A computer chatted to itself in alarm as it noticed an airlock open and close itself for no apparent reason. This was because Reason was in fact out … - Douglas Adams

The Total Perspective Vortex derives its picture of the whole Universe on the principle of extrapolated matter analyses.
To explain — since every piece of matter in the Universe is in some way affected by every other piece of matter in the Universe, it is in theory possible to extrapolate the whole of creation — every sun, every planet, their orbits, their composition and their economic and social history from, say, one small piece of fairy cake.
The man who invented the Total Perspective Vortex did so basically in order to annoy his wife.
Trin Tragula — for that was his name — was a dreamer, a thinker, a speculative philosopher or, as his wife would have it, an idiot.
And she would nag him incessantly about the utterly inordinate amount of time he spent staring out into space, or mulling over the mechanics of safety pins, or doing spectrographic analyses of pieces of fairy cake.
“Have some sense of proportion!” she would say, sometimes as often as thirty-eight times in a single day.
And so he built the Total Perspective Vortex — just to show her.
And into one end he plugged the whole of reality as extrapolated from a piece of fairy cake, and into the other end he plugged his wife: so that when he turned it on she saw in one instant the whole infinity of creation and herself in relation to it.
To Trin Tragula’s horror, the shock completely annihilated her brain; but to his satisfaction he realized that he had proved conclusively that if life is going to exist in a Universe of this size, then the one thing it cannot afford to have is a sense of proportion.

I was created to fulfill a function and I failed in it. I negated my own existence.

"The deep roar of the ocean.

The break of waves on farther shores that thought can find.

The silent thunders of the deep.

And from among it, voices calling, and yet not voices, humming trillings, wordlings, and half-articulated songs of thought.

Greetings, waves of greetings, sliding back down into the inarticulate, words breaking together.

A crash of sorrow on the shores of Earth.

Waves of joy on — where? A world indescribably found, indescribably arrived at, indescribably wet, a song of water.

A fugue of voices now, clamoring explanations, of a disaster unavertable, a world to be destroyed, a surge of helplessness, a spasm of despair, a dying fall, again the break of words.

And then the fling of hope, the finding of a shadow Earth in the implications of enfolded time, submerged dimensions, the pull of parallels, the deep pull, the spin of will, the hurl and split of it, the fight. A new Earth pulled into replacement, the dolphins gone.

Then stunningly a single voice, quite clear.

"This bowl was brought to you by the Campaign to Save the Humans. We bid you farewell."

And then the sound of long, heavy, perfectly gray bodies rolling away into an unknown fathomless deep, quietly giggling."