Even Einstein made mistakes

In fact he made lots of them. But there was one which even Mr Albert himself called "his greatest blunder". In 1917, looking at his newly forged theory of General Relativity, he realised the equations predicted that the universe should be either expanding or contracting. Einstein's world view made him unhappy about this, so he introduced a cosmological constant to counteract such movement. After all, everybody 'knew' that the universe was static. He defended this position for years, even though there was no physical or gravitational reason for such a mathematical constant to exist.

In 1929 astronomer Edwin Hubble observed that galaxies appear to be moving away from us, and the further away, the faster they receded. The universe was expanding and Einstein could have predicted it years before. He considered this to be his big mistake and the cosmological constant was dumped.

Interestingly, in more recent years, observations show the universe is not just expanding, but accelerating. This implies a force pushing empty space apart. Mathematically, it is strangely akin to Einstein's cosmological constant. Perhaps the old guy was onto something after all...

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Dynamic Einstein generator from hetemeel.com.