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20

You aren't creating a vacuum, but you are reducing the pressure in your lungs when you inhale. In effect your lungs are working as a diaphragm pump. When you pull your diaphragm down, and/or expand your chest, this increases the volume inside your lungs. Boyle's law tells us: $$ P_0V_0 = P_{\rm inhale}V_{\rm inhale} ,$$ where $P_0$ and $V_0$ are ambient ...


5

Let us look at the instantons of an ordinary pure Yang-Mills theory for gauge group $G$ in four Euclidean dimensions: An instanton is a local minimum of the action $$ S_{YM}[A] = \int \mathrm{tr}(F \wedge \star F)$$ which is, on $\mathbb{R}^4$, precisely given by the (anti-)self-dual solutions $F = \pm \star F$. For (anti-)self-dual solutions, ...


3

A lot of things are possible if you want to throw a lot of money at it. Is it practical? No. First, I would estimate that a rocket would be thousands of dollars. Low Earth orbit would get you the high range ($10^{-6}$ torr), high Earth orbit would possible get $10^{-9}$ torr. The next difficulty is to have the container returned to Earth (it needs to be ...


2

To make a long story short - Yes, it is possible, but you would have no practical reason to do it. To make a long story long, read on. While space is not a perfect vacuum, like you stated, it is close, and many applications of earth-generated vacuums are for simulating the conditions of outer space. In theory, one could put a pressure vessel in a orbital ...


2

The article you quoted is really badly written. Instead of unnatural the correct world should have been "tuned" or something similar. The issue is related to the fact that we know that, if the fundamental constants of nature would have been slightly different, the universe would have been completely different. For instance, carbon would not be formed at ...


2

The example of unnaturalness you describe is the example of the mexican hat for the higgs mechanism ( if you look at this page up on the left you will see the mexican hat in the PHYSICS logo). As all should know this symmetry is naturally broken at our energy levels, as in this the example, which is correct, that the pencil sits precariously and can break ...


2

Yes, cavitation creates a "vacuum". But the liquid will start evaporating the moment the void is created, so it is not a vacuum in the strict sense of "nothing there". When a cavitation bubble collapses (which usually happens very shortly after it forms), the temperature inside can rise very quickly - due to adiabatic compression of the little gas that has ...


1

A paper by Colosi and Rovelli that I read may have another interesting answer to the question. Consider space partitioned off (arbitrarily) into two regions $R_1$ and $R_2$. The global Fock vacuum is found by solving for the global Hamiltonian which includes the possible correlations between the regions. A local detector in a region $R_1$ is governed by a ...


1

Never mind cost in dollars, it costs more in energy. Assume you had perfectly efficient pumps. To create a vacuum you have to push the air out of your chamber, if we assume we want $1 \text{ L}$ of vacuum, this takes $$ W = PV = (1 \text{ atm}) (1 \text{ L}) = 10^9 \text{ erg} $$ of work. But if you want to get your vacuum from space, even assuming you ...



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