Arguments for the universe expanding toward a singularity.
1. It fits with Hubble's law and time dilation. 2. It does not require the supposition of unverifiable new substances. 3. It relies solely on empirical data. 4. There is no evidence to the contrary.
It’s a fact that the universe is expanding. Hubble’s law is simple: double the distance and the galaxies are moving away twice as fast.
Gravity affects time. This is another fact, which Albert Einstein predicted before completing his theory of general relativity. In 1976, the Chesapeake Bay experiment confirmed time dilation—atomic clocks run slower at ground level than up in the air.
From Einstein’s Universe, Nigel Calder elaborates:
“In Einstein’s theory the main features of gravity around the Earth are exactly the same as they would be if our planet were hollow, with a faked-up papier-mâché surface of mountains and seas, but having a black hole at the centre with the same mass as Earth” (74).
The way atomic clocks behave around a black hole singularity, or any massive body, is simple: double the distance from the black hole, and the slowdown of the clock halves.
The Big Bang is a popular interpretation of this evidence.
The BHUM suggests the universe is expanding toward a singularity.
While difficult to visualize, the benefit of this explanation is twofold: it doesn’t require the introduction of exotic new substances, and, it relies solely on demonstrable physical results.
When you take a few pennies (i.e. galaxies) and toss them off a tall building one after the other, the distance between the pennies will increase as they fall because the first penny dropped will always be moving faster than the second, and the second than the third, and so on—because of the acceleration due to gravity.
Perhaps a better analogy, with regard to spacetime, is to imagine the successive pennies funneling down one of those spiral wishing well things you see at the mall. The distance between the pennies will increase. Of course, the singularity is where all the money goes.