In 5 billion years, the expansion of the universe will have progressed to the point where all other galaxies will have receded beyond detection.  Indeed, they will be receding faster than the speed of light, so detection will be impossible.  Future civilizations will discover science and all its laws, and never know about other galaxies or the cosmic background radiation.  They will inevitably come to the wrong conclusion about the universe……We live in a special time, the only time, where we can observationally verify that we live in a special time.

– Lawrence M. Krauss

Just imagine – a day when the skies are completely black at night and no matter how advanced technology gets (if classical physics is right and light speed is the max), they will never know anything about other stars or galaxies. The only evidence that they ever existed would be old stories. Mind blowing stuff.

By the way, I’ve heard a question in response to this quote basically wondering how the galaxies can be receding faster than light speed if light speed is the maximum. The reason is because the receding of galaxies is not “physical” travel through space, but rather it is the expansion of the fabric of space-time. Those familiar with science will understand this. If it helps, imagine two dots on the surface of a balloon. As you inflate the balloon, the two dots move farther apart because the surface of the balloon is expanding, but their physical locations on the balloon is still the “same” (i.e. the dots aren’t moving along the balloon, they’re still where you put them – it’s the surface of the balloon that’s stretching).

Advertisements