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Cosmo Italiano Multiverso Universi Paralleli Universo

Il Principio Cosmologico Perfetto, o la Cosmologia dell’Ecclesiaste

Analizzando le conseguenze di un modello del Cosmo come collezione di un numero molto grande di Universi Paralleli (un “Multiverso”), scrivevo un anno e mezzo fa (sul mio blog in inglese):

[…] Abbiamo capito che il nostro pianeta non e’ al Centro dell’Universo. A parte la capacita’ di sostenere la vita, la Terra e’ un pianeta qualunque in orbita intorno a una stella mediocre in una Galassia non molto speciale, che appartiene a un Gruppo Locale ordinario legato a un Superammasso di Galassie come ce ne sono tanti, in un angolo dell’Universo che non e’ straordinario per niente.

Chiamiamolo il “Principio di Banalita’“, con noi almeno fin dai tempi di Copernico […]

In effetti, e’ davvero chiamato il “Principio Copernicano“.

Sarebbe gia’ importante cosi’, visto che significa che possiamo studiare la Fisica intorno a noi e ipotizzare che le Leggi che troviamo saranno le stesse per tutto l’Universo.

Ma c’e’ un altro passo che si puo’ fare e di solito non si fa: se solo espandiamo il Principio Copernicano perche’ includa anche il Tempo, allora l’ipotesi diviene che le stesse cose continuino a ri-capitare.

Questo e’ il cosiddetto Principio Cosmologico Perfetto, rigettato in passato perche’ considerato incompatibile con le innumerevoli prove in favore della teoria del Big Bang, che e’ un “inizio” e quindi un “tempo speciale” nell’Universo.

Questo modo di pensare, pero’, non e’ piu’ valido in un Cosmo-Multiverso, visto che il Big Bang diventa solo “uno dei tanti”.

E allora davvero l’Ecclesiaste sarebbe nel giusto:

1, 9: Quello che è stato è quel che sarà; quello che è stato fatto è quel che si farà; non c’è nulla di nuovo sotto il sole.

Categories
Cosmos English Universe

The Perfect Cosmological Principle, or The Cosmology of the Ecclesiastes

While analyzing the consequences of modelling the Cosmos as a collection of a huge number of Parallel Universes, I wrote some 18 months ago:

[…] We have learned that our planet is not the Center of the Universe. Apart from being able to harbor life, Earth is a run-of-the-mill planet in an average star in a not-so-special galaxy, belonging to an ordinary Local Group gravitationally linked to a Supergroup like many others, in a corner of the Universe that is not extraordinary at all

Let’s call that the “Banality Principle”, with us since at least since the times of Copernicus […]

As it happens, it is called the Copernican Principle indeed.

It is already quite important as it is, since it means we can investigate physics in our own vicinity and assume that the laws we observe are the same throughout the Universe.

There is another step usually missed though: if we just expand the Copernican Principle to include time, then the hypothesis is that then the same things will keep happening.

This is the so-called Perfect Cosmological Principle, rejected in the past because undermined by the overwhelming evidence for the Big Bang, a”Beginning” and therefore a “special Time” in the Universe.

However, this argument fails in in a Multiverse Cosmos, where the Big Bang is just one of many. If that is the case then, the Ecclesiastes may very well be right:

1,9: The thing that hath been, it is that which shall be; and that which is done is that which shall be done: and there is no new thing under the sun

Categories
AGW catastrophism Omniclimate Policy Science Skepticism

When Public Health Trumps Science…

…solutions could be far from optimal, because “right” but for the wrong reasons.

This lesson that could be applied to AGW can be learnt from the story of the “war on cholesterol”, as described (and denounced) by Gary Taubes in the pages of The New York Times:

Because medical authorities have always approached the cholesterol hypothesis as a public health issue, rather than as a scientific one, we’re repeatedly reminded that it shouldn’t be questioned. Heart attacks kill hundreds of thousands of Americans every year, statin therapy can save lives, and skepticism might be perceived as a reason to delay action. So let’s just trust our assumptions, get people to change their diets and put high-risk people on statins and other cholesterol-lowering drugs.

Science, however, suggests a different approach: test the hypothesis rigorously and see if it survives. If the evidence continues to challenge the role of cholesterol, then rethink it, without preconceptions, and consider what these other pathways in cardiovascular disease are implying about cause and prevention. A different hypothesis may turn out to fit the facts better, and one day help prevent considerably more deaths.

Well, at least we can state now: AGW is not a matter of science, but of public health. And the whole fixation on declaring that “the science is settled” makes a little bit more sense…