Some physicists believe that the universe erupted from a single black hole some 13.8 billion years ago.
While the claim that there was a £38bn 'black hole' in the Ministry of Defence's finances when the Coalition took office - repeated on last night's Question Time by Conservative MP Nadhim Zahawi - isn't quite as old as that, it is one that has enjoyed a relatively long shelf life by political standards.
Whether or not it deserves that longevity is more dubious. When we first looked at the issue in 2011 we found no published evidence in support of it. Nor was any forthcoming when we sent a Freedom of Information request to the department. The most we were told was that:
"£20.5 billion of overspending was due to equipment/procurement with a further £17.7 billion funding gap on other resources, including personnel."
When the National Audit Office looked at the 'black hole' it found it was less supermassive than had been claimed, suggesting that the size of the budget shortfall the Coalition inherited would be £6bn over a decade (assuming that the Ministry's budget was protected in real terms). Writers in the Telegraph and Daily Mail have also taken issue with the £38bn figure, with the former calling it a "big lie".
If politicians are to continue to use the claim, a little light might therefore need to be shed on this particular black hole.