Death of the universe?(4)
So, when the universe was young, gravity was the most dominant force. And so what we see here is galaxies as particles on the surface of the water are bound together by gravity. And the point about seven billion years ago, dark energy and gravity are pretty well in balance. But the universe continues to expand, the density goesdown, and so dark energy starts to take over. And lo and behold, the universe starts to accelerate. So dark energy is now the dominant property of space. So, the universe started out with the certain amount of energy. And we know, we're trying to understand how much energy there is. And we know the universe is expanding as it moves outward with time. We also know now that the universe's expansion is accelerating. And we don't know, is that acceleration going to slow down or not. We're still trying to understand that. So in understanding what's going to happen to the fate of the universe, we have to know how much energy is there?How much matter is there?
Well, the history of the universe is really a battle between dark matter and dark energy.These two forces are in opposition. And so both the history of the universe and its ultimate fate is really the competition between these two forces. The Big Crunch theory was a result of scientists interpreting that dark matter is the dominant force. But astronomers now suspect that dark energy might be much stronger. If so, the end could be dramatic and violent .
It pull apart solar systems, it pulls apart stars. And eventually it grows so strong that it pulls apart matter itself, breaks bonds pulls apart atoms, and reduces everything to fundamental particles and that's the end of the universe.
The battle between dark matter, the force that holds the universe together, and dark energy, the force seeeking to tear it apart, has set the universe on the path of destruction. If dark matter is the victor, the universe might collapse. If dark energy rules the cosmos, it could rip to shreds. The expansion grows so strong that it tears up the entire universe. It'll be a strange twist of fate. Dark energy, the force that propelled matter to form a magnificent universe, continues to push it outward and drive it to its demise.
To find out the dark energy is in fact winning the battle, scientists will first need to know how fast the universe is actually expanding. The most remarkable feature of the universe is that it's expanding, Every galaxy is moving away from every other galaxy. We can illustrate that with this balloon as we expand it. We see that every dot drawn on this black balloon, like the night sky, is moving away from every other dot. Buy there is something else that we know about the universe, something else that we know about that expansion. That is that the expansion is getting faster. The universe is accelerating. The size of the universe is getting bigger at a faster and faster rate. And we don't know exactly how fast it's accelerating. But if it's accelerating fast enough, then something really dramatic could happen. The universe could end up tearing itself apart in a Big Rip.
Doctor Robert Caldwell attempts an Earth-bound experiment to show how dark energy affects the acceleration of the universe. He use a paintball gun mounted on a truck. He send the truck coasing down an inline. Earth's gravity pulls the vehicle downhill, which is similar to how dark energy propels the universe outward, causing it to expand. Gravity pull the truck forward at an increasing speed. The gun fires paint at the ground at regular one second intervals. Caldwell measures the distance between the paint dots to calculate just how fast the truck was accelerating.
This demonstration then gives a sense of the dramatic rate of expansion that appears to be happening in the cosmos.By eye it might be difficult to appreciate how good a fit it is. But we can tell you that the rate of statistics indicates that an accelerating universe is a very good fit to this data.
If like the truck the universe is conyinually accelerating, then billions of years from now the universe might tear itself apart. All the distant stars and galaxies would be pulled away from each other. They'll be pulled away from us. But more over, we won't have time to grow cold and lonely. It'll actually be pretty exciting and dramatic and violent. Stars are ripped apart, planets are ripped apart, and even atoms are torn apart before the universe end. It wouldn't happen for at least fifty billion years. But still, it's an interesting fate for the universe.
Death of the universe?(1)
Death of the universe?(2)
Death of the universe?(3)
Death of the universe?(5)
Death of the universe?(6)
Death of the universe?(7 end)
