Prior the recombination into atoms, the now visible matter of the universe consisted of electron-nucleus plasma. The nuclei in there were basically hydrogen (three fourth) and helium (one fourth). Their abundances were defined by the available number of protons … Continue reading
Supernova explosions are rather rare events so the last one seen by the naked eye in our galaxy was described by Johannes Kepler in 1604. For several months, that was the brightest star in the sky so one can … Continue reading
The simplest and the oldest way to measure distances to stars is the parallax method. This utilizes variation of the angle between a star and a benchmark direction as an observer changes its position in space, basically moving with … Continue reading
The speed of sound waves as well as the speed of light is not changed by the motion of a source of waves. For example, when a sound source moves towards a listener, each next vibration reaches the listener’s … Continue reading
Indeed, we can see stars and planets while particles of cosmic dust are only detectable since they change spectra of stars’ radiation reddening them. As light passes through interstellar cosmic dust, its particles absorb blue photons more than the … Continue reading
First of all, it was recently discovered that despite the temperature and matter density being cosmically low, chemical reactions at the surface of a dust particle can create organics that could be a cradle of life. Being glued up … Continue reading
It started with the fact that the ancient Greek scientist Hipparchus compiled a star catalog in the century II BC. He subdivided the stars into classes according to their brightness. Then, after three centuries, Ptolemy in his scientific treatise … Continue reading
How electrons began to remain in orbits In the early hot universe, free electrons were being captured by protons, forming hydrogen atoms. The photons, emitted in this process called recombination, took away the difference between the summary mass of free … Continue reading
Increasing the visible size keeping the same amount of light emitted When we look at a distant source of light that spreads in all directions, we see only a portion of the photons emitted by it. As the distance from … Continue reading
About how the pressure of the Fermi gas restrains from compression There are the reactions of nuclear fusion in the core of a star — of the formation of more heavy atomic nuclei, which is accompanied by the release of … Continue reading
Conversion of the protons of star into neutrons with the emission of neutrinos So-called supernova explosion occurs as a result of gravitational collapse of a star, completing its life cycle, if its weight exceeds a few solar masses (the Chandrasekhar … Continue reading
On searches for antimatter in space… The observed domination of protons, neutrons and electrons over their antiparticles means that our universe has got the so called baryon quantum number. This is composed of baryon numbers of each of nucleons. It … Continue reading
Passage of dark matter particles through substances without interacting… The dark matter makes up more than 80% of the matter of the universe. This does not almost radiate electromagnetic waves and manifests itself basically by its gravitational interaction. It may … Continue reading
How the decay of particles overtook that of antiparticles… It is observed that the number of baryons in the universe (protons and neutrons) exceeds the number of antibaryons at least ten thousand times. Such an asymmetry could arise in the … Continue reading