53
THE CONCEPT OF TIME IN THE SCIENCE OF HISTORY (1915)

physics, one seeks equations in which the most general lawful relations regarding processes can be applied to the respective fields.

But modern physics has not stopped here. It has discovered basic laws that permit, on the one hand, the inclusion of parts of acoustics and theory of heat in mechanics and, on the other, optics, magnetism, and the theory of radiant heat in the theory of electricity. Today, the numerous special fields of physics have been reduced to two: mechanics and electrodynamics or, as it also is put, the physics of matter and the physics of ether. As hotly as the battle between the mechanical and the electrodynamic “worldviews” (!) has raged, the two fields will, as Planck says, “in the long term not at all be able to be sharply demarcated.”2 “Mechanics requires for its foundation in principle only the concepts of space, time, and that which moves, whether one considers this as substance or state. And neither can electrodynamics do without these same concepts. This is why a sufficiently generalized mechanics could also well include electrodynamics, and there are in fact many favorable signs that these already partially overlapping fields will eventually be unified into a single field—that of a general dynamics.”3

It is with this that the goal of physics as a science must be brought into relief. Its goal is the unity of its picture of the physical world, tracing all appearances back to the basic mathematically definable laws of a general dynamics, to the laws of motion of a still undetermined mass. Now that we know what the goal of physics is, we can formulate our second question: What function is appropriate for the concept of time in this science?

Stated briefly, the object of physics is the lawfulness of motion. Motions run their course in time. What exactly does this mean? “In” time has a spatial meaning; however, time is obviously nothing spatial—indeed, we always contrast space and time. But it is just as clear that motion and time are somehow related. In a passage from his Discorsi, Galileo speaks precisely of an “affinity between the concepts of time and motion.” “For just as the uniformity of motion is determined and comprehended through the equality of the times and spaces . . . , so through this same equality of the segments of time we can also comprehend increase in velocity (acceleration) which has come about in a plain and simple manner.”4 In the relation between motion and time, what is clearly at issue is measurement of motion by means of time. As a quantitative determination, measurement is the concern of mathematics. Theoretical, i.e., mathematical, physics forms the foundation of experimental physics. Thus if we wish to obtain precise concepts of motion and time, we must examine them in their mathematical form.

The position of a material point in space is determined by the spatial point with which it coincides. Let us assume now that space is empty except for the material point whose position is to be determined. But space is infinite—each point in space is equal to every other and likewise each direction to every other. Thus it is impossible to determine the position of the material point in question


Martin Heidegger - Supplements: From the Earliest Essays to Being and Time and Beyond