Popular Physics
Recent publications discuss the size of chemical rockets for long-distance travel, to be launched from a planet. Here I point out that such a rocket cannot be tall and slim but will be short and fat.
We show that the Lyapunov exponents of a periodic orbit can be easily obtained from the eigenvalues of the monodromy matrix. It turns out that the Lyapunov exponents of simply stable periodic orbits are all zero, simply unstable periodic…
Statistical tools have been developed to quantify the agreement between a hypothesis or a model and the observed data for probabilistic phenomena. In this work, we define statistical methods used to measure the properties of the higgs boson…
The Nebra disk has been object to investigations since its discovering. In order to understand its meaning for the ancient people we are forced to find reasonable astronomical motivations which led its builders to make it. Here a possible…
World ships are hypothetical, large, self-contained spacecraft for crewed interstellar travel, taking centuries to reach other stars. Due to their crewed nature, size, and long trip times, the feasibility of world ships faces an additional…
In this paper we consider efficiency of self-reproducing extraterrestrial Von-Neumann micro scale robots and analyse the observational characteristics. By examining the natural scenario of moving in the HII clouds, it has been found that…
Power-meter measurements together with GPS measurements are used to study the model that accounts for the use of power by a cyclist. The focus is on estimating the coefficients of the air, rolling and drivetrain resistance, uncertainties of…
To develop a spacefaring civilization, humankind must develop technologies which enable safe, affordable and repeatable mobility through the solar system. One such technology is nuclear fusion propulsion which is at present under study…
A century after observing the deflection of light emitted by distant stars during the solar eclipse of 1919, it is interesting to know the concepts emerged from the experiment and the theoretical and observational consequences for modern…
An explanation is given for two peculiar phenomena - Foo Fighters and microwave oven plasma balls. Both are proposed to arise from the interaction of microwave energy with areas of hot, partially ionized, gas. In the former case it is…
We revisit our 2013 claim [arXiv:1303.7476] that the Universe is the result of a conspiratorial plot, and find that it cannot be trusted, because even the belief in this conspiracy likely results from a conspiracy. On the basis of…
It is a widely accepted view that COVID 19 is either transmitted via surface contamination or via close contact of an un-infected person with an infected person. Surface contamination usually happens when infected water droplets from…
Radiation hazard on board of a relativistic rocket can be of internal and external origin. Because of its highest specific energy density, antimatter is considered to be the preferred rocket fuel for accelerating a multi-ton rocket up to…
A novel use of high temperature superconducting (HTS) electromagnets for human sized microgravity research and mitigation is outlined. Recent advances in HTS technology have resulted in electromagnets that potentially could levitate large…
In their recent comment, Cockell et al. argue that the habitability of an environment is fundamentally a binary property; that is to say, an environment can either support the metabolic processes of a given organism or not. The habitability…
On January 30, 2020 Current Biology released the report "A Chronobiological Evaluation of the Acute Effects of Daylight Saving Time on Traffic Accident Risk" doi: https://doi.org/10.1016/j.cub.2019.12.045 by Fritz, et al., where it was…
We present a two-sphere dumbbell configuration of a rotating settlement at Earth-Moon L5. The two-sphere configuration is chosen to minimize the radiation shielding mass which dominates the mass budget. The settlement has max 20 mSv/year…
Proteins are key building blocks of virtually all life, providing the material foundation of spider silk, cells, and hair, but also offering other functions from enzymes to drugs, and pathogens like viruses. Based on a nanomechanical…
Thermoelectricity describes phenomena that allow us to convert heat into electricity and vice versa. The practical implications of this conversion are obvious. However, research on thermoelectric effects also leads to a deep understanding…
We employ simulated annealing to identify the global solution of a dynamical model, to make a favorable impression upon colleagues at the departmental holiday party and then exit undetected as soon as possible. The procedure, Gradual…