On Heidegger's reception of Einstein's relativity.

It is commonly thought that at the beginning of the 20^th century both science and philosophy gave up the presumption of holding the incontrovertible truth. With the rise of post-modernism and the stress on the limits of scientific practice, science and philosophy are deemed to be nothing more that biased, embodied and embedded practices – their status is purely performative. It is often thought that the final blow to “classical absolutism” was delivered by the two most important thinkers of the 20^th century, namely Albert Einstein and Martin Heidegger.

But what if this what not the case? What if Einstein's influence on Heidegger, and therefore on the consequent history of thought, provided a renewed interpretation of the status of science and philosophy? (What if the 20^th century harbored more than post-modernism and reductionism?)

The Heideggerian elements of our analysis will be presented in a simple fashion, congenial to the scientific topic. we will rely mainly on the 1905 paper On the Electrodyanamics of Moving Bodies: we are interested in Einstein's science, not in his philosophy. Last but not least, given the novelty of the argument, our analysis will rely on one of the few in-depht paper about the philosophical relationship between the two, prof. Adam Beck's Heidegger and Relativity Theory.¹

§1 – The philosopher's relativity.

Martin Heidegger

Already in 1924 Heidegger, during a meeting of theologians in Marburg, made reference to Einstein's relativity:

« The current state of this research is established in Einstein's relativity theory. Some of its propositions are as follows: Space is nothing in itself; there is no absolute space. It exists merely by way of the bodies and energies contained in it. (An old proposition of Aristotle's:) Time too is nothing. It persists merely as a consequence of the events taking place in it. There is no absolute time, and no absolute simultaneity either. In seeing the destructive side of this theory, one readily overlooks what is positive about it, namely, that it demonstrates precisely the invariability, with respect to arbitrary transformations, of those equations describing natural processes »².

As Adam Beck notices, the last sentence accurately paraphrases the relativity principle from Einstein's STR as expressed in 1905.³ It is precisely a certain “nothingness” of space and time that grants the general covariance of the laws, their not being affected by the motion of the system they describe – in other words, their absoluteness. We either have absolute space (ether) and time and posited extrinsecal local space and time (like in Lorentz's case), or relative space and time and locally posited absolute space and time.⁴

The principle of relativity is not a convention nor a mere mathematical aid to make the numbers check out. On the contrary, it provides us a specific physical interpretation of what space and time are. The absence of one privileged frame of reference does not seem to curb the scientific epistemic project; it rather grants that every frame of reference (or, to use Einstein's words, body of reference⁵) is a “privileged” frame of reference. Nature in itself, with its absolute laws, is accessible exactly through the different “contradictory” phenomena.⁶

If the principle of relativity leads to lenght contraction and time dilation in the STR, in the GTR it leads to the equivalence of inertial and gravitational forces. These equivalences are explicitly deemed by Einstein to be physical interpretations.⁷ As Beck puts it, the equivalence of inertial and gravitational forces is not just a physical phenomenon grounded in another physical phenomenon. It is rather the very consequence of nature being the same when accessed from any point of view. In other words: « space-time must be curved in order to look the same from all point of views »⁸.

Both the STR (which states the equivalence of space and time) and the GTR (which introduces the notion of space-time) are grounded on axiomatic « logically simple mathematical condition[s] »⁹. Pure (machian) empiricism is thus rejected, so that Heidegger can say, in 1925: the aim of the theory of relativities « is to find the in-itself of nature by way of the detour through the problem of gravitation, concentrated as a problem of matter »¹⁰.

The object of physics is now the in-itself of nature. We might remember that Kant already noticed that space and time are nothing in themselves. According to Heidegger, Einstein's relativity could provide the physical interpretation of such insight. The philosopher, infact, was not looking at one of the two theories of relativity in particular – he was interested in the principle of relativity in general, or to put it better, in the meaning of relativity, and in its consequences for our relationship to nature and science.

In aforementioned context Heidegger said:

« Relativity theory is a theory of relativities, a theory of the conditions of access and modes of conception, which are to be arranged so that in this access to nature, in a specific mode of space-time measurement, the invariance of the laws of motion is preserved »¹¹.

The theory of relativity is interpreted as a theory of conditions of access, dependent on space-time measurement.

In his rejection of the conventionalist interpretation of the relativity principle, Einstein said something quite symptomatic of the nature of his own theory as described by Heidegger:

« With the given physical interpretation of co-ordinates and times, this is by no means a purely conventional step, but implies certain hypotheses concerning the actual behaviour of moving measuring-rods and clocks, which can be experimentally validated or disproved »¹².

The principle of relativity is not (just) about objects in general, but it primarly refers to « moving measuring-rods and clocks », that is, scientific tools that enable a specific spatio-temporal access to nature¹³ – conditions of access to nature. Our access to physical nature is always itself physical, and only for this reason phenomena as lenght contraction and time dilation arise. But what this means is that physical nature itself allows access to its own laws by itself – we are no longer separated from the external world, insecure of our faculties, like flies in a bottle. But neither we are back in the newtonian absolute space and time. This is essentially why Einstein's view, as Diego Malquori noticed, was « somehow oscillating between realism and idealism »¹⁴. The words we are looking for, to account for this oscillation, are « Dasein » and « being-in-the-world ».

The heideggerian notions of Dasein and being-in-the-world are actually a very complex, as they go, with the evolution of Heidegger's thought, through a process a resignification and deepening. For our purposes, it is enough to say this:

• the Dasein is the human place of spatialization and temporalization – the place where space becomes and is space and time becomes and is time.¹⁵

• being-in-the-world means our human embeddedness in a world as in a net of ready-to-hand objects, tools, meanings, signals – in other words, equipment. « Equipment is essentially 'something in-order-to...' ["etwas um-zu..."]. A totality of equipment is constituted by various ways of the 'in-order-to', such as serviceability, conduciveness, usability, manipulability. »¹⁶

Now, what interests us is they way scientific equipment spatializes space and temporalizes time. In other words: how is that that space and time are essentially measurable? And consequently: how is it that physical nature is what it is (therefore determined by mathematical rules and so on) at all? Infact, we must first note that the definitions of nature and science are deeply interwined with those of space and time. Natural laws are supposed to be universally valid – otherwise either there would not be laws at all, or there would be more than one physical nature. Such laws are universally valid over what? Classical physics answered in this way: natural laws hold throughout the whole of newtonian space and newtonian time. But Einstein's relativity answers differently: laws hold over frames of references, whose movement determines our very access to said laws. For this reason « The principle of relativity should be read both as a definition of natural law and as a rule for where to find them »¹⁷.

Now, if laws are, in some sense, nothing more than the conditions of measurement, we can also put it the other way round: we can understand the essence and the validity of natural laws (therefore including our notions of space and time in the equation) through a scientific-equipment analysis. Before we get into it, we should obviously present the physicist's point of view.

§2 – The physicist's relativity.

Albert Einstein

Einstein introduced the STR in the 1905 paper On the Electrodyamics of Moving Bodies. In the first part of the paper (the kinematical part) he gives an explicit interpretation of time. According to him « all our judgments in which time plays a part are always judgments of simultaneous events »¹⁸. To describe the motion of a material point means to establish a relation of simultaneity between two events, namely the motion of the material point and what the clock says. The clock is not just an object like any other – it is an object whose being consists in the very measurement of simultaneity in time.¹⁹

Now, in order for our measurement of time (that is, our ability to say “now when... this happens”) to be valid everywhere, it has to be possible to synchronize two clocks (A and B) in a way that our measurement is « independent of the standpoint of the observer with the watch or clock »²⁰. As Einstein shows in the first paragraph (§1) of the paper, we achieve such synchronization, in a stationary system, establishing by definition that « the “time” required by light to travel from A to B equals the “time” it requires to travel from B to A »²¹. If such condition is met, the two clocks are synchronized – a « “common time” »²² for the two clocks (and for the transitive property²³, for every clock in the stationary system) is established. In this way, according to Einstein, we

« have evidently obtained a definition of “simultaneous,” or “synchronous,” and of “time.” The “time” of an event is that which is given simultaneously with the event by a stationary clock located at the place of the event, this clock being synchronous, and indeed synchronous for all time determinations, with a specified stationary clock »²⁴.

The time of an event is, so to say, its “temporal place”, the “now” accessed by a clock

• whose notation (i.e. « 19h 36m 24s », « 2.2 µs »²⁵, « at noon ») is simultaneouos to the event;

• which is synchronized with another clock.

In other words, we have found the absolute temporal co-ordinates of the event. If, as Einstein said, a judgment of time is a judgment of simultaneity, we have succeded in assignin an absolute “now” to the event, shared with everything that is simultaneous to it – shared with every stationary system of reference, therefore valid everywhere – in absolute space.

Unfortunately, there does not seem to be any absolute rest. This method of synchronization does not work when our system of reference – the clock itself – is set in motion. In particular, this failure becomes evident when we approach the velocity of light. Logically speaking, every velocity is relativistic velocity.

Experimental evidences of this failure can be found allover the history 19^th century physics. Einstein refers to particularly cogent problems such as the asymmetry between the reciprocal action of a magnet and a conductor, or the unsuccesful attempt to detect any luminiferous medium. According to him, « Examples of this sort [...] suggest that the phenomena of electrodynamics as well as of mechanics possess no properties corresponding to the idea of absolute rest »²⁶.

At the same time, if there are natural laws at all, the consequent conjecture that « the same laws of electrodynamics and optics will be valid for all frames of reference for which the equations of mechanics hold good »²⁷, must be elevated to the status of axiom. This is the genesis of the first principle, the principle of relativity. This is Einstein's original formulation:

« 1. The laws by which the states of physical systems undergo change are not affected, whether these changes of state be referred to the one or the other of two systems of co-ordinates in uniform translatory motion »²⁸.

As we have seen, we can ruminate a lot about the philosophical meaning of the first principle, where the relativity of space and time and the universality of the laws overlaps in an almost paradoxical fashion. The second principle, however, is harder to decipher, as it appers to be, at first glance, only a merely physical principle – an « empirically well-confirmed regularit[y] »²⁹ elevated to the status of axiom. The principle of the constancy of light goes as follows.

« Any ray of light moves in the “stationary” system of co-ordinates with the determined velocity c, whether the ray be emitted by a stationary or by a moving body »³⁰.

As the first principle, the second principle was heavily supported by evidence too.

According to Einstein, at first these two principles can appear « irreconcilable »³¹. And indeed they are, as long as we hold the classical worldview. The contradiction does not arise in the stationary system situation. When things are set in motion, the only thing for the synchronization of clocks to result in a everywhere-valid common now-sequence is to add the velocity of the system to that of light originating from that system. This would be in clear contradiction with the second principle and all the evidence that supports it. If the velocity of light in the void is one and fixed for all systems of reference, wether moving or stationary, a moving system of reference will always be “late” or “early” in respect to another.

If we have to give up the (Galilean) law of addition of velocities, how can we account for the impossibility of absolute synchronization and, at the same time, for the invariance of laws in all systems of reference? Einstein's solution resides in the relativity of simultaneity. To make a long story short: « two inertial observers moving with respect to one another will disagree on whether events at different locations happen at the same time or not ».³²

The Einsteinian interpretation of space and time starts to take shape. If, as Einstein said, judgement about time and space is all about detecting simultaneities, then two different observers moving to respect to one another will disagree about time space. In particular, they will disagree about the lenght of objects and the flow of time. To put it in Janssen's words:

« Judgments about the simultaneity of events at different locations are involved in measuring the rate of moving clocksand the length of moving rods. As a consequence, we find that moving clocks must tick at a lower rate than those same clocksat rest [...] and that the length of moving rods must be less than the length of those same rods at rest »³³.

Moving rods and clocks are our acces keys to nature. In a classical galilean system, all clocks tick at the same rate, and all rods have the same lenght. We can thus make the same judgements of time and space everywhere: if we are moving we can judge about events and objects at rest in respect to us, and viceversa. This is, after all, our everyday experience.

But our everyday experience crumbles when we travel at relativistic velocities, that is to say, when we take the second principle into account. In a Galilean system we suppose that we see things as they are in the moment wee see them. We look at the sky and we think to see stars as they are right now. In other words, we tacitly assume an infinite signal velocity. Information does not “travel” from one point to another. It immediately arises in our consciousness, abstractly. We access nature by means of pure observation.

In radical opposition to this, the second system states that, no matter how fast we move, we have to wait for light to reach a certain destination and come back, if we want, for example, to synchronize two clocks. Light (in a vacuum) travels at its own finite velocity. Observation is itself physical.

To be fair, already Galileo suspected that light velocity was finite, and the failure of the Michelson-Morley experiment suggested that it was not influenced by motion as well. It was Einstein, however, who saw the implications that came with accepting the velocity of light and the invariance of laws both as grounding principles.

§3 – Scientific-tool-analysis.

We will now try to account for the shift from classical physics to relativistic physics in terms of the relationship between our “idea of nature” and our equipment, as we have anticipated in §1. To be more precise, we will show that different equipments imply different spatializations and temporalizations of space and time, and that Einstein's intuition consisted in shifting the status of light and clocks from “ready-to-hand” to “present-at-hand”.

Although he does not mention “measuring rods”, in Being and Time Heidegger devotes many pages to the problem of the clock: what is a clock? what is the relationship between the Dasein and the clock? Or, to put it in Heidegger's words: « what mode of the temporalizing of Dasein's temporality becomes manifest in » our way « of time-reckoning and clock-using »³⁴?

Heidegger is notoriously critical of the physical interpretation of time, as it reduces time to a flat series of nows, obliating the deeper “existential” structure of Dasein's temporality.³⁵ What matters for us is that we recognize the Dasein's process of temporalization in Einstein's STR. In this way we will achieve not only a philosophical understanding of Einstein's theory, but also a “philosophical clue” of the influence that the physicist might have had on the philosopher. In the context of a clarification of the relationship between “space” and “time”, Heidegger writes a note:

« Here we shall not go into the problem of the measurement of time as treated in the theory of relativity. If the ontological foundations of such measurement are to be clarified, this presupposes that world-time and within-time-ness have already been clarified in terms of Dasein's temporality, and that light has also been cast on the existential-temporal Constitution of the discovery of Nature and the temporal meaning of measurement. Any axiomatic for the physical technique of measurement must rest upon such investigations, and can never, for its own part, tackle the problem of time as such »³⁶.

For our part, this is exactly what we are going to do. Although humbly and unpretentiously, we are going to clarify the “within-time-ness” (intratemporality) of things for the scientific Dasein and the temporality of our access to nature through time measurement.

When we are talking about scientific time, we are talking about public time. Public time is that time which is “external”, “real”, a nows-sequence³⁷ common to every human and every thing. It is the antipode of the subjective experience of “duration”, nor it comes from the latter: « time has [always] already made itself public in concern. One directs oneself according to it, so that it must somehow be the sort of thing which Everyman can come across »³⁸. Time becomes public through time-reckoning.

Time-reckoning is what makes time public, common to everyone and everyplace. We encounter things in public time because our very way of being-in-the-world is temporal and public. Our being-in-time is always already in the mode of dating: « This dating of things […] is a way of assigning time which can be done in our Being with one another 'under the same sky', and which can be done for 'Everyman' at any time in the same way »³⁹. In order for us all to be in public time, we need a common access to the same mode of temporalization. This access is granted by the clock.

« This public dating, in which everyone assigns himself his time, is one which everyone can 'reckon' on simultaneously; it uses a publicly available measure. This dating reckons with time in the sense of a measuring of time; and such measuring requires something by which time is to be measured – namely, a clock. This implies that along with the temporality of Dasein as thrown, abandoned to the 'world', and giving itself time, something like a 'clock' is also discovered – that is, something ready-to-hand which in its regular recurrence has become accessible in one's making present awaitingry. »⁴⁰

What is this regular and common measure upon which everyone can agree, so that a common time – in which a common nows-sequence provides the ground for all the intratemporal events of our common world: in other words, simultaneity – is established? Heidegger talks about a « 'natural' clock »⁴¹, the sun running across the vault at the same velocity for everyone. We think that Einstein provides us with a more rigorous « measure » for the establishing of common time:

2AB / (t'A – tA) = c.⁴²

This quantity is the universal constant of the velocity of light in empty space, as accessed by stationary clocks. Through this universal unit of measure we can synchronize two stationary clocks and use them in any Galilean system of reference, everywhere on this planet. In this way, the stationary clock, and the very velocity of light through which we have used for the synchronization, are ready-to-hand.

What does it mean for something to be ready-to-hand? To cut a long story short, a ready-to-hand object withdraws itself from our attention, so that we can use it without focusing on it. In Heidegger's words:

« The peculiarity of what is proximally ready-to-hand is that, in its readiness-to-hand, it must, as it were, withdraw [zuriickzuziehen] in order to be ready-to-hand quite authentically »⁴³.

We pay attention to not to the keyboard we are using, but to what we are writing. Even what we are writing is itself ready-to-hand, as it refers to yet another thing (a philosophical research, a university exam and so on) of our concern.

« That with which our everyday dealings proximally dwell is not the tools themselves [die Werkzeuge selbst]. On the contrary, that with which we concern ourselves primarily is the work-that which is to be produced at the time; and this is accordingly ready-to-hand too. The work bears with it that referential totality within which the equipment is encountered »⁴⁴.

To use a clock means to read off the time. When we say « now, at 12:00, this happened », we are not just « observing the changes in some item of equipment which is ready-to-hand, and following the positions of a pointer »⁴⁵. We are rather « look[ing] at the clock and regulat[ing] ourselves according to the time, we are essentially saying "now" »⁴⁶. « Saying "now", however, is the discursive articulation of a making present »⁴⁷. Usually, our saying-now is about a “now-when...”. The now is itself ready-to-hand, it withdraws to “make room” for what is present that we are interested in. However, when we are making a (scientific) judgment of time, the clock is ready-at-hand in order to bring something to presence-at-hand exactly its (everywhere-valid) now-ness. What interests us is the very being-now of what is present-at-hand. This is, in Heideggerian terms, nothing different from what Einstein himself said.⁴⁸

When something does not work as planned, and the chain of “in order to...” (um... zu) breaks down, what “fails” obtrusivly lies in front of us.

« The helpless way in which we stand before it is a deficient mode of concern, and as such it uncovers the Being-just-present-at-hand-and no-more of something ready-to-hand. »⁴⁹

It is when things fail to meet our expectations that we look at them for what they are, in their bare being, un-referring to anything. What once was the tool for the access to an object is now the very object of our concern. If the ink of the pen runs out, we stop writing and focus on the pen; if our ether-drift experiment fails to detect the earth's motion through the ether, or if experimental evidences point out to contradictory facts, we focus on what may have caused this failure. In this case, what Einstein found was not a way to “fix it” and restore the chain. He changed the chain alltogether.

In the 1905 paper the problem is presented in terms of synchronization of clocks. The method of synchronization used in paragraph §1 implied galilean relativity, and therefore a common time. The “end” of the scientific chain of ready-to-hand tools consisted in the description of an object's being-now at a certain time here and everywhere. When we cannot achieve this result, we can either try to fix our method of synchronization or reinterpret the “failed synchronization”.

In paragraph §2 of the paper Einstein confronted the measurements of a moving rod as taken respectively by an observer moving along with the rod (therefore at rest with respect to it) and a stationary observer. The former simply superposes a measuring-rod to the rod to be measured, and ascertains the lenght of the measured rod, as if they were in a stationary system. The latter

« By means of stationary clocks set up in the stationary system and synchronizing in accordance with §1, […] ascertains at what points of the stationary system the two ends of the rod to be measured are located at a definite time ».⁵⁰

The stationary observer establish a common time, which should hold for them as much as for the moving observer. This common time can be established only through common space (2AB is the same for all observers). In accordance to the principle of relativity, the two observers should measure the same lenght – but they do not. To of the two the rod appears shorter in lenght.

Another mental experiment involves a sationary and a moving observer, both synchronizing their clocks to others which are “synchronous in the stationary system”. They will find that their respective clocks are not synchronized – that one of the two clock's time⁵¹ has dilated.⁵²

Why is this descrepancy so important? Their measurements differ not because one of the two is using a “broken equipment”, but precisely because their measurements are both right. Both the observer are a Dasein, each one thrown in its world-equipment. There is no privileged Dasein.

Einstein's scientific proposal accurately expresses the Dasein's factual structure of temporalization. A moving observer and a stationary observer are thrown in two different world-equipments, whose functioning becomes clear in the moment in which the expectations are not met. From its being “naively” ready-to-hand, the equipment becomes present-at-hand – is itself a matter of scientific inquiry. What once was just an “abstract”⁵³ means of access to nature, is now seen as part of nature itself, in its physicality and mathematicality. But the Dasein discloses its own temporality and spatiality “through” its own being-in-the-world. The Dasein is not thrown at its own conditions.⁵⁴ (To paraphrase an important passage about the essence of truth, readjusting to our condition of spatiality and temporality: only because space and time, as uncovering, are modes of Being which belong to Dasein, can it be taken out of the province of Dasein's discretion.⁵⁵) Space and time are now disclosed by a new equipment, one which makes evident the physicality of one's disclosure of space and time through measurement – one's reliance on light's velocity as finite and constant signal velocity. The “publicization” of time is forever subject to one physical condition: c.

Now we come again to the aforementioned passage, where Heidegger clarifies the relationship between space and time for Dasein (in a relative note, as we have seen, the philosopher critically refers to the theory of relativity). Here Heidegger says that being-in-the-world is what makes spatialization possibile, and that « spatial Dasein has – out of a "yonder" which has been discovered – allotted itself a "here" »⁵⁶. Because of this

« the time with which Dasein concerns itself in its temporality is, as regards its datability, always bound up with some location of that Dasein. Time itself does not get linked to a location; but temporality is the condition for the possibility that dating may be bound up with the spatially-local in such a way that this may be binding for everyone as a measure »⁵⁷.

In the first phrase Heidegger is apparently only saying that “time is always local”. This is indeed true – time is always accessed through the Dasein's “here” as opposed to a “there”, so that (ideally) everything that is present-at-hand for a judgment of time is “here” for the Dasein.

But time is not just extrinsecally “linked” to a location. The Dasein's possibility of temporalization (their “temporality”) is such that, in accessing time through time measurement and dating⁵⁸, it is bound to the « spatially-local », so that the latter is the universal measure for every spatial and temporal Dasein.⁵⁹ As we have seen, the process of dating is grounded on a common measure. We have found that c stands at the same time for this common measure and for the physical limit of the very publicization of time. In which sense c is the « spatially-local » which is binding for everyone? How can it be so, if, by the second principle, it is totally indipendent from the motion of its source?

« Time does not first get coupled with space; but the 'space' which one might suppose to be coupled with it⁶⁰, is encountered only on the basis of the temporality which concerns itself with time. »⁶¹

The temporality « which concerns itself with time » is of course that of measurement and dating by means of the synchronization of clocks and so on. Our encounter with “space” is possible on the basis of measurement and dating. But what space do we encounter thanks to our “new” kind of dating (that process which is supposed to establish a common time), relying on c? We specifically encounter a kind of space which is accessible only recognizing the “limits” of our dating (of our method of synchronization): relative time.

As space determines the validity of our time measurement, with it relative time is given.

The connection between spatialization and temporalization by means of our physical equipment is thus made explicit. What is now given is space-time. As Heidegger will say twenty years later, in a note:

« Space [is] neither in addition to [neben] time, nor reduced [aufgelöst] to time, nor inferred (or deduced) [deduziert] from time »⁶².

Space is not « deduced », or rather reduced from time, so that time is nothing more than the different given “spaces”. It is now clear how Heidegger interprets Einstein's relativity:

« The principle of the theory of relativity – that all time is the time of a certain place – is a principle that is grounded in the very essence of time, insofar as what is present in the sense of being present in nature can be determined only place-wise – i.e., only in terms of a place and relative to a place »⁶³.

We have finally achieved was set out to: a determination of the within-time-ness of things and temporality disclosed by our access to nature.

• How are things within-time? ( Things are placed in time thanks to a ready-to-hand clock referring to their being-now. By means of dating, « This time⁶⁴ which is 'universally' accessible in clocks is something that we come across as a present-at-hand multiplicity of "nows" »⁶⁵. Dating is possible only thanks to a common meausure (c). However, because of this, lenght contraction and time dilation arise. The way a thing appears as present-at-hand depends on the kinematical conditions of its observer.

• How does our acces to nature through measurement temporalizes (natural, public) time? The intratemporality of things is thus grounded on their spatiality, in their being accessed as present-at-hand “here” in opposition to a “there”. But “here” means: “here in this system of reference”. This establishes the limits of the possibility of making something present “here for everybody”. Spatialization and temporalization of this relativity equals to relativity of space and time.

§4 – A “physical” interpretation of the scientific crisis.

The shift from the status of ready-to-hand to that of present-at-hand of our our conditions of access to nature has one interesting implication: what enables us to do science is, by its own nature, a scientific fact itself. Science does not seem to need any external or transcendental foundation – it has now achieved self-sustainability and indipendence from philosophy. In other words, science (at least at a certain level) does not need to rely on metaphysics, becuase it builds its own foundations.

Heidegger certainly noticed this new character and credited Einstein for this. While he was generally critical of science's lack of depth and awareness regarding the very essence of time (scientific time is not the originary phenomenon, but a derivative one), he never criticized its lack of philosophical foundation. Scientists, simply put, know their job. This lack of criticism has got, however, interesting implications. According to Adam Beck, Einstein's revolution provided Heidegger with an encouraging example of how science is an originary existentail possibility of the human Dasein – along with Dasein, science is given too. This possibility is disclosed by scientific crisis.

We should first of all notice that Heidegger is neither committed to an ante litteram Kuhnian theory of science⁶⁶ nor to Husserlian transcendental foundationalism. It is possible, however, to hypothesize a distinction between « normal science » and « revolutionary science »⁶⁷ within the scientific Dasein's possibilities.

During the 1920s Heidegger often begun his lectures by referring to what is usually called the « foundational crisis » of that time. However, the philosopher was critical of this “slogan”, as it springed « from a peculiar misjudgement about the essence of science »⁶⁸. As Beck reports it, Heidegger noted:

« Outwardly it seems curious at first that the sciences which are subject to foundational crisis [Grundlagenkrisis] don’t cave in upon themselves, but on the contrary – we only have to think of contemporary physics and also biology – often undergo major development. One speaks of a crisis of ground laying [Grund-lagen-krisis], shaking of the foundations, and yet the structure does not begin to totter »⁶⁹.

Wasn't science, so to say, boosted by the fin de siècle crisis? Didn't Einstein's revolution put science back on the right tracks, after it had gone astray trying to catch the ether wind? The so called foundational crisis (as much as any other crisis) was not meant to be “overcome” or “solved”. Rather, it

« should become alive, and not only so that the sciences should become better and faster and more unimpeded in their progress, but so that the sciences may become existent in accordance with their essence at all »⁷⁰.

Crisis allows science to become what it is. In other words, the scientific Dasein becomes authentic ( self – as if relying on itself, on what it is, on its own essence).

In Being and Time the notion of authenticity is interwined with the problem of death and one's ownmost existential possibilities, and it is dislcosed, accessed through, anxiety.⁷¹ In particular, anxiety arises when the phenomenon of the world is made explicit.⁷² But when do we notice that we are-in-a-world (a world-equipment) if not when our gaze does not slip from one ready-to-hand tool to antoher anymore, but it abruptly stops on an obtrusively present-at-hand being? – when « entities deworld themselves »⁷³? If we recall what we have said in the previous paragraph, it is evidently clear that, for the scientist, « anxiety is equivalent to readiness for crisis »⁷⁴. Being ready for something does not mean to escape from it, to fix it and reduce it to something else. It means rather to take it for its own being.

According to Heidegger, science is one with its foundational crisis, that is to say, with its peculiar lack of foundations. But what kinds of foundations are we talking about? As we have said before, the problem does not reside in the lack of a grounding being – it was not, for example, the abandonment of the notion of ether what threw science in a state of crisis. Was the problem a lack of world-view and physical interpretations? And if this was the case, how could a world-view provide a foundation for beings (instead of needing one)? This dicothomy is probably unsolvable, as both the access to beings and grounding beings (beings and their causes) and our world-view, our considering real a certain picture rather than another, are grounded on our being-in-the-world. Something happened, with the scientific crisis between the 19^th and the 20^th century, at the level of scientific Dasein.

Today we are used to think to time and space as the Minkowskian space-time of the GTR. Education, popular science and sci-fi books and films have spread a new world-view consisting of warped space-time, twin-paradoxes and black holes. It appears that, after a phase of crisis, we have reached a new normalilty. Science seems to be going through a (quite exciting) period of normal science too. Every great discovery of our time seems to be the umpteenth confirmation of Einstein's GTR. Doubts about its very existence aside⁷⁵, time is still conceived as something “out-there”, and we still see ourselves (and every other object) as “within-time”. It may not be the classical rigid Newtonian time, but a warped by gravity space-time, but it still provides a solid ground for our understanding of the presence of things. Heidegger's analysis of the Dasein's publicization of time seems to hold now as much as, if not more than, before. Time is again ready-to-hand, and we can dispose of it through relativistic corrections (like in the GPS case⁷⁶). Our contemporary technological implant – or to use an Heideggerian word, Gestell – requires maximum precision of synchronization, and relativistic space-time is no less ready-to-hand than the old newtonian one. In some sense, Einstein's relativity arised exactly from the need to overcome the impossibility of synchronization.

The Global Navigation System (which, for the record, was developed in the 70s by the United States Department of Defense for the U.S. Military) relies on relativistic corrections. For it to function, the GPS system requires nanosecond accuracy. If certain relativistic effects (predicted by both the STR and the GTR) were not taken into account, « a navigational fix based on the GPS constellation would be false after only 2 minutes, and errors in global positions would continue to accumulate at a rate of about 10 kilometers each day! The whole system would be utterly worthless for navigation in a very short time »⁷⁷. We can only imagine (as sci-fi did) ho much relativity will have to be taken into account in the future as technology and space exploration become more and more advanced. The relativity of space and time seems to be reduced to a merely technological problem, confirming Heidegger's interpretation of contemporary Dasein as Ge-stell, the all-exploiting “technological framework”.⁷⁸ It is now technology itself that spatializes and temporalizes “public space-time”, when and where needed. This understanding of relativity is, from an Heideggerian point of view, worlds apart from that « readiness to crisis » we have seen before. Did we lose something of Einstein's relativity in the process? Or is it, perhaps, that Einstein's revolution was always already inscribed in what Heidegger calls the “oblivion of Being” – the end of metaphysics by means of the reduction of every being (in this case, time) to our use and exploitation?

Heidegger's stance towards science has always been ambiguous. In the 1925 lecture The Concept of Time he explicitly states that « Once time has been defined as clock time then there is no hope of ever arriving at its original meaning again »⁷⁹. Years later, in 1953, he went so far to say that:

« As physics, physics cannot make any claim about physics. Every assertion of physics speaks physically. Physics itself cannot be object of experimental physics »⁸⁰.

As « one cannot establish what mathematics is through mathematical calculation »⁸¹, we could be tempted to say that one can not find out what physics is through physics itself. But isn't this exactly what Einstein did? Didn't Einstein make physics itself a physical thing, grounding its absolute access to nature on physical constants (instead of doing the opposite, as philosophy of science tried to do in the 18^th and 19^th centuries)? Beck suggests that the Heideggerian insight of Einstein's STR is that it is not that our experiments are theory-laden, but rather, « all theories are necessarily equipment-laden »⁸². If the essence of science is one with its crisis, the genesis of the STR confirms our interpretation of the crisis as a crisis of our mode of temporalization and spatialization. Its overcoming, however, did not just restore or update the old metaphysical implant. It made science self-reliant, totally immanent in itself. In other words, it turned, for the very first time, the old metaphysics into proper physics.⁸³

Finally, Einstein's reference the the physical interpretation implied by the principles of relativity thus acquires a new, deeper meaning. For example, the relativity of space and time (for the STR) and the equality of inertial and gravitational mass (for the GTR) are not explained on the basis of some other physical fact. Rather, they represent a new sense of φύσις, of nature as disclosed by the invariance of physical laws for all the observers. Einstein's physical interpretation is at the same time an interpretation of physical laws and of physics itself.

§5 – Conclusions.

In the end, what's good about our analysis? Did we achieve something – forgive my choice of words... – relatively relevant?

We detected a possible influence of Einstein's relativity on Heidegger's thought. In his physical proposal, Einstein already seems to have “practiced”, so to say, Heidegger's tensive notions of being-in-the-world (which interprets the relativity principle) and of presence-at-hand (which interprets the light principle). Given Heidegger's words about Einstein, we can confidently say that the phyisicist's relativity inspired the philosopher's reflection about the scientific Dasein, both in Being and Time and throughout the 1920s lectures about science and time.

Our analysis also provided insights about Einstein's philosophical relevance, at least from a Heideggerian point of view. Although only partially, we have seen that Einstein's relativity consists in a refutal of any transcendental foundation of science. This refutal consisted at the same time in what is called the « foundational crisis » that tormented scientists as well as philosophers at the turn of the 19^th and the 20^th century. Einstein's relativity showed (and still showes) at the same time the possibilities and the limits of science. Science is an atonomous practice, whose epistemic value is determined by its very physical interpretation; at the same time, science has to reduce the originary phenomena of space and time to its measurement methods, in order to mantain both indipendence and significance.

From a Heideggerian point of view, a deeper analysis of Einstein's science (not his philosophy!) might even provide crucial clues to understand the state of today's thought and understanding of Being. Today, metaphysics seems to have been replaced by physics. But if this is true; if, as Heidegger believed, metaphysics is the heart and the essence of every human (and as such it is disclosed by the Dasein); and if the history of metaphysics is the history of Being as it gives itself in human thought (Da-sein); then the history of science is one with the history of metaphysics. In other words, science is an essential possibility of human nature – nay, of Being itself. Scientific truth is thus something more than a contingent set of experiments and propositions.

1A. Beck, Heidegger and Relativity Theory, in Angelaki: Journal of the Theoretical Humanities, 2006.

2M. Heidegger, Der Begriff der Zeit, 1925, eng. translation by W. McNeill The Concept of Time, 1992, p. 3E.

3See Heidegger and Relativity Theory, p. 168.

4As Michel Janssen noted, the difference between Einstein and Lorentz is a matter of interpretation of Lorentz invariance (see M. Janssen, Reconsidering a Scientific Revolution: The Case of Einstein versus Lorentz, in Physics in Perspective, 2002, p. 421).

5See A. Einstein, The Special and General Theories – A Popular exposition, as quoted in Beck, Heidegger and Relativity Theory, p. 177.

6It would be pleonastic to speak of “perceptions” or “observations of phenomena”.

7Ivi, p. 169.

8Ivi, p. 170.

9A. Einstein, Autobiographicl notes, as quoted in ibidem.

10M. Heidegger, Prolegomena Zur Geschichte Des Zeitbegriffs, 1925, eng. Translation by Theodore Kisiel, Prolegomena to the History of the Concept of Time, 1985, §1.

11Ibidem.

12Autobiographical notes, as quoted in Heidegger and Relativity Theory, p. 169.

13Used by Einstein himself in the Gedankenexperiment from the 1905 STR paper.

14D. Malquori, Einstein, Gödel, Heidegger. Some Observations about the Concept of Time, eng. translation of the Spanish version published in Pensamiento, 2011, p. 15.

15It is my opinion that we should go one step (if not many more) beyond the typical “subjectivistic” interpretation of the Dasein as our throwness in space and time – what is here (Da-) is Being itself (Sein), so that is Being itself what is thrown in / what gives itself as space and time. This interpretation could account for the claim that Einstein's relativity aims at the in-itself of nature.

16M. Heidegger, Sein und Zeit, 1927, eng. Translation by J. Macquarrie and E. Robinson, Being and Time, Blackwell, 1962, p. 97.

17Heidegger and Relativity Theory, p. 171.

18On the Electrodynamics of Moving Bodies, p. 2.

19In this sense, as Heidegger noticed, a sundial and even the sun are clocks as well, although not very accurate (see Being and Time, §80).

20 On the Electrodynamics of Moving Bodies, p. 2.

21Ivi, p. 3.

22Ibidem.

23« If the clock at A synchronizes with the clock at B and also with the clock at C, the clocks at B and C also synchronize with each other », ibidem.

24Ibidem. Emphasis added.

25The lifetime of a muon.

26Ivi, p. 1.

27Ibidem.

28A. Einstein, Zur Elektrodynamik bewegter Körper, 1905, Annalen der Physik, eng. transaltion: On the Electrodynamics of Moving Bodies, p. 4.

29Reconsidering a Scientific Revolution: The Case of Einstein versus Lorentz, p. 426.

30On the Electrodynamics of Moving Bodies, p. 4.

31Ivi, p. 1.

32M. Janssen, Appendix, Special Relativity, p. 459.

33Ibidem.

34Being and Time, p. 468.

35However, he is not a sophisticated Kantian or Bergsonian: « contrary to Kant's opinion, one comes across world-time just as immediately in the physical as in the psychical, and not just roundabout by way of the psychical » (ivi, p. 471).

36Ivi, p. 499; see p. 470.

37See Being and Time, §79.

38Ivi, p. 464.

39Ivi, p. 466.

40Ibidem.

41Ibidem.

42On the Electrodynamics of Moving Bodies, p. 3.

43Being and Time, p. 99.

44Ibidem.

45Ivi, p. 469.

46Ibidem.

47Ibidem.

48See note 18.

49Ivi, p. 103. Emphasis added.

50On the Electodynamics of Moving Bodies, p. 4.

51The tick-rate of a clock is the nows-sequence disclosed by it.

52Ivi, pp. 4 – 5.

53As it was nothing nothing more than its own function.

54See also Being and Time, §58.

55See « And only because 'truth', as uncovering, is a kind of Being which belongs to Dasein, can it be taken out of the province of Dasein's discretion », ivi, p. 270.

56Ivi, p. 470.

57Ibidem.

58See note 39 and relative quote.

59See also the italian translation: « la temporalità è la condizione della possibilità che la datazione si leghi a ciò che è spaziale e locale, in modo che ques'ultimo funga da misura valida per tutti » (Essere e Tempo, a cura di F. Volpi, Longanesi, Milano, 2005, p. 489, emphasis added.

60With time.

61Being and Time, p. 470.

62M. Heidegger, Brief über den « Humanismus », 1946, eng. translation by M. Groth, Letter on "Humanism", p. 25.

63M. Heidegger, Logik: Die Frage nach der Wahrheit, 1976, eng. Translation by T. Sheenan, Logic: the Question of Truth, Indiana University Press, 2005, p. 290. Emphasis added.

64Time as being-now.

65Being and Time, p. 470

66Although Kuhn's “paradigm” and Heidegger's “understanding of Being” may look similar, they are parts of completely different philosophical projects.

67In our case, this wording is preferable to « scientific revolution »: science itself becomes « revolutionary », abnormal – a change occurs in the scientific Dasein.

68Ivi, p. 165.

69Ibidem.

70Ibidem.

71See Being and Time, §§46-60.

72See ivi, §40. I.e.: « That in the face of which one has anxiety [ das Wovor der Angst] is Being-in-the-world as such », p. 230.

73Heidegger and Relativity Theory, p. 173.

74Ivi, p. 167.

75See for example C. Rovelli, L'ordine del Tempo, Adelphi, Milano, 2017.

76See for example the Wikipedia article on Error analysis for the Global Positioning System – Relativity.

77W. Pogge, Real-World Relativity: The GPS Navigation System.

78See for example M. Heidegger, Die Frage nach der Technik, 1953.

79The Concept of Time, pp. 18E – 19E.

80M. Heidegger, Wissenschaft und Besinnung, 1953, in Gesaumtasgabe, vol. 7, p. 59, my translation.

81Ivi, p. 60, my translation.

82Heidegger and Relativity Theory, p. 174.

83No wonder that 20^th century physics has appropriated all the themes that once belonged to classical metaphysics. We can see how today's physics answers to Kant's antinomies of pure reason (unsolvable and necessary aporias about the idea of “world”). Is the world spatially and temporally finite or infinite? Space is expanding at accellerating rate, while Time itself begun 13.8 billions years ago. Is there a causality? Phenomena are described by state-equations, where every “now” is equally present and linked only to its time variable.