Black holes and other astrophysical objects are true monsters. Some interesting tools from web pages to learn about these free catalogues: WATCHDOG and BLACKCAT. Also, the blackhole.org page and the sounds of spacetime for gravitational waves are suitable for you. … Continue reading

# Category Archives: Relativity

Some time ago, Zeldovich derived the following expression for the vacuum energy density: (1) or equivalently, with a link to Caianiello’s maximal acceleration formula, (2) Remark: the above vacuum energy density is related to the cosmological constant via … Continue reading

Newton’s gravity reads: In extra dimensions, , , it reads For extra dimensions, if their size are much smaller than considered distances, , then by matching So, gravitational is weak in our … Continue reading

From the Michelson-Morley experiment, some clever experimentalist tried to derive the light speed through the “ether wind”. It is very similar to a river being rowing by sailors in a boat. The times for journey “upstream” and “downstream” are: … Continue reading

Absement is generally defined as (1) We can even integrate the absement -times (position integrated -times) to get (2) i.e. (3) with dimensions of and units of . However, if time is multidimensional, and the time vector … Continue reading

Happy New Year 2018, dear followers! Today is a special blog post! My 200th post! After a really terrible 2017 from the viewpoint of family, health and productivity, I wish this one will be a great year for me and … Continue reading

If you believe in both, relativity AND quantum mechanics, something that I presume you do due to experimental support, you are driven to admit that the speed of light is the maximal velocity (at least, the maximal 1-speed, in single … Continue reading

The second and last blog post in this thread is about the analogies between black holes and condensed matter theory, in particular with phases of matter like fluids or superconductors. That is what explains my previous picture…And this post! Are … Continue reading

Hi, doctorish ladies and gentlemen! I am going to teach some bits of black hole today. For the simplest static (non-rotatory) black hole, the whole space-time is fully specified by mass , and some constants, like . The critical … Continue reading

Hello, metriplectic followers and friends! I have often written about Stoney units or Planck units in this blog. Indeed, I have a complete thread about systems of units. For Stoney and Planck units, you get some basic units of S.I. … Continue reading