Australasian Science: Australia's authority on science since 1938

Infinity Equals Nothing

By Simon Grose

The work of Australia’s new Nobel Laureate challenges the semantics of the absolute.

The full text of this article can be purchased from Informit.

Not long after the team led by Prof Brian Schmidt and another group published the work that would win them the 2011 Nobel Prize for Physics (see p.36), another journalist and I shared a congenial lunch with Schmidt at Mt Stromlo Observatory. He talked us through the evidence that the expansion of the universe is accelerating, beguiling us by saying: “The universe is infinite and it is expanding”.

The notion that infinity could be getting bigger was an interesting excursion into relativity (not Einstein’s general version). Dictionary definitions of “infinity” have an absolute tenor to them, like “limitless time, space or distance” or “boundless distance”.

Go to a scientific dictionary and the definitions get mathematical but not necessarily less absolute, like “mathematical quantity that is larger than any fixed assignable quantity”, “the result of dividing any number by zero”, or even the mindbending “minus infinity – a quantity having a value that is less than any assignable value”.

While common dictionary definitions reflect the popular notion of infinity, for astrophysicists the universe defines infinity. Because it is expanding, at any one moment it has a boundary, so it is neither “boundless” nor “limitless”. But because the universe is all there is, it is at least a proxy infinity.

Until 1998, when the Nobel-winning research was published...

The full text of this article can be purchased from Informit.

Simon Grose is a Director of Science Media (sciencemedia.com.au).