Popular Physics
Here we extrapolate the idea of launching SpaceX's Starlink satellites and study the possibility of building planetary megastructures (either designed as solid objects or as a web of satellites) by Type-I civilizations and the consequent…
Gas and vapour explosions have been involved in industrial accidents since the beginnings of industry. A century ago, at 11:55 am on Friday 24th September 1920, the petroleum barge Warwick exploded in London's docklands and seven men were…
Egyptian faience is a non-clay ceramic semi-transparent material, formed of a quartz core and alkali lime glaze with some cases exhibiting an interaction layer between them. Several possible glazing methods have been identified. Previous…
First contact with another civilization, or simply another intelligence of some kind, will likely be quite different depending on whether that intelligence is more or less advanced than ourselves. If we assume that the lifetime distribution…
The 2020 Nobel Prize in Physics distinguished two research projects on black holes, which are one of the most striking predictions of General Relativity. The prize was divided in two parts. The first half was awarded to Roger Penrose in…
The tumuli of Newgrange and Knowth in Ireland are among the most monumental heritages of the Neolithic era. The megalithic constructions date back to around 3'200 BC, centuries before the completion of Stonehenge and the Egyptian pyramids.…
We updated the agent based Monte Carlo code HERITAGE that simulates human evolution within restrictive environments such as interstellar, sub-light speed spacecraft in order to include the effects of population genetics. We incorporated a…
There is a wide-ranging debate about the merits and demerits of searching for, and sending messages to, extraterrestrial intelligences (SETI and METI). There is however reasonable (but not universal) consensus that replying to a message…
We describe the very nature of the elementary particles, which our (visible) Universe consists of. We point out that they are not point-like, and we depict their ways of interacting. We also address puzzles that occur even in the absence of…
In this pedestrian approach I give my personal point of view on the various problems posed by dark matter in the universe. After a brief historical overview I discuss the various solutions stemming from high energy particle physics, and the…
A long-lasting belief is that the gravitational stress by the moon would be responsible for earthquakes because of causing a tidal deformation of Earth's crust. Even worse, earthquakes are sometimes said to be correlated with eclipses. We…
Without evidence for occupying a special time or location, we should not assume that we inhabit privileged circumstances in the Universe. As a result, within the context of all Earth-like planets orbiting Sun-like stars, the origin of a…
The objective of this work is to provide a mathematical analysis on how a Thoroughbred horse should regulate its speed over the course of a race to optimize performance. Because Thoroughbred horses are not capable of running the whole race…
Stellar engines are hypothesized megastructures that extract energy from the host star, typically with the purpose of generating thrust and accelerating the stellar system. We explore the maximum potential speeds that could be realizable by…
Einstein's genius and penetrating physical intuition led to the general theory of relativity, which incorporates gravity into the geometry of spacetime. However, the theory of general relativity leads to perspectives which go far beyond the…
The Cosmological Constant Lambda, a concept introduced by Einstein in 1917, has been with us ever since in different variants and incarnations, including the broader concept of Dark Energy. Current observations are consistent with a value…
We fantasize about an alternative history for theories of electromagnetism and gravitation.
Power-meter measurements are used to study a model that accounts for the use of power by a cyclist. The focus is on relations between rates of change of model quantities, such as power and speed, both in the context of partial derivatives,…
The author thinks that the main ideas or Relativity Theory can be explained to children (around the age of 15 or 16) without complicated calculations, by using very simple arguments of affine geometry. The proposed approach is presented as…
Even if it tends to hide more often in the current autumnal season, our host star, the Sun, is the principal source of energy on our planet. It has a luminosity of 3.828e26 Watts, and despite that we receive only 2 parts per billion of…