Because the Heart of Gold spaceship is powered by the “Infinite Improbability Drive,” it naturally represents the strange and “improbable” things that happen in life and, of course, the novel itself. As Trillian and Zaphod fly through space in this aircraft, they try to calculate the measures of improbability that fuel the ship, but they find themselves unable to do so because they eventually arrive at an “irrational number that only has a conventional meaning in Improbability Physics.” In this way, the notion of improbability in the novel remains abstract and unfathomable. In turn, readers’ inability to fully grasp the logic underlying this central plot point forces them to proceed through the story with a certain suspension of disbelief. In this way, the Heart of Gold comes to represent not only improbability, but also the idea of accepting uncertainty.
The Heart of Gold Quotes in The Hitchhiker’s Guide to the Galaxy
The principle of generating small amounts of finite improbability by simply hooking the logic circuits of a Bambleweeny 57 Sub-Meson Brain to an atomic vector plotter suspended in a strong Brownian Motion producer (say a nice hot cup of tea) were of course well understood […]. [One] thing [scientists] couldn’t stand was the perpetual failure they encountered in trying to construct a machine which could generate the infinite improbability field needed to flip a spaceship across the mind-paralyzing distances between the farthest stars, and in the end they grumpily announced that such a machine was virtually impossible.
Then, one day, a student […] found himself reasoning this way:
If, he thought to himself, such a machine is a virtual impossibility, then it must logically be a finite improbability. So all I have to do in order to make one is to work out exactly how improbable it is, feed that figure into the finite improbability generator, give it a fresh cup of really hot tea…and turn it on!
“Can we work out,” said Zaphod, “from their point of view what the Improbability of their rescue was?”
“Yes, that’s a constant,” said Trillian, “two to the power of two hundred and seventy-six thousand, seven hundred and nine to one against.”
“That’s high. They’re two lucky lucky guys.”
“But relative to what we were doing when the ship picked them up…”
Trillian punched up the figures. They showed two-to-the-power-of-Infinity-minus-one to one against (an irrational number that only has a conventional meaning in Improbability Physics).
The Heart of Gold fled on silently through the night of space, now on conventional photon drive. Its crew of four were ill at ease knowing that they had been brought together not of their own volition or by simple coincidence, but by some curious perversion of physics—as if relationships between people were susceptible to the same laws that governed the relationships between atoms and molecules.
As the ship’s artificial night closed in they were each grateful to retire to separate cabins and try to rationalize their thoughts.
This is a complete record of [the sperm whale’s] thought from the moment it began its life till the moment it ended it.
Ah…! What’s happening? it thought.
Er, excuse me, who am I?
Why am I here? What’s my purpose in life?
What do I mean by who am I?
Calm down, get a grip now…oh! this is an interesting sensation, what is it? It’s a sort of…yawning, tingling sensation in my…my…well, I suppose I’d better start finding names for things if I want to make any headway in what for the sake of what I shall call an argument I shall call the world, so let’s call it my stomach.
[…] What’s this thing? This…let’s call it a tail—yeah, tail. Hey! I can really thrash it about pretty good, can’t I? Wow! Wow! That feels great! Doesn’t seem to achieve very much but I’ll probably find out what it’s for later on. Now, have I built up any coherent picture of things yet?