The question of how something can come from nothing has puzzled philosophers, theologians, and scientists for centuries. At first glance, it seems nonsensical – how could anything come into being without a source or cause? Yet discoveries in modern physics suggest that not only can something emerge from nothing, but that it likely did at the moment of the Big Bang.
What do we mean by “nothing”?
To unpack this question, we first need to define what we mean by “nothing.” In philosophy and physics, this refers to the complete absence of space, time, matter, and energy – no spacetime framework and no pre-existing substance from which a universe could arise. True philosophical “nothingness” is difficult for our minds to grasp, as we have no direct experience of such a void.
Some equate nothing with empty space or the quantum vacuum. But empty space is not actually nothing, as it contains spacetime and fluctuating quantum fields. Similarly, the quantum vacuum seethes with virtual particles constantly popping in and out of existence. While vacuum energy and virtual particles arise spontaneously out of the vacuum, the vacuum itself is still something.
When physicists and cosmologists talk about the universe arising from nothing, they are referring to the absence of pre-existing space, time, particles, and fields. So the question is no longer how something can come from nothing, but rather how did spacetime and matter first originate if the universe once contained no space, time, particles or fields?
Challenges with the concept of “creation from nothing”
The notion that the universe spontaneously sprang into existence from nothing can be difficult to accept intuitively. Our everyday experiences make this hard to imagine, as we never see something arising from nothing in the world around us. It seems axiomatic that “out of nothing, nothing comes,” as the Greek philosopher Parmenides put it.
There are a few reasons this common-sense view poses challenges for understanding the beginnings of the universe:
- We tend to project our everyday intuitions onto a quantum context where they break down. At tiny distance scales, quantum effects take hold and everyday causality does not apply.
- Our minds are not equipped to easily comprehend the physics at the beginning of the universe, when even space and time as we know them did not exist.
- When thinking about cosmology, we have no direct observational data points to ground our intuitions. The earliest moments of the universe are not directly accessible through experiments.
While something coming from nothing defies common sense, the counterintuitive nature of this idea does not rule out its possibility. As we’ll see, quantum mechanics and cosmology provide contexts where we need to move beyond everyday intuitions and experience. Next, we’ll look at how modern physics opened up new ways of thinking about “nothing.”
The concept of “nothing” changes in quantum physics
In classical physics, the idea of particles appearing out of empty space violated the deeply-held principle of conservation of energy. But in the early 20th century, quantum mechanics revealed that the classical view of empty space was incorrect. Rather than being completely empty, the vacuum is described by quantum field theory as a field of fluctuating virtual particles constantly popping into and out of existence.
This discovery showed that the notion of “nothing” needed to be revisited. While not composed of matter or perceptible energy, the vacuum contains quantum fluctuations and latent energy. The probabilistic rules of quantum physics allow for particles to spontaneously arise out of the vacuum, as long as they vanish quickly enough to preserve conservation of energy.
Studies of the quantum vacuum revealed that, at very small scales, empty space is highly dynamic and allows processes that would be forbidden in classical physics. This opened up the possibility that the universe itself could have spontaneously arisen from empty space due to a quantum fluctuation.
Does the universe have a quantum origin?
In the prevailing cosmological model, known as inflationary theory, the early universe went through an extremely rapid exponential expansion driven by the energy of the quantum vacuum. The universe inflated from a microscopic subatomic size to astronomical scale in a tiny fraction of a second. The theory proposes that all the matter and energy in the universe today originated from excitations of the quantum vacuum during this early inflationary phase.
Rather than coming from pre-existing material, as in the classical view of creation, matter emerged directly from the primordial quantum vacuum. While this vacuum was originally thought to be truly featureless “nothingness,” we now know that it is actually seething with latent energy. This allows matter to arise spontaneously, without violating conservation of energy.
One way to think about this is that the net energy of the universe adds up to zero. The positive energy of matter is offset by the negative potential energy of gravity. As physicist Lawrence Krauss puts it, “In a closed universe, gravity can have negative potential energy, and when the potential energy is added to all other energy in the universe, it may sum to zero.” So the emergence of matter does not require adding new energy into the system.
While inflationary theory is the prevailing paradigm, other cutting-edge cosmological theories also propose a quantum origin for the universe. Stephen Hawking and James Hartle developed a “no boundary” model where the universe arises spontaneously from nothing, with equal probability of all initial configurations. Meanwhile, Alexander Vilenkin’s proposal of quantum tunneling from literally nothing posits that a spacetime vacuum fluctuation allowed spacetime itself to originate.
The different mathematical formulations vary in details, but all modern cosmological models share the idea that the universe had a spontaneous quantum origin from some form of primordial emptiness, whether a featureless void or a quantum vacuum field.
The role of quantum uncertainty
One key to understanding how this could occur is the Heisenberg uncertainty principle of quantum mechanics. At very small scales, there is an intrinsic uncertainty in measuring properties like position and momentum. Vacuum fluctuations arise randomly due to this uncertainty, allowing particles to appear and vanish.
While the precise details are still unknown, it appears uncertainty and quantum vacuum fluctuations could drive not just particles but also spacetime itself to pop into existence spontaneously. As Hawking describes, “The uncertainty principle of quantum mechanics implies that the quantum vacuum state is not exactly nothing. The uncertainty principle says that the position of a particle and its velocity cannot both be precisely determined at the same time.”
Challenges and open questions
Despite the compelling nature of these theories, a universe arising from nothing via quantum vacuum fluctuations faces challenges as a complete description:
- The proposals do not explain where the quantum vacuum or initial laws of physics originated from. They take the properties of quantum fields as a given.
- The cosmological models rely on speculative physics at extremely high energies that cannot be experimentally tested with particle accelerators.
- Some argue that the theories don’t fully eliminate causality, as the quantum vacuum must have very specific properties to allow a universe with our physical constants.
Due to these issues, some theorists propose cosmologies where our universe emerged from larger hyperspace dimensions or parallel worlds, rather than from complete nothingness. Others argue only evidence from a “theory of everything” combining quantum physics and general relativity can convincingly address the ultimate origins question.
While current models cannot be the final word, they provide plausible mechanisms for how an orderly universe can take shape spontaneously from emptiness, understood as the absence of space, time, and particles. The key is starting from the quantum vacuum rather than the classical notion of empty space.
Does science point to atheism?
Some argue that a universe arising from a quantum vacuum supports an atheistic worldview, removing the need for a creator. But quantum origins do not rule out non-theistic interpretations that are open to some form of higher intelligence or consciousness.
And they certainly do not disprove conceptions of God as source of all being beyond space and time, rather than as an additional cause within the universe. Theistic perspectives that view God as the ground of existence itself remain compatible with scientific accounts of cosmic evolution from primordial nothingness.
While physics describing a spontaneously appearing universe may challenge biblical literalism, it does not rule out more sophisticated theological views of creation as a non-temporal and non-spatial act. Questions like why there is something rather than nothing, or why the laws of nature take the form they do, lie outside the scope of science.
Doesn’t quantum physics remain speculative?
It’s true that theories of something arising from nothing rely on quantum physics principles that remain untested at the tremendous densities and temperatures characterizing the earliest moments of the universe. No high-energy experiments can probe the extreme conditions near the Big Bang, so theories of the early universe remain somewhat speculative today.
However, quantum physics is an exceptionally well-tested and verified theory within its domain of applicability. Its predictions about the quantum vacuum and uncertainty principle have passed stringent experimental tests. While we can’t test models of the extreme early universe directly, these models apply quantum principles in a consistent and mathematically rigorous way. Their indirect explanatory power provides confidence in their ability to describe nature accurately.
Eventually, once we have a theory unifying quantum mechanics and general relativity, some of these speculative extrapolations to the beginning of the universe can be placed on a more rigorous footing. Though current theories have gaps and uncertainties, they should not be dismissed out of hand but rather viewed as our current best models subject to further refinement.
Doesn’t causality require that “something” always existed?
This is a deep philosophical objection to the idea that the universe came into being spontaneously without any prior existence or cause. However, quantum physics seems to show that causality as we know it breaks down at the most fundamental levels of nature. Vacuum fluctuations can arise randomly without any deterministic cause.
Some argue that even if particles appear probabilistically, there must be something that gives rise to the fluctuations in the first place. Whether it is called the inflaton field, the quantum vacuum, or cosmological “nothingness,” this substrate has specific properties that many consider the ultimate cause. However, in certain no boundary cosmological models like Vilenkin’s, the initial state is truly nothing, not even defined by any laws of physics.
So while intuitive doubts about something coming from nothing are understandable, current physics suggests normal notions of causality do not apply at the most basic level. The requirement that “something has to exist” seems to arise from our limited vantage point as observers within space and time.
Doesn’t quantum physics still presuppose an existing spacetime?
A common reaction is that while quantum fluctuations can produce particles from the vacuum, there must still be a spacetime framework for this to occur. Of course, this raises the question of where the spacetime manifold itself originated.
Inflationary theory proposes that the spacetime continuum spontaneously expanded from an initial singularity, essentially a quantum fluctuation to initiate the Big Bang. So according to inflation, spacetime grew out of a substratum where no spacetime existed, whether defined as a primordial vacuum or true nothingness.
This ability of space and time to “emerge” from non-spacetime follows from general relativity, where spacetime is a dynamic entity rather than an unchanging stage. The quantum generation of matter can be generalized to the quantum generation of spacetime itself.
Admittedly this is perplexing from our standpoint as observers already within a classical spacetime. But at the deepest foundations of nature, the framework of quantum physics allows for the spontaneous origination of spacetime from non-spacetime quantum degrees of freedom.
| Framework | Allows something from nothing? |
|---|---|
| Classical physics | No |
| Quantum physics | Yes |
| General relativity | Yes (for spacetime itself) |
Doesn’t causality require an absolute beginning?
Some argue that if the universe truly began to exist a finite time ago, as the Big Bang theory suggests, there must have been a first cause to bring it into being – a necessary uncaused originator that exists beyond time. For some, this points to the existence of a divine creative source.
However, other cosmological models such as an eternal chaotic inflationary multiverse do not have an absolute beginning. While individual pocket universes may arise and perish, the larger spacetime fabric exists eternally and does not require a creator to originate it. Speculatively, the laws of quantum physics themselves might allow a spontaneous and uncaused origin.
In quantum cosmology, even with a finite age there is no guarantee of an identifiable first cause, since quantum fluctuations can arise spontaneously without deterministic origins. So the necessity of a creator is predicated on particular assumptions about cosmic origins that are not universally agreed upon by physicists.
The arrow of time
A related objection notes that since the Second Law of Thermodynamics dictates that entropy increases over time, there must have been a beginning where it was minimal. However, while entropy increases in our pocket universe, the epoch prior to inflation was subject to symmetries and quantum uncertainty that allow decreasing entropy. While the thermodynamic arrow of time prevents origins without a low-entropy past in classical physics, this does not necessarily hold at quantum scales.
Conclusion
The prospect of something coming into existence from complete nothingness will always stretch the limits of human intuition. But the conceptual problems raised by common sense do not clearly invalidate current scientific theories of the universe originating spontaneously from randomness at the quantum level.
Rather than ruling out a scientific account, the very strangeness of particles arising from empty space reinforces just how far our everyday notions of causality and existence break down when pushed to the extremes of the cosmic order. The universe seems capable of operating in ways unimagined by our earthly perspectives.
While a Universe from Nothing remains counterintuitive, modern physics provides a plausible framework for how this could occur. The crucial step is viewing nothingness as the quantum vacuum rather than classical empty space. Only by moving beyond everyday intuition can we begin to grasp how emergence from “nothing” could happen.