The Eridanus Void … a Cosmological Conundrum
Well, the readers have spoken. Today’s post will be about a space mystery. Good thing too, Afghanistan is such a depressing subject. And there will be lot’s of time to discuss Afghanistan, as I understand it our new mission there is “We are staying forever.” Still, took me awhile to come up with an appropriate space mystery, most of them seemed so, well, pedestrian. The Phobos Monolith = it’s a rock. Weird dunes on Titan = sometimes the wind there blows in different directions. The face on Jupiter = I just made that up.
Moving right along, the Eridanus Void. A true space mystery. Anf there’s a nice double entrendre there too, because that is exactly what the Eridanus void is, a mysterious space in space. A what now? The Eridanus Void is an area of the Universe about one billion light years across (that’s really big) that appears to contain essentially no matter. No galaxies, no stars, no dust, no nothing. It’s billions of light years from Earth though, so not an easy thing to study. The void was found a few years back when they were looking at the cosmic background radiation. There was this big spot with very little background radiation. Then they compared that to a map of the Universe’s galaxies, and lo and behold there weren’t any there.
So, a big empty spot in space? What’s the big deal? Well, the big deal is that there shouldn’t be a big empty spot in space. It would be like finding part of the Earth’s surface where there was no atmosphere, how could that be? In the chaotic creation and expansion of the Universe shouldn’t there be stuff everywhere? Yes, yes there should. So the Eridanus Void is a problem. However, if this void actually exists, and it’s not completely certain yet, it would be one of the largest structures in the Universe. So it’s an exciting problem to people who get excited about the structure of the Universe.
OK, so, what are the possibilities? The first is that it is just a statistical fluke, and doesn’t really mean anything at all. IE it only appears strange because it is surrounded by more dense areas. Sounds good to me. One of the problems with trying to understand, let alone explain, these sort of cosmological mysteries is that frankly I don’t understand them very well myself, and that is particularly the case with stuff like this. Another possibility that has been proposed is that the void is something called a cosmic texture. If I understand that correctly, a cosmic texture is a defect in space time. Such defects are apparently allowed by theory, but none has ever been observed. I’m not really sure I can or want to understand exactly what that means, but again, if there is a defect in space time, I’m glad it’s billions of light years away.
It’s also been suggested that the void is simply a giant black hole. A billion light year across black hole. Even Captain Picard would have trouble dealing with that. While there doesn’t seem to be any known way such a huge black hole could form, there’s also to known way such a huge void in the Universe could form, so it’s not a completely off the wall suggestion. If I understand this theory, the black hole would have as much mass as the rest of the Universe. And the Universe would in fact be “orbiting” around this black hole. Again, it’s very fortunate that we are nowhere near if this is the case, because then as we speak entire galaxies are being pulled to their doom.
Lastly we come to the most interesting and exotic theory. One Dr. Laura Mersini-Houghton, a professor of theoretical physics and cosmology has claimed that the void is the result of quantum entanglement with another Universe, and is empirical proof that parallel universes exists. She sounds like one hell of a smart person, so this theory, though controversial, is apparently testable and mainstream. I can’t really explain what it means, but suffice it to say that she claims the void is a “smudge” left where our universe was in contact with another universe during the first moments of the Universe’s existence. At least I think this is what she means. Apparently if it is a remnant of contact with another universe, there should be another void on the opposite side of the sky. I’m sure scientists are looking as I type.
And that’s all that can be said. Despite all the weird implications, the core mystery is pretty simple. There’s a huge hole in space, and cosmologists and astronomers can’t explain why. Coming next week, who knows, I’m open to suggestion. Have a great weekend everyone.
(The above image of the “cold spot” in the CMB radiation is being used leghally in accordance with it’s creator: This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. Image credit: Nernom at en.wikipedia Here is the best link I’ve discovered yet on the void, it’s not exactly all over the net. A giant black hole?)