相关论文: Vacuum balloon -- a 350-year-old dream
In this work the linear elastic properties of materials containing spherical voids are calculated and compared using finite element simulations. The focus is on homogeneous solid materials with spherical, empty voids of equal size. The…
Boron is the fifth element in the periodic table and possesses rich chemistry second only to carbon. A striking feature of boron is that B12 icosahedral cages occur as the building blocks in bulk boron and many boron compounds. This is in…
The long-awaited Higgs particle H around 125 GeV has been observed at the LHC. Interpreting it as the standard model Higgs boson and if there is no new physics between electroweak and Planck scale, we then don't have a stable vacuum. Here,…
The hard sphere model is known to show a liquid-solid phase transition, with the solid expected to be either face centered cubic or hexagonal close packed. The difference in free energy between the two structures is very small and various…
We propose an improved effective-medium theory to obtain the concentration dependence of the viscosity of particle suspensions at arbitrary volume fractions. Our methodology can be applied, in principle, to any particle shape as long as the…
The impact and rupture of water-filled balloons upon a flat, rigid surface is studied experimentally, for which three distinct stages of the flow are observed. Due to the impact, waves are formed on the balloon's surface for which the…
Ball lighting (BL) has been observed for centuries. There are large number of books, review articles, and original scientific papers devoted to different aspects of BL phenomenon. Yet, the basic features of this phenomenon have never been…
We study the contribution of instantons to the binding and the mass of the lightest scalar glueball, in gluondynamics. We show that the short-range correlations introduced by such non-perturbative vacuum fluctuations are sufficient to give…
A graphene nanobubble consists of a graphene sheet, an atomically flat substrate and a substance enclosed between them. Unlike conventional confinement with rigid walls and a fixed volume, the graphene nanobubble has one stretchable wall,…
A toy model giving rise to long lived super heavy particles and an small vacuum density energy, of the order of the one measured in the present universe, is constructed. This model consists in hidden sector invariant under an $SU(2)_L$…
Although street artists have the know-how to blow bubbles over one meter in length, the bubble width is typically determined by the size of the hoop, or wand they use. In this article we explore a regime in which, by blowing gently, we…
Metallic thin-walled round tubes are widely used as energy absorption elements. However, lateral splash of the round tubes under impact loadings reduces the energy absorption efficiency and may cause secondary damages. Therefore, it is…
Although real materials are finite in size, electronic structure theory is built on the assumption of infinitely large solid, which led to a longstanding controversy: where is the vacuum level? Here, we introduce an analytic real-space…
The concept of jamming has attracted great research interest due to its broad relevance in soft matter such as liquids, glasses, colloids, foams, and granular materials, and its deep connection to the sphere packing problem and optimization…
Soap bubbles form when blowing air through a suspended thin film of soapy water and this phenomenon entertains children and adults alike. The formation of soap bubbles from thin films is accompanied by topological transitions, and thus the…
The classic double bubble theorem says that the least-perimeter way to enclose and separate two prescribed volumes in $\mathbb{R}^N$ is the standard double bubble. We seek the optimal double bubble in $\mathbb{R}^N$ with density, which we…
A model for a possible variable cosmic object is presented. The model consists of a massive shell surrounding a compact object. The gravitational and self-gravitational forces tend to collapse the shell, but the internal tangential stresses…
We evaluate the continuum limit of the valence (quenched) approximation to the mass of the lightest scalar quarkonium state, for a range of different quark masses, and to the mixing energy between these states and the lightest scalar…
The bottle-flip challenge -- the upright landing of a partially filled bottle after tossing and flipping it in the air -- unexpectedly became a viral mechanics exercise. Through high-speed visualization, we evidence that fluid content…
The Bubble Nebula (or NGC 7635) is a parsec-scale seemingly spherical wind-blown bubble around the relatively unevolved O star BD+60$^\circ$2522. The small dynamical age of the nebula and significant space velocity of the star suggest that…