Does physical reality exist without an observer?

Question

This question also considers principles of quantum physics.

When electrons or any other subatomic particles are "observed" or "measured", their wavefunction collapses to a certain point, i.e. the value at which it is observed. Its position, velocity, momentum etc. become 1 quantity - that is, the quantity that we know.

What causes this wavefunction collapse? Is it the instrument used, the observer looking at the results, or the observer understanding and analyzing the result?

If certainty exists with an observer and uncertainty exists without an observer, then what is the fundamental force that drives everything in the universe? Is it the tendency to achieve entropy, or the tendency to achieve pattern?

If reality is a consequence of consciousness, then are infinitely many realities possible?

Since it is impossible for humans to feel the consequence of every action in the universe, does the tendency to achieve pattern, certainty and observers imply the existence of other life/higher dimensions in the universe?

Thank you!

Answer 1

I will give you a physicist's view. The Universe existed for billions of years before the sort of life we consider conscious evolved on Earth. Do you suppose that the laws of physics changed when conscious life appeared? Do you supposed that if all life on Earth were snuffed out overnight the laws of physics would be changed tomorrow? When in physics we say a wave function collapses, we mean that it changes. When we say it collapses as a result of observation, we mean that it changes when the electron interacts with the equipment being used to observe it. Consciousness- or human consciousness at least- has nothing to do with it. Indeed, many quantum physics experiments generate results without humans watching, since they are highly automated.

Of course, it could be that the way in which electrons, for example, interact with other matter is because everything has some degree of consciousness, but that is speculation currently unsupported by compelling evidence.

Answer 2

Of course reality does not need an observer: Life is a late phenomenon in the universe. During most of the time there was no life and no observer.

1. According to the Copenhagen interpretation quantum mechanics (QM) deals with the state of a system as a set of probabilities for its observables. Each measurement of a given observable prepares the system to be in a state with a definite value of the observable: Instantaneous reproduction of the measurement gives the same value.

2. What causes the transition from the space of probabilities to a state with a definite value of the observable - the “collapse of the wave function” - is not completely understood.

   In any case it is not the observer but the interaction of the system with the apparatus, used for the measurement. The interaction of the system with the environment destroys any possible interference of the wave function. This mechanism is named decoherence.

For further study I recommend Quantum coherence and the lectures by Leonard Susskind on QM Quantum mechanics.

Answer 3

You ask:

Does physical reality exist without an observer?

Well, for science, you'll get the answer yes. But as we are a philosophical forum, the answer might be more complicated like, it depends on whose metaphysical presuppositions you favor. That is, despite science being a dominant way of thinking about the world (it certainly is my way), it is not the only way. George Berkeley, for instance, would claim no. Let's explore.

It is a central tenet of modern physicalism (SEP) that physical and external reality exists prior to consciousness. That is to say, minds and their observations of the world, supervene upon the physical world, and the world is mind-independent. Perhaps the broadest, contemporary school of thought on this is scientific realism (SEP). From the SEP:

Metaphysically, realism is committed to the mind-independent existence of the world investigated by the sciences. This idea is best clarified in contrast with positions that deny it. For instance, it is denied by any position that falls under the traditional heading of “idealism”, including some forms of phenomenology, according to which there is no world external to and thus independent of the mind. This sort of idealism, however, though historically important, is rarely encountered in contemporary philosophy of science. More common rejections of mind-independence stem from neo-Kantian views of the nature of scientific knowledge, which deny that the world of our experience is mind-independent, even if (in some cases) these positions accept that the world in itself does not depend on the existence of minds.

Of course, idealism (SEP) is the classic rejection of the mind-independence of the world. Idealism was the dominant view before the 20th century. From the SEP:

This entry discusses philosophical idealism as a movement chiefly in the eighteenth and nineteenth centuries, although anticipated by certain aspects of seventeenth century philosophy and continuing into the twentieth century. It revises the standard distinction between epistemological idealism, the view that the contents of human knowledge are ineluctably determined by the structure of human thought, and ontological idealism, the view that epistemological idealism delivers truth because reality itself is a form of thought and human thought participates in it... between epistemological and metaphysical arguments for idealism as itself a metaphysical position.

So, when a physicist gives you their perspective, you should expect them to reject idealism. The mind-independence of the world is part of the modern scientific worldview. If you are looking for good counterarguments, therefore, you need to look past the chorus of scientists and find philosophers who have different presuppositions. One good starting place is the work of George Berkeley (SEP):

But what exactly is a material thing? Interestingly, part of Berkeley’s attack on matter is to argue that this question cannot be satisfactorily answered by the materialists, that they cannot characterize their supposed material things. However, an answer that captures what exactly it is that Berkeley rejects is that material things are mind-independent things or substances. And a mind-independent thing is something whose existence is not dependent on thinking/perceiving things, and thus would exist whether or not any thinking things (minds) existed. Berkeley holds that there are no such mind-independent things, that, in the famous phrase, esse est percipi (aut percipere) — to be is to be perceived (or to perceive).

So, is physical reality mind-independent? Science presumes it and to answer 'no' would be considered non-scientific. But there are other worldviews other than science and scientism, so some may certainly reply 'no'. You'll have to continue reading to decide for yourself.

Answer 4

When we look at the relations which can exist between being and consciousness we see clearly that only two positions are possible: either being is primary (materialism), or consciousness is primary (idealism). Or, to put it another way, the fundamental principle of materialism is the independence of being from consciousness; of idealism, the dependence of being on consciousness.

Georg Lukács

So in short, those who say it can exist without an observer are what Lukacs puts into the being camp. Those who say it cannot are in the consciousness camp.

The root question of Vedanta is particularly interesting here: Do you exist in deep dreamless sleep?

Answer 5

A wavefunction is a probabilistic understanding of the state of something which is collapsed by determinative interaction. The former is more abstract than the reduced state of the thing.

OTOH This answer addresses the title question:

OP: Does reality exist without an observer?

Before examining the things in the world an understanding needs to be made of existence, and in the case for human beings that means grasping what being means for interpreting things in the environment. The first step therefore is experience itself. It seems so obvious that we overlook it. Taking Descartes' cogito ergo sum—he has no idea where his sum comes from. And if he looks at the indeterminacies of infinite causal chains he still has no idea, until inevitably he realises his 'sum' is the foundation, his only ground for existence, and nothing more can be said about its origin except that "it is". Simples, n'est-ce pas? Finding footing in an infinite or indeterminate causal chain that we speculatively call 'the universe'.

Determining the petere principium, the reaching out to the supporting ground, is Heidegger's aim in Being & Time e.g.

Basic concepts determine the way in which we get an understanding beforehand of the area of subject-matter underlying all the objects a science takes as its theme, and all positive investigation is guided by this understanding. H. 10

Ontological inqury is indeed more primordial, as over against the ontical inquiry of the positive sciences. But it remains itself naive and opaque if in its researches into the Being of entities it fails to discuss the meaning of Being in general. H. 11

Sciences are ways of Being in which Dasein comports itself towards entities which it need not be itself. But to Dasein, Being in a world is something that belongs essentially. Thus Dasein's understanding of Being pertains with equal primordiality both to an understanding of something like a 'world', and to the understanding of the Being of those entities which become accessible within the world.a So whenever an ontology takes for its theme entities whose character of Being is other than that of Dasein, it has its own foundation and motivation in Dasein's own ontical structure, in which a pre-ontological understanding of Being is comprised as a definite characteristic. H. 13

So, no, nothing exists without the observer.

"For thinking and being are the same." - Parmenides, 5th century BCE

Cogito ergo sum - Descartes, 17th century CE

Answer 6

Does physical reality exist without an observer?

Yes, of course. Assuming otherwise would be hubris of the largest order.

Rough sketch if you really need logic for this: Observers are part of the physical universe today, so observers exist. But after the big bang, there was a very short but not zero time where no observers existed.

To quote Wikipedia:

The earliest phases of the Big Bang are subject to much speculation, given the lack of available data. In the most common models the universe was filled homogeneously and isotropically with a very high energy density and huge temperatures and pressures

There is obviously a very large uncertainty regarding the early times of the big bang, but this is what we came up with so far, based on the indirect observations we have available. In this "ur-soup" there clearly were no observers (this is implied by it being "filled homogenously and isotropically", which means basically without complex structures like brains or even simple mechanical measurement devices).

So we have a point in time where no observers existed, and a later point of time where observers exist, and a pretty seamless evolution of the universe between those. At some point in time there must have been the first instance of an observer, and we have absolutely no indication whatsoever to assume that before that time the physical reality somehow popped into existence spontaneously.

So TLDR: yes, clearly, by observation and our best current standard theories of physical reality, the universe existed before any observers existed.