Neutron stars are the smallest in the universe, the remnants of supernovae. Their diameters are comparable to the size of a city like Chicago or Atlanta, but they are incredibly dense, with masses bigger than that of our sun. So think of the sun, compressed into a major city — and then think of two of them violently crashing into each other.
Archiv: gravitational waves
Everything you thought you knew about gravity is wrong
(02.08.2019)
“What are you talking about? Gravity is the force of attraction that makes things fall straight down.” But say it to a physicist, and the answer you’ll get is, “That’s right.”
I know, because those are the two answers I’ve been getting for the past few years, ever since I figured out that nobody knows what gravity is, and that just about nobody knows that nobody knows what gravity is. The exception is physicists: They know that nobody knows what gravity is, because they know that they don’t know what gravity is.
Missing Link: Zweifel trotz Nobelpreis – Streit über Graviationswellen-Messungen
LIGO und Virgo sind die ersten Experimente ihrer Art. Die Kollaboration umfasst mehrere tausend Physiker und damit fast jeden, der heute als Experte zu Graviationswellen durchgeht. Aus diesem Grund kann die LIGO/Virgo-Kollaboration es sich leisten, Kritik einfach zu ignorieren, auf ihre eigenen Analyseverfahren zu vertrauen und die Welt im Unklaren darüber zu lassen, genau wie sie eigentlich was analysiert.
Everything you thought you knew about gravity is wrong
(02.08.2019)
“What are you talking about? Gravity is the force of attraction that makes things fall straight down.” But say it to a physicist, and the answer you’ll get is, “That’s right.”
I know, because those are the two answers I’ve been getting for the past few years, ever since I figured out that nobody knows what gravity is, and that just about nobody knows that nobody knows what gravity is. The exception is physicists: They know that nobody knows what gravity is, because they know that they don’t know what gravity is.
Solving a century-long mystery: the origin of galactic cosmic rays
(04.04.2019)
The word ‘astronomy’ means the direct observations of extra-terrestrial objects. This definition is relevant to photons, neutrinos, and gravitational waves, i.e. massless, neutral and stable particles. But for cosmic ray electrons, protons, and nuclei, the term ‘astronomy’ is used with a certain reservation. Because of the deflections of electrically charged particles in the chaotic interstellar and intergalactic magnetic fields, the information about their original directions pointing to the sites of their production is lost. Instead, on the Earth, we detect an (almost) isotropic flux of cosmic rays contributed by a huge number of galactic and extragalactic sources.