Gerald James Whitrow: Quotes about time

“We have assumed that the laws of nature must be capable of expression in a form which is invariant for all possible transformations of the space-time co-ordinates”

Gerald James Whitrow

The Structure of the Universe: An Introduction to Cosmology (1949)
Context: The philosophical consequences of the General Theory of Relativity are perhaps more striking than the experimental tests. As Bishop Barnes has reminded us, "The astonishing thing about Einstein's equations is that they appear to have come out of nothing." We have assumed that the laws of nature must be capable of expression in a form which is invariant for all possible transformations of the space-time co-ordinates and also that the geometry of space-time is Riemannian. From this exiguous basis, formulae of gravitation more accurate than those of Newton have been derived. As Barnes points out...

Law , Nature , Time

“The development of rational thought actually seems to have impeded man's appreciation for the significance of time.”

Gerald James Whitrow

Time in History: Views of Time from Prehistory to the Present Day (1988)
Context: The development of rational thought actually seems to have impeded man's appreciation for the significance of time.... Belief that the ultimate reality is timeless is deeply rooted in human thinking, and the origin of rational investigation of the world was the search for permanent factors that lie behind the ever-changing pattern of events.<!--p.22

Time

“In 1922, Friedmann… broke new ground by investigating non-static solutions to Einstein's field equations, in which the radius of curvature of space varies with time. This Possibility had already been envisaged, in a general sense, by Clifford in the eighties.”

Gerald James Whitrow

The Structure of the Universe: An Introduction to Cosmology (1949)
Context: The models of Einstein and de Sitter are static solutions of Einstein's modified gravitational equations for a world-wide homogeneous system. They both involve a positive cosmological constant λ, determining the curvature of space. If this constant is zero, we obtain a third model in classical infinite Euclidean space. This model is empty, the space-time being that of Special Relativity.
It has been shown that these are the only possible static world models based on Einstein's theory. In 1922, Friedmann... broke new ground by investigating non-static solutions to Einstein's field equations, in which the radius of curvature of space varies with time. This Possibility had already been envisaged, in a general sense, by Clifford in the eighties.<!--p.82

Sense , Time

“The absence of free mobility in time makes it much more difficult for us to be sure that a process takes the same time whenever it is repeated.”

Gerald James Whitrow

Natural Philosophy of Time (1980) as quoted by Suk-Jun Kim, "Time felt and places imagined in my compositions" (2011)
Context: Although the peculiarly fundamental nature of time in relation to ourselves is evident as soon as we reflect that our judgments concerning time and events in time appear themselves to be 'in' time, whereas our judgments concerning space do not appear themselves in any obvious sense to be in space, physicists have been influenced far more profoundly by the fact that space seems to be presented to us all of a piece, whereas time comes to us only bit by bit. The past must be recalled by the dubious aid of memory, the future is hidden from us, and only the present is directly experienced. This striking dissimilarity between space and time has nowhere had a greater influence than in physical science based on the concept of measurement. Free mobility in space leads to the idea of the transportable unit length and the rigid measuring rod. The absence of free mobility in time makes it much more difficult for us to be sure that a process takes the same time whenever it is repeated.

Time

“To obtain a greater degree of permanence the time symbols of oral speech had to be converted into the space symbols of written speech.”

Gerald James Whitrow

Time in History: Views of Time from Prehistory to the Present Day (1988), p.22
Context: To obtain a greater degree of permanence the time symbols of oral speech had to be converted into the space symbols of written speech.... The crucial stage in the evolution of writing occurred when ideographs became phonograms...

Time

“Galileo had raised the concepts of space and time to the status of fundamental categories by directing attention to the mathematical description of motion.”

Gerald James Whitrow

The Structure of the Universe: An Introduction to Cosmology (1949)
Context: Galileo had raised the concepts of space and time to the status of fundamental categories by directing attention to the mathematical description of motion. The midiaevel qualitative method had made these concepts relatively unimportant, but in the new mathematical philosophy the external world became a world of bodies moving in space and time. In the Timaeus Plato had expounded a theory that outside the universe, which he regarded as bounded and spherical, there was an infinite empty space. The ideas of Plato were much discussed in the middle of the seventeenth century by the Cambridge Platonists, and Newton's views were greatly influenced thereby. He regarded space as the 'sensorium of God' and hence endowed it with objective existence, although he confessed that it could not be observed. Similarly, he believed that time had an objective existence independent of the particular processes which can be used for measuring it.<!--p.46

Mathematics , Time

“Consider an event, for example the outburst if a nova… Suppose this event is observed from two stars in line with the nova, and suppose further that the two stars are moving uniformly with respect to each other in this line. Let the epoch at which these stars passed by each other be taken as the zero of time measurement, and let an observer A on one of the stars estimate the distance and epoch of the nova outburst to be x units of length and t units of time, respectively. Suppose the other star is moving toward the nova with velocity v relative to A. Let an observer B on the star estimate the distance and epoch of the nova outburst to be x' units of length and t' units of time, respectively. Then the Lorentz formulae, relating x' to t', arex' = \frac {x-vt}{\sqrt{1-\frac{v^2}{c^2}}}; \qquad t' = \frac {t-\frac{vx}{c^2}}{\sqrt{1-\frac{v^2}{c^2}}}
These formulae are… quite general, applying to any event in line with two uniformly moving observers. If we let c become infinite then the ratio of v to c tends to zero and the formulae becomex' = x - vt; \qquad t' = t.”

Gerald James Whitrow

p, 125
The Structure of the Universe: An Introduction to Cosmology (1949)

Star , Time

“Space-time is curved in the neighborhood of material masses, but it is not clear whether the presence of matter causes the curvature of space-time or whether this curvature is itself responsible for the existence of matter.”

Gerald James Whitrow

p, 125
The Structure of the Universe: An Introduction to Cosmology (1949)

Time

“By the time of Comte, scientists unanimously rejected the idea that there was any essential difference between celestial and terrestrial matter, but they still had no empirical evidence to support their view any more than had Aristotle to support his, and to the positivist philosopher it seemed that none could ever be obtained. …The possibility of a solution to this problem appeared shortly after Comte's pronouncement with the rise of the science of astronomical spectroscopy…”

Gerald James Whitrow

"Why the Sun Shines" (18 July 1957)

Idea , Support , Problem , Appearance

“[Time is not] a mysterious illusion of the intellect... It is an essential feature of the universe.”

Gerald James Whitrow

The Nature of Time (1961) as quoted by Douglas Martin, "Gerald J. Whitrow, 87, Author Of Philosophic Tomes on Time" The New York Times (June 27, 2000)

Universe , Time

“Let us suppose that an explosion occurs on Mars, which is observed by an astronomer on earth, who records the instant when he sees the flash. If light travelled instantaneously with an infinite velocity, this instant would coincide with the time… recorded by the… observer on Mars. In this way a meaning could be attached automatically to absolute time and the simultaneity of events at different places; indeed, the classical theory is now regarded as the limiting form of Einstein's theory when the velocity of light becomes infinite. But as there is a mass of experimental evidence supporting the view that light takes a finite time to travel… the terrestrial observer must correct the time recorded on his watch. This correction… will depend on assumptions concerning the velocity of light and the measurement of distance. Thus the concept of a world-wide simultaneity ceases to be a primitive idea.”

Gerald James Whitrow

p, 125
The Structure of the Universe: An Introduction to Cosmology (1949)

World , Way , Travel , Idea

“It became clear that our Galaxy is only one system among many, and that the universe is far vaster than the particular stellar system to which the Sun and planets belong. Since then developments have been more rapid than at any time since the days of Copernicus, Digges and Bruno when the geocentric hypothesis of the cosmos received its death-blow.”

Gerald James Whitrow

"Theories of the Universe" (10 Apr 1958)

Death , Universe , Time , Sun

“Newton's laws of motion and gravitation achieved their original success when applied to the solar system. The first definite evidence that they were applicable on a larger scale came from the study of binary stars towards the eighteenth century. In recent times the limitations of Newton's theory have become apparent. Even on the scale of the solar system, it has been challenged by Einstein's.”

Gerald James Whitrow

"Newton and the Stars" (10 Oct 1957)

Law , Star , Study , Time

“Although the Special Theory of Relativity does not account for electromagnetic phenomena, it explains many of their properties. General Relativity, however, tells us nothing about electromagnetism. In Einstein's space-time continuum gravitational forces are absorbed in the geometry, but the electromagnetic forces are quite unaffected. Various attempts have been made to generate the geometry of space-time so as to produce a unified field theory incorporating both gravitational and electromagnetic forces.”

Gerald James Whitrow

p, 125
The Structure of the Universe: An Introduction to Cosmology (1949)

Time

“Consider an event, for example the outburst if a nova… Suppose this event is observed from two stars in line with the nova, and suppose further that the two stars are moving uniformly with respect to each other in this line. Let the epoch at which these stars passed by each other be taken as the zero of time measurement, and let an observer A on one of the stars estimate the distance and epoch of the nova outburst to be x units of length and t units of time, respectively. Suppose the other star is moving toward the nova with velocity v relative to A.”

Gerald James Whitrow

Let an observer B on the star estimate the distance and epoch of the nova outburst to be x<nowiki>'</nowiki> units of length and t<nowiki>'</nowiki> units of time, respectively. Then the Lorentz formulae, relating x<nowiki>'</nowiki> to t<nowiki>'</nowiki>, are<center><math>x' = \frac {x-vt}{\sqrt{1-\frac{v^2}{c^2}}} ; \qquad t' = \frac {t-\frac{vx}{c^2}}{\sqrt{1-\frac{v^2}{c^2}}}</math></center>
These formulae are... quite general, applying to any event in line with two uniformly moving observers. If we let c become infinite then the ratio of v to c tends to zero and the formulae become<center><math>x' = x - vt ; \qquad t' = t</math></center>.
The Structure of the Universe: An Introduction to Cosmology (1949)

Star , Time