Everyone knows about the Big Bang, right? The explosion-into-being of the entire universe, however many billions of years ago? Of course they do. Trouble is, the Big Bang has always been something of a fudged theory… and now Wun-Yi Shu of the National Tsing Hua University in Taiwan has come up with a new theory that fits a lot of observed evidence far more thoroughly… while dumping on some accepted truths.

Shu’s idea is that time and space are not independent entities but can be converted back and forth between each other. In his formulation of the geometry of spacetime, the speed of light is simply the conversion factor between the two. Similarly, mass and length are interchangeable in a relationship in which the conversion factor depends on both the gravitational constant G and the speed of light, neither of which need be constant.

So as the Universe expands, mass and time are converted to length and space and vice versa as it contracts.

This universe has no beginning or end, just alternating periods of expansion and contraction. In fact, Shu shows that singularities cannot exist in this cosmos.

As with all such theories, not everything fits perfectly:

One of the biggest problems he faces is explaining the existence and structure of the cosmic microwave background, something that many astrophysicists believe to be the the strongest evidence that the Big Bang really did happen. The CMB, they say, is the echo of the Big bang.

How it might arise in Shu’s cosmology isn’t yet clear but I imagine he’s working on it.

Even if he finds a way, there will need to be some uncomfortable rethinking before his ideas can gain traction. His approach may well explain the Type-I supernova observations without abandoning conservation of energy but it asks us to give up the notion of the Big Bang, the constancy of the speed of light and to accept a vast new set of potential phenomenon related to the interchangeable relationships between mass, space and time.

So, yeah, bit of a revolutionary idea. Reading stuff like this always makes me wish I’d knuckled down more at college and gotten to grips with the heavy-lifting end of physics; that way I might have ended up making a living from speculating about how the universe works. What could be more fun?

And while we’re talking cosmology, here’s a Fermi Paradox rethink [via SlashDot]:

… a new approach by Igor Bezsudnov and Andrey Snarskii at the National Technical University of Ukraine.

Their approach is to imagine that civilisations form at a certain rate, grow to fill a certain volume of space and then collapse and die. They even go as far as to suggest that civilisations have a characteristic life time, which limits how big they can become.

In certain circumstances, however, when civilisations are close enough together in time and space, they can come into contact and when this happens the cross-fertilisation of ideas and cultures allows them both to flourish in a way that increases their combined lifespan.

[…]

The parameters that govern the evolution of this universe are simple: the probability of a civilisation forming, the usual lifespan of such a civilisation and the extra bonus time civilisations get when they meet.

The result gives a new insight into the Fermi Paradox. Bezsudnov and Snarskii say that for certain values of these parameters, the universe undergoes a phase change from one in which civilisations tend not to meet and spread into one in which the entire universe tends to become civilised as different groups meet and spread.

Bezsudnov and Snarskii even derive an inequality that a universe must satisfy to become civilised. This, they say, is analogous to the famous Drake equation which attempts to quantify the number of other contactable civilisations in the universe right now.

Of course, the only way to prove the theory is to wait until we can get more data… so you might want to read a book or something in the meantime.