Asked by: Ray Pravel, Reading
Sceptics have a simple answer: intelligent aliens have not contacted us because they don’t exist. But others argue that, given the enormous size of the Universe, it’s pretty much guaranteed that intelligent life must be out there somewhere.
Maybe so, but there’s no guarantee it exists nearby, or has learned of our existence through the ‘leakage’ of our TV and radio signals into space. So unless they’ve found a way of travelling far faster than the speed of light, we might be in for a long wait until they get here. Another explanation for what’s been called the Great Silence is that as soon as aliens attempt to make themselves known to others, they are attacked by a race of marauding ETs.
Alternatively, perhaps they’re already here and we’re just too stupid to realise.