Starship Asterisk*

Qev,

John Dobson's "Beyond Space and Time" available several places on the web.

I happen to have his book right in front of me!

He is talking about how we measure distances, and uses the analogy of two ships captains, one using polar north and the other using magnetic north, to plot their courses between two islands. They take different paths, (two frames of reference) to get there and have different numbers for the separations in terms of NS and EW dimensions of the triangles, but they both agree on the distance between the two islands. If the islands are several thousand miles apart it becomes a 3 dimensional problem, not two as when they are close together. OK

Now I'll quote a couple of pages to layout what he is saying.

"For a three-dimensional space the equasion of separation between two points becomes
D=(square root sign) X^2 + Y^2 + Z^2
where the directions X,Y and Z are taken perpendicular to each other.
Suppose we want to measure the distance diagonally across a room from the southeast corner at the floor, to the northwest corner at the ceiling.
If the walls and the floor are perpendicular to each other, we simple have to measure along the base of one wall to the far corner, then along the base of the far wall and, finally up the corner to the ceiling. These distances will be our x, y, and z in the equasion, to find the distance.

"But the world is not objective in three dimensions either. We live in a Universe of four dimensions, and, as Einstein pointed out in 1905, time also must come into this equasion if the equasion is to remain invariant for observers moving with respect to each other. Our problem is not how to measure from the southeast corner at the floor to the northwest corner at the ceiling, but rather, how to measure the total separation, the four-dimensional separation, between an event at one of those corners and another event at the other. [like further out in space between stars]

"Our difficulty arises because the distance alone turns out not to be objective. That is, two people moving with respect to each other measure different distances between those events. Also, the time separation between two such events is not objective. Observers moving with respect to each other disagree on the length of time that has elapsed between two events. Only four-dimensional addresses such as here-now and there-then are objective, and the separation between any two such addresses(events) is also objective.

"Here, "moving with respect to each other" corresponds to our two ships' captains choosing different coordinate systems, i.e., choosing different directions along which to measure north or east. Just as our ships' captains differed in their estimates of the distances north and east to the second island, just so, two observers moving with respect to each other might differ in their estimates of the space and time separations between two events. But just as our ships' captains agreed on the total distance between the islands, just so, our two observers, moving with respect to each other, will agree on the total separation between any two events.

"Einstein's equasion of separation takes the form;
S = (square root sign) X^2 + Y^2 + Z^2 - T^2

"We write S instead of D because the four-dimensional separation is no longer simply a distance between here and there, but rather, a space-time separation between here-now and there-then.

"Now S is invariant, that is, if we agree to measure the distances x, y, and z in the same units and the time, t, in a corresponding unit, then the separation, S, between any two events will be seen to be the same to all observers regardless of their states of motion with respect to each other. S is invariant, i.e., it is objective. It is the same for all observers regardless of their motion or their points of view.

"(Einstein never liked the term relativity theory. He wanted it called the theory of invariants.)

"This, then, is our new geometry designed to save the objectivity of the Universe. But does it? For any two events, say here-now and there-then, this equasion can be simplified to;
S = (square root sign) X^2 - T^2

"So long as the x direction is chosen from here to there or from there to here, so that y and z are zero.

"It should be noted that time comes into this equasion as MINUS T^2, so that if one observer sees a greater distance, x, between two events, he will also see a greater time, t. Between the events here-now and there-then, one observer will see a greater distance between here and there and a greater time between now and then. It is only the total separation, S, that is objective, or invariant.

"SPACE AND TIME AS OPPOSITES

"With the equasion of separation in this form,
S = (square root sign) X^2 - T^2, it becomes immediately obvious that space and time are opposites because where x and t are equal,
S=0.
That is, for the events here-now and there-then, if the space separation between here and there is equal to the time separation between now and then, then the total separation between here-now and there-then is zero.

"Under what conditions is it true that the total separation will be zero? Is it simply a trivial case? No, it is by no means trivial, because it is true for any two events one of which can be seen from the other. If what we call a light beam can go from the event there-then to the event here-now, or from here-now to there-then, then the events must be considered adjacent, that is, the total separation between them must be zero. It is true for every event of our perception. The separation between the event of perception and the event perceived is zero. We see the whole Universe in the past. We cannot see anything when it happens. We can't see the back of our hands when we hold them at arms length, in the now. We see everything late. Every event that we see as away from us in space we see backwards in time, and it is only on the basis of such perceptions, where the separation between the perceiver and the perceived is zero, that we have come to the conclusion in the first place that the Universe exists outside.

"The ancients used to say the "the mind goes out through the eye and takes the form of a pot." The moderns say that "the photons come in from the pot and take that form in the eye." The equasion says that it makes no difference which mistake we make -- the separation is zero. In an effort to save the objectivity of the Universe, we have had to abandon the separation between the perceiver and the perceived.

"The Universe which we see is set up in this very peculiar way so that we cannot see anything when it happens. We see the whole show in the past. If we see an event in the Andromeda Galaxy at a distance of two and half million light years from us, we see it two and a half million years ago. Why? Usually we say that is because light travels at a finite velocity. But really, of course, it is because what we call the speed of light is simply the ratio of space to time. One light year is equal to one year. And we see a Universe as if outside of us by this elaborate trick of seeing everything as back in time, and in just such a way that the total separation between the perceiver and the perceived remains zero."

===

Now I am not seeing that all of this is shedding any light on the previous postings problems of redshift being connected to time dilation. It rather proves the case for redshift to be connected to time dilation.
So I stand corrected ! Thanks Qev !
It is more of a tangential subject of philosophical inquiry in regards to perception in general.

One of Dobson's pet peeves is "there are no Photons ! " There is nothing bebopping all over the place in the 'all possible probabilities' in a 'sum over histories' fashion to account for the observed behaviour of light.
There is nothing that goes from there-then to here-now, that we call photons, because the space-time separation between the observer and the event observed is zero. If there were photons, spacetime would be so clogged up and filled in every possible history of path of traverse, we couldn't force our way through them all to cross the room. haha

There is something we are missing, and keeping our noses to the grindstone of photons is limiting our seeing the truth of the universe and the essential nature of existance. Dobson doesn't claim to have the ultimate knowledge of the Universe, but he points out some very important mis-takes we are making in our western sciences. He is an important voice in the search for reality and its underlying causes and forces. But of course mainstream science is ignoring him as he is not in accordance with their ideology.
This is not the only earth shaking illumination he has in his book, but it is better if you hear it directly from him rather than through the lens of me.

Inflation implies a vastly expanded concept of what the universe is. But the concept is also helping us to understand the universe we see around us. Take, for example, the recent observation that the universe is not only expanding—a fact astronomers have known for over seven decades—but actually accelerating outward.

While we can never directly "see" the whole of the universe or glimpse its farthest horizons, we can discover how it is behaving—how fast it's growing, whether its growth will one day come to a halt, and what forces have been driving its evolution on the largest of scales. The evidence for the cosmic acceleration—the observations of distant exploding stars.

Whatever could produce that acceleration? Certainly there is nothing in our Earthly experience that prepares us for such a possibility. This is where the theory of inflation comes into play. Now about two decades old, inflation entertains the idea that there is a kind of energy that causes space to expand. This energy competes with gravity, though certainly not on local scales. However, should this form of energy come to dominate, watch out! While gravity tries to crush, this energy—call it vacuum energy, or the scalar field, or the energy represented by the Cosmological Constant in Einstein's equations describing the dynamics of the universe—tries to expand the fabric of space, pushing everything apart. The basic proposition of the inflation model is that this form of energy once dominated gravity and caused our universe to burst forth.

It turns out that the basic inflation picture satisfies a number of observed facts about the universe. One fact is particularly interesting because the better our observations become the more tightly they agree with a prediction of the inflation model. This is that the universe should be "flat"—no overall curvature of space. Spectacularly convincing evidence—recent measurements of irregularities in the microwave background radiation—supports this proposition.

The theory of inflation predicts a precise recipe of how structure would form from little things merging into big things and tells us how many little things there should be for each big thing. The observations match with expectations if the mix of energy and matter is the same as that suggested by the supernovae experiments. Inflation also solves the old controversy over the Hubble Constant, the relationship between the rate galaxies are flying apart and the distances between them. If the Hubble Constant is large then galaxies are relatively close together and the implied age of the universe is way too short if the universe has been briskly expanding. The universe cannot be younger than things in it. However, if the universe has been loitering and is now accelerating, then it is old enough and a large Hubble Constant is still possible. And we can actually make a direct measurement of the mass density of the universe by looking at the motions of galaxies that slosh in the gravitational wells of the matter. We find something that has come to be called "dark matter" there. If the universe is "flat," then this state is achieved through the sum of the mass and energy density. Measurements of gravity perturbations reveal just the needed complement of matter offsetting the repulsive energy indicated by the supernova measurements.

The last couple of years have seen a remarkable convergence of evidence, all suggesting that we live in a universe with a few percent of the normal matter of our everyday experience, maybe 25% of something called "dark matter," which is a name given to hide our ignorance of what it is, and 75% of this energy that wants to push space apart—call it "dark energy." If true, then relatively recently in the history of the universe the "dark energy" has become dominant over "dark matter." During the transient dominance of dark matter, it caused the collapse into all the structure of the universe that we have come to know and appreciate.