Popular Physics
A civilization in the habitable zone of a dwarf star might find it challenging to escape into interstellar space using chemical propulsion.
The Milky Way Galaxy contains an unknown number, $N$, of civilizations that emit electromagnetic radiation (of unknown wavelengths) over a finite lifetime, $L$. Here we are assuming that the radiation is not produced indefinitely, but…
Many rocky exoplanets are heavier and larger than Earth, so-called "Super-Earths". Some of these may be habitable, and a few may be inhabited by Super-Earthlings. Due to the higher surface gravity on these worlds, space-flight is much more…
Following from the results of the first systematic modern low frequency Search for Extraterrestrial Intelligence (SETI) using the Murchison Widefield Array (MWA), which was directed toward a Galactic Center field, we report a second survey…
With the wealth of planets that have been discovered over the past $\sim$ 20 years, the field can broadly be divided into two regimes. For understanding broad occurrence and formation rates, large numbers of planets allow for population…
"Winter is coming". As far as meteorological predictions go, the words of House Stark are both trivial and not very helpful for a scientific analysis to explain the chaotic sequence of the seasons in the world of "Game of Thrones". The…
A recent arXiv manuscript, arXiv:1801.03278, claims that a cosmic background radiation with a black body temperature of $T_{\rm BB}$ ~ 500 K (440 F) was just barely visible to human eyes, thus fixing the onset of the Dark Ages at about 5…
No present observations suggest a technologically advanced extraterrestrial intelligence (ETI) has spread through the galaxy. However, under commonplace assumptions about galactic civilization formation and expansion, this absence of…
While SETI is often thought of as a part of radio astronomy with optical SETI, artifact SETI, METI, and other approaches to finding intelligent life considered to be allied fields, SETI is better understood as an interdisciplinary field…
The 21 cm hydrogen line is considered a favourable frequency by the SETI programme in their search for signals from potential extra-terrestrial civilizations. The Pioneer plaque, attached to the Pioneer 10 and Pioneer 11 spacecraft,…
The shadow is a separated feature in the satellite images specially high resolution images. It may be looked as a problem when it causes a loss in the ground ray response to the shaded area, and may be, from other view, considered as an…
The economy and fate of extraterrestrial civilizations should depend on the abundance of gold and uranium, made in neutron star mergers.
We suggest an unified presentation to teach fundamental constants to graduate students, by introducing four lower limits to observed phenomena. The reduced Planck constant $\hbar$ is the lowest classically definable action. The inverse of…
The AutoCAD is one of the most famous Computer Aided Drawing programs with high and accurate specifications in the engineering design. It is highly qualified and contains many of the tools it needs in many engineering departments. A useful…
It is shown that orbital period ratios of successive secondaries in the Solar planetary and giant satellite systems and in exoplanetary systems are preferentially closer to irreducible fractions formed with Fibonacci numbers between 1 and 8…
This chapter presents a physical method to solve a maze using an electric circuit. The temperature increase due to Joule heating is observed with a thermal camera and the correct path is instantaneously enlightened. Various mazes are…
Traditional techniques used by navigators in the Marshall Islands include the use of wave patterns as influenced by reflection and refraction around islands. The dilep is one such pattern, apparently providing signals to guide a navigator…
Using information technology, humans have brought about the Information Revolution, which is changing the world faster and more profoundly than ever before. How is this possible? An answer is suggested by comments of James Moor, regarding…
The current preferred envisioned method for transmitting power to a space elevator climber is a laser/photovoltaic (PV) system. In this, a ground-based laser beam would transmit megawatts of optical power through the atmosphere to an…
Drag and lift coefficients of recent FIFA world cup balls are examined. We fit a novel functional form to drag coefficient curves and in the absence of empirical data provide estimates of lift coefficient behaviour via a consideration of…