Cosmic Relief
David Grinspoon18 August 2014 sky & telescope
Stuff Just Got Real
An astrobiologist comes to grips with the new cosmology results.
from the origin of
the universe: gravitational waves from tiny quantum fl uc-
tuations in the instant after the Big Bang (last month’s
issue, p. 18). It’s clearly an incredibly important discovery,
and my friends all want to know what I think. Even worse,
they want me to explain it.
But dammit Jim, I’m an astrobiologist, not a cosmolo-
gist. People think that I know all about this stuff because
it’s out there in space, just like those stars, planets, and
moons I’m always going on about. I follow cosmology
and particle physics on the level of reading S&T and
Scientifi c American, and if I were a 19th-century natural
philosopher, I might be able to know all of science, or at
least make a better stab of it. But now science has grown
to a sprawling, branching tree of knowledge, and we rely
on the authority of those in other fi elds to tell us what’s
important, what’s believable, and what it means.
When I tell people that I study other planets, some-
times they look at me like I’m from Neptune. I suppose
what I do is abstract and esoteric compared to sellingSo they found ripples cars, fi xing bridges, or running a frozen yogurt company.
But compared to cosmology or particle physics, it feels so
concrete. At least I can picture planets as cratered, rocky
plains or wave-tossed seas under an alien sun.
But what about the worlds of subatomic particles and
baby universes ballooning out of nothingness? There are
good reasons to believe. The math is elegant and, most
importantly, predicts other patterns and phenomena that
we then observe. I’ve taken university courses in general
relativity and quantum mechanics, and though I couldn’t
reproduce the logic or math in any depth now, having
been through it once gave me an appreciation for their
depth and veracity. I’ve taught the cosmic microwave
background in intro astronomy courses and planetarium
shows. I dutifully report on how tiny quantum bumps
became frozen into the distribution of matter as the
cosmos expanded from unimaginable tininess to incon-
ceivable vastness, and miniscule vacillations evolved into
massive superclusters of trillions of stars. I know the
drill, but I also have a voice in my head saying “Really? It’s
a good story, but do we really know this?”
I must confess to having doubts about the Big Bang.
Not that I have any better ideas, it’s just that ideas about
the early universe seem to rest on so many layers of
abstraction. I get that it fi ts an impressive amount of data,
but I can imagine that it might all somehow be wrong,
a beautiful and complex edifi ce that may someday come
crashing down in a paradigm-shifting upheaval of reality.
We’ll never visit the early universe. But that’s also true
of Earth’s early Archean era, and perhaps the exoplan-
ets, and yet planetary scientists study these times and
places. We do, at least, have rocks from the Moon and
mineral grains from the Archean (June issue, p. 16). And
now, it seems, we have the equivalent for the primordial
universe. Detecting these gravitational waves, closely
conforming to predictions, makes it a lot more real to me.
Maybe these folks really are on to something! I’m very
glad people are studying these things, and I’m glad that
someone keeps the yogurt machines running too. ✦David Grinspoon is a senior scientist at the Planetary Science
Institute, which is based in Tucson, Arizona. Follow him on
Twitter at @DrFunkySpoon.FPO
on the authority of those in other fi elds to tell us what s
important, what’s believable, and what it means.
When I tell people that I study other planets, some-
times they look at me like I’m from Neptune. I suppose
what I do is abstract and esoteric compared to sellingKICKER: SHUTTERSTOCK / TUNGPHOTO; BALL: NASA / WMAP SCIENCE TEAM