Last time we had a look at a rather exotic problem of extra spatial dimensions, so how about we switch to cosmology this time. In this edition of “The Great Unsolved Problems in Physics” we take a look at a problem, which happens to have a really cool name — the Space Roar.
So what is the Space Roar? According to the best university in the world called Wikipedia, it is a signal discovered by NASA’s ARCADE instrument, which currently has no explanation. So the guys from NASA, besides having a great talent in making up acronyms, actually built a great instrument, which did a good job of measuring the heating of the universe by the first stars and galaxies after the big bang. The interesting part is that it also detected something else — an unexpected background radio signal, now termed “Space Roar”, which is 6 times stronger than anything that is predicted by cosmologists.
Now, when it comes to mysterious signals from outer space, there’s always a smell of a great discovery in the air. As an example, let’s remember the good old discovery of the cosmic background radiation by Arno Penzias and Robert Woodrow Wilson. These two guys, back in the 60s, were working with a rather funny looking antenna, specifically designed to detect radio waves bounced off echo balloon satellites. Of course, as you might guess, they found much more than expected — they discovered the so called cosmic microwave background radiation, which ended up being one of the most important tests for the Big Bang theory. So might something similar happen with the so called Space Roar? Might it be a sign of new physics, or maybe a confirmation of some more exotic theories of cosmology?
Well, without jumping to speculations, let’s discuss some of the possible explanations to the Space Roar. Here’s a quote from Dr. Alan Kogurt — the head of the ARCADE team. “The universe really threw us a curve,” Kogut said. “Instead of the faint signal we hoped to find, here was this booming noise six times louder than anyone had predicted. Typical Radio Galaxies can’t account for the noise as you would need the entire universe filled of them to produce signal strengths this high, six times higher than the combined emission of all known radio sources in the universe. The energy alone that could generate this level of signal is incomprehensible. This discovery has become known as Space Roar”.
The horn antenna that was used to discover the CMBR
So currently the primordial stars and all other known radio sources in the observed region of the sky were ruled out. Thus it seems we’re running out of simple explanations. But, don’t worry, as always, there are some rather crazy explanations, one of which is given by David Brown right here. So basically, there’s a popular book by Stephen Wolfram called A New Kind of Science which systematically studies computational systems such as cellular automata. And somewhere along the way Wolfram introduces the idea that the universe itself could be some sort of a computational system. So David Brown uses some of the ideas described in the book and attempts to explain the phenomena of Space Roar by using some experimental astrophysics data.
To summarize, there doesn’t seem to be a single accepted explanation to the Space Roar phenomena yet. Perhaps one of the most interesting explanations is that by David Brown, but I have failed to find a source that would confirm the explanation yet. Well, either way, it seems that Space Roar is another big mystery, which adding to the great mysteries of dark matter and dark energy forms the conclusion that these are interesting times we are living in, especially if one happens to be a cosmologist.
For more information: