I read Einstein’s twins paradox (http://www.einstein-online.info/spotlights/Twins) and I found it very hard to believe.
How can the traveling twin returns to find his brother older when he comes back to earth? If the aging is calculated by heart beats then both of them had the same count of heart beats during this trip.
What will happen when someone is traveling with a speed as near as speed of light? Let’s think about the following scenario to understand more. If you are driving your car and look in the mirror on a car that has the same speed, then it will look like as if the car is not moving. If the speed of the other car is higher, then it will be moving toward you. If it is slower it will be moving backward. The same effect would happen when traveling with a speed that is close to speed of light.
Let’s assume that the first twin is driving his car on earth, and the second twin is leaving earth with a speed near speed of light (accelerating from 0 to 95% of the speed of light), at slow speed he will see the car of his bother moving regularly and as he increases his speed his brother will start to appear slowing down. When the velocity reaches exactly the speed of light he will see the car not moving (because he is moving with the light coming from the car when it was in a specific point). When the speed exceeds the speed of light he will start to see the car moving backward (traveling to history).
The paradox is misleading because it does not consider what will happen when the brother is on his road back, in that case the contrary effect will happen, the car that was moving backward will slowdown, and stop and move forward again, and when the brother reaches earth slowing down to speed near 0, he will see his brother moving with expected speed and reaching the expected point.
Today we can see stars that do not exist currently anymore, because it took the light long time to reach earth, same would happen if we can travel to another universe with speed that exceeds the speed of light (using black holes or any other mean), the same effect will happen, we will be seeing the history of earth (because the light coming from the history of earth has just arrived to the other far universe!). So if we can take with us a very complex technology that enables us to see extremely far places like earth from the other universe, then we will be able to see dinosaurs. When we come back to earth with the same speed the effect will be rolled back and we will come back to current moment.
So I think the whole thing is illusion, related to light, and related to whether we can reach a point before the light can reach it or not, when coming back to earth that illusion will go away, and we come back to reality!
