Talk:Dirac sea

Dirac's Ocean

Can someone have searches for "Dirac's Ocean" redirect to this? I ask because some translations of Neon Genesis Evangelion use that particular wording, and when I looked it up, I couldn't get any direct results. -- dethtoll

Importance Rating

I just added an assessment rating, but, as my knowledge of physics is limited to the equivalent to 1 year of freshman level physics in college, I have never dealt with a Dirac Sea, nor do I know its importance. [Whoops, didn't read article carfully enough, missed a part I asked a question about. Question removed. Sorry]Oneoverzero 20:39, 2 July 2007 (UTC)[reply]

Inelegance of Dirac sea

The statement here is a bit confusing: "Landis" also notes that Pauli exclusion does not definitively mean that a filled Dirac sea cannot accept more electrons, since, as "Hilbert" elucidated, a sea of infinite extent can accept new particles even if it is filled. Landis and Hilbert are mentioned abruptly without appropriate introduction.

For this statement "This happens when we have a chiral anomaly and a gauge instanton," It will be good to comment about the chiral anomaly and instant, how these are related to the Dirac sea and Dirac fermions coupling to gauge fields.

Modern Applications

The section on modern applications using the Dirac sea to explain semiconductors is misleading, at best. The valence band is not like an infinite sea of electrons, and holes in no way resemble positrons. Hole's are merely the absence of an electron in a band, allowing the net charge of a substance to become more positive. Positrons are very different creatures indeed (see the first several sentences of the wiki article on electronic holes). this section should be changed and/or removed. Play4thesport (talk) 18:51, 24 June 2008 (UTC)[reply]

Is this something still accepted, or has it been completely replaced? That should be in the intro. --141.155.12.146 (talk) 04:35, 18 February 2009 (UTC)[reply]

In Fiction

I'm proposing the removal of any plot-spoiling references to whatever fictional media is mentioned in the "In Fiction" section, specifically the bit regarding Chaos;Head. Such elements are not necessary to the informational purposes of the article and as such should be removed to avoid the unnecessary spoiling of various plot devices. -Randazzius 05:05 PM July 09, 2009 (EST)

That being said, no part of it is a plot spoiler, since you'd technically need to understand the concepts of the game first, and by that time, it would no longer be a plot spoiler. Sooo zetta slow! 16:20, 16 August 2011 (UTC) — Preceding unsigned comment added by SonicGamer (talk • contribs)

Basic explanation

Evangelion provides a very easy to understand explanation/interpretation of the Dirac Sea. I suggest that this article make mention of the Dirac Sea and how it is used in evangelion.67.84.159.28 (talk) 16:27, 15 May 2010 (UTC)[reply]

Negative solution?

"Here the negative solution is antimatter, discovered by Carl Anderson as the positron." I thought the positron (and antimatter in general) has both positive mass and positive energy, so it would not correspond to the negative solution E = −mc². Is there something I'm missing, or is the article misleading? --Jmk (talk) 12:01, 5 July 2010 (UTC)[reply]

The positron is often described as the absence of a negative energy electron, thereby giving it positive energy and charge. As is usual in quantum theory, such word descriptions are necessarily rather loose analogies, but relating negative energy solutions of the equations to antiparticles is clearly valid in the context of the standard model. See also the history section of the positron article. Tim Shuba (talk) 18:05, 18 July 2010 (UTC)[reply]

Antimatter and negative-matter are not the same thing. In matter-antimatter annihilation, two photons of equal (and positive)energy are released. This implies that both matter and antimatter have positive mass and, therefore, positive energy. See http://en.wikipedia.org/wiki/Antimatter#Origin_and_asymmetry.

Paul Dirac, himself, stated this in his Dec. 12, 1933 Nobel Prize Lecture: "An examination of the behaviour of these states in an electromagnetic field shows that they correspond to the motion of an electron with a positive charge instead of the usual negative one - what the experimenters now call positron.

One might, therefore, be inclined to assume that electrons in negative-energy states are just positrons, 
but this will not do, because the observed positrons certainly do not have negative energies.

We can, however, establish a connection between electrons in negative-energy states and positrons, in a rather more indirect way." -NobelPrize.org, http://nobelprize.org/nobel_prizes/physics/laureates/1933/dirac-lecture.pdf

 — Preceding unsigned comment added by Nfcopier (talk • contribs) 21:06, 21 January 2011 (UTC)[reply]

Sigh I wish people would sign there comments. Actually your point about negative matter is slightly off. Most people confused the negative mass-energy density that is called for by wormholes as negative matter. In reality, it is very similar to the negative energy states when we talk about quantum foam or antimatter-matter reaction. Physics16 (talk) 14:20, 2 November 2011 (UTC)[reply]

anti-gravity

Calling Dirac's sea an ether would be wrong, I believe, as an ether lacks relative vantage and since he applied relativity and quantum mechanics to Maxwell's ether, it stopped being an ether and became a quantum field theory that attempt to unify with relativity. Semantics, but ether was debunked because of its definite non-relative vantage... unlike fields.

Also, how would this http://www.universetoday.com/84934/antigravity-could-replace-dark-energy-as-cause-of-universes-expansion/ fit in with Dirac's theory, assuming you removed his monopoles idea and otherwise updated it? -Reticuli 71.65.115.103 (talk) 21:31, 17 December 2011 (UTC)[reply]

When I accelerate through space-time I feel acceleration. When space-time accelerates through me it is exactly the same thing, but we call it gravity. As the electron curves in it's orbit it radiates which slows it down. There is an energy-producing system inside the atom that replaces that energy, and it burns space-time as a fuel. The inward flow of space-time is gravity. The Michleson-Morley experiment was flawed, it will never hetrodyne. If you take a roll of a few miles of the silvered glass fiber inside a photo optic cable and point a laser in one end and the other end into a photo transistor, and a parallel five foot fiber the same, then the flow of space-time will be detectable. However, lightening bolts create gravity pulses that will also be detected. Have fun! <ambientlivinginc@gmail.com 31 March '15> — Preceding unsigned comment added by 50.11.85.51 (talk) 05:49, 31 March 2015 (UTC)[reply]

Electric Charge of the Dirac Sea

I am confused by this statement in the article: "The existence of the sea implies an infinite positive electric charge filling all of space. In order to make any sense out of this, one must assume that the "bare vacuum" must have an infinite negative charge density which is exactly cancelled by the Dirac sea."

I have two questions. The first is that, since the article emphasizes the example of electrons so heavily, if this statement refers to a Dirac sea of electrons, wouldn't such a sea have an infinite negative charge? In which case the "bare vacuum" would have to balance that somehow by possessing an infinite positive charge? "Holes" in this electron sea are what would act like isolated positive charges in this case, but the sea itself would be negative. However, the statement in the article does not mention electrons explicitly; so, could it be referring to something else, such as protons perhaps? This leads to my next question. Since all of the fermion particles must have their own seas in Dirac's picture, and since positively and negatively charged fundamental fermions exist in equal proportions, I don't understand why the vacuum needs to have any intrinsic charge density at all. The variety of different fermions can balance their own charges easily enough. Is the concern that these different seas wouldn't naturally be expected to fill to equal zero-point energy levels, so that something about the vacuum would be necessary to force this?50.174.178.168 (talk) 05:37, 20 May 2015 (UTC)[reply]