These will be corrected in future printings of the book.


Page: 3

Erratum: “[Quasars] are powered by massive black holes at the centres of galaxies, into which entire stars are falling – up to several per day for a large quasar – shredded by tidal effects as they spiral in.”

Correction: That should read “They are powered by massive black holes at the centres of galaxies, into which interstellar gas is falling. For the brightest quasars, enough mass to make an ordinary star falls in every few days. Occasionally, entire stars are engulfed, shredded by tidal effects as they spiral in.”

Thanks to: Kevin Schawinski for pointing out this error.


Page: 46

Erratum: “Moreover, we are an uncommon form of ordinary matter. The commonest form is plasma (atoms dissociated into their electrically charged components), which typically emits bright, visible light because it is in stars, which are rather hot.”

Correction: In fact most of the plasma in the universe is in the intergalactic and interstellar media. Only a small proportion is in stars. So this should read “Moreover, we are an uncommon form of ordinary matter. The commonest form is plasma – atoms dissociated into their electrically charged components. Stars are made of it, and are dense enough for those components continually to recombine, emitting bright visible light, and to be knocked apart again because of the intense heat.”.

Thanks to: Gendou for pointing out this error.


Pages: 62-3

Erratum: “a typical child born in the United States today is more likely to die as a result of an astronomical event than a car accident”

Correction: That should read “an aeroplane accident”. A true comparison with aeroplane accidents appears on p207, using slightly different statistics.

Note: The probability of dying in a car accident is at least 12 times and perhaps as much as 100 times as great as that of dying from an astronomical event. As road safety improves, this will presumably continue to fall rapidly during the lifetimes of children born today — but then, so will the probability of dying from an astronomical event.

Thanks to: Josh Jordan for pointing out this error.


Pages: 66

Erratum: “Nicholas de Condorcet”

Correction: Should be “Nicolas de Condorcet”.

Thanks to: Bastien Rokk for pointing out this error.


Pages: 184-5

Erratum: “Hence also – as the mathematician Kurt Gödel had discovered using a different approach to Hilbert’s challenge – almost all mathematical truths have no proofs. They are unprovable truths.

It also follows that almost all mathematical statements are undecidable: there is no proof that they are true, and no proof that they are false.”

Correction: Oh dear. That’s badly garbled. Gödel did discover unprovable mathematical truths and undecidable mathematical statements, and there are infinitely many of them. That ‘almost all’ mathematical truths have no proofs is false. (Truth is a property of propositions, which can be represented as strings of characters.) What is true is that almost all mathematical facts (properties of abstract objects) cannot be stated, let alone proved, but that has nothing to do with Gödel’s theorem. It’s just that the number of such facts is a much larger infinity than the number of strings of characters.

Thanks to: Jan Krajicek and Scott Aaronson for pointing out this error.


Page: 221
Erratum: “For if any of those earlier experiments in optimism had succeeded, our species would be exploring the stars by now, and you and I would be immortal.”

Correction: In the overwhelming majority of universes in which they succeeded, no one remotely resembling you or me exists. It would more accurately read “the likes of you and me would not exist”, but that’s not very satisfactory either.

Thanks to: Matjaž Leonardis for pointing out this error.


Page: 405

Erratum: “parrot’s vocal cords”

Correction: Parrots don’t have vocal cords. It should read “parrots’ equivalent of vocal cords”.