Faster Than the Speed of Light: E = mc², Except When It Doesn't

NY Times ^ | 2/09/03 | George Johnson

[Ichneumon]

Perhaps you are unfamiliar with how cranky Sir Isaac Newton was when it came to discussions of "his" calculus.

There's no denying that Newton was a real prick. But he could still get his ideas accepted by people (some slower than others, of course). That's different from the cranks who can't find *any* professional acceptance for their ideas and then go on rants about how they're being "kept down by the Man", so to speak.

[PatrickHenry]

As Physicist says so much better than I, "The same thing that is south of the South Pole."

Let's keep this our little secret, but I still consider this ["before the BB"] to be a very open question. As a practical matter (whatever that may mean in this context) Physicist's answer is quite sufficient. But at some level, which is probably more psychological than cosmological, it fails to satisfy.

[Dead Corpse]

Yep. Already got that. Your analogy is also one of the reasons that inflationary theory is still just a theory. If we are considered on the "inside of the balloon", even if you are thinking in 4D space/time, you should still be able to find the area of least expansion. Unless there is "more universe" pouring out of that "spot", we should be able to detect a "center" to it.

They can't. They probably never will. The Universe isn't "closed" and it will never expand to a point where everything becomes a uniform level soup after the black holes all evaporate. Things will continue to recycle.

[Condorman]

Let's keep this our little secret, but I still consider this ["before the BB"] to be a very open question. As a practical matter (whatever that may mean in this context) Physicist's answer is quite sufficient. But at some level, which is probably more psychological than cosmological, it fails to satisfy.

Oh, I quite agree. If I understand things correctly, we are not privy to any evidence about the state of things prior to the BB. I personally believe that any theory we come up with is equally likely as any other answer, and that's where faith steps in to lend a hand.

But as far as we puny humans are concerned, natural history started at the Big Bang.

[Boot Hill]

Ichneumon:   "I hope this helps clear things up some."

LOL, oh sure, real clear, right up until that moment one of your damn pigeons crapped on my glasses!

Your balloon-pigeon analogy, like all analogies are only an image of reality, and at some point breaks down into meaninglessness. Take for instance the presumption(?) that all the matter expanded at the same rate from the moment of the BB (i.e., all matter was on the surface of the balloon). To use your balloon analogy, I would expect the balloon to have and infinite number of concentric inner layers, all having some amount of the matter on each of those balloon surfaces.

--Boot Hill

[uncbuck]

The distances from the earth were infered to be in a linear form, with th earth in the center. Therefore the galaxies are in there gretest distance from eachother, in relation to that moment in time.

[uncbuck]

See 46

[Nataku X]

Ah, but we are not in the inside of the balloon--just on the surface. Just like we're not actually on the inside of the Earth. There's no "center" on the surface of the balloon any more there is a center on the surface of the Earth.

[Boot Hill]

Ichneumon:   "But [Newton] could still get his ideas accepted by people..."

You mean like his ideas on alchemy? (You do recall what they found inside his body when they exhumed him, don't you?)

Ichneumon:   "That's different from the cranks..."

If I got excited every time I ran into a "cranky" PhD, I'd have had to change professions decades ago. I both expect and ignore their "eccentricities" and that is how I view João. Maybe he has something to offer, maybe he doesn't, or maybe all he can do is to stimulate my thoughts down avenues he never intended. But I'll read him before I make that judgment.

--Boot Hill

[headsonpikes]

I can't believe I just wasted so much time reading this thread.

[camle]

the distance from Earth is liner to each of the galaxies in question, but not necessarily are the Earth and each galaxy colinear. could be a triangle formation, which is my point.

whilst three points define a plane, there's a fourth to consider: the Origin. So now we move from 2 to 3 dimensions. Nowhere in the suppositions given did I see that the Origin, earth and two galaxies are coplanar. therefore they need not be. And that triangle emerges again.

[camle]

anyway, I must go. thank you for s stimulating conversation!

[scouse]

According to the logic of the Big Bang theory, the light was emitted 10 billion years ago and is just now reaching this part of the universe.
Now turn around and look 10 billion light-years in the opposite direction. You have successfully observed two regions of the universe that themselves are 20 billion light-years apart.

When you are standing at the North Pole no matter which way you face you are always looking south. Therefore this begs the question; Is the Earth at the North Pole of the Universe?.

[Publius6961]

I prefer to take this argument another direction. Let's go to the very nanosecond after the "big bang"... what was there before that nanosecond? Scientists too quickly dismiss creationism as fairy tale without acknowledging that their grand theories hold no water.

LOL!
I prefer the short version:

First there was nothing...
Then it exploded.

Hmmmmm

[Teacher317]

Not quite. You still aren't getting it. If you can look 10 billion light years in one direction, and 10 billion in the other, and the Universe is SUPPOSEDLY only 15 billion years old, then the two galaxies at either end would have still been 5 billion light years apart when the Big Bang supposedly went off. Got it?

Umm, you're neglecting the important point that both galaxies are moving away from the focal point in opposite directions. There's no discrepancy there. In 10 billion years, they can get 20 billion light years apart (travelling at the speed of light), since each travelled 10 billion LY from the focus.

[Teacher317]

the big deal is that it took 15E9 years to get that galaxy to that distant point and another 10E9 years for the light to get back to us and that is a total of 25E9 years in a universe only 15E9 years old!

That would have been a "paradox" even one second into the universe.

The one second travel time away from the center + the one second of time if took for the light to get back to the center = 2 seconds, which is > the one second that was the age of the universe at that time.

Instant paradox!

In our hypothetical, either the age of the universe number is off, the distance to the outer edge is off, or the speed of light is off... this is where the interesting speculation comes in.... which one is off any why?

[Teacher317]

Excellent explantions. Thanks for clearing the picture up. My fumbling thoughts weren't very satisfying.

[Boot Hill]

Teacher317 suggests:  "...either the age of the universe number is off, the distance to the outer edge is off, or the speed of light is off..."

Or a fourth possibility: We are off!
Ichneumon seems to think so. Check his post 40

--Boot Hill

[Boot Hill]

Oops, I see you found reply 40 already.

--Boot Hill

[Ichneumon]

Your balloon-pigeon analogy, like all analogies are only an image of reality, and at some point breaks down into meaninglessness.

Well, sure. But parts of it serve as aids to mental visualization of how observations in an expanding universe will nessecarily differ from those in a "flat", non-expanding one.

Take for instance the presumption(?) that all the matter expanded at the same rate from the moment of the BB (i.e., all matter was on the surface of the balloon).

That's not an assumption, that's a given. I'm sorry if I wasn't clear enough (and perhaps there's some confusion caused by cross-over concepts with the earlier "raisin loaf" example, is not directly comparable).

A curved 2D universe would be like the surface (and *only* the surface) of the balloon. Any points inside or outside the surface of the balloon itself wouldn't even be *in* the universe as anything observable by inhabitants of that 2D universe. They and all the contents of their universe would exist and interact *only* within the curved surface of the balloon.

Similarly, although our 3D universe has curvature, it's through a direction/dimension that is beyond the constraints of our own 3D existence. All objects and all expansion takes place entirely within our 3D realm. In the balloon analogy, all objects are on the surface of the balloon, any moving object (including photons) travels along/around the surface of the balloon, and can not "shortcut" through the air-filled area in the middle. If they could, they would be seen vanishing from the "ballooniverse" and then suddenly reappearing elsewhere after an inferred "faster than light" travel through a wormhole (since light itself in the "ballooniverse" is constrained to traveling along the curving surface of the balloon.

To use your balloon analogy, I would expect the balloon to have and infinite number of concentric inner layers, all having some amount of the matter on each of those balloon surfaces.

This is not the "raisin bread" example. As the balloon expands, all points and objects on its surface expand outward with that surface. None are "left behind" inside the balloon, and none were inside the balloon to start with even when the balloon was not so much inflated.

For that matter, the same issues apply to a flat rubber sheet that is being stretched outward in all directions, which helps avoid the distraction of the "inside" of the balloon, but a balloon being blown up is more familiar and easier to visualize.