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Gravitational Waves

In search of a previously unobserved part of Einstein’s theory.

One of our 2015 ‘Numbers of the Year’ predictions might have come to pass. There is great excitement over rumours that one of the predictions Einstein made in his theory of General Relativity has finally been observed. But it’s not the first time it’s been reported that ‘gravitational waves’ have been discovered, and the last time proved to be an equipment test.

What is the total number of possible tweets that could be created from 140 characters? In a recent programme Professor John Allen-Paulos told us that when you take into account all of the symbols available, the total number of possible tweets is Googol^2.8 (which is a 1 followed by 280 zeros.) But has he missed some options?

(Image: A photographer looks at the sky at night to see the annual Geminid meteor shower on the Elva Hill, in Maira Valley, near Cuneo, northern Italy on December 12, 2015. Credit: AFP / Getty Images)

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9 minutes

Last on

Mon 18 Jan 2016 14:50GMT

Broadcasts

  • Fri 15 Jan 2016 20:50GMT
  • Fri 15 Jan 2016 21:50GMT
  • Mon 18 Jan 2016 02:50GMT
  • Mon 18 Jan 2016 03:50GMT
  • Mon 18 Jan 2016 04:50GMT
  • Mon 18 Jan 2016 05:50GMT
  • Mon 18 Jan 2016 07:50GMT
  • Mon 18 Jan 2016 13:50GMT
  • Mon 18 Jan 2016 14:50GMT

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