Demetris Nicolaides

π is an irrational number. Irrational literally means that there is no ratio, none at all, that can provide an exact numerical value for pi. Putting it differently, there is literally not enough paper in the entire universe to write pi completely! #piDay2023

"Give me a place to stand on, and I will move the Earth."—Archimedes #Physics #Science

OK, Tree: 1. Material = wood (or some mixture of earth water air fire) 2. Form/al = that it is a tree not a table or a person 3. Efficient (agent of tree’s change) = sun, water, soil, gardener 4. Final/Telos = to make shade or olives Excerpt from Aristotle's Physics book II.3

The first image of the supermassive #BlackHole (of mass equal to four million suns) found at the center of our #MilkyWay galaxy was published today. It was the result of 5 years rigorous work, of collecting and fitting different telescope images together, like a jigsaw puzzle.

March 8 - #InternationalWomensDay Astronomer Henrietta Leavitt (1868-1921) discovered cosmic beacons—stars whose brightness fluctuates periodically. Her work was seminal. It was used by Hubble to measure galactic distances, speeds, and ultimately the expansion of the #universe.

I’m happy to announce that the #Greek edition of my latest #book, "In Search of a Theory of Everything" ("Αναζητώντας μια θεωρία των πάντων"), has just been published.

#Space is pushing me down—that’s how #gravity works in #Einstein’s general #relativity. But the electromagnetic #force (between the electrons of the #atoms of my hands and those of the atoms of the tree) is pushing me up. The result: a scientifically spirited balancing act.

A curious visitor (a Hitchcock #bird) flew on my movable office this morning to ask about aerodynamics. I knew the #Theory well, but my winged friend, the #practice—and incidentally, knew everything about #dinosaurs.

Astronomers are kind of archeologists: the farther out they look the more back in #TIME they see. #NASA’s #Webb Space Telescope, to be launched on Dec 25, can see how the baby universe looked like a mere 0.3 billion years after its “birth” (the big bang).

In the expanding #universe galaxies are not moving away from each other through #Space. Rather, they are being moved by space—they are being carried away from each other by the expanding space.

By solving #Einstein’s eqs of general relativity, Georges Lemaître, a Belgian Catholic priest and physicist, was the first to conceive the idea of the #BigBangTheory—of how the universe expanded from a primordial dense state—only he called the concept "the day without yesterday."

Tides are caused mainly by #moon's gravity (but also of the sun's), and #Earth's rotation. The ancients knew the moon played a role in tide formation because they related the daily delay in the rising of the moon with the same daily delay in the formation of the tides.

Newborn #stars began forming for the first time, and almost simultaneously, from matter pulled together by gravity about a billion years after the #BIGBANG. The dark sky, if we lived then to see it, would suddenly look like fireworks of stars.

Two awe-inspiring images, #MilkyWay's center & #Raphael’s The School of Athens, melted harmoniously on the cover of my recent book. A philosophical contemplation of cutting-edge #Physics, In Search of a Theory of Everything offers readers groundbreaking insight into the unknown.

The increasing #entropy of the #UNIVERSE is not necessarily a bad thing.

A cosmic straight line that geometer Euclid would have enjoyed viewing, I’m sure.

The m, in #E=mc^2, depends on the speed (v) of an object: the faster v is, the bigger m becomes. And as v approaches c, m approaches infinity. But an infinite mass requires infinite force—which doesn’t exist—to increase its speed to c; thus, c is unattainable by material objects.

The alchemists used to mix and heat different substances in hopes to make new ones (such as medicines) or reproduce existing ones (such as gold). They couldn’t make gold but massive stars can--via nuclear fusion reactions--as they become #supernova.