Entry 221, on 2005-09-13 at 14:24:12 (Rating 1, Science)
Its time to move away from trivial subjects, such as national and global politics, and concentrate on something that really matters, like the ultimate fate of the Universe. Compared to that, the subjects being discussed by politicians really do look a bit pathetic!
We know the Universe is expanding, but it has always been difficult to tell what the rate of expansion was. We thought that there had to some sort of slow down because of the effect of the gravity of all the mass-energy in the Universe. But more recently it was discovered, much to the surprise of most people, that the rate of expansion was actually increasing. A new phenomenon, known as "dark energy" was created to explain this repulsive force - a sort of anti-gravity. The bizarre thing was that Einstein originally included a cosmological constant in his equations, which had the same effect.
So if this dark energy continues indefinitely with the same effect it currently has, the Universe will just keep getting bigger and bigger. The galaxies will drift apart, all the energy will be used up, and the Universe will end as a featureless mass of vacuum particles. This will take trillions of years, so it is of no immediate concern!
If the effect of dark energy gets less (it can't have always been as strong as it is now or the Universe wouldn't exist in its current form at all), or stops completely, the Universe will eventually stop expanding, and contract again until we get the opposite of the Big Bang, often known as the "Big Crunch". Maybe another Big Bang will then occur, giving us an "Oscillating Universe". The big crunch might occur in considerable less time than the other option I mentioned above, maybe in only a few tens of billions of years.
The problem is, no one has any idea what this dark energy actually is. Maybe its a new type of matter or energy, maybe its the result of extra spatial dimensions, maybe its something else. One things for sure, the big questions in physics still haven't been answered. One of the major aims I see for the next 10 to 20 years is to discover what dark energy is, and answer the question about the fate of the Universe.
There are no comments for this entry.
You can leave comments about this using this form.
Enter name, email (optional), enter number, comment, click Add. You can leave the name blank if you want to remain anonymous. Enter your email address to receive notifications of replies. Comment should appear immediately (authorisation is inactive).
BLOG PAGE
