IF all celestrial bodies were legitimately spherical, and all orbits were syncroneous...

[poo thrower]

...THEN - would there be "no need whatsoever for general or spacial relativities" ?.

i.e. we could all have got on with our lives after newton

- or is that not right ? (- i can't do math).

thanks.

 

 

[Markus Hanke]

Even if that were the case, you would still see relativistic effects - for example gravitational time dilation, frame dragging around rotating bodies, gravitational light deflection, relativity of simultaneity etc etc. It would not really change anything.

The theory of General Relativity, in this particular context, is largely about the empirical observation that (small enough) freely falling bodies are not subject to any forces - which is to say that if you attach an accelerometer to such a body, the instrument will read exactly zero at all times during free fall. That’s why you get a funny feeling in your tummy as you fall after jumping off a high board into a swimming pool. And yet free fall bodies are very clearly affected by gravity, so the force-based Newtonian model (though it works very well as an approximation) is ultimately not adequate as an explanation for gravity. Also, when you start looking at situations involving very strong gravitational fields, the Newtonian model makes increasingly inaccurate numerical predictions. This would continue to be the case, even if everything were nicely spherical and regular.

P.S. Even Newtonian gravity does not predict everything to be spherical and “synchronous” - depending on the particulars of a given situation, you can get some very complicated dynamics in Newtonian gravity, too. You can even get chaotic dynamics, i.e. situations that are deterministic, but still not predictable into the indefinite future. So even simple laws can lead to complex outcomes.

Edited December 28, 2019 by Markus Hanke
Addendum

[swansont]

If all celestial bodies were perfectly spherical, then relativity would be wrong. They deform because of their rotation, which is Newtonian physics. They would have to be perfectly rigid to remain spheres, but relativity forbids perfectly rigid materials

We would have no need of an incorrect theory.

[Janus]

11 hours ago, poo thrower said:

...THEN - would there be "no need whatsoever for general or spacial relativities" ?.

i.e. we could all have got on with our lives after newton

- or is that not right ? (- i can't do math).

thanks.

 

 

If the Earth were perfectly spherical, and you put a clock in a geosynchronous orbit around it,  that clock would still tick at a different rate than one on the ground.  This is not in accordance to what Newton would predict, so yes, you would still need Relativity to explain this.

I'm curious as to why you would think that perfectly spherical bodies and synchronous orbits would have any effect on whether or not Relativity holds.

[swansont]

2 hours ago, Janus said:

If the Earth were perfectly spherical, and you put a clock in a geosynchronous orbit around it,  that clock would still tick at a different rate than one on the ground.  This is not in accordance to what Newton would predict, so yes, you would still need Relativity to explain this.

I'm curious as to why you would think that perfectly spherical bodies and synchronous orbits would have any effect on whether or not Relativity holds.

Also: if the earth were rotating, clock rates would vary with latitude on the surface, at the same elevation. It’s because of the deformation that they don’t 

[poo thrower]

16 hours ago, Markus Hanke said:

P.S. Even Newtonian gravity does not predict everything to be spherical and “synchronous” - depending on the particulars of a given situation, you can get some very complicated dynamics in Newtonian gravity, too. You can even get chaotic dynamics, i.e. situations that are deterministic, but still not predictable into the indefinite future. So even simple laws can lead to complex outcomes.

thankyou very much - yes sorry; i was thinking IF (big if) everything conformed to "shapes" ("spheres") and the universe conformed to circular orbits - THEN would newtons maths be bang on ? (i can't do times tables let alone calculus).

"i will concede the principle of equivilance, if you concede i am a figment of your imagination"...

9 hours ago, swansont said:

If all celestial bodies were perfectly spherical, then relativity would be wrong. They deform because of their rotation, which is Newtonian physics. They would have to be perfectly rigid to remain spheres, but relativity forbids perfectly rigid materials

We would have no need of an incorrect theory.

so i would be right if there was no such thing as "time" ? (time is over-rated...).

5 hours ago, Janus said:

If the Earth were perfectly spherical, and you put a clock in a geosynchronous orbit around it,  that clock would still tick at a different rate than one on the ground.  This is not in accordance to what Newton would predict, so yes, you would still need Relativity to explain this.

I'm curious as to why you would think that perfectly spherical bodies and synchronous orbits would have any effect on whether or not Relativity holds.

they have quantum clocks nowadays i believe so maybe that does not hold correct to this day (? i very much don't know ?), but i am asking because; "gravity" seems like a "explaination" of melding of the positives and negative poles of electromagnetism - i.e. a "wonky bridge to explain electromagnetism (of the earth) prior to that knowlege being available" (??).

i believe that perhaps newton didn't plagurise hooke per sey..., because hooke couldn't work out "electromagnetism" at that time, newton could (kind of...) and it became "gravity"....

...then einstein came along and said "that bridge is wonky"; see; you need to glue it with "space time", ....and then quantum physics came along and said "you can't fix wonky bridges with metaphysical glue that is neither in solid nor liquid state..." and here we are today....

with the limit of our computer power (quantum super state computers) STILL not being able to model "electromagnetism" and yet newton predicted the bending of light, but was not accurate enough or something (i can't do math thus don't understand the relevance).

-----

can anybody please help me with - you know physicists say "newton works well in A) example but fails B)" can anybody give me a real real laymens example of it's success and failings ? - like person throwing tennis ball thought experiment kind of thing ? versus ??

that would be very much appreciated, thankyou

 

[Ghideon]

36 minutes ago, poo thrower said:

so i would be right if there was no such thing as "time" ? (time is over-rated...).

Without ”time” wouldn’t Newton, and also most other models such as relativity, loose their meaning? What would you be right about if there is no time?

[studiot]

1 hour ago, poo thrower said:

can anybody please help me with - you know physicists say "newton works well in A) example but fails B)" can anybody give me a real real laymens example of it's success and failings ? - like person throwing tennis ball thought experiment kind of thing ? versus ??

that would be very much appreciated, thankyou

 

Newton and his contemporaries described the world in terms of 'forces'.

Neither Newton, (nor Hooke) knew about the fourth great natural force  - the electromagnetic force.
In fact they only knew of two of the four of what we now call the four fundamental forces of nature.
They also built upon the newly invented (by Descartes) maths of coordinate geometry.
It should be understood that the maths and physics go hand in hand so force methods are suited to cartesian geometry and this type of geometry conditions physics thinking.

Most people have an intuitive idea of a force as a driver which causes something to happen or change.
They are also familiar with the idea of one force resisting another, leading to the notion of a balance of forces.

The two forces (mechanical and gravity) coupled with the opposition / balance notion are enough to generate a whole wide range of physical phenoma from structural theory to vibrations at light frequencies (Newton did not do  this ) to understanding why we do not fly off the spinning planet to ballistic theory enabling warships to aim for and hit targets they cannot see over the horizon and just so much more.

So when asked "Why do the planets orbit as they do?" Newton's theories answered in terms of forces and the balance between mechanical (inertial) forces and gravitational ones.

 

The next step was not relativity but energy methods that were developed one to two centuries after Newton.
Here the idea was to consider the energy involved when a force acts or is opposed or balanced.
A new notion of 'least energy' was introduced and names such as Castigliano, Maxwell, Hamilton and Lagrange came onto the Scene.
A devotee and substantial developer of Newtonian thinking was Euler.
Right at the end of the time a new type of geometry appeared, developed by Riemann.
This new gometry was just as well because it allowed the flaws in the Newtonian system that had become apparent in two centuries of development, to be addressed.
 

Thus was ushered in the new system of Relativity, which is really a change of Geometry, not Physics., although derived from physical considerations by Einstein.
It was substantially fleshed out mathematically by maths professors Minkowski and Weyl.

Along with the discovery of the electromagnetic force and two nuclear forces replacing Newton's collection of mechanical forces, the energy methods went on to blossom into the quantum theory.

 

This is a very short form history of 500 years or so of development into modern Science.

 

 

 

 

Edited December 28, 2019 by studiot
spelling

[Markus Hanke]

16 hours ago, swansont said:

relativity forbids perfectly rigid materials

Good point! I did not think of this one.

7 hours ago, poo thrower said:

can anybody please help me with - you know physicists say "newton works well in A) example but fails B)" can anybody give me a real real laymens example of it's success and failings ? - like person throwing tennis ball thought experiment kind of thing ? versus ??

Suppose you have two clocks - you keep one down on Earth, and put the other one into a geostationary orbit. Newton works really well in allowing you to calculate all you need to know about the orbit of the clock in space, as well as the physics of the rocket launch to get it there. However, you will empirically find that, when you compare the readings of the two clocks, they actually record (slightly) different intervals; Newton fails to explain or predict this. The differences in readings will be small, but they still matter and need to be accounted for in some real-world applications, such as e.g. GPS satellites. This phenomenon is called gravitational time dilation.

This is just one specific example, there are many many others.

[Janus]

17 hours ago, poo thrower said:

they have quantum clocks nowadays i believe so maybe that does not hold correct to this day (? i very much don't know ?),

 

The type of clock used makes no difference.  Your statement makes it seem like you think the Relativistic effects are caused by something acting on the mechanism of the clock.  This not the case.   The method by which the clock operates plays no role.   Relativity is about the fundamental nature of "time" and "space" and how they relate to each other and it doesn't care about what kind of clock you use, only that they are accurate enough. ( For instance, if you are trying to measure an accumulated difference of 1 nanosecond over a 24 hr period, you need to use clocks that you know that, if placed side by side, would drift apart in their readings much less than 1 nanosecond per 24 hrs.)

[studiot]

The earliest and still classic experiment involving the relativity of time (and space) is the lifetime of cosmic muons v laboratory ones.

Here is a direct comaprison where Newton breaks down and Einstein takes over.

http://hyperphysics.phy-astr.gsu.edu/hbase/Relativ/muon.html

[poo thrower]

4 hours ago, Janus said:

The type of clock used makes no difference.  Your statement makes it seem like you think the Relativistic effects are caused by something acting on the mechanism of the clock.  This not the case. 

are you 100% ?

Quote

the ion clock's measured frequency to the current standard is 1121015393207857.4(7)Hz

if "they don't have "clock mechanisms" / measure particle frequency ? (and like i say i can't do maths and am "self educated via kerbals space program"... but) i figured they "would have the same reading because of "quantum entanglement"" - is that incorrect ?.

(if they "are as rubbish as wrist watches", then kind of waste of time building them imho ???. (confused))

4 hours ago, studiot said:

The earliest and still classic experiment involving the relativity of time (and space) is the lifetime of cosmic muons v laboratory ones.

Here is a direct comaprison where Newton breaks down and Einstein takes over.

http://hyperphysics.phy-astr.gsu.edu/hbase/Relativ/muon.html

thankyou! - thats my mind proverbialed for the forseeable future - i will attempt to do some reading (hieroglyphs "great"....).

Edited December 29, 2019 by poo thrower
to attempt to sound more coherant

[Janus]

34 minutes ago, poo thrower said:

are you 100% ?

they don't have "clock mechanisms" - they measure particle frequency ?, like i say i can't do maths and am "self educated via kerbals space program"... but i figured they "would have the same reading because of "quantum entanglement"" - (benefit of not being able to do my times tables)

if they "are as rubbish as wrist watches", then kind of waste of time building them ???.

 

I'm 100% sure that the type of clock doesn't matter.

 

And atomic clocks are not "as rubbish as wrist watches", they are much, much more accurate.  A typical wristwatch might gain or lose a second per day, while an atomic clock could run for a 100 million years before losing or gaining a sec.

The tick rate difference between a ground and orbiting clock is not due to the clocks not accurately measuring time, but due to the fact that time itself is different for the orbiting clock frame than it is for the ground frame. 

[poo thrower]

thankyou (relativity is seemingly outside of my functioning of brain...) - can anybody help me with - you know with the equivalance principle (vs. relativity (vs. my most fundamental force being "stupidity").

why this doesn't apply to photons then ? - i don't get it...

like how do they know that time is the thing that is not linear ? (AND as opposed to me trying to understand relativity....).

 

[iNow]

20 minutes ago, Janus said:

And atomic clocks are not "as rubbish as wrist watches", they are much, much more accurate.  A typical wristwatch might gain or lose a second per day, while an atomic clock could run for a 100 million years before losing or gaining a sec.

Said another way, my boss doesn’t generally care when I’m 100 milliseconds late to a meeting. So long as I’m within plus or minus 5 minutes we’re good. 

 

3 minutes ago, poo thrower said:

why this doesn't apply to photons then ?

Photons never have a valid reference frame since by definition they travel at the speed of light and are never at rest. Said another way, they don’t experience measurable time. 

[poo thrower]

4 minutes ago, iNow said:

Said another way, my boss doesn’t generally care when I’m 100 milliseconds late to a meeting. So long as I’m within plus or minus 5 minutes we’re good.

so wrist watches are fine then...

5 minutes ago, iNow said:

Photons never have a valid reference frame since by definition they travel at the speed of light and are never at rest. Said another way, they don’t experience measurable time. 

so because "physicists can't keep up with them" they have exluded them from einsteins model..... "oh right".

also; how can you label them a particle if they have no mass, are never at rest AND don't even have a valid reference frame ?

 

[iNow]

2 hours ago, poo thrower said:

so because "physicists can't keep up with them" they have exluded them from einsteins model..... "oh right".

No. That is not a valid representation of what I shared with you. A valid reference frame comes from a point of rest relative to other reference frames. Photons are never at rest relative to any reference frame. 

2 hours ago, poo thrower said:

how can you label them a particle if they have no mass, are never at rest AND don't even have a valid reference frame ?

You should study more to find out. I’m not the one who created the labels so you’re really tilting at wind mills here. 

[poo thrower]

1 minute ago, iNow said:

so you’re really tilting at wind mills here. 

point taken...

sorry for being argumentative and thankyou for the help and direction.

as sure as an ape, will not only use said matter as protectile, he will ALSO aim directly for your face..

i am going to quit (the forums...) whilst i am behind, safe in the aquired, from you, knowlege (thankyou); that time is non-linear, and photons are INFACT high velocity electon poop, hitting EVERYTHINGS faces, ALL OF THE TIME.

physics is rather poetic, we can all agree on that.

[iNow]

3 hours ago, poo thrower said:

how can you label them a particle if they have no mass, are never at rest AND don't even have a valid reference frame ?

Why do we park on driveways but drive on parkways? Why are goods moved by cars called shipments but goods moved on ships are called cargo?

[zapatos]

49 minutes ago, iNow said:

Why do we park on driveways but drive on parkways? Why are goods moved by cars called shipments but goods moved on ships are called cargo?

Why can you be superstitious but not a little bit stitious?

[MigL]

OK I'll play too...

Why are attached dwellings called APARTments ?
Why are the places where you sit at a sports game called the STANDs ?

Edited December 30, 2019 by MigL

[iNow]

Lol. Thanks fellas. I didn’t mean to derail the thread.

My core point is that language is a living breathing part of culture that evolves based on how people use it, yet words themselves are sometimes frozen in the past even after we learn new things and abandon old models for more refined and accurate ones. 

Summarized: Asking why photons are called particles is more of a history discussion, not a physics one. Physics uses maths as it’s language, and for good reason. 

I return you now to your previously scheduled program. 

https://en.m.wikipedia.org/wiki/Photon#Nomenclature

https://en.m.wikipedia.org/wiki/Elementary_particle

Edited December 30, 2019 by iNow

[MigL]

Just to be technical, photons are called 'quantum' particles, which conveys a whole different meaning than 'classical' particles.

[swansont]

Photons are named thus to differentiate them from EM waves, and showing the particle nature of light — discrete energy bundle, localized interaction.

[poo thrower]

On 12/30/2019 at 1:25 AM, iNow said:

Why do we park on driveways but drive on parkways? Why are goods moved by cars called shipments but goods moved on ships are called cargo?

language... - physics is MATHS:

On 12/30/2019 at 2:39 AM, iNow said:

Summarized: Asking why photons are called particles is more of a history discussion, not a physics one. Physics uses maths as it’s language, and for good reason.

no because, if one is two things and at one time, and you have picked one of the two things that it can not be, then that is called "avoiding eating vegetables to save more room for pudding (...and then going to play with spaceships)"

see:

On 12/30/2019 at 12:41 PM, swansont said:

Photons are named thus to differentiate them from EM waves, and showing the particle nature of light — discrete energy bundle, localized interaction.

i came back (in not time...) because spacial relativity is too difficult but one imagines time machines can not be built from cardboard...

thank god for f5 f9 on kerbals space program.