Life, the Universe and Everything (Hitchhiker's Guide to the Galaxy #3)

Is there ... any experiment that could distinguish between ... the MWI and the Copenhagen interpretation using currently available technology? The author can only think of one: a form of quantum suicide in a spirit similar to so-called quantum roulette. It requires quite a dedicated experimentalist, since it is amounts to an iterated and faster version of Schrödinger's cat experiment with you as the cat.

The apparatus is a "quantum gun" which each time its trigger is pulled measures the z-spin of a particle. It is connected to a machine gun that fires a single bullet if the result is "down" and merely makes an audible click if the result is "up". The details of the trigger mechanism are irrelevant (an experiment with photons and a half-silvered mirror would probably be cheaper to implement) as long as the timescale between the quantum bit generation and the actual firing is much shorter than that characteristic of human perception, say 0.01 seconds. The experimenter first places a sand bag in front of the gun and tells her assistant to pull the trigger ten times. [Everyone] agrees that the "shut-up-and-calculate" prescription applies here, and predict that she will hear a seemingly random sequence of shots and duds such as "bang-click-bang-bang-bang-click-clickbang-click-click." She now instructs her assistant to pull the trigger ten more times and places her head in front of the gun barrel. This time the shut-up-and-calculate recipe is inapplicable, since probabilities have no meaning for an observer in the dead state, and the contenders will differ in their predictions. In interpretations where there is an explicit non-unitary collapse, she will be either dead or alive after the first trigger event, so she should expect to perceive perhaps a click or two (if she is moderately lucky), then "game over", nothing at all.

In the MWI, on the other hand, the state after the first trigger event is [...] Since there is exactly one observer having perceptions both before and after the trigger event, and since it occurred too fast to notice, the MWI prediction is that [the experimenter] will hear "click" with 100% certainty. When her assistant has completed his unenviable assignment, she will have heard ten clicks, and concluded that collapse interpretations of quantum mechanics are ruled out at a confidence level of 99.9%. If she wants to rule them out at "ten sigma", she need merely increase n by continuing the experiment a while longer. Occasionally, to verify that the apparatus is working, she can move her head away from the gun and suddenly hear it going off intermittently.

Note, however, that almost all terms in the final superposition will have her assistant perceiving that he has killed his boss. Many physicists would undoubtedly rejoice if an omniscient genie appeared at their death bed, and as a reward for life-long curiosity granted them the answer to a physics question of their choice. But would they be as happy if the genie forbade them from telling anybody else? Perhaps the greatest irony of quantum mechanics is that if the MWI is correct, then the situation is quite analogous if, once you feel ready to die, you repeatedly attempt quantum suicide: you will experimentally convince yourself that the MWI is correct, but you can never convince anyone else!

- Noi non siamo ossessionati da nessuna mania, capite - continuò Ford.
- ...
- Ed è proprio questo il fattore decisivo: l'ossessione. Non potremo mai vincere contro dei maniaci. Loro hanno la fissazione da soddisfare, noi no. E' quindi destino che vincano loro.
- Anch'io ho le mie fissazioni, i miei interessi – disse Slartibartfast con la voce che gli tremava in parte per il risentimento, in parte anche per il dubbio.
- Ah si? Quali?
- Bé – disse il vecchio - m'interessa la vita, m'interessa l'U

- Noi non siamo ossessionati da nessuna mania, capite - continuò Ford.
- ...
- Ed è proprio questo il fattore decisivo: l'ossessione. Non potremo mai vincere contro dei maniaci. Loro hanno la fissazione da soddisfare, noi no. E' quindi destino che vincano loro.
- Anch'io ho le mie fissazioni, i miei interessi – disse Slartibartfast con la voce che gli tremava in parte per il risentimento, in parte anche per il dubbio.
- Ah si? Quali?
- Bé – disse il vecchio - m'interessa la vita, m'interessa l'Universo. Tutto, direi. I fiordi.
- Morireste per loro?
- Per i fiordi?- chiese Slartibartfast, battendo gli occhi per lo stupore - No.
- Ecco, visto?

Sarò io che non l'ho cap

Sarò io che non l'ho capito, ma non l'ho apprezzato come i due precedenti.
L'ironia, le situazioni assurde e tutte le altre caratteristiche che mi avevano fatto adorare i precedenti volumi della saga ci sono tutti, ma questa volta la trama era troppo assurda, con troppo nonsense; ed ad un certo punto mi sono perso, non capivo come si fosse arrivati ad una certa situazione. Probabilmente questo ha precluso il farmi capire il libro.
Però fa ridere. E questo giustifica da solo le tre stelline...

Paradossalmente, della Domanda (con la D maiuscola), ovvero la Domanda sulla Vita, l'Universo e tutto Quanto-la cui risposta, come certamente saprete se avete letto La Guida Galattica per gli Autostoppisti, è 42-non si parla che alla fine del libro, quindi non capisco il perché di tal titolo per il libro.

staremo a vedere che succederà nel prossimo libro

As such this novel feels a little strained at times in bringing all the original Hitchhiker's cast back for a third outing, with Arthur Dent and Ford Prefect's idyllic prehistoric life at the end of The Restaurant at the End of the Universe transformed into a nightmare they can be rescued from, and Marvin having his death in the previous book undone. By far the biggest change though is Slartifartbast, who has changed from an eccentric planet designer into the main plot-driver of the book, essentially taking over the Doctor's role as would be saviour of the universe and guardian of the timelines, with his new background in the Campaign For Real Time replacing the role of Doctor Who's Time Lords.

However, the odd strained moments are more than offset but the typically brilliant concepts on display - including the Hitchhiker's art of flying by throwing oneself at the ground and missing, Slartifartbast's Bistromathematical spaceship, and the re-acquaintance of the sentient bowl of petunias from Hitchhikers Guide to the Galaxy that results in Arthur Dent glimpsing his own future.

Not quite up to the standard of the first two books in the series, Life, the Universe and Everything is nevertheless clever enough and funny enough to be essential for fans of the earlier novels.

Another hilarious book in The Hitchhiker's Guide to the Galaxy series. In this book, Arthur and Ford get off prehistoric Earth and join forces with Slartibartfast to save the universe from the whimsical inhabitants of Krikkit, who want to be left alone. This volume had a very coherent plot, and I was actually extremely surprised at some of the turns it took.

My only complaint about the book was that it takes a bit for the plot to get moving. The beginning of the novel is mostly Arthur saying, "Wh

Another hilarious book in The Hitchhiker's Guide to the Galaxy series. In this book, Arthur and Ford get off prehistoric Earth and join forces with Slartibartfast to save the universe from the whimsical inhabitants of Krikkit, who want to be left alone. This volume had a very coherent plot, and I was actually extremely surprised at some of the turns it took.

My only complaint about the book was that it takes a bit for the plot to get moving. The beginning of the novel is mostly Arthur saying, "What," which while very funny did make the beginning a bit slower than the previous two books. The jokes and absurdity are still hilarious and laugh out loud worthy. Trillian is given new purpose, and Zaphod new depths...kind of. Ford is increasingly annoyed with the whole business, and Arthur discovers a new talent. New characters are introduced that I expected to be for comedic value only, but who actually contributed to the plot, which made it twice as good. In short, keep reading the series. It's still utterly brilliant.