Hi, there! Today some Kepler third law stuff plus cosmic speed calculations and formulae. Cosmic speed sounds cool…But first… From High School, you surely calculated how fast is A PLANET moving around the sun (or any star, indeed). To simplify … Continue reading

# Category Archives: Relativity

Have you ever asked yourself why there is no elephants or humans with atomic sizes? Have you ever asked why Earth is so big in comparison with atoms? Why nuclei are 10000 times smaller than atoms? I will be discussing … Continue reading

Time of Cosmic Voyages https://www.youtube.com/watch?v=xEdpSgz8KU4 This is a long post, despite not being a special post (remember I make one of those every 50 posts). What are we going to see here? A five part post! Part(I). A descriptive prelude. … Continue reading

Surprise! Twice in a day! Yes, I have much to tell yet, alive…Beyond the holographic principle, and things like gravity is Yang-Mills squared or that open strings squared are closed strings, we have had other important development in the theory … Continue reading

Hello, again! Yes, three consecutive days posting. A change! I missed blogging these months of nightmares. I hope these posts terminate your wait. The wait is over. And I can not wait too. Tempus fugit. Today, we will be discussing … Continue reading

Some weeks ago, the Riemann zeta function and the Riemann hypothesis were again in the news. Sir Michael Atiyah proposed a (wrong) failed proof of the Riemann hypothesis. My blog has an history of being controversial from time to time. … Continue reading

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

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