What is Zero-point energy: Definition and 34 Discussions

Zero-point energy (ZPE) is the lowest possible energy that a quantum mechanical system may have. Unlike in classical mechanics, quantum systems constantly fluctuate in their lowest energy state as described by the Heisenberg uncertainty principle. As well as atoms and molecules, the empty space of the vacuum has these properties. According to quantum field theory, the universe can be thought of not as isolated particles but continuous fluctuating fields: matter fields, whose quanta are fermions (i.e., leptons and quarks), and force fields, whose quanta are bosons (e.g., photons and gluons). All these fields have zero-point energy. These fluctuating zero-point fields lead to a kind of reintroduction of an aether in physics, since some systems can detect the existence of this energy; however, this aether cannot be thought of as a physical medium if it is to be Lorentz invariant such that there is no contradiction with Einstein's theory of special relativity.Physics currently lacks a full theoretical model for understanding zero-point energy; in particular, the discrepancy between theorized and observed vacuum energy is a source of major contention. Physicists Richard Feynman and John Wheeler calculated the zero-point radiation of the vacuum to be an order of magnitude greater than nuclear energy, with a single light bulb containing enough energy to boil all the world's oceans. Yet according to Einstein's theory of general relativity, any such energy would gravitate and the experimental evidence from both the expansion of the universe, dark energy and the Casimir effect shows any such energy to be exceptionally weak. A popular proposal that attempts to address this issue is to say that the fermion field has a negative zero-point energy, while the boson field has positive zero-point energy and thus these energies somehow cancel each other out. This idea would be true if supersymmetry were an exact symmetry of nature; however, the LHC at CERN has so far found no evidence to support it. Moreover, it is known that if supersymmetry is valid at all, it is at most a broken symmetry, only true at very high energies, and no one has been able to show a theory where zero-point cancellations occur in the low energy universe we observe today. This discrepancy is known as the cosmological constant problem and it is one of the greatest unsolved mysteries in physics. Many physicists believe that "the vacuum holds the key to a full understanding of nature".

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  1. AndreasC

    I Exploring the Cosmological Constant Problem & Zero-Point Energy

    Reading the Wikipedia page on it, one reads: But on the other hand, as far as I know and if I'm not mistaken, zero point energy is not a physical thing, and it is merely a mathematical artifact in QFT. Someone correct me if I'm wrong on that. So if that is the case, then why is it a "problem"...
  2. frankinstien

    I Zero-Point Energy and Gravitational Influence

    I ran into another article demonstrating the Casimir effect and it hit me that zero-point energy is real mass and therefore would have a gravitational influence on our universe. Is there something wrong with this idea, am I missing something?
  3. jaketodd

    B Are zero-point energy and inertia incompatible?

    With zero-point energy, endlessly jittering everything around randomly, nothing is ever at rest, and never moving at a constant speed (inertia). But we've been getting along without knowledge of it for quite a while! Haha. So, since it's random, and produces such little variations, maybe it...
  4. Mayhem

    Zero-point energy of diatomic hydrogen (particle in a box)

    If we take ##H_2## as a "particle" in a box, can the zero-point energy of the overall molecule be calculated as the sum of the zero-point energies of all particles in ##H_2##? That is $$E_ {1,H_2}=\frac{2h^2}{8m_{\mathrm{H^+}}L^2} + \frac{2h^2}{8m_{\mathrm{e^-}}L^2}=...
  5. J

    I Zero-point energy of the harmonic oscillator

    First time posting in this part of the website, I apologize in advance if my formatting is off. This isn't quite a homework question so much as me trying to reason through the work in a way that quickly makes sense in my head. I am posting in hopes that someone can tell me if my reasoning is...
  6. I

    A Zero-point Energy Contribution Below the Planck energy cutoff

    Is it possible to determine the amount of zero-point energy contributed by all fields below the Planck energy cutoff?
  7. SemM

    A Interesting article on gravity and the zero-point energy

    Hi, I found this rather interesting article on gravity and the zero point energy. Here is the link and abstract Abstract When Planck introduced the 1/2 hv term to his 1911 black body equation he showed that there is a residual energy remaining at zero degree K after all thermal energy ceased...
  8. S

    A Does zero exist in the energy term?

    Hi, did the energy of the universe, right before big bang equal to zero? And if so, does zero as zero-point energy in relativistic theory and quantum mechanics make any sense? If this is not possible, are there any models, including the standard model, SUSY or QFT which consider ground state...
  9. A

    I Constant particle motion due to zero-point energy....

    Hi all, Just a clarification to ask about: if a have an electron (all by its lonesome) in its ground state, it will have non-zero kinetic energy (zero-point energy), even at absolute zero. This should mean the particle (oscillating field excitation in QFT) is always moving. Now, to be clear...
  10. S

    I How can the total orbital angular momentum be zero?

    I'm trying to understand the rotations of rigid diatomic molecules such as HCl. My understanding of the orbital angular momentum is that it is quantized with a total value equal to $$E=\frac{\hbar^2}{2I}J(J+1)$$ where I is the rotational moment of inertia and J is the quantum number. Also, J...
  11. JG1009

    Zero-point energy and QED vacuum state

    I'm relatively new to QFT and was wondering how the QED vacuum has a dormant zero average-field condition if there is a zero-point energy of the field as well? How is there a zero average and a zero point energy?
  12. Helios

    Zero-point energy density evaluation

    Dear cosmology people, What is a theoretical value for the zero-point energy density of the vacuum? It must be hard to know or even controversial. Even though the zero point field is a QFT topic, the question seems to be cosmological, because only the cosmologist seem to be forthcoming on the...
  13. G

    Zero-point energy + Thermal runaway

    IF I am in error, forgive me. but I had this thought cross my mind today. IF absolute 0 is the stopping of all atomic (or molecular) movement. and you induce a thermal reaction, i.e. splitting the nuclei. would the reaction be slowed down at all? (to make a slow burn) Yea. I understand...
  14. G

    Will this anology for zero-point energy work?

    Take a large round basin of water and introduce running waves on the surface in such a manner that the combination of all waves will establish a standing wave of some sort of pattern, letters of the alfabet, appear above the original surface. The original surface level in between the apperently...
  15. J

    Zero-point energy from Schroedinger equation using Ritz variaton principle

    Homework Statement Calculate the zero-point energy of the hydrogen atom using the Ritz variaton principle and the approach \psi_{\alpha}. Hint: The stationary Schroedinger equation in spherical coordinates is ... Homework Equations \left\{...
  16. J

    Simple proof that the zero-point energy spectrum is Lorentz Invariant?

    In his article on the Zero-point Energy: http://www.calphysics.org/zpe.html Bernard Haisch says: That the spectrum of zero-point radiation has a frequency-cubed dependence is of great significance. That is the only kind of spectrum that has the property of being Lorentz invariant. The...
  17. J

    Zero-point energy stops space shrinking?

    According to John Baez, Einstein's Field equations can be written in the following form: V'' / V = - 1/2 (rho + P_x + P_y + P_z) (http://math.ucr.edu/home/baez/einstein/node3.html where V is the volume of a small region of space, rho is the energy density P_x, P_y, P_z is the...
  18. J

    Zero-point energy cancelled by its gravitational energy?

    Consider the uncertainty principle: dp * dx = hbar For photons we have the relation: E = p c Substituting into the above uncertainty principle: dE = hbar c / dx (1) As we look at a smaller and smaller piece of the zero-point field the (positive) energy diverges. But...
  19. J

    Zero-point energy in empty space

    Could the zero-point field energy at each point in empty space be zero because it is canceled by its own negative gravitational self-energy? Inside particles zero-point energy modes that are larger than the particle size are excluded leading to an excess negative gravitational energy inside...
  20. J

    Extracting zero-point energy using the Casimir effect?

    Hi, People have hypothesized that one could extract energy from the zero-point field using the Casimir effect by letting the two conducting plates move together and do some useful work. But surely to reset the system one needs to supply the same amount of work to separate the plates again...
  21. J

    Zero-point energy, dark energy and space

    Hello. I've looked on the internet a lot about this: what is the zero-point energy and dark energy? From what I gathered, they both mean the same thing. Is that so? Also these two energies represent minimal energy densities *in* space. But what about energy *of* space itself. I mean here...
  22. tom.stoer

    Solution to the Cosmological Constant, Zero-Point Energy, P.D. Mannheim

    Has anybody studied this paper? http://arxiv.org/abs/0909.0212v4 Comprehensive Solution to the Cosmological Constant, Zero-Point Energy, and Quantum Gravity Problems Philip D. Mannheim (Submitted on 1 Sep 2009 (v1), last revised 7 Jan 2010 (this version, v4)) Abstract: We present a...
  23. C

    The differences in zero-point energy between isotopes

    Hi all, May I know which would have a higher vibrational energy at ground state, zero point energy, maximum vibrational quantum number, between the these 2 isotopes: H2 and D2 and why?
  24. E

    Working out Zero-Point Energy and ration of potential to kinetic for a particle.

    Homework Statement Consider a particle with mass, m moving in one dimensional potential U=kx^2/2 as in a mass-spring system. The total energy of the particle is E= (p^2/2m) + (kx^2/2) Classically, the absolute minimum of the enrgy, E=0 is acheived when p=0 and x=0. In quantum mechanics...
  25. N

    Understanding Zero-Point Energy: An Explanation for Confused Minds

    I'm fed up. Quantum mechanics keeps confusing me. Is there anyone who can explain in as straightforward a way as possible what exactly zero-point energy is? In particular, there are two things I find quite confusing: 1) Why could zero-point energy be infinite? 2) It is said that the zero...
  26. J

    Zero-Point Energy, Relativity

    Homework Statement Consider an electron confined in a region of nuclear dimensions (about 5fm). Find its minimum possible KE in MeV. Treat as one-dimensional. Use relativistic relation between E and p. Homework Equations KE = p2/(2a) = \hbar2/(2ma2) p = h/\lambda E = hf E2 = (mc2)2 +...
  27. H

    Zero-Point Energy of a Debye Solid

    Homework Statement Show that the zero point energy of a Debye solid is: (9/8) N k (Debye Temp) Homework Equations zero point energy = sum of (1/2 w hbar ) over all i The Attempt at a Solution I used the Debye spectrum g(w) = 9N w^2 / w(D)^3, for w < w(D) g(w) = 0 for w>w(D) Then I...
  28. S

    Explaining Zero-Point Energy & Quantum Foam

    First, my apologies if this topic is in the wrong section but since I don't know anything about physics and I sometimes wiki stuff, I have some sort of very amateur knowledge on that subject. Anyway, Stargate SC-1 and Atlantis are the TV shows which got me interested in all the technotalk, and...
  29. G

    Is Zero-Point Energy Fact or Pseudoscience?

    What is the current peer-considered consensus opinion on the status of 'Zero-Point Energy'? Given that so much counter-intuitive stuff in quantum physics is also observable, palpable, fact, I am having a hard time weeding out the crackpot fantasies. They now come with all the terminology of...
  30. A

    Zero-Point Energy: Calculating the Minimum Value

    "Consider a particle with mass m moving in a potential U=1/2kx^2, as in a mass-spring system. The total energy of the particle is E=p^2/(2m)+1/2kx^2. Assume that p and x are approximately related by the Heisenburg Uncertainty Principal, px approximately equals h. a) Calculate the minimum...
  31. M

    Zero-point energy of a linear harmonic oscillator

    Hi. I'm given a problem with a harmonic oscillator where the potential is V= (kx^2)/2 with a mass m (KE = 1/2 mv^2). I have to use the Heisenberg Uncertainty principle to show what the minimum energy is, but I'm not sure where to start... I think I have to combine KE + V and minimize that, but...
  32. M

    Zero-Point Energy Manipulation

    This might be a stupid question, but I've been reading a lot about zero-point energy and I still don't fully understand what it is. I've always had a dream of coming up with plans for a gravity manipulator that could reduce an objects mass to absolute zero creating a black hole, but sustaining...
  33. T

    Zero-point energy - a question for you all.

    Greetings, I have a question about Zero-Point energy. I know that is occurs due to the Casimir Effect which is a product of putting two metal plates very close together, so that large wavelengths of background radiation cannot exist in between the plates. The result is a EM vacuum that...
  34. wolram

    Exploring the Significance of Zero-Point Energy

    there is much written and on the web about ZPE it is an ofshoot of real physics ,with as far as i know no proof. my question is why anyone gives it creedence. why has it become so important? must go my overunity teamaker is boiling best wishes