"But," said the Medical Man, staring hard at a coal in the fire, "if Time is really only a fourth dimension of Space, why is it, and why has it always been, regarded as something different? And why cannot we move in Time as we move about in the other dimensions of Space?"
The Time Traveller smiled. "Are you sure we can move freely in space? Right and left we can go, backward and forward freely enough, and men always have done so. I admit we move freely in two dimensions. But how about up and down? Gravitation limits us there."
"Not exactly," said the Medical Man. "There are balloons."
-H. G. WELLS
The Time Machine (1894)
Who denies that future things do not exist as yet?
Time is like an infinitely rotating circle; the descending arc is the past, the ascending one is the future; above, there is an indivisible point that touches the tangent and is the now.
The World as Will and Idea (1788-1860)
The mathematical formalism of field theory suggests that these lines can be interpreted in two ways; either as positrons moving forward in time, or as electrons moving backward in time!
The Tao of Physics (1975)
electron-photon scattering positron-photon scattering
All motions may be accelerated and retarded, but the flowing of absolute time is not liable to any change.
Mathematical Principles of Natural Philosophy (1687)
Time flows in a single direction from past to future. We cannot manipulate time, we cannot travel back to the past.
Order Out of Chaos (1984)
The new age and the old are absolutely different, though one grew out of the other.
Natural Reality & Abstract Reality (1919-1920)
Why do we remember the past but not the future? -STEPHEN W. HAWKING A Brief History of Time (1988)
If everything that is moving is always in the now, then an arrow in flight is at rest.
-ZENO OF ELEA (490-430 BC)