Searcharxiv⌕ Search

arXiv subjects

S. Parnovsky

Publications and source records attributed to S. Parnovsky.

3 recordsLinked to original sources
arXiv2023

Vacuum solutions of Einstein equations that depend on one coordinate

In the famous textbook written by Landau and Lifshitz all the vacuum metrics of the general theory of relativity are derived, which depend on one coordinate in the absence of a cosmological constant. Unfortunately, when considering these solutions, the authors missed some of the possible solutions discussed in this article. An exact solution is demonstrated, which is absent in the book by Landau and Lifshitz. It describes space-time with a gravitational wave of zero frequency. It is shown that there are no other solutions of this type than listed above and Minkowski's metrics. The list of vacuum metrics that depend on one coordinate is not complete without the solution provided in this paper.

gr-qc↗
arXiv2023

The egg steamer paradox

Why do we need to pour less water in an egg steamer to prepare more eggs to the same degree of doneness? We discuss the physical processes at work in the electric egg steamer and resolve this seeming paradox. We demonstrate that the main heat transfer mechanism from steam to egg is due to latent heat through condensation. This not only explains the paradox, but also allows us to estimate the amount of water reduction. Comparing the preparation time to the one for traditional boiling, we estimate the eggshell temperature during steaming. We also describe the device design and provide further theoretical estimates and experimental kitchen measurement data for this appealing kitchen experiment that can be easily accomplished at home.

physics.ed-ph↗