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L'anello di Caronte (1990)

di Roger MacBride Allen

Altri autori: Vedi la sezione altri autori.

Serie: La caccia alla Terra (1)

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373468,532 (4.03)4
Larry Chao, experimenting with gravity control and the manufacture of black holes on a research station on Pluto, is dumbfounded when his instruments show planet Earth to have disappeared. But the horror has only just begun. Could the entire Solar System be about to disappear?
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I read this in 1995 and I thought it’d be a good time to re-read it. Big frigging mistake…the only thing I remembered from back then was what happened in the following quote:

“ ‘T minus five, four, three, two, one, zero”. We are getting the first…‘ In the middle of screen three, Earth flashed out of existence. The Moon hung in the telescope view. Alone. […] Everything. Larry sat, motionless, his heart pounding. They would search for an answer, a malfunction in their gear. But Larry knew. No evidence, no explanation, but he knew. Somehow the beam, the harmless gravity-wave beam, so weakened at that range it could have squashed a fly or mussed a child’s hair…somehow it had vaporized the Earth.”

Good grief! Larry Chao although young is supposed to be a top-notch physicist!

It's “gravitational” waves ffs Alec! Not gravity waves. If I want to detect gravity waves I can visit the beach. Will some grave dud want to surf them? I don’t know, we have clouds out there, we have solar winds, and we may have gravitational waves, oddly enough many things that are seemingly mirrored here on earth. Anyway, if there where currents we cannot see, perhaps we could make use of them in the future by traveling on them to reach other parts of the universe, at least they would provide an alternative way of getting around instead of the predicted supposed ‘wormholes’. Waves of water need water. Waves sound need air. Waves of empty space need ... space that isn't empty. When people figure out what empty space is made of is when I'll consider the rationale of gravity waves. It could be filled with dark matter and energy (*scoffing*). We also have currents in the sea, we have air currents, we don’t know what space is, so who’s to say there isn’t such a thing as space currents (have you ever read Asimov's "The Currents of Space"?), after all the galaxy must be stirring things up if it is revolving, along with the planets and everything else within it. Effinger plays with the ability to produce a “gravity” directional beam. The gravitational waves are in the order of 100,000th the width of a proton. That degree of smallness is constantly overwhelmed on earth by constant different waves from other sources, such as seismic activity and passing freight trains ten miles from the detector. It takes a lot of concentrated effort, of listening very, very carefully, to isolate the shifting lengths caused by the gravitational waves...

The reason why gravity is considered weak is because the magnitude of the constant in GR (or even Newtonian Gravitation) is tiny compared to those in the other forces. But, all other forces fall off far quicker with distance than gravity - except the electromagnetic force - so, after any real distance, everything except EM and gravity is effectively zero.

EM will be easier discussed using an example. Consider an electron and proton. Because of those constants, the two particles couple far more strongly to the electric field than the gravitational field (speaking in Weinberg terms now - see comment below). So the attraction between them is dominated by the electric field.

But when you start to talk about galactic scales, you have to remember two things. First, there's no negative mass (as far as we know), so all the matter in the galaxies create an attractive force. There's a hell of a lot of mass attracting other galaxies - even over vast distances. Second, there are negative electric charges so, on average, a galaxy is neutrally charged - and then there's no net attractive electric force between it and another galaxy. Hence gravity is still far weaker on those scales than the electric field in absolute terms between two individual (oppositely charged) particles - but there's a lot more matter interacting than there is net charge difference, and so gravity now dominates.

(my copy bought at Xenon Shopping - Tema Bookshop which no longer exists...)

That is where quantum mechanics comes in. When two entangled particles are in question, either the two entangled particles cannot exist or the so called space that is separating them cannot exist. Those who believe in materialism or realism cannot explain space. However QM has already debunked realism and materialism. They are trying to confirm something, because try as they might, that can't debunk QM. General relativity is pretty much confirmed and QM is rock solid but the two are incompatible with each other and it is driving the materialists crazy. It shouldn't. If they just drop the realism and materialism and accept that there perceptions are ruled by QM and GR, it wouldn't matter because perception isn't reality. However they are so sure that their perception is their reality, they have to prove that either GR is wrong or QM is wrong, so the hunt for these waves.

Gravity waves manifests itself through ripples of space-time, like wind manifesting itself through ripples on a pond. But space-time is very rigid and inflexible, so only gigantic outburst of energy can cause ripples in space-time we are able to measure.

Think of a pond made from syrup, only a very strong wind will cause ripples we can see.

They don't overcome gravity in black holes, where the force is rather strong.

By the way the magnetic force between two objects follows the inverse cube law, whereas the gravitational force between two objects follows the inverse square law. At longer distances, gravity is a much stronger force than magnetism. Clumps of galaxies operate in a way that shows they respond to the mutual gravitational attraction. So, while I may be able to lift my eyelids every morning, for some reason I can't jump off this planet, where I am inexorably held by this weakest of forces by orders of magnitude.

While an individual gravitational wave may be weak, there are a hell of a lot of them. ( )
  antao | Aug 21, 2021 |
I took this book up after finishing another series by the same author. I liked the other series, obviously, and while this is different, it is interesting to me.
This story involves a violent conflict between two cultures. However, one participant in the struggle does not realize there is a battle going on.
This book is heavily immersed in space science. Gravity and other astrophysics terms are mentioned on every page.
Readers who are likely to appreciate this book are happy with hard science books. There are several main characters who are based on Earth, the Moon, Mars and Pluto. The POV changes in each chapter.
I found the book very entertaining. I was in a mood for this type of book with cultural conflict and hard science. ( )
  superant | Jul 4, 2014 |
Experiments in gravity manipulation wake up a dormant race of robotic aliens around the solar system, with their main control unit buried deep below the lunar surface. In an instant the Earth disappears and the invaders begin to dismantle the planets to create a Dyson Sphere. Once I started reading The Ring of Charon I couldn’t put it down. This book is a perfect look at how far our technology can take us, and how dangerous technology can become. While machines attacking humanity isn’t a new concept in science fiction, this novel takes it to a new and epic level. ( )
1 vota cbradley | Jul 15, 2009 |
Ich habe ein Buch bei BookCrossing.com registriert!
http://www.BookCrossing.com/journal/14035419
  Stonerrockfan | Oct 8, 2023 |
Mostra 4 di 4
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» Aggiungi altri autori (3 potenziali)

Nome dell'autoreRuoloTipo di autoreOpera?Stato
Allen, Roger MacBrideautore primariotutte le edizioniconfermato
Haag, JohnNarratoreautore secondarioalcune edizioniconfermato
Pavlík, JanTraduttoreautore secondarioalcune edizioniconfermato
Vallejo, BorisImmagine di copertinaautore secondarioalcune edizioniconfermato
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To Charles Sheffield -
friend, colleague, and the sanest man in this business
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One million gravities, and climbing.
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Two thoughts echoed in his head, one incredible, the other simply insane.
Larry Chao had destroyed the Earth.
And somehow, Simon Raphael was going to see to it that it came out of Larry's pay.
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Larry Chao, experimenting with gravity control and the manufacture of black holes on a research station on Pluto, is dumbfounded when his instruments show planet Earth to have disappeared. But the horror has only just begun. Could the entire Solar System be about to disappear?

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