# What is Zeno: Definition and 47 Discussions

Flavius Zeno (; Greek: Ζήνων, translit. Zénōn; c. 425 – 9 April 491) was Eastern Roman emperor from 474 to 475 and again from 476 to 491. Domestic revolts and religious dissension plagued his reign, which nevertheless succeeded to some extent in foreign issues. His reign saw the end of the Western Roman Empire following the deposition of Romulus Augustus and the death of Julius Nepos, but he was credited with contributing much to stabilising the Eastern Empire.
In ecclesiastical history, Zeno is associated with the Henotikon or "instrument of union", promulgated by him and signed by all the Eastern bishops, with the design of solving the monophysite controversy.

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2. ### Mathematica Simulating the quantum Zeno effect using Mathematica

I'm trying to simulate the quantum Zeno effect using Mathematica and I need to apply von Neumann and projection operator on to same density matrix and in a loop one by one, it's basically switching between two evolutions in time., so I need help on how to do it.
3. ### A Call for experiment : Delayed Choice and Quantum Zeno Effect

Under several historical experiments, measurement back-action has exhibited the ability the suppress a system's transitions to other states, especially when measurements are taken at a high frequency in time. This phenomena has become known as the Quantum Zeno Effect. In short, a quantum...
4. ### Three paradoxes explained with Calculus.

Up and Atom gives a look at some Calculus tools which a layman can follow.
5. ### Quantum Zeno Effect and Evolution Operator Properties

Homework Statement Let ##U_t = e^{-iHt/\hbar}## be the evolution operator associated with the Hamiltonian ##H##, and let ##P=\vert\phi\rangle\langle \phi\vert## be the projector on some normalized state vector ##\vert \phi\rangle##. Show that \underbrace{PU_{t/n}P\dots PU_{t/n}}_{n\text{...
6. ### B Zeno Effect: Quantifying the Impact of Observation on Events

[this thread was forked from https://www.physicsforums.com/threads/zeno-effect-standard-derivation.951929/; the "equation above" can be found there] If the quantum Zeno effect is real and if it can be quantified shouldn't the maths be specific to the event being observed? For example...
7. ### I Zeno effect - standard derivation?

Hi, I'm trying to grasp the standard derivation of the quantum Zeno effect. But my calculus is limited. I would love some assistance! Schroedinger evolution tells us that the state at time t, given the initial state at time t=0, is: |\psi_t\rangle = e^{-i H t} |\psi_0 \rangle We can then...
8. ### I Quantum Zeno effect to influence a particle's movement

Hi, I've had an idea I would like feed-back. Let's imagine a particle on an x axis. On it's initial state it is localized in segment [0,1] as a purely symmetric wave. The quantum Zeno effects tells us that if we measure wether the particle is still in [0,1] n times during one second, the...
9. ### I Under what conditions do the Zeno and anti Zeno effects occur?

https://www.sciencedaily.com/releases/2000/06/000602074805.htm The article says that the zeno effect only applies to certain systems while the anti zeno effect applies to all systems. Is this true?
10. ### I Question about the quantum Zeno effect again

When measuring the decay of a radioactive atom with a geiger counter, we collapses the superposition of the decay and undecayed state. This will affect the rate of decay of the atom. However the geiger counter does not actively interact with the atom. It does not shoot any particle at the atom...
11. ### A Can the quantum Zeno effect be applied to the Higgs field

This sounds weird and i suppose that i got some concepts wrong. For all i know, the higgs field may be metastable and the zeno effect states that the rate of decay for an unstable system can be changed by interaction. Can the zeno effect be applied to the higgs field if it is indeed metastable?
12. ### I Does this explain the Zeno effect observed

Quantum zeno effect states that an unstable particle can be prevented from decaying by being observed/measured. It has been experimentally proven. However, this observation/measurement does not refer to simply looking at it. This effect vanishes as we zoom out to the macroscopic world. Hence, a...
13. ### B Zeno's arrow paradox and general relativity?

I don't know much about general relativity, but I'm curious if Zeno somehow foresaw the reallty of the universe many many years before Einstein did(without any rigour ofc, but still the idea holds?). Understanding the Zeno's arrow paradox, stating that an arrow is motionless at a certain moment...
14. ### I Can quantum Zeno effect be applied to macroscopic systems?

I was just wondering if the quantum Zeno effect can be applied to macroscopic systems. It's applies to microscopic systems such as atoms but how about macroscopic systems like the universe?
15. ### I Keeping a subspace decoherence free, with the Zeno Effect

I am currently reading papers discussing the Zeno Effect, which discuss how measuring a system at high frequencies can almost freeze the state of a system, or keep the system in a specific subspace of states. This can be easily seen using the projection postulate. Often the topic of decoherence...
16. ### "Motion is impossible" claims modern Zeno

Let me set up a situation: A piano rests on a frictionless surface. I am standing next to the piano (on a frictional surface) and I claim that the following two statements prove it is impossible for me to move the piano: (1) ... The kinetic energy of the piano is equal to the work I've done on...
17. ### Question about the Quantum Zeno Effect

If I get it right, the Quantum Zeno effect shown in the experiment of W. Itano et al in 1990 is one of the most amusing and easy to understand for non-experts about quantum superposition and the "role of observation" in quantum systems, which I would choose to explain these subjects to...
18. ### Radioactivity and Quantum Zeno Question

Radioactivity is independent of the time the radioactive element was produced. If i remember correctly (which is a big IF, correct me if I'm wrong) this has to do with the collapse of the wavefunction into a definite state by "measurements" and then slipping back into a wave to evolve again...
19. ### Quantum Zeno Effect: What is the argument? (Part II)

Every general explanation of the quantum zeno effect I've found is (from my perspective) so full of gaps that I cannot understand the explanation. My understanding has improved due to responses to a previous post on this topic as well as to a detailed but still gappy paper that was recommended...
20. ### Quantum Zeno Effect: What is the argument?

Every general explanation of the quantum zeno effect I've found is (from my perspective) so full of gaps that I cannot understand the explanation. I am wondering if anyone can help me fill in the gaps here? The most detailed explanation I've found runs something like this: Let |ψ0> be the...
21. ### Quantum Zeno effect rules out many-worlds?

Hi, I've read somewhere that the Quantum Zeno effect, should it really exist, rules out the many-worlds interpretation. However I did not understand the argument (actually there was no argument, seems the author considered it obvious). Could someone please elaborate on this? BTW, what's...
22. ### Quantum Zeno effect for position measurement

Hello, The quantum zeno effect is well understood and experimentally confirmed as regards polarization measurements (as discussed here). It's the quantum analogue of "the watched pot never boils" as it allows "continuous" measurement to inhibit certain state evolutions. Does the effect...
23. ### Understanding the Quantum Zeno Effect (QZE)

Hi there, I'm trying to understand the Quantum Zeno Effect (QZE) but am coming across some difficulties. A common experiment used to illustrate the effect uses polarization directions of photons (http://arxiv.org/abs/1211.3498). The photons are either "vertical" or "horizontal", but one can...
24. ### Why we can't see quantum Zeno effect in macroscopic object?

Hello, I'm reading a book "How to teach quantum physics to your dog" from Chad Orzel, which is of great fun. Recently I become interested in quanntum Zeno effect. I can't understand why we can't see the quantum Zeno effect in daily life. Below is what I posted on my facebook, and my friend's...
25. ### Quantum Zeno Effect - Explained

I've heard an interesting explanation of how the Quantum Zeno effect works, but I am still confused. Here is a summary of that explanation, as I understood it... When constant observations (or a series of observations taken at very short intervals) are made of a system in a superposition of...
26. ### Observation time and its relation to the quantum Zeno effect

Hi. I have a problem to understand the following situation regarding observation of a quantum system: Imagine we have an unstable particle in a box, together with many sensors where each is connected to a lamp. The sensors continuously monitor the particle, the lamp turns on whenever the...
27. ### Solving the Quantum Zeno problem with path integral QG

Schroeren's new paper "Decoherent histories of spin networks" made me aware of some work by two people at Cambridge DAMTP and London Imperial's Blackett Lab on the Quantum Zeno (QZ) effect in the path integral e.g. decoherent histories (DH) context. Schroeren's paper...
28. ### Doesnt qtm zeno effect contadict the idea that hup is there even when not observed?

in q zeno effect, measuring, or observing a particle will effect its outcome. however, its been said on this forum that the hup is there whether we observe it or not. contradiction?
29. ### Doesnt the quantum zeno effect dissallow the possibility of randomness?

if a nucleus decays at random, it should be impossible to effect that in any way and if observered, you are effecting something that is by definition supposed to be random. for example if i am a particle and have true randomness, then being observed at certain intervals, probability would...
30. ### How Does Calculus Resolve Zeno's Paradox of Motion?

It is said the sum of infinite series 1/2+1/4+1/8...=1, i.e it say there are infinite points. It also means if it goes on like this it will approach the limit which is 1 in this case but never ever will it be able to reach 1. Or in other words it says 1 is the point that would never be...
31. ### Quantum Zeno Effect and quantum decay

Quantum Zeno Effect and quantum "decay" Howdy, My understanding of QM is mostly mathematical (I have a basic understanding of the Hamiltonian of something like the particle in the box, and the rest of what I know is from Quantum Information Science, with very little physics knowledge), so...
32. ### Quantum Zeno Effect and Decoherence

I've read the Quantum Zeno (QZ) Effect is caused by Quantum Decoherence (QD), and that QD is, in general, a representation of the wave-function collapse of a quantum system (the Wikipedia explanation on this is confusing to me, to say the least). If I understand the QZ Effect correctly...
33. ### Ballentine on the quantum Zeno paradox

I know that many people here have a very high opinion on the Ballentine's QM textbook. I am also one of them, but one particular subsection of it is (in my opinion) wrong. This is the subsection on the quantum Zeno paradox, or as Ballentine calls it, the "watched pot" paradox in Section 12.2...
34. ### Set-Theory, a paradox from Zeno and Russell/Cantor confusion.

I can't come to a comfortable conclusion which doesn't make positive, negative, real, imaginary, complex, irrational or transcendental numbers seem much different fundamentally. Zeno (to the best of my interpretation) illustrates a large part of my problem with: "If there are many, they...
35. ### Zeno's 4th Paradox & Quantized Space: SR & GR Effects

I am trying to ascertain whether the 4th paradox proposed by Zeno (the Stadium) can be used to refute the idea of quantized space and whether such conclusion is affected by SR. Let us assume: - Two equal blocks moving towards each other: block A from left to right and block B from right to...
36. ### Anti-Zeno Effect: Verified & Explained

hi, does anyone there know what is exactly the anti Zeno effect, if it is well experimentally verified, and accepted?
37. ### Can the Quantum Zeno Effect be solely attributed to decoherence?

Can the Quantum Zeno Effect be solely attributed to decoherence? In every single case? Is the consensus on this matter opinion, or rigorously tested fact in which every case can be attributed to decoherence? On a more well known note, can the supposed wavefunction collapse (which gives...
38. ### Unlock the Mysteries of Quantum Zeno Effect

Hi, I don't know much about physics but the limited amount of reading I've done on this particular observation (is that what you call it?) is mind boggling. http://en.wikipedia.org/wiki/Quantum_Zeno_effect Wtf? Is this statement 100% accurate? If it is, what are the consequences for us?
39. ### Can the Zeno Paradox be Resolved Through Infinite Divisions?

I may have discovered an explanation to the Zeno Paradox. However, in this explanation, the concept of a race between to objects at different speeds is simplified into one object traveling a given distance. The distance traveled in this example can be represented by the variable D. If the...
40. ### Geometry of Time, Axiom of Choice, and Neuro-Biological Quantum Zeno Effect

Is ther a mass loss at the time of death? Can brain states be frozen? [9] arXiv:0704.1054 [ps, pdf, other] : Title: Geometry of Time, Axiom of Choice and Neuro-Biological Quantum Zeno Effect Authors: Moninder Singh Modgil Comments: 13 pages Role of axiom of choice in quantum...
41. E

### The Paradox of Zeno: An Analysis of the 2000-Year-Old Puzzle

"The Paradox of Zeno" "The Paradox of Zeno" The Paradox of Zeno is 2000 years old and its apparent ability to prove that all motion is impossible was not resolved until the mathematical techniques of Calculus became available, even though that technique is not required. One form of the paradox...
42. E

### The Paradox of Zeno: A 2000 Year Old Puzzle Resolved by Calculus

"The Paradox of Zeno" "The Paradox of Zeno" The Paradox of Zeno is 2000 years old and its apparent ability to prove that all motion is impossible was not resolved until the mathematical techniques of Calculus became available, even though that technique is not required. One form of the paradox...
43. ### How Does Zeno's Paradox Influence Quantum Gravity and Modern Science?

Here is an entertaining [albeit pretty tough in places] read. It's kind of wide ranging, flitting between logic, physics and the interleaved mathematical formalisms. I found it particularly interesting from a quantum gravity perspective. It certainly serves as a reminder to be careful before...
44. ### Zeno of Elea created one of the first and most perduring paradoxes

Many of you will know that Zeno of Elea created one of the first and most perduring paradoxes of all. If any of you think you have solved it.....you ARE wrong. sorry. But you can try it: Imagin you want to fo from here to there and th distance is one meter (it works with any distance and...
45. ### Disproving Parmenides and Zeno: A Logical and Mathematical Analysis

Hello I don't know a whole lot about mathematic philosophy, but I am truly interested. I am learning about Parmenides and then of course Zeno and I was asked if I could disprove Zeno logically or mathematically. Specifical to disprove the theory of motion and change is an illusion. And...
46. ### A philisophical Heisenberg and Zeno question

Hello this is my first post. I am a 15 year old 10th grade student in a philosophy program and now we are studying the famous Greek philosophers. I have a problem that was asked by a teacher that I would like to answer. And although I have tried I have not come up with an answer on my own...
47. ### Thrown Ball on Planet Zeno: Find Height & Time to Ground

Problem 9. If a ball is thrown vertically upward on the planet Zeno at 100m/s, then it's approximate height in meters t seconds later is given by h(t)=45t-9t^2. a.After how many seconds does the ball hit the ground? b. How high does the ball go?