What armchair "scientists" get out of reading popular science magazines or websites? Mostly they get excited about "out there" speculation that gets batted on wired.com or io9.com. Holographic universe. Preferred direction in the universe.
What a real astrophysicist's answer to "what do you think about this?" is: nothing.
Some of us in the Center For Inquiry eat up science news about astronomy and cosmology. Especially the more sensational pieces that popular science websites like to publish. But sometimes we get a reality check in an encounter with a real, practicing astrophysicist, such the one who gave a presentation on cosmology and black holes at the CFI Austin Science Cafe in December 2011. He is a Ph.D. student in the field. I will not give his name here, because I haven't checked if that's OK with him.
A slide from the lecture: "The first black holes were probably about 30-100 the mass of the Sun. Within about 1 billion years, some of them managed to grow to 1,000,000 the mass of the Sun, and perhaps more." See more pictures from Center For Inquiry Austin events in my photo gallery.
Holographic universe? He hasn't heard about it. Oh, it's a universe that's fully described by what happens at the boundary? His response was that it's debatable or perhaps undecidable whether the state of the universe at any moment in time could be determined by initial conditions alone. He probably thought that's what we asked about. But holographic theory is NOT about the initial conditions of the universe. If this theory is so fringy that it's not widely known among bread-and-butter cosmologists, then... just how accepted in the "real" science community is it? It's clear why wired.com, Scientific American, or io9.com are batting it around -- it sounds sensational. But perhaps it's not as seriously entertained by real scientists as those sites would like us to believe.
What about the universe appearing to have a preferred direction, in the sense that there appears to be more matter in one "side" of the universe (as observed by us on Earth) than the other? Or that matter appears to move faster in a certain direction? According to the astrophysicist, the universe appears red-shifted in one direction and blue-shifted in the other because our own local corner of the universe (Milky Way and surrounding galaxies) is moving at a rapid speed. It is either 600 kilometers per second or 6000, I don't remember which one. This is the movement that started with the Big Bang and the following rapid expansion of the universe.
But if the explanation was that simple, wouldn't the scientists mentioned in the io9.com article know about it? Or are they are talking about some other kind of preferred direction? Direction is what you, as a layperson, lose when you try to look past the tantalizing science headlines.
A slide from the lecture: "By determining the rate of expansion of the universe we live in, astronomers are able to better estimate the age of the cosmos. If the universe is decelerating, it is likely to be young. But if it is coasting or accelerating -- expanding faster as the repulsive force pushes galaxies apart -- it is probably older." See more pictures from Center For Inquiry Austin events in my photo gallery.
What do astrophysicists consider serious or interesting problems, then? If we've been paying attention to the news, we've probably seen this "laundry list":
Did inflation really occur? if not, what could have made the universe so flat?
What happened before the Big Bang?
What is dark energy?
What is the ultimate fate of the universe? I.e. will it expand indefinitely and die a heat death? Or shrink back into a point (Big Crunch)?
What is dark matter?
How did all of the first particles form?
How does gravity relate ot the other forces of nature?
What were the first stars and galaxies like?
How did supermassive black holes get so big?
That last question is a particular research interest of our lecturer. It sounds like a "mundane" problem compared to the ones that turn your ontology on its head, like holographic universe, but when we dig deeper into it, it's amazing that the mass of black holes can be determined with a relative accuracy at all. How do you tell a difference between a 5-million-masses-of-the-Sun black hole, and 6 million masses? The answer is that the stars around the black holes are moving, and we can measure how fast they are moving. From that we can estimate the mass of a black hole.
"The universe summarized". A slide from the lecture recapitulates cosmology in six sentences.
The universe was once in a very hot, compact state.
It began expanding and cooling, we call this the "Big Bang".
All matter in the universe has always been a part of the universe, there will never be any more or less "stuff". All matter that we see took its form within the first few minutes after the Big Bang.
We can measure the heat signature of the early universe (relics of the Big Bang) in the Cosmic Microwave Background.
The first black stars and galaxies formed about 500 million years after the Big Bang.
We do not know the ultimate history of the universe, but the expansion seems to be accelerating. This acceleration is termed 'dark energy'."
See more pictures from Center For Inquiry Austin events in my photo gallery.
So perhaps it truly is amazing that science is capable of this at all, of determining such a precise difference in masses of objects millions of light-years away that we can't even observe directly. (Considering those distances, I think a difference of 1 million masses of But getting excited about "mundane" facts of physics is a little like trying to get excited about eating broccoli, isn't it? Yes, it healthy for you to be grounded in reality, to appreciate the amazing things scientific method can do, and yes, broccoli has amazing health properties, and you wouldn't expect such a humble vegetable to have molecular "levers" to unlock life-extending cellular mechanisms, just like you wouldn't expect that humans, bound to a small, out-of-the-way planet, armed only with logic and primitive tools, would find a "lever" to unlock the properties of gigantic, invisible objects millions of light-years away. And yet the tastebuds of our mind are not satisfied with broccoli alone; they long for something that would feel like magic. Skeptics, too, long for a sense of wonder, and for them magic wouldn't be dragons or vampires, but something that would turn our worldview on its head.
But you can get that from mainstream cosmology. You only have to stop and think what exactly it does means that the Universe is expanding. Is the space itself expanding? The distances between our atoms? And in that case, what would explain collision of two galaxies like Milky Way and... uh... that other universe?
It turns out, no. If you gain a clothing size, it is, alas, not because the space between your atoms got bigger. (Besides, the clothes would have gotten bigger too, so you wouldn't notice.) Locally, gravity counteracts the force of expansion. And by "locally" we mean a region of the universe that includes Milky Way and nearest galaxies. Andromeda galaxy is 2 million light-years away from us, but yes, it's still "local" enough so that gravity prevents any significant expansion. But according to our astrophysicist it is possible that at some point expansion will become significant enough to counteract gravity even within this cozy neighborhood.