Reply to comment
In our online poll to find out what Plus readers would most like to know about the Universe, you told us that you'd like to find out what happened before the Big Bang. We took the question to the renowned cosmologist John D. Barrow, Professor of Mathematical Sciences at the University of Cambridge, and here is his answer. The Universe is an infinitely self-perpetuating foam of bubbles, it seems...
Read more and feel free to discuss the answer by leaving a comment on this blog. We'll periodically check back with the experts to try and answer interesting further questions.
posted by Plus @ 11:00 AM
- At 2:01 PM, said...
Barrow's remark in his final sidebar that dark matter "consists of stars that don't shine in the dark,..." seems a little beyond our current knowledge. While evidence indicates dark matter reacts to gravity, do we have data showing that its clustering actually produces star-like bodies? ...and thus, by extension, perhaps even "dark black" holes??
- At 5:17 AM, said...
This may be the best bit of cosmology for the lay person I've ever read.
Until very recently there has been a strong bias toward the view that the observable universe is representative of the universe as a whole. Barrow does a very good job of looking beyond this to suggest that there is probably a whole range of "universes" and that ours seems special only insofar as we seem to be in the center of it.
Someday historians of science may look back on the conception of the "multiverse" in much the same way as we view the Copernican revolution and the vastly more unsettling recognition of "island universes" (galaxies). As first our solar system and then our galaxy seemed islands in something much more vast and unknowable, so too is the bubble we call the "universe"
- At 9:18 AM, said...
One of our readers asked (in response to the accompanying podcast) whether the laws of physics have to be the same in each bubble. We asked Professor Barrow and here is his response:
""Indeed, we know that in some theories of fundamental physics there is the possibility that important aspects of physics, like the strengths of basic forces or the masses of elementary particles, will fall out differently in the
different regions we have called 'bubbles'. Other local features, like the level of non-uniformity in the material density or the balance between matter and antimatter may also be different.
At present we don't believe there can exist atom-based life like ours except where things are very close to what we
observe in our 'bubble'.
String theory also allows the number of large dimensions of space to be different from one bubble to another. But we know that with more than three large space dimensions no atoms or planets or stars can exist. The attractive forces of nature fall off too rapidly with distance to hold things together. For example, in an N dimensional space the familiar 'inverse square' laws of gravity and electromagnetism become inverse (N-1) laws."
- At 10:04 AM, said...
What the author fails to do is answer the basic question, "What happened before the Big Bang?", or "What existed prior to the creation of the material universe?" He simply answers (paraphrasing), "The source was quantum foam", or "It has always existed", neither of which provide any sort of solid answer. Where did the 'quantum foam' come from?Until he can provide definitive information on the origin of life and the universe, then all his words are fantastic hot air at best and complete bluffing and deception at worst.
- At 4:10 PM, Medice said...
Is it possible that before the big bang the Universe or whatever we want to call it, was in fact composed of super condensed black matter. At the centre of this matter and due to extreme gravitational forces a portion,particle of light matter came into existance and the interaction of light matter and dark matter created the Universe as we know it today, ie dark matter is now at the edge of the universe and accelerating pulling the exisitng Galaxies with it ,expanding the universe. When the fabric of the dark matter becomes for want of a better word thinned out,the accelerating light matter will come into contact with sufficient dark matter to reverse the whole process making the universe 99.999% dark matter, unitl the gravitational forces once again create particles of light matter and once again interact with the dark matter, thus repeating the whole exercise again and again. Also could we know call the God particle the initial interacting light material