torsdag 20 juni 2013

Den lilla blå bleka punkten - igen

För oss som är någorlunda vetenskapsintresserade var Carl Sagans bok från 1994 "Pale blue dot" en väldigt fascinerande upplevelse. Han baserade den lilla dikten som gett namn åt boken på ett foto Voyager 1 tog 1990 av jorden sedd från det yttre av vårt solsystem. Nu har Cassini gjort samma sak, fast genom Saturnus ringar. I skrivande stund är förmodligen fotot på väg till jorden med ljusets hastighet, vilket på det stora avstånd som sonden befinner sej från oss gör att vi lekmän inte får se fotot i sin helhet förrän om ett par månader. Bilden måste redigeras och "tvättas" så att inga störande pixlar finns kvar. Dessutom måste UFOn och astronauter som ger varandra kaninöron tas bort från bilden.

Jag ser verkligen fram emot detta foto. Med lite tur kan vi få ett fantastiskt foto av samma slag som det som togs av Saturnus med solen bakom för några år sen. Synd att Carl Sagan inte får uppleva detta.

Cassinis hemsida hos NASA
Cassinis hemsida hos JPL

"Look again at that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there-on a mote of dust suspended in a sunbeam.

The Earth is a very small stage in a vast cosmic arena. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot.

Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.

The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.

It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known.

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