Leonida Valeri

[Art @Art93539166]

Sailing

[Curiosity @CuriosityonX]

🚨: NASA confirms Voyager 1 will reach one light-day from Earth in 2026, after travelling for 48 years.

[Earth @earthcurated]

Witness a stunning sky show on February 28, 2026, during the early morning hours.

Six planets will line up together, creating a rare and beautiful sight for stargazers ✨🌌

[All day Astronomy @forallcurious]

🚨: February 2026 is officially being dubbed a "Perfect Month" because there are four exact weeks that start on a Sunday and ends on a Saturday, fitting perfectly into four complete rows on a standard calendar.

This hasn't happened since 2015, and won't again until 2037.

[Photos Nathalie @Paysages_lands]

Sunset 🧡

[NASA @NASA]

"The Eagle has landed."

On July 20, 1969 — 55 years ago today — #Apollo11 touched down on the Moon.

[Physics In History @PhysInHistory]

1950: A. Einstein's Letter to Erwin Schrödinger where he talks about the famous Schrödinger's cat thought experiment ✉️

Dear Schrödinger,
You are the only contemporary physicist, besides Laue, who sees that one cannot get around the assumption of reality—if only one is honest. Most of them simply do not see what sort of risky game they are playing with reality—reality as something independent of what is experimentally established. They somehow believe that the quantum theory provides a description of reality, and even a complete description; this interpretation is, however, refuted, most elegantly by your system of radioactive atom + Geiger counter + amplifier + charge of gun powder + cat in a box, in which the ψ-function of the system contains the cat both alive and blown to bits. Is the state of the cat to be created only when a physicist investigates the situation at some definite time? Nobody really doubts that the presence or absence of the cat is something independent of the act of observation. But then the description by means of the ψ-function is certainly incomplete, and there must be a more complete description. If one wants to consider the quantum theory as final (in principle), then one must believe that a more complete description would be useless because there would be no laws for it. If that were so then physics could only claim the interest of shopkeepers and engineers; the whole thing would be a wretched bungle.

You are completely right to emphasize that the complete description cannot be built on the concept of acceleration, nor, it seems to me, can it be built on the particle concept. Only one of the tools of our trade remains—the field concept, but God knows whether this will stand firm. I think it is worthwhile to hold on to this, i.e. the continuum, as long as one has no really sound arguments against it.

But it seems certain to me that the fundamentally statistical character of the theory is simply a consequence of the incompleteness of the description. This says nothing about the deterministic character of the theory; that is a thoroughly nebulous concept anyway, so long as one does not know how much has to be given in order to determine the initial state.

It is rather rough to see that we are still in the stage of our swaddling clothes, and it is not surprising that the fellows struggle against admitting it.

Best regards!

Yours,
A. Einstein

[Leonida Valeri @LeonidaValeri]

https://t.co/68DCDWsuhI

[Leonida Valeri @LeonidaValeri]

https://t.co/gRbGLUqQrf

[Leonida Valeri @LeonidaValeri]

https://t.co/2Mojg2NpCN

[Physics In History @PhysInHistory]

Today's date is quite interesting, numerically. ✍️

[Physics In History @PhysInHistory]

Einstein’s 1950 Letter to Erwin Schrödinger
https://t.co/L0gXl7OUDx

[Prof. Feynman @ProfFeynman]

If you cannot explain something in simple terms, you don't understand it.

[Asteroids and Comets @AsteroidMisses]

asteroid (2016 HV3) missed earth by 28 lunar distances: diameter ~413 m, velocity 15 km/s, energy ~3 gigatons. https://t.co/pCiN3WRmpN

[Asteroids and Comets @AsteroidMisses]

asteroid (2004 UU1) missed earth by 11 lunar distances: diameter ~242 m, velocity 17 km/s, energy ~806 megatons. https://t.co/h26KRcDuah

[raicultura @RaiCultura]

Il #23agosto 1868 nasce Edgar Lee Masters. Dopo aver tentato invano i suoi primi esperimenti poetici, ispirato dalla lettura di “Elegia scritta in un cimitero di campagna” di Thomas Grey e degli epigrammi greci dell’Antologia Palatina, scrive “L’antologia di Spoon River”.

[NSFVoyager2 @NSFVoyager2]

20 August 1977 - launch date for Voyager 2. I was launched 46 years ago today. I have now been in service for 16,802 days, the longest running space hardware.

[Leonida Valeri @LeonidaValeri]

https://t.co/KKAqSQy1wq

[Leonida Valeri @LeonidaValeri]

https://t.co/ho6mKAA7Zw

[raicultura @RaiCultura]

Era il #7agosto 1420 quando Brunelleschi iniziava i lavori per la cupola del Duomo, riscoprendo i modelli costruttivi dell'età classica e mutando l'organizzazione del cantiere, con la separazione dei ruoli del progettista e del costruttore. L’opera fu poi completata nel 1471.