Vacuum Definition and 1000 Threads

In theory (please correct me if I am wrong in any point), if our vacuum were metastable (i.e. in a "false vacuum" state), it could go through a phase transition into a stable state (a "true vacuum" state). Depending on the properties of the new vacuum, fundamental forces and particles could...

In this paper [1] which considers the possibility that the Lorentz symmetry could be broken, at page 4-5 the author says: "We now introduce a Higgs sector into the Lagrangian density such that the gravitational vacuum symmetry, which we set equal to the Lagrangian symmetry at low temperatures...

Hi I live in a high Altitude around 2500 meter over sealevel. I have a vacuum pump, at max my vacuum meter shows 21 inHG inside the vacuum chamber . my vacuum pump(welch 2014B) has a max of 40 torr it say the technical datasheet. What is now my endpressure in torr in my vacuumchamber?It's...

Just wondering if anyone here finds these video/picture leaks about UAP's (Unidentified Aerial Phenomenon) interesting and inspiring enough to try and figure out how they work? Pretty big game changer of technology and would be fun to discuss. I'm hoping at least someone agrees.

I have always read that vacuum energy and zero point energy are established facts of physics supported by various observations of their effects both indirectly and even directly. But I have also read some comments from various physics discussion sites where they say that it is not a fact that...

All data I see online about reflectivity of metals is about aluminum in the atmosphere meaning oxidized aluminum, but pure aluminum in vacuum in case of the James Webb telescope would also be extremely reflective but building it on Earth means it's going to get oxidized, similarly there are a...

Hey everyone, My question is simple. Has quantum vacuum information ? And can we measure it with Shannon Entropy and the other ways. By the way I just started to learn english so ı have any grammer mistake please tell me. I know this is out of subject but thank you.

I recently found three old vintage diffusion pumps left over by the previous lab owners: 1. Veeco EP 2A 2. Veeco EP 2A-1 3. Edwards Speedivac F203 Is there a possibility that these pumps have PCB based oil inside? I do not have access to PCB oil testing at the moment. Also any further...

As we all know, light itself is the fastest thing in the universe, and the cosmic speed limit, basically. That said, it is said to go at 299,792,458 meters per second in a vacuum. That is pretty fast. However, I have a question I want to ask... Does light really go that fast in a vacuum? I ask...

Hello, everyone! I am calculating the time of substrates' heating in the vacuum chamber. It is a simple mathematical model to calculate roughly how much time does it take to heat polycor substrates in the vacuum chamber. At least all the tube heater`s power heats the substrates (this is...

Im trying to find an advanced thermodynamic equation for a vacuum flask. I am looking for an equation to find the temperature of a liquid at time t as it cools down. Ignore the cap and bottom section; assume there is no heat loss in those areas. I'm just interested in the cylindrical...

When studying the QFT, one considers the vacuum state when the field is not excited and therefore no particles are present. Now for the matter fields this makes sense to me. But what about the radiation field? Suppose we have an arbitrary small volume of space in the universe without any matter...

Consider the decay in a quantum field theory from a metastable vacuum to the "true" vacuum. Here's i my understanding: 1. For a scalar field potential U(\phi), the transition amplitude is finite per unit volume for a finite energy splitting between the 2 classical minima of the potential...

Hi all, I'm currently reading about instantons and theta vacua (section 93, p 572 of http://web.physics.ucsb.edu/~mark/ms-qft-DRAFT.pdf) Srednicki remarks in passing the following: What is a good way to "see" 93.5 is true? Is there a slightly simpler way than below which is my current...

Recent jailbreak of a robot vacuum from a Cambridge TraveLodge https://www.bbc.co.uk/news/uk-england-cambridgeshire-60084347

Research into the Higgs boson suggest that the universe is in a false vacuum but I heard many physicists do not take it seriously as they think that if it were true we cannot even exist as it would have wiped us out billions of years ago. For example Katie Mack said that its like a piece of...

We are a group af hobby butchers, that use curing with salt as one method. Now a question has come up about the use of a vacuum sealer to speed up the process. So the question is probably easy for a physician. Will the salt solution go into the meat faster under vacuum than if we just put the...

A great video biography of James Dyson and his struggles to get his vacuum cleaners to the market.

I'm excitedly close to the end of proofing my latest novel, and as happens, tweaking of passages occurs. In this instance, a fleet of warships travel together in a collective warp space bubble that has inconsistent gravity, especially around the edges. To facilitate shuttle transfers between...

\langle \phi_0| \hat{c}_{-k \downarrow} \hat{c}_{k \uparrow}\hat{c}^\dagger_{k \uparrow}\hat{c}_{-k \downarrow}|\phi_0\rangle = \\ \langle \phi_0| - \hat{c}_{k \uparrow} \hat{c}_{-k \downarrow} \hat{c}^\dagger_{k \uparrow}\hat{c}_{-k \downarrow}|\phi_0\rangle = \\ \langle \phi_0| \hat{c}_{k...

In Carroll "Spacetime and Geometry" I found the following explanation for why the analytically extended rindler modes share the same vacuum state as the Minkowski vacuum state: I can't quite understand why the fact that the extended modes [\tex]h_k^{(1),(2)}[\tex] are analytic and bounded on...

I have a system, in which Reactor vent is connected to scrubber. Due to which reactor is under slight vacuum, ~400 mmWC Solid is being charged to the reactor at a very low rate manually. Is there any way to calculate approximate amount of solid which will get carryover to scrubber due to...

What determines the order of the vacuumpolarisation? I've added 2 Feynman Diagrams for refference. The first one shows the vacuumpolarisation of the lowest order the second shows the vacuumpolarisation of the 2nd order. What is the difference?

In This wikipedia article is said: "If the quantum field theory can be accurately described through perturbation theory, then the properties of the vacuum are analogous to the properties of the ground state of a quantum mechanical harmonic oscillator, or more accurately, the ground state of a...

In the first figure, air goes forward and the can goes backward. My question is why does the air exert the pressure gradient force on the can. Can I have a hint for why the can doesn't move when air is being sucked in in the second photo.

Before that, Lawrence Kraus stated "Empty space is a boiling, bubbling brew of virtual particles that pop in and out of existence in a time scale so short that you can't even measure them" . After reading https://www.physicsforums.com/insights/physics-virtual-particles/ especially this statement...

So... I've been writing my work about the vacuum and quantum vacuum. Now my problem is that I've come to realize that I can't really bring my thoughts and research onto paper the way I would like it. I am now in 12th grade in high school I know that this is a crazy demand but hear me out: I...

We (company I am interning for) are meeting with various suppliers in efforts to find a new source of vacuum pumps for our brake boosters. We are looking to make a switch to an electrical pump versus the mechanically-driven pump we used previously. One of the issues we are having with this is...

So in the image below from a video I watched , the narrator states “gas pressure from the refrigerator rushes into the low-pressure chamber “ So, I do understand that gas will push its way into a low-pressure area from a high-pressure (high to low)….but what I am unclear of is to how that...

Consider a single atom (or particle) in a vacuum (without electric, magnetic or gravitational field) at near zero kelvin (i.e., no photons or particles striking it). I am curious if it will still have a magnetic dipole? If there still is (which I believe), had this been shown experimentally?

Hello, there. From another post, I read the insights Learn the Physics of Virtual Particles in Quantum Mechanics and Explore The Vacuum Fluctuation Myth in Quantum Theory. Also, I sometimes see a statement that the vacuum is not empty from some media. Most often, it says the vacuum can create...

Also, I have heard from physicists that vacuum energy fluctuation (creation and destruction of virtual particles) violates energy conservation. The reason, they justify, is based on uncertainty principle (energy-time form of uncertainty principle), energy can exist and disappear for a very short...

I have attached my work here. I don't know how to proceed further?

Sorry I just typed out my query .For some reason I can't seem to find the buttons for attaching files on this thread. When writing the QED vacuum polarization loop, the numerator ,consisting momenta slashed + m from the fermion propagators and the two gamma matrices, has a trace over all of it...

Hello! I am currently reading Itzykson Zuber QFT book and on Chapter 7 where for the first time loops are considered. Particular method of dealing with divergences namely Pauli-Villars regularization is considered in section 7-1-1 considering vacuum polarization diagram. I do understand physics...

To a non-physicist, I know some papers can appear very abstract, and Sakharovs equation was one of them. You can follow his ideas from various articles, here's a few to chew on...

Hi folks, very simple question, but have not been able to find an answer: Assume a vacuum pump pulls air through a pipe. Also assume that within the pipe run, there is an area with reduced cross section, creating a temporary increase in air velocity. Also assume the air is very moist, and is at...

Hello all, The merits of the full-flow cycle are without question and have been fielded with Starship tests to the point of my complete buy-in into Raptor's capability as a launch engine. Elon Musk loosely discusses further refinement of their vacuum-optimized engine that they have created...

I'm trying to do the math for a backyard thermodynamic pump experiment, and getting stuck. Suppose an empty 3.79 liter container was airlocked by a vertical 25 cm long empty tube whose end sits at the top of an unlimited supply of water in a basin. The tube protrudes through the container such...

Got a vacuum to create bubbles in water, they advertised it as "boiling water" but it didn't seem like boiling in my book. If there were bubbles in water I am guessing there was a vacuum of 20% (20% atmosphere.) I am just estimating the 20% number. In any case, there didn't seem to be any...

Summary:: Trying to find good books so that I can continue writing my paper about the vacuum Hello fellow physics enthusiasts, I require your support to find good and scientific literature about: Lamb Shift Vacuumpolarisation Zero point energy It can be a long source too, so don't be afraid...

I understand that it is one of Einstein's postulates, however I don't know of any direct experiments which show that it is true.

Hey all, So if a gas is combusted, would it travel faster through a vacuum tube or a regular ole' tube? I would assume the vacuum tube, as there are less particulates collisions in the way of the fast-moving gas molecules. Yet this also implies pressure on the outside of the thin barrier _ 2...

Hi I purchased a vacuum container on amazon, the type with the glass and rubber lid. I didn't want to spend a bunch of money to buy an electronic air vacuum so I just bought a hand pump instead. Only problem is the hand pump doesn't seem to create a vacuum, even though I verified the hand pump...

https://physics.csuchico.edu/~eayars/publications/AJP00961.pdf http://www.phys.utk.edu/demoroom/MECH/The%20Vacuum%20Canon.pdfSo I get the outside atmosphere is what provides air density and such in the pdf above^. However, why is it that most cannon demonstrations use just the air from the...

Hi there. I would like to start saying that I am not an engineer or scientist, and that my knowledge about vacuum and vacuum systems, in general, is limited, and I would like to apologize in advance if I am not describing the problem accurately. The application I am posing this question about...

Why doesn't the balloon burst in this video? To me it seems that the differential (guage) pressure between inside and outside the balloon is what matters, and I would think it would be the same as a balloon inflated in the usual way. https://youtube.com/shorts/3HZ0JkgtpDU?feature=share

Hi First question: In one end there is vacuum something like 15HgV, other end is something like 25HgV, in the middle there is high viscosity fluid that is pre vacuumed in 25HgV for any air bubbles. 15HgV , space, high viscosity fluid, space, 25HgV . Does the fluid move to the higher vacuum or...

Hi all - related to a question I asked some time ago: If one introduces a momentum cutoff, the result in the most basic case is Lorentz violation. That is, some form of preferred frame must be introduced. I'm wondering what this does to the vacuum state? That is, how does one keep the vacuum...

This is a question for experimentalists working in Condensed Matter Physics. What do you think is the most striking example of QFT vacuum state fluctuations affecting the results of an experiment? I have vague memory of reviewing some abstracts about quantum criticality in cuprate...