dont notice they have grown

so imho neglecting the size dimention because your mind tells you things dont change size is trusting too much our senses as to trust blindly the sun revolves around earth because thats what my senses tell me

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Are you basing your presumptions on the single equation d = vt because im fairly sure neither Newton or Einstein discovered it, thats a simple equation for a moving object. I don't know a great deal about either of their mathematics but im fairly sure you'll find that they have an equation that accounts for size, have you checked?

If not im sure we can draw one up??

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I'm not sure what you mean by size. An observer at a distance of r from centre of the earth will measure earth's size as r. So, it becomes one of the coordinates required to interpret the observer's position in a spherical coordinate system, the other two being latitude and longitude.

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I'm not sure what you mean by size. An observer at a distance of r from centre of the earth will measure earth's size as r. So, it becomes one of the coordinates required to interpret the observer's position in a spherical coordinate system, the other two being latitude and longitude.

He means if something like earth was growing in size, while we were travelling in a spaceship back to earth the distance will shorten.

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if you account for the size dimention you could explain newtons falling apple as still in space and the earth inflating with which the ground accelerates up and hits it

after all when youre at free fall you feel zero g like your still in space and its only when youre on the ground still you feel the force like acelerating and the g forces

also if you picture an inflating earth by relativeness you could picture a shrinking space or what einstein called a curved space

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not if theyre groing simultaneously

if theyre growing simultaneously they wont notice theyre growing but the metric tape they have in their pocket to measure distance has grown as well so APPARENT distance has decreased

If your ruler is growing, then your distances depend on the size of the ruler.

This has nothing to do with the size of objects. And is the reason we choose a standard which will not change. (And if everything you could possibly use to measure size or distance changes in the same way, then that is equivalent to no change at all.)

if 2 guys both double their size the metric tape they have in their pocket will have grown as well, their eyes have grown the measure instrument has grown, so universally they have grown but of course RELATIVILY to each other or to the measure instrument or to their eyes size remains constant and they dont notice they have grown

How would you tell the difference between this and no doubling in size? Or halving in size?

but newton assumed a 4 dimentional spacetime when there are five relevant dimentions:

x,y,z,time and size

When you arrange to meet someone, you just need to specify four coordinates. You don't need to specify their size. Because: not a dimension.

Edited by Strange
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He means if something like earth was growing in size, while we were travelling in a spaceship back to earth the distance will shorten.

So, that is not a separate coordinate.
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So, that is not a separate coordinate.

It's irrelevant to the equation, in a computer simulation it would be a requisite.

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It's irrelevant to the equation, in a computer simulation it would be a requisite.

But it is still irrelevant to the OP's point.

(And, I can't imagine why it would be a requirement in simulation. But start another thread if you want to explain.)

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But it is still irrelevant to the OP's point.

(And, I can't imagine why it would be a requirement in simulation. But start another thread if you want to explain.)

not here to be pedantic mate

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I think the op point is more philosofical than physical.

In physics its irrelevant weather you take space as equal to vt with constant v and constant t than you take v as tending to infinite and t tending to zero.

Apparently according to him he claims in the equation s=vt v tends to infinite and t to zero and once v reaches infinity and time zero they change sense and infinite then tends to zero and zero tends to infinite with the sign reversed. This is some transfinite maths i wonder if theres a model for.

Are two particles trully moving or they just change size simultaneously with a fake sensation of motion?

I think the most interesting part is philosophical

Can our mind decieve us about the nature of the universe?

When an object gets close to you does it really translate or is it just growing and you assume things by your minds construct

philosophically speaking you could say space is equal to one unit so one=v as it tends to infinite * t as it tends to zero

but he claims they reach those extreme values and then reverse with a reversed sign

so 1= 0*8=-8*-0

and this would be valid for any value instead of 1

if you take 1 youre taking a grid in space of one unit but that formula would be true for any number even zero

so you could take a grid in which all axes are located at (000)

so this would be the oneness parmenides meant though i see more likely a twoness time and spaceplaying all the time with infinity and zero

so there are just two numbers in the whole universe there are just two real things and real numbers the rest are constructions of the mind missguided by appearance

zero and infinite

who are you, myself i think im zero

edit.

i think to obtain the formula for motion as inflation its in perspective drawing:

Edited by strangelove
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I don't follow the OP's full train or question as it is too long, but his post#6 on size is suggestive of non linear geometry, where exactly those issues arise.

The last posts by Strange and Strangelove are about projective geometry which is different again.

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I don't follow the OP's full train or question as it is too long, but his post#6 on size is suggestive of non linear geometry, where exactly those issues arise.

The last posts by Strange and Strangelove are about projective geometry which is different again.

here theres a 5 min video that explains it maybe more didactically:

But it is still irrelevant to the OP's point.

(And, I can't imagine why it would be a requirement in simulation. But start another thread if you want to explain.)

lets do a simulattion with our minds:

two objects are separated 1 m and are 1 cm big AND THEYRE STILL

after each grow to a size of 50 cm after x time they will meet

but they havent moved theyve just had an illusory perception of motion due to not noticing the change in size for relatively to each other they havent changed size

so when you apply a force on an object what youre really doing it its shrinking it and acelerating its time rate

thats why as a car moves away it gets smaller and slower

Edited by strangelove
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lets do a simulattion with our minds:

two objects are separated 1 m and are 1 cm big AND THEYRE STILL

after each grow to a size of 50 cm after x time they will meet

but they havent moved theyve just had an illusory perception of motion due to not noticing the change in size for relatively to each other they havent changed size

They haven't moved and there is no illusory perception of movement. They have just got bigger.

so when you apply a force on an object what youre really doing it its shrinking it and acelerating its time rate

Nonsense. Applying a force to an object does not appreciably shrink it. Nor does it accelerate is time rate. If anything, from the perception of the stationary observer, the moving objects clock slows.

thats why as a car moves away it gets smaller and slower

Er, no. That is called "perspective". Sheesh.

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They haven't moved and there is no illusory perception of movement. They have just got bigger.

Nonsense. Applying a force to an object does not appreciably shrink it. Nor does it accelerate is time rate. If anything, from the perception of the stationary observer, the moving objects clock slows.

Er, no. That is called "perspective". Sheesh.

should i clarify the separation is from their centers if their centers are separated one meter and theyre each half meter big theyre touching they arrived

i didnt say applying a force "shrinks it" i said applying a force on a ball means you sent it away but with no motion that would imply you just shrinked it

youre arguing as the sun seems to revolve it must revolve

perspective can both account for motion as for just shrinking my point was that taking motion as shrinking you could use the equations derived from perspective rules

in fact this is a question of perspective its as right to say it moves and it appears to grow as its right as well to say that it grows and appears to move

the question would be what the universe really does and which perspective explain things farther, if a 4 dimensional perespective or a 5 dimensional

this problem takes us to a philosophical question

your mind tells you and object moves and change of size is an ILLUSION

your senses tell you, hey this tiger is bigger and bigger i better run

edit:

so do you agree now that two objects in empty space one cm big separated their centers 1 m after growing to 50 cm will meet?

if you agree to this and please answer me because this doesnt seem to be a valid point i can go next stage and explain you how can they go past each other, hint zenos dichotomy

anyway this idea is not intractable.

http://www.mindship.org/meyerst.htm

If your ruler is growing, then your distances depend on the size of the ruler.

exactly so distance is 1 meter between each center of two guys that are floating in space

the guys are one cm big and their ruler is one cm big as well

when the ruler is two cm big change they didnt notice theyll think now theres left 50 units of that 2 cm now rule not 100 like before

Edited by strangelove
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i didnt say applying a force "shrinks it" i said applying a force on a ball means you sent it away but with no motion that would imply you just shrinked it

That makes no sense. Applying a force will make it move so how can you say "with no motion".

so do you agree now that two objects in empty space one cm big separated their centers 1 m after growing to 50 cm will meet?

Well, obviously. Despite the fact they don't move. They are still 1 m apart.

when the ruler is two cm big change they didnt notice theyll think now theres left 50 units of that 2 cm now rule not 100 like before

Yep. Which is exactly what I said.

That has nothing to do with movement or size being a dimension. In fact it explains why size is NOT a dimension.

And what does any of this have to do with the thread title: the definition of time?

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ok ill try again:

two guys are separated from their centers one km and theyre one m big

if they have a ruler in their pocket of 1 m

what distance will show the ruler when both guys and the ruler grow to half km radius

a prescholar question:

how ,many times does a 1 m ruler fit in one km distance?

how many times does a 500 m ruler fit in one km?

please answer me this question its quite easy and well have to go very small steps at a time im afraid

maybe someone who understand and is english native speaker can explain this guy?

edit:

here a diagram of apparent motion just by change of size i hope you finally understand:

Edited by strangelove
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Obviously if you change the size of the ruler then you will measure a different distance. But if you switch from measuring in miles to km, it doesn't mean the objects have got further apart.

And, of course, changing the scale or units is not a dimension because it is not an independent value (as you have explained very well).

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