TED

The TED video I decided to write about was called "Is our universe the only universe?".  The lecture was given by a theoretical physicist named Brian Greene in Long Beach in February of 2012.  The video summarizes the multiverse theory and gives some good evidence to believe that the theory is true.  He goes into detail and explains that dark energy is responsible for the increase in speed of expansion.  He gives the exact number of dark energy which is needed to account for the rate of change in speed.  He explains string theory and how it unifies all the forces of the universe.  He explains that the math needed to explain string theory must include other dimensions on a microscopic level.  He talks about the shapes that were predicted and how the list grew and grew.  Then he speculates that the number that we predicted correlates to the shape of the possible extra dimensions and that the number may be different in different universes.  This means that our universe is "just right".  If the number were too big, matter would not form galaxies and if the number were too small, the same thing would happen.  Then he talks about the big bang and how it might not be a unique event.  He also talks about the CMB and how it may be able to provide tangible evidence of other universes.  This was my favorite part of the lecture.

The CMB is a cosmic microwave background.  Astronomers use their telescopes to view the hot and cold parts of the early universe on a HUGE scale.  Greene suggests in the video that if our universe were to collide with another, we might be able to see some disruptions in the CMB.  It might look like a ripple of some sort as the heat of another universe interferes with the heat of our own.  It would be really cool to see that one day, but I don't think it would happen like he suggests in the video.

Since this is all highly speculative I want to insert an idea I had based on other readings and my own knowledge of the subject.  The number that Greene suggests, which would differ between universes and also cause the difference in "vibrations" of the strings, would create universes with strings vibrating in completely new dimensions.  Like he said in the video, these vibrations of strings would make up new particles.  The numbers in the video represent the amount of dark energy in the given universe.  Since the amount of dark energy is accepted to make up 72% of the universe and the rest is made up of matter and dark matter, the laws of physics would change as that 72% changes. Gravity and the nuclear forces may be lacking from these universes completely and may perhaps be replaced by forces completely foreign to us.  My readings prior to this video suggest that changes in physics come hand in hand with new dimensions, which does not seem so far-fetched after viewing the video.  This means that things would be unimaginably different from our own universe.  I would imagine that if our universe suddenly collided with another, nothing could happen because our matter and energy (heat) may exist in a different dimension than those of the universe that we are colliding with.  The heat of our own universe could not change or ripple like in the video because it would be colliding with virtually nothing at all.   The universe would occupy a space which would be completely unknown, even if it were superimposed on top of our universe, we may not be able to sense its properties because of a gap of dimensional occupation.  Only a portion of its properties may be able to collide with our own.  Heat may not be one of these properties.  To make this easier for someone to understand, imagine setting a cube on top of a piece of paper.  The cube's bottom face would be the only thing interacting with the piece of paper, and it is because of the difference of dimensions between the two objects.  There is no way for the height of the cube to interact with the piece of paper.  Similarly, if the heat of any given universe existed in some 'nth' dimension of space, there would be no way for it to interact with our own three dimensional space.  Again, everything here is highly speculative, but it is fun to think about and that's why I love the subject.

I would highly recommend this video to anyone who likes to think deeply about big things.  It is an extremely interesting speculation and the video is also a very good introduction to string theory, other dimensions, and the future of the universe.