Frame of Reference as Subject in Subjective Idealism

[tar]

Objective idealism is an idealistic metaphysics that postulates that there is in an important sense only one perceiver, and that this perceiver is one with that which is perceived. One important advocate of such a metaphysics, Josiah Royce, wrote that he was indifferent "whether anybody calls all this Theism or Pantheism".

 

Owl,

 

You say that "one perceiver" is clearly theistic, but I don't think it has to be taken that way. It is you that are the perceiver, or me, or whoever, but this one perceiver, who perceives the world at a particular time, and at a particular place, is not "other than" the world which he/she/it perceives. "The perceiver is one with that which is perceived."

 

I don't think this requires an Anthropomorphic being, to be true. I think it simply is true.

 

There is no place or time, other than reality from which a perceiver can evolve. By definition we must be both of and in reality.

 

My feel, (or thought) is that our brains hold an analog representation, or model of reality, that we constantly "check" against that which is "happening".

 

We improve our model by "discovering" or "learning" what is going on. (this normally aids in our survival, and our ability to predict and modify and "use" what is going on, to our benefit, and avoid what would be harmful)

 

And we have the ability to "put ourselves in someone else shoes." Here is where the "frame of reference" comes in, in my book. We HAVE the ability to consider the world from more than one. We can consider that the world fits together well, and ANY frame of reference will "add back" to ours, flawlessly. Thus establishing both a subjective reality AND an objective reality that exists for us to have evolved from, and to exist in, and to perceive.

 

I do not think that this way of looking at it denies either science or religion. But I do not know which camp these thoughts would put me in, in regards to this thread.

 

I personally look for the ways that "everybody" is "correct". And figure that most difficulties are "in the translation".

 

Regards, TAR2

[Schrödinger's hat]

Schrodinger's hat:

 

 

 

"Space is four dimensional" requires the following distinction: 3-D space plus time or 4-D space? I think you mean the former, so...

 

My premise is that space is empty volume (except, of course, where occupied by objects) with three dimensions, and that time is event duration as objects move through space. Neither is a thing, and combining them into 'spacetime' still does not make spacetime a malleable medium which is curved by mass/energy. That s what the ontological debate is about. If you want to call my above premises faulty, it behooves you to show how so.

Both of these. Space and time are the same quantity.

As far as spacetime being malleable, I do not understand General Relativity well enough to discuss it with you. As far as I can gather the discussion has only been about flat spacetime.

If you wish for the reasoning behind this, either open up any relativity textbook, or come to Brisbane, Australia and we can discuss it over coffee. It's not the kind of thing that can be explained easily in a forum post.

 

If you say (or anyone says) that reality is dependent on frames of reference, you throw philosophical realism out and subscribe to a form of idealism in which things ARE as they are seen, having no intrinsic properties of their own, independent of frames of reference.

None of us are saying that reality depends on frames of reference. We are saying that measurements of spaces, distances, and times depend on frames of reference.

 

The rest is window dressing, including the claim that a severely oblate earth is just as accurate/real as the "proper" nearly spherical shape that is so well documented that we can confidently teach our children that it is not, in fact, squished nearly flat.

We're saying that distances change in different reference frames because distances are not a true measure of reality.

Maybe another Euclidean example will help.

Get (or imagine) a piece of paper in front of you on the desk/table/floor.

Cut it into a circle

this is your two dimensional Earth.

The surface of your table/desk is space, which has the x and y dimensions.

The vertical dimension is time.

Now, tilt your circle on an axis parallel to x so it's almost 90 degrees.

Measure its length along the x axis

You'll find it's almost 0.

If you restrict yourself to only making x and y measurements of where the edges of the circle are you find that the circle is now an ellipse.

For the people on the circle, the table contracted the same way.

 

Reality hasn't changed to make the circle an ellipse (or to make the desk far shorter), it's just that you are no longer measuring something that reflects reality (you need to measure [math]\sqrt{x^2 + y^2 + z^2}[/math] not just [math]\sqrt{x^2 + y^2}[/math].

 

Down to the presence of a minus sign Boost (change in velocity) is exactly like rotation.

This process is almost exactly mirrors (to be a precise Euclidean version of length contraction you'd need to use a cylinder, and you'd find that length would dilate) what you describe by taking measurements of earth from different reference frames without taking into account the times at which different points (note that 4d points are events) appear.

You need to measure [math]\sqrt{c^2t^2 - x^2 - y^2 - z^2}[/math] (interval -- sometimes the thing inside the square root is negative, so we usually use interval squared, not interval) not [math]\sqrt{x^2+y^2+z^2}[/math]

 

@owl, this description and model is -- to the best of my knowledge -- the mainstream one and is based on certain assumptions (namely the constancy of the speed of light, and liberal use of occam's razor to exclude things like lorentzian relativity).

As you have not stated a set of assumptions for this discussion, people have been using what is largely regarded as scientific fact in their arguments. If you disagree with this (and are not starting a discussion on the premise that they are/might be false) then the onus is on you to disprove it.

If you hold some assumptions (ie. there is a universal, well defined Now) to be more or less important than other assumptions (ie. the speed of light is constant), you are going to come to completely different conclusions.

Of the two assumptions, one is known not to come into contradiction with any known experimental result.

The other leads to something like Lorentzian relativity. I do not know how well this holds up in discussions of gravity, but it does give some valid results in special relativistic scenarios (note that in this theory things actually do change size if they are moving, but they do it in such a way that you can't tell which one is moving).

It is also rejected by mainstream science because it is more convoluted (involves an un-measurable stationary aether).

 

 

Do you realize that it is a meaningless tautology to say that “Time is that which clocks measure?” ("Time is that"... that what but duration?)

This is the same answer you will get from a scientist if you ask any other question.

We can break things down to their parts, but when you ask 'what is time' or 'what is an electron' eventually we just have to point at one.

There often comes a time when we can break a concept down further, but then you will just ask 'what is _smaller part_' and we're back to square one.

 

I understand very well what the conceptual components of SR are.

I think you have made it abundantly clear that you don't. I also think that you should make an effort to understand the concept of minkowski spacetime (even if you consider it wrong) before discussing alternative interpretations of the mathematics.

 

Philosophy of science examines its basic assumptions, the focus of this thread. Is the world as-is, in- and- of- itself and all its parts, independent of observation/measurement (objective realism);.

This is not the only assumption you're operating on. You appear to be operating on a number of assumptions, some of which are contradictory, or at least contradictory with assumptions that everyone else on the thread is operating on.

 

@everyone else: This is a philosphy thread, not a science thread we should stop bashing our heads together and figure out what exactly it is that owl is trying to discuss, rather than trying uselessly to teach him concepts from relativity over and over.

 

@everyone

Let's lay down some base assumptions.

 

Here are some possibilities. I am not stating that these are true, just that some of the participants may have been using them with or without everyone (including the poster) realising.

1) The speed of light is constant in all inertial reference frames

 

2) There is a global and well defined now

 

3) Three coordinates (x,y,z) are sufficient to describe shapes

 

4) Time dilation is a proven phenomenon

 

5) Length contraction is a proven phenomenon

 

6) Aether theories have been disproven for long enough that nobody cares about them

 

7) Space is the same type of thing as time and we live in a 4 dimensional (3,1) hyperbolic universe

 

8) Spacetime is flat

 

9) Gravity doesn't exist

 

10) There is a global and well defined coordinate system

 

11) Reality is objective

My posts as far as I recall have assumed 1, 4, 5, 6, 7, 8, 9, 10, and 11.

8, 9 and 10 are not actually true, but they greatly simplify discussion.

[owl]

First a "process" note: By the nature of such a forum, my discussions with swansont on "no preferred frame of reference" as a form of idealism, and with Cap 'n R on what time is and the meaning of SR theory (aside from the math) will likely get swept under the rug by subsequent replies and replies to replies.

I hope that doesn't happen here as I go ahead and reply to the immediately above.

TAR:

You say that "one perceiver" is clearly theistic, but I don't think it has to be taken that way.

 

The Wiki quote on objective idealism said, "...only one perceiver, and that this perceiver is one with that which is perceived."

 

"Only" makes it theistic, whether mono- or pan-theistic.

 

Objective realism does not require "god" to posit that the world/cosmos is real all by itself, independent of observation and measurement. The relevant question is then, how can science best investigate that reality? It is obvious to me that the scientific method must minimize unknown variables as best it can. That means, to me, at rest with what is observed, or as close as possible to that, not via the notorious near 'C' fly by frame relative to the object investigated.

 

I personally look for the ways that "everybody" is "correct".

A fine sentiment, but those who claim that a nearly flattened earth is just as correct as a nearly spherical earth (etc. with a very shortened AU or meter) are not correct. It requires a belief in an obviously absurd and experimentally unverified dogma, length contraction, to make two drastically different versions of earth's shape "equally true."

 

Schrodinger's hat:

Both of these. Space and time are the same quantity.

 

Saying so doesn't make it so. I say space is 3-D volume and time is duration of travel or movement of any object through space.

 

As far as spacetime being malleable, I do not understand General Relativity well enough to discuss it with you. As far as I can gather the discussion has only been about flat spacetime.

 

Check out the discussion and references in my ontology of spacetime thread. "Flat spacetime" is an invention of non-Euclidean geometry/cosmology. If it is just a coordinate system, ontology requires verification of the "real territory" to which "the map" refers.

Euclideans see "flat" as describing a 2-D plane.

 

None of us are saying that reality depends on frames of reference. We are saying that measurements of spaces, distances, and times depend on frames of reference.

 

Alllength contraction advocates here are saying that a very out of round earth is just as "real" as a nearly spherical earth, because it all depends on frame of reference, and none is "preferred" over another.

Measurement of a meter rod as 12 cm is wrong, due to the error of measuring it while passing by at near lightspeed rather than stopping and coming to rest next to it. (Not saying that Lorentz transformation formula does not have useful application for "transforming" the observed 12cm measurement to the 100 cm that the meter is intrinsically, as an "objective" object in the real world.

We're saying that distances change in different reference frames because distances are not a true measure of reality.

 

Well, either earth stays about 93 million miles from the sun (give or take in its elliptical orbit) or it varies to as little as 12 million miles, as seen from a high speed frame of reference. If you believe that such variation in the AU is "real" then you subscribe to the version of idealism that insists that reality Is as it appears from any/all frames of reference, no matter how extreme, short of full lightspeed.

 

Any games with geometry you propose must answer to the above, as well as to the fact that earth can not be both shapes, as above. It is, in fact, not a very oblate spheroid, but nearly spherical.

Here is your mind game vs the real world:

Get (or imagine) a piece of paper in front of you on the desk/table/floor.

Cut it into a circle

this is your two dimensional Earth.

 

Earth is geometrically a 3-D near-sphere.

The surface of your table/desk is space, which has the x and y dimensions.

The vertical dimension is time.

 

In the real world, space is 3-D (1-D = a line; 2-D = a plane; 3-D = volume = space.) And time is "that which elapses" as things move through space.

Now, tilt your circle on an axis parallel to x so it's almost 90 degrees.

Measure its length along the x axis

You'll find it's almost 0.

If you restrict yourself to only making x and y measurements of where the edges of the circle are you find that the circle is now an ellipse.

For the people on the circle, the table contracted the same way.

Amazing! If earth were a flat circle and you turned it on edge... it would look like a 1-D line. (No argument.)

..it's just that you are no longer measuring something that reflects reality

For sure! Starting with earth as a flat circle.

 

To be brief re:

...taking into account the times at which different points (note that 4d points are events) appear.

 

Time is how long it takes something to go from A to B in 3-D space.

Real world objects don't change with measurments from different frames of reference, including looking at them at different times (discounting things like watching a tree grow or the earth getting 'fatter' over eons of spinning.)

me:

Do you realize that it is a meaningless tautology to say that “Time is that which clocks measure?” ("Time is that"... that what but duration?)

You:

This is the same answer you will get from a scientist if you ask any other question.

We can break things down to their parts, but when you ask 'what is time' or 'what is an electron' eventually we just have to point at one.

You are clearly unfamiliar with ontology, which does ask "What is time?" and will not accept the above tautology as an answer.

We can observe clocks slowing down at high velocity, but we can not observe "time" slowing down, or "dilating." Then the question becomes, "Why do clocks slow down at high velocity?', not "what is this thing/medium/whatever that "dilates?"

 

Time is not 'like' electrons. You can't point at "time", but you can identify the energy shells in the elements which are composed of swarms of "electrons." Not an appropriate similarity.

Gotta go.

Edited August 23, 2011 by owl

[tar]

Owl,

 

I don't wish to interfere with your discussions. I thought I might be augmenting.

 

Perhaps not, but I am enjoying this thread none-the-less.

 

I am still hung up on time being the same type of thing as space as Schrödinger's hat points out in 177.

 

I lean in your direction on this Owl, and think it something else that exists along with, or because of, or as a result of 3-D space.

 

What seems to be always swept under the rug, is the fact that this moment is different than the one that just past, and the one that is about to happen. It is this difference that is time.

 

A stationary room, say Point A, will feel the effects of it, even if it doesn't move at all. All the physical processes going on inside the room will continue to happen. Things will grow and die, be built and fall apart, within the room, given the interplay between the components of the room.

 

Even the vacuum of space inside a void between strings of galaxies will have the rest of the universe "going on" around it, and the photons of an immense number of "events" passing through any given volume, "all the time", or "at any given time."

 

One of the things I have "figured out" in the last couple years, is that space, in its enormity, "loses" important characteristics, if thought of, all together, "at one time". It simply does not exist this way...ever.

 

That "now" where Alpha Centuri exists and we will "see" it in 4.5 years CANNOT be seen together with "this" now, except at a midway point in 2.25 years. And there is no actual way to coordinate the experiences together as "one thing".

 

And the "event" that is occurring "now" on Alpha Centuri, does not actually "end". It continues through the midpoint in 2.25 years, through the Solar System in 4.5 years, and right on past to the environs behind us (as we face Alpha Centuri).

 

Every event, everywhere has this "ripple" effect through the rest of the universe, and every point in the universe is continually buffeted by the continual ripples sent out from every other point in the universe.

 

In an important sense there IS only one perceiver, because if not at the particular place "here", and the particular time "now", there is no place or time to be.

 

Regards, TAR2

 

'Cept all those "other" places and times we can consider in reference to "this one."

Edited August 23, 2011 by tar

[Schrödinger's hat]

Saying so doesn't make it so. I say space is 3-D volume and time is duration of travel or movement of any object through space.

Saying 'saying so doesn't make it so' doesn't make it not so either.

Your point is?

 

Mine is that the 4D spacetime picture of things is entirely consistent with the maths and with the experiments we've performed.

If you want an example of an experiment you can try at home which does not work if we replace the relativistic frame change equations with ones which keep earth as a sphere, try this:

 

Get a battery, a length of thin wire, and a nail.

Wind the wire into a coil.

Connect the battery

Lift the nail with your electromagnet.

We know of no reason that the moving current should effect the nail without taking relativity into account.

It was this very effect that led people to coming up with the Lorentz Transforms some time before Einstein was around, they just didn't know why they disagreed with the Galilean transforms.

 

Earth is geometrically a 3-D near-sphere.

No it's not.

A slice of Earth at any given time is a near-sphere.

Earth at all times is more like a helix (if you're looking at it from, say, the sun, or Pluto).

If you slice it right you can get an oblate sphereoid.

We just call it a 3D sphere because that's good enough.

Amazing! If earth were a flat circle and you turned it on edge... it would look like a 1-D line. (No argument.)

You're almost there!

Now if earth (locally) were a 4D hypercylinder and you rotated it then took a slice, it'd look like an oblate sphereoid.

A fine sentiment, but those who claim that a nearly flattened earth is just as correct as a nearly spherical earth (etc. with a very shortened AU or meter) are not correct. It requires a belief in an obviously absurd and experimentally unverified dogma, length contraction, to make two drastically different versions of earth's shape "equally true."

Length contraction is a logical consequence of the Lorentz transform, so is time dilation.

If Maxwell's equations are correct then the Lorentz transforms are, too.

The Lorentz transforms are also the only linear transformation of coordinates that maintain a constant speed of light(and one or two other conditions, like Newtonian physics being a rough approximation).

There are probably other transformations, but Occam's razor told us to use this set.

You say this is obviously absurd.

The entire universe -- and by extension all of physics -- is absurd. Get used to it.

The scientific community (and all science students since) begrudgingly accepted such things because it is the simplest logical explanation for what we observed.

You are clearly unfamiliar with ontology, which does ask "What is time?" and will not accept the above tautology as an answer.

We can observe clocks slowing down at high velocity, but we can not observe "time" slowing down, or "dilating." Then the question becomes, "Why do clocks slow down at high velocity?', not "what is this thing/medium/whatever that "dilates?"

I am quite familiar with ontology. I was explaining why you got a tautology when you asked a scientist to define it.

No-one I know of has a better one. Your talk of durations between events is just as tautological.

When a scientist talks of time (unless he's a crazy theoretical physicist like abj -- they may have an actual definition), it's just filler for 'the amount of __unknown thing/process/material or medium__ that causes the radiation from a Caesium atom to oscillate 9,192,631,770 times'.

'time dilates' is just shorthand for clocks (and all observable processes) moving slower.

This is exactly the same as pointing to a 1m ruler when asked what a metre is, or holding up your hands when asked what space is.

 

One thing we do know, however, is that the mathematics (which accurately predicts many things) indicates that metre sticks for one person will sometimes measure time for another, and clocks in one frame measure distance in another.

 

 

Oh, and I re-iterate: Please state your assumptions, or at the very least answer this question:

Is there a global and well defined present?

Edited August 23, 2011 by Schrödinger's hat

[owl]

Schrodinger’s hat:

“Space and time are the same quantity.”

me:

“Saying so doesn't make it so.”

 

My point is to be taken at face value. You state the above as a fact. I disagree, but my saying ‘space is 3-D volume and time is duration of movement through space’ doesn’t make it so either, though I believe it is true, based on a long life as an amateur scientist and as a critic of non-Euclidean geometry/cosmology.

You:

I am quite familiar with ontology. I was explaining why you got a tautology when you

asked a scientist to define it.

No-one I know of has a better one. Your talk of durations between events is just as tautological.

 

My beef with ‘time dilation” is that it appears to reify time, as if “it” were ‘something’ that expands/dilates. So I speak of event duration of physical processes to clarify what time means. I agree with your statement, "'time dilates' is just shorthand for clocks (and all observable processes) moving slower.”

 

Also, when “it” is “woven together with space” to make “ the fabric of spacetime” then both are reified into a malleable medium. When you say,

“that metre sticks for one person will sometimes measure time for another, and clocks in one frame measure distance in another.”...

you seem to subscribe to this ‘fabrication.’ Of course the speed of light is well used as a ‘measuring stick’ for distance, as in “light minutes/years.” But that is clearly distance traveled in a specific duration of time. The debate over “spacetime” is still in full swing, as my spacetime ontology thread illustrates.

 

Oh, and I re-iterate: Please state your assumptions,

 

Yet again, my argument for objective realism assumes that “Real world objects don't change with measurements from different frames of reference,”

 

or at the very least answer

this question:

Is there a global and well defined present?

 

Given the above argument for what time is (and isn’t), there are no local time environments or local present/now environments. It obviously takes time for light to travel from 'there to here,' but now is now everywhere. Need we re-define "is," or is that a clear enough definition? If not, please explain whatever boundaries you see around time or “now” (this instant) that make 'it' local.

 

me: “Earth is geometrically a 3-D near-sphere.”

You:

“No it's not.

A slice of Earth at any given time is a near-sphere.”

 

Again, given my “real world objects” statement above as a basic assumption of objective realism, “slicing” it and/or measuring it from Pluto does not change its intrinsic, nearly spherical shape, nor does flatly denying the extremely well established earth-science description of it.

You:

“If you slice it right you can get an oblate sphereoid.”

 

Maybe you are so into the model/theory that you don’t see that theoretical ”slicing” to “get an oblate spheroid” doesn’t actually make it an oblate spheroid.

Rather, you seem to believe that frames of reference create reality, and that there is no objective reality independent of measurement from different frames of reference. (Idealism.)

Edited August 23, 2011 by owl

[tar]

Schrödinger's hat,

 

There are several issues I have with "understanding" what you are talking about.

 

I have been told to dispose of certain notions I have of reality, which do not agree with the math that describes reality "better" than my notions of it.

 

I am somewhat bewildered by this. I am not certain how one is supposed to imagine anything without making an analogy to something "already" understood.

 

If we are "aware" of reality, it is because we know what space is, and our position in it, and we know what time is, and our position in it.

 

If we are to assume (assumption number 1) that the speed of light is a constant thing, when measured from an inertial reference frame, then we have to PREsume that there is a constant thing that measures space and a constant thing that measures time.

 

How can you have a constant of 186 thousand miles per second, if you are not prepared to hold either miles constant or seconds constant? The whole idea of constancy loses its meaning. All the SI units are interrelated. Each defined in reference to the others. If meters are shorter than meters and seconds are longer than seconds to make C an integer, namely 1, in your formula, then you just changed the meaning of every other scientific unit in the book. How the laws of physics can hold under these circumstances appears more like a shell game, than a description of reality that I should yield to, instead of holding on to a sensible notion.

 

I never did understand the difference between a "real" force and a "ficticous" one. If it throws me off the merri-go-round, it is sufficiently real for my consumption.

 

There are "ways" that we sense, remember and predict reality. We have analogies we draw, maps we make, things we discover and share, names we give to stuff we collectively experience. We are not gods, we cannot see Alpha Centuri and our hand pointing at it, at "the same time" except in the manner that it actually happens. Our existence at a particular place and time, allows us to put everything else in perspective, and measure the "distance" things are from us. But that assumes the speed of light is a constant 186,000 miles per second. And a mile stays a mile, and a second stays a second. Otherwise, what exactly is it that you are holding constant?

 

Regards, TAR2

[Schrödinger's hat]

My point is to be taken at face value. You state the above as a fact. I disagree, but my saying ‘space is 3-D volume and time is duration of movement through space’ doesn’t make it so either, though I believe it is true, based on a long life as an amateur scientist and as a critic of non-Euclidean geometry/cosmology.

 

My beef with ‘time dilation” is that it appears to reify time, as if “it” were ‘something’ that expands/dilates. So I speak of event duration of physical processes to clarify what time means. I agree with your statement, "'time dilates' is just shorthand for clocks (and all observable processes) moving slower.”

 

Also, when “it” is “woven together with space” to make “ the fabric of spacetime” then both are reified into a malleable medium. When you say,

“that metre sticks for one person will sometimes measure time for another, and clocks in one frame measure distance in another.”...

you seem to subscribe to this ‘fabrication.’ Of course the speed of light is well used as a ‘measuring stick’ for distance, as in “light minutes/years.” But that is clearly distance traveled in a specific duration of time. The debate over “spacetime” is still in full swing, as my spacetime ontology thread illustrates.

The speed of light is the ratio of these two things in your own frame. If you want to make your measurements agree with someone in another frame you have to include your (and their) measurements of time and space.

Much as you have to include measurements of how far in the x direction, the y direction and the z direction to get a true measure of the distance from one side of the paper circle to the other.

Yet again, my argument for objective realism assumes that “Real world objects don't change with measurements from different frames of reference,”

Then we agree, but you are presenting a false dichotomy.

1) The world is three dimensional and relativity is correct -- thus the world is subjective.

2) The world is three dimensional (and objective) and therefore relativity is incorrect

Whenever anyone presents option 3) The world is objective and four dimensional you just respond with 'I think it isn't'.

 

It is obvious that assuming the model on which relativity is based is incorrect will lead you to finding paradoxes if you assume the results of that model are true.

 

Given the above argument for what time is (and isn’t), there are no local time environments or local present/now environments. It obviously takes time for light to travel from 'there to here,' but now is now everywhere. Need we re-define "is," or is that a clear enough definition? If not, please explain whatever boundaries you see around time or “now” (this instant) that make 'it' local.

Now we're getting somewhere (hur hur, see what I did there).

The notion of now has no physical meaning in a relativistic world. You can define a set of events and call it delta t=0, but that's doesn't make them more or less important than any other random set of events.

All relativity leaves us with is:

The past (things that can effect us). This is defined by one's light cone (the set of events that are closer than ct away from you, where t is the amount of time since the event happened).

Here and now (this event right here, right now, that is being effected by the past and effects the future). This is what people talk about when they say the present is only defined locally.

The future (things we can effect).

 

If you assume 'now is now everywhere' you are going to reach many paradoxes.

 

Again, given my “real world objects” statement above as a basic assumption of objective realism, “slicing” it and/or measuring it from Pluto does not change its intrinsic, nearly spherical shape, nor does flatly denying the extremely well established earth-science description of it.

 

It's not denying the well established description, it's extending it.

Earth science doesn't deal with high velocities so they do not have to consider the four dimensional nature of the universe.

Maybe you are so into the model/theory that you don’t see that theoretical ”slicing” to “get an oblate spheroid” doesn’t actually make it an oblate spheroid.

Exactly. It is objectively a four-dimensional shape. Not any type of sphere or sphereoid.

Only when you restrict yourself to looking at a thin slice does it look like a sphere or oblate sphereoid.

Rather, you seem to believe that frames of reference create reality, and that there is no objective reality independent of measurement from different frames of reference. (Idealism.)

Objective reality is four dimensional.

 

 

 

I am somewhat bewildered by this. I am not certain how one is supposed to imagine anything without making an analogy to something "already" understood.

You are right to be bewildered. Most modern physics is highly counter-intuitive, and this discussion got right into the thick of things rather than starting at the beginning.

You can extend your understanding and imagination in a number of ways. The most common seems to be 'just shut up and calculate', whereby the student of physics is made to calculate results, and do experiments which depend on these results over and over again until it starts to become intuitive to them. This method is rather inefficient.

 

Another is to make analogies to the Euclidean and three dimensional equivalents of certain concepts. I'll eventually get around to writing something on this. Unfortunately everything I know of written on the subject requires at least some facility with mathematics.

Perhaps someone else here can suggest a good book.

 

If we are "aware" of reality, it is because we know what space is, and our position in it, and we know what time is, and our position in it.

 

If we are to assume (assumption number 1) that the speed of light is a constant thing, when measured from an inertial reference frame, then we have to PREsume that there is a constant thing that measures space and a constant thing that measures time.

 

How can you have a constant of 186 thousand miles per second, if you are not prepared to hold either miles constant or seconds constant? The whole idea of constancy loses its meaning. All the SI units are interrelated. Each defined in reference to the others. If meters are shorter than meters and seconds are longer than seconds to make C an integer, namely 1, in your formula, then you just changed the meaning of every other scientific unit in the book. How the laws of physics can hold under these circumstances appears more like a shell game, than a description of reality that I should yield to, instead of holding on to a sensible notion.

Setting C to 1 and using that system of units (which is not SI) is very common among mathematicians and computational/theoretical physicists -- much to the chagrin of anyone who has to do experiments with their results.

Ignore the fact that distance is defined by time for now, this is a result of the constancy of the speed of light.

The constant thing that measures space can be a ruler, or a tape etc.

The constant thing that measures time can be a clock (or oscillation of some radiation) etc.

If you keep your clock still relative to your ruler, and use them to measure the speed of a beam of light you will always get the same result no matter where you are or how fast you're moving (if your clock and ruler accelerate or are in a strong gravitational field you won't always get the same result -- it'll depend on the acceleration).

If you are in a different frame to the ruler and the clock you'll get the same result for the speed of the beam of light, but you'll disagree on the position parts of the apparatus were in, and the times at which the other frame made their measurements.

 

If you want a full explanation from the beginning I'm happy to provide it, but I do not think it is in the scope of this thread. Also there are plenty of explanations around which people smarter than me have put more effort into.

[Iggy]

Think of it this way, Tar...

 

Two people who are floating away from each other at great speed in deep space can each measure the speed of the same ray of light and get the same answer... 300 thousand meters per second (or whichever units you like)... as Schrodinger says...

 

So, as an analogy...

 

Imagine someone standing in the street watching a bus drive away from them. They measure the bus move away from them at 60 miles per hour. Every hour the guy in the street notices that the bus is another 60 miles away from him.

 

Someone else is driving in a car chasing the bus. They drive their car 58 miles per hour relative to the guy standing in the street. The person in the car measures the speed of the bus relative to himself and gets 60 miles per hour. Every hour the guy in the car notices that the bus is another 60 miles away from himself.

 

Someone else is driving a car in the opposite direction. They drive their car 50 miles per hour relative to the guy standing in the street. This person measures the speed of the bus relative to himself and also gets 60 miles per hour. Every hour this guy finds that the bus is another 60 miles away from himself.

 

Everyone, no matter how fast they are going in either direction on the road, measures that the bus moves 60 miles relative to themselves each hour.

 

In this analogy the speed of the bus, 60 mph, is constant. In our world 300 thousand km/s is constant.

[Schrödinger's hat]

So what you're saying, Iggy, is we'll never catch the dragon bus and no matter how hard we try we'll never get as high close as we once were?

[owl]

Follow me if you will on a journey into objective realism. This will require setting aside for the moment the dictum/dogma of relativity that everything is relative and that there is no preferred frame of reference, i.e., that measurements/descriptions of objects from all frames are equally correct.

 

So, imagine a world/cosmos with no intelligent observers and no clocks or measuring sticks.

It does not disappear just because it is not being observed and measured. It is intrinsically real and has intrinsic properties. Galaxies form and diversify into solar systems and planets. Most of the latter (stars and planets,) due to the well known laws of physics, are nearly spherical in shape, though no one is around to observe that fact. Distances between objects vary only as they physically *move* closer together or further apart. (Nobody is flying around at near lightspeed taking measurements!)

 

*Movement* takes “time” (duration from here to there) even though nobody is “clocking” any particular movement event.

 

All objects and the space they exist in are three dimensional, not counting the elapsed time factor,( not another “dimension”) for movement. There is no one around to invent a fourth dimension, but three cover all the axes: line, plane, volume or distance, area volume. Space is simply this volume, on all scales, whether the space between subatomic particles, stars and planets, or galaxies.

 

Light travels at a constant velocity through space, so it still takes exactly the same amount of time for sunlight to reach earth even without assigning time and distance units to this velocity.

 

This is the cosmos according to objective realism. No flattened earth. No shrinking or expanding objects time or distance* as different observers see things differently. (*Except as natural growth/shrinkage or, as above, objects moving closer or further from each other,)

 

At this point I feel like resting my case as argued in this thread. I could be talked out of it, but that would require that respondents were actually able to fulfill the above opening requirement, not just continue beating the drum for “everything is relative to observational frames of reference.”

 

Thanks to whomever actually “followed me” on this one.

[Schrödinger's hat]

Light travels at a constant velocity through space

With respect to? A galaxy? A planet? Everyone?

[owl]

With respect to? A galaxy? A planet? Everyone?

"Setting aside relativity" for the moment...

Its speed from sun to earth, as above, is the same as its speed from Alpha Centauri to earth... constant, like 186,000 mps without the "miles" or "seconds'... or, light from galactic center to earth... same speed.

[Schrödinger's hat]

You didn't really answer my question.

What would someone moving towards the sun at 180,000 mps measure?

[owl]

You didn't really answer my question.

What would someone moving towards the sun at 180,000 mps measure?

You still didn't get the point of my post, re-iterated above:

"Setting aside relativity" for the moment..."

 

Specifically, just for now, if you are willing to indulge my thought experiment (apparently not)...

Consider a world/cosmos "as it is," independent of measurement...

Sunlight always takes a bit over 8 minutes* to reach earth (*regardless of specific conventional time units), and there is no traveler going at near lightspeed trying to measure distance or travel time... in my presentation.

They tell me* that "for a photon" there is no distance between sun and earth and no travel time. But "reality for a photon" is significantly different than the Reality of sun and earth and their relationship in space and light's actual travel time.

*(Others say a photon has no inertial frame of reference. I suppose that is why you knocked 6000 mps off lightspeed for the traveler's speed.)

[swansont]

So, imagine a world/cosmos with no intelligent observers and no clocks or measuring sticks.

It does not disappear just because it is not being observed and measured. It is intrinsically real and has intrinsic properties. Galaxies form and diversify into solar systems and planets. Most of the latter (stars and planets,) due to the well known laws of physics, are nearly spherical in shape, though no one is around to observe that fact. Distances between objects vary only as they physically *move* closer together or further apart. (Nobody is flying around at near lightspeed taking measurements!)

 

*Movement* takes “time” (duration from here to there) even though nobody is “clocking” any particular movement event.

 

All objects and the space they exist in are three dimensional, not counting the elapsed time factor,( not another “dimension”) for movement. There is no one around to invent a fourth dimension, but three cover all the axes: line, plane, volume or distance, area volume. Space is simply this volume, on all scales, whether the space between subatomic particles, stars and planets, or galaxies.

 

Light travels at a constant velocity through space, so it still takes exactly the same amount of time for sunlight to reach earth even without assigning time and distance units to this velocity.

 

This is the cosmos according to objective realism. No flattened earth. No shrinking or expanding objects time or distance* as different observers see things differently. (*Except as natural growth/shrinkage or, as above, objects moving closer or further from each other,)

 

At this point I feel like resting my case as argued in this thread. I could be talked out of it, but that would require that respondents were actually able to fulfill the above opening requirement, not just continue beating the drum for “everything is relative to observational frames of reference.”

 

Thanks to whomever actually “followed me” on this one.

 

Fine. Imagine it. But don't for a second think that this description applies to the universe in which we reside. Don't examine it too closely, either, because you will discover some descriptions to be in conflict with each other.

[Iggy]

"Setting aside relativity" for the moment...

Its speed from sun to earth, as above, is the same as its speed from Alpha Centauri to earth... constant, like 186,000 mps without the "miles" or "seconds'... or, light from galactic center to earth... same speed.

Iggy:

 

On the grounds that everything is moving and velocity requires specificity as to "moving how fast relative to what."(as I've said a few time already.)

Could you answer Schrödinger's question, please? If "velocity requires specificity as to 'moving how fast relative to what'", and its speed is "186,000 mps", then *with respect to what* is that its speed?

 

By refusing to say, you are directly contradicting yourself.

 

Most of the latter (stars and planets,) due to the well known laws of physics, are nearly spherical in shape, though no one is around to observe that fact.

The best explanation for the bulging spherical shape of planets and stars is general relativity. A rotating gravitationally bound object has a surface of constant potential making it a surface of constant proper time.

[owl]

Fine. Imagine it. But don't for a second think that this description applies to the universe in which we reside. Don't examine it too closely, either, because you will discover some descriptions to be in conflict with each other.

Swansont,

So, no specifics against my argument, as usual. Just, ‘you are wrong, cuz relativity, in all its particulars (including length contraction) is right.'

No addressing:

This is the cosmos according to objective realism. No flattened earth. No shrinking or expanding objects time or distance* as different observers see things differently...

 

or: Distances between objects vary only as they physically *move* closer together or further apart. (Nobody is flying around at near lightspeed taking measurements!)

 

Iggy:

Could you answer Schrödinger's question, please? If "velocity requires specificity as to 'moving how fast relative to what'", and its speed is "186,000 mps", then *with respect to what* is that its speed?

 

By refusing to say, you are directly contradicting yourself.

 

You are really not paying attention, as usual. Sunlight traveling from sun to earth has the well known constant velocity relative to both sun and earth. From Alpha Centauri to earth, its velocity is relative, again, to both source and destination of the light. (186,000 mps from sun or Alpha Centauri to earth.)

 

The best explanation for the bulging spherical shape of planets and stars is general relativity. A rotating gravitationally bound object has a surface of constant potential making it a surface of constant proper time.

 

Ever heard of centrifugal force?

Wiki:

Centrifugal force... represents the effects of inertia that arise in connection with rotation and which are experienced as an outward force away from the center of rotation.

 

The spinning of earth for ages has pushed out a bulge at the equator where inertial centrifugal force is at its greatest.

[swansont]

Swansont,

So, no specifics against my argument, as usual. Just, ‘you are wrong, cuz relativity, in all its particulars (including length contraction) is right.'

No addressing:

This is the cosmos according to objective realism. No flattened earth. No shrinking or expanding objects time or distance* as different observers see things differently...

 

or: Distances between objects vary only as they physically *move* closer together or further apart. (Nobody is flying around at near lightspeed taking measurements!)

 

No actual data to support your assertions, as usual. Shirking the burden of proof, as usual. Relativity is the best explanation, and I have 100 years of experimental data to back this up. All you have countered this with is personal incredulity.

 

 

Iggy:

 

 

You are really not paying attention, as usual. Sunlight traveling from sun to earth has the well known constant velocity relative to both sun and earth. From Alpha Centauri to earth, its velocity is relative, again, to both source and destination of the light. (186,000 mps from sun or Alpha Centauri to earth.)

 

 

 

Ever heard of centrifugal force?

Wiki:

 

 

The spinning of earth for ages has pushed out a bulge at the equator where inertial centrifugal force is at its greatest.

 

Centrifugal force isn't a real force, but even if you do the analysis with pseudoforces the surface of a spinning fluid is an equipotential.

[owl]

swansont:

No actual data to support your assertions

 

Assertion: That earth is nearly spherical, based on all the scientific evidence and compiled data since earth was thought to be flat.

S:

Centrifugal force isn't a real force, but even if you do the analysis with pseudoforces the surface of a spinning fluid is an equipotential.

 

Double-talk.

Have you ever been thrown off a playground "merry-go-round" that got going too fast? (I don't know; maybe you never played. Just a whimsical aside.) How real was that force, which throws one off? Very real when you hit the dirt... or foam padding, as the case may be.

[Schrödinger's hat]

From Alpha Centauri to earth, its velocity is relative, again, to both source and destination of the light. (186,000 mps from sun or Alpha Centauri to earth.)

So you're saying that no matter what is emitting the light, it will always arrive at its destination moving 186,000 according to the people at the destination?

[swansont]

swansont:

 

 

Assertion: That earth is nearly spherical, based on all the scientific evidence and compiled data since earth was thought to be flat.

 

IOW, no data from other frames of reference. Merely an assertion that flies in the face of a well-established theory which you contradict with no evidence to support you.

 

 

Double-talk.

Have you ever been thrown off a playground "merry-go-round" that got going too fast? (I don't know; maybe you never played. Just a whimsical aside.) How real was that force, which throws one off? Very real when you hit the dirt... or foam padding, as the case may be.

 

No, physics. When thrown from the merry-go-round you do not fly off radially, as you would expect from a centrifugal (outward-seeking) force. You fly off at a tangent to the circle, in accordance with Newton's laws. You feel like there is a centrifugal force, but that's because you are in a non-inertial reference frame. The actual force on you is toward the center of the circle. This is one of those misconceptions that normally gets cleared up in physics 101.

[Iggy]

You are really not paying attention, as usual. Sunlight traveling from sun to earth has the well known constant velocity relative to both sun and earth.

I'm sorry if you feel like people aren't paying enough attention to you, but you in fact did not say "relative to both sun and earth". You didn't say what the velocity was relative to, and that's why I asked. I would assume it's why Schrodinger asked as well.

 

From Alpha Centauri to earth, its velocity is relative, again, to both source and destination of the light. (186,000 mps from sun or Alpha Centauri to earth.)

But, if distance and duration are constant (i.e. the same in all frames) then that cannot be.

 

It is a small matter of deduction to prove this. The blue planet has a velocity relative to the green planet.

 

The lines mark distance. Fill in some numbers. Try showing that the red arrow, the light, has the same speed relative to both planets. It obviously can't. The change in the length of the red line over time is the speed of light relative to the blue planet and the change in the length of the green line over time is the speed of light relative to the green planet. They can't be the same.

 

Without time dilation and length contraction you just have classical mechanics -- in which the speed of light is not constant. This should literally be the first thing you learn when learning relativity.

 

Ever heard of centrifugal force?

You missed my point. I guess I should explain in more detail.

 

To your assertion that stars and planets take on their oblate spheroid shape "due to the well known laws of physics", and that it is somehow separate from relativity, it should be pointed out that general relativity is that well known physics.

 

Newtonian physics, including Newton's law of gravitation, is different from relativity -- it makes different predictions. Where those differences have been tested the results support general relativity and disagree with Newton's system.

 

The spinning of earth for ages has pushed out a bulge at the equator where inertial centrifugal force is at its greatest.

"for ages"?

 

Earth becomes more spherical over time.

[owl]

Schrodinger’s hat:

So you're saying that no matter what is emitting the light, it will always arrive at its destination moving 186,000 according to the people at the destination?

 

In the thought experiment I asked you to consider (which you continue to refuse), there is no “according to the people,” because there are no people. Light from the sun or any star, or any source travels from the source at “lightspeed,” which, of course, is constant.

Your, "according to the people" insists on a frame of reference, while I argue that frame of reference does not determine reality in objective realism but only in idealism. This does not deny that the light source is obviously the reference point from which it travels, 186,000 miles further for every second it travels. (More editing for clarification) Also, obviously, light traveling toward earth gets 186,000 miles closer every second... which I thought goes without saying, but...)

 

Science based on objective realism will not grant equal validity to a severely oblate earth (of say a 1000 mile diameter) or an AU of only 12 million miles.

 

So, the question, "How oblate is it, objectively, and why?" is really beside the point if you endorse the validity of an earth of 1000 mile diameter as seen from the extreme frame cited in support of length contraction.

 

Swansont,

First, this an off-topic attempt (initiated by Iggy) to derail the philosophical point of my post of 8/24.

 

Second, I was using "centrifugal force" as the concept is commonly understood, notwithstanding the technical disclaimer that it is a "fictitious force."

 

I will repeat the common understanding from Wiki:

Centrifugal force (from Latin centrum, meaning "center", and fugere, meaning "to flee") represents the effects of inertia that arise in connection with rotation and which are experienced as an outward force away from the center of rotation.

 

As a kid hangs on to the rotating device, centripetal force, toward the center of rotation, holds him on. When he lets go, centrifugal force as commonly understood above, away from center of rotation, throws him off. Yes, his inertia will carry him tangent to the spinning disk. ... And, yes, technically speaking, one could re-define centrifugal force as lack of centripetal force

 

Wiki continues:

The concept of centrifugal force is applied in rotating devices such as centrifuges, centrifugal pumps, centrifugal governors, centrifugal clutches, etc....

 

Do you suppose all those devices should be renamed for the “real" dynamics involved with all of them? What would you like to rename a centrifuge? How a bout “lack-of-centripetaluge?”

 

Can we get back to my topic now?

Edited August 25, 2011 by owl

[swansont]

Science based on objective realism will not grant equal validity to a severely oblate earth (of say a 1000 mile diameter) or an AU of only 12 million miles.

 

Science is not based on or subservient to a philosophy. It is based on empirical observation and the models that are based on and supported by that observation. "Science" based on objective realism is wrong, since it is contradicted by empirical data. You have presented no data to support objective realism. You have your observation from the one reference and then shut your eyes and yell "lalalala I can't hear you" rather than actually investigate other frames of reference. IOW you haven't tested the hypothesis. You don't get to use the term"science" since you have done nothing scientific.

 

An apt statement would be "A world view based on objective realism will not grant equal validity to a severely oblate earth (of say a 1000 mile diameter) or an AU of only 12 million miles." There are world views in which the earth is 6000 years old, too, and the same level of scientific denial is present — many of the same arguments are used as you have presented here.