Liquid Space

New Scientist ^ | 03 November 2001 | Paul Davies

[pistola]

IS SPACE just space? Or is it filled with some sort of mysterious, intangible substance? The ancient Greeks believed so, and so did scientists in the 19th century. Yet by the early part of the 20th century, the idea had been discredited and seemed to have gone for good.

[Consort]

It's a space-time matter-energy universe. Time is just the duration of movement and space doesn't exist. It's all matter and energy (plus thought and consciousness).

[PatrickHenry]

Gotcha. Thanks. I was temporarily confused because an orbiting object, like the moon, is in free fall. But of course, a falling object is always in free fall, and it undergoes acceleration, so the one doesn't preclude the other. I'm often confused, it seems.

[FormerLurker]

No, but then I haven't heard Einstein discussing "astral light" and "dancing Wu-Li masters" without blushing.

I don't think anybody mentioned "dancing Wu-Li masters". What the other poster had mentioned was that ancient civilizations acknowledged the existance of an Aether. The Akasha mentioned IS another name for Aether, and the word Akasha is derived from ancient Sanskrit.

In any case, Einstein never accepted quantum mechanics, let alone quantum field theory, so his beliefs on the structure of the vacuum must be regarded as outmoded.

Although Einstein may never have fully accepted quantum mechanics, quantum theory is now heading back towards the concept of an Aether.

As Einstein pointed out, there can be no General Relativity without the Aether...

Recapitulating, we may say that according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an ether. According to the general theory of relativity space without ether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense.

Albert Einstein - 1920

[RightWhale]

Michael Faraday

The one who upset physicists of his day and sparked Maxwell to devise his vector model of Electromagnetic phenomena. A simple experiment, a demonstration in the front of the lecture hall, and the revolution was off and running.

Michelson and Morley, sponsored by A. Graham Bell similarly upset the physics of their day. A simple demonstration, not small and inexpensive that time, though, and not in a lecture hall.

Could happen again.

[FormerLurker]

Very annoying. I know some have said there is no ether, but its existence is assumed in most electromagnetic theory, relativity, etc..., and it has never, ever been "discredited."

SPACE, by very definition, is SOMETHING. It cannot be just NOTHING.

[tet68]

Behold the void, realize it as thine own intellect, blissful
and shining.
Tibetian Book of the Dead.

[longshadow]

I'm often confused, it seems.

The thing to remember is that, as per Newton, things in motion tend to stay in motion unless acted upon by an outside force. In particular, any CHANGE in EITHER speed or direction requires a force acting upon the object, as

dv(t)/dt = a(t)

and

f = ma

hence

f = mdv(t)/dt

Thus, for the velocity to change (either speed or direction), a force must act upon the object, producing an acceleration of the object. The acceleration is, by definition, the change in velocity with respect to time.

If the earth's gravitational attraction ("force") were to cease to act on the moon, the moon would go sailing off in a straight line; it would not continue to "orbit" the earth. Likewise the electrostatic attraction between an electron and the nucleus of the atom around which it wanders.

Absent a force, producing an acceleration that changes the direction the object travels, objects would only travel in straight lines.

(geek alert: this explanation is based on the simplified Newtonian view; in the GR version, the "force" of gravity is replaced by a curvature of space-time, but the results are the same.)

[PatrickHenry]

If the earth's gravitational attraction ("force") were to cease to act on the moon, the moon would go sailing off in a straight line; it would not continue to "orbit" the earth.

Historical footnote: In Galileo's time (before Newton), one of the arguments used to "prove" that the earth was the center of the universe was the motion of the moon. If the earth moved, they thought, the moon would be left behind. For this reason, the discovery that Jupiter had orbiting moons was particularly devastating (they had no doubts that Jupiter moved).

[FormerLurker]

You're correct, but simply a = dv/dt would have explained it...

Any change in velocity equates to acceleration.

[TigersEye]

Jimer has already found this but for the rest of you fans of mind bending experiences here's a bump.

[TigersEye]

SPACE, by very definition, is SOMETHING. It cannot be just NOTHING.

Behold the void, realize it as thine own intellect, blissful and shining.
Tibetian Book of the Dead.

Space is the concept of distance between objects. Void is the concept of space without objects.

[Consort]

SPACE, by very definition, is SOMETHING.

---

What's the definition of space?

---

It cannot be just NOTHING.

---

If space cannot be nothing, then what is nothing?

[FormerLurker]

Space is the concept of distance between objects.

E=mc² implies that space is something more than simply distance. You see, spacetime is a fabric, and that fabric permeates the Universe.

If energy can relate to matter as a function of space and time, then space AND time are SOMETHING, not simply a void intermingled with objects. And as Einstein stated, General Relativity cannot exist without the ether (or Aether)...

[JoeSixPack1]

Hey - SuperMicroScopicCosmicSpaceDust - Is that like space snow only a whole lot smaller?

[FormerLurker]

If space cannot be nothing, then what is nothing?

Nothing = NO THING. Meaning, that which does not exist.

[FormerLurker]

Behold the void, realize it as thine own intellect, blissful and shining.

Does the "void" in this context equate to the Abyss (Daath)?

[tet68]

Void is the concept of space without objects.

Not for Buddhists.
The intellect,the clear light of reality,unobstructed,blissful and shining.

[eddie willers]

[TigersEye]

But how do you define space? All words are concepts.
What concept does the word space define?