Q&A: Dark Matter

Q:
Could dark energy simply be the effect of gravity from other universes which surround this universe and big bangs occur when the material from adjacent universes collide, condense then explode again?

A:
Dark energy is still a mystery, it could be many things. Most scientists favor a simpler answer than other universes, such as postulating a cosmological constant which is just a small amount of energy in each square meter of empty space. There are other questions that follow from that simple postulate (such as why that precise amount, where does the energy come from, etc.) but it is still not as radical as other universes. We have an interview with Professor Michael Turner which deals with this subject, in particular the question of what dark energy could be:
http://chandra.harvard.edu/photo/2004/darkenergy/turner_interview.html

For a description of the methods thus far for detecting dark energy (which can help you think about what it could be), please see our Chronicle article here:
http://chandra.harvard.edu/chronicle/0204/darkenergy/index.html