Translator: Reiko Bovee Reviewer: Elisabeth Buffard
OK, so you're probably looking up at that title and thinking,
"Why is this guy talking about two completely unrelated subjects,
beer and Space?"
With that lovely intro, you probably got an idea
that I have a day job as an astronomer,
and I have a hobby, brewing my own beer.
But it actually goes quite a bit deeper than that.
It comes down to this character here.
This is my dad.
Once upon a time when I started off my astronomy career,
my dad said to me,
"So, son, what are you working on?"
I said, "Well, dad, the subject of my PhD thesis is
The Association of Ultra-compact H2 Regions
and Methanol Maser Emission."
(Laughter)
As I was saying these words to him,
I could see his eyes were starting to glaze over,
and he started losing interest in what I was saying.
Up until I said the word "methanol,"
and his eyes lit up, and he went,
"Ah, methanol, right? That's alcohol, so you found beer in Space!"
(Laughter)
I said, "Sorry, dad, methanol is actually a very bad form of alcohol.
It's poisonous to you; if you drink that stuff,
it can make a bloke go blind, it can even kill you.
So you don't want to be drinking that stuff."
Ethanol is the good alcohol
that you find in beer and other alcoholic drinks.
At that stage, we hadn't found any out in Space.
So, by this time, my dad had basically stopped listening to me
and not paying attention to the conversation any more.
So this talk is some sort of justification for my dad
and my entire astronomy career.
(Laughter)
So, starting off with this question -
can we make beer in Space? -
let's find out what goes into beer,
and then see if we can find it out in Space.
So, by far, the most important ingredient in beer is water,
95% of the volume is water.
Then we have barley which provides sugars and starches
and also the characteristic malty flavor of beer.
We have hops which also add their own little flavor to beer
and give beer its distinctive bitterness.
And we have yeast which are the single-celled organisms
that do all of the work of converting the sugars
into ethanol and carbon dioxide.
And that's, ladies and gentlemen, is pretty much it.
Those are the four ingredients that you need to make a world-class beer.
Now thinking about going out into Space and finding these things,
we're actually off to a pretty good start
because there's plenty of water out in Space.
But from there on it gets a little bit tricky.
Thinking about yeast for a moment,
it's debatable if we'll be able to find single-celled organisms out in Space,
but quite unlikely we'll be able to find the right ones
that can do the job of changing the sugars into ethanol and carbon dioxide for us.
It gets even more tricky when we think about the other ingredients.
Are we going to find hop vines out in Space?
I think it's very unlikely
or even something like fields of barley out in Space.
No, I don't think so.
However on this last point,
I will mention that with some circumstantial evidence,
somebody out there knows something about it.
(Laughter)
So, we've got to look at this from a different perspective.
Let's look at it from a chemicals perspective.
See what chemicals are that go into beer,
and see if we can find those out in Space.
As I said we start off with water, the most important ingredient,
and then we have alcohols, in particular, ethanol
which gives you the characteristic dryness in beer,
but is also the intoxicant that makes you drunk.
We have carbon dioxide, the bubbles in beer,
sugars and starches are a major player in the flavor of beer;
it basically comes down to this molecule here.
This is the sugar molecule glucose.
The great thing about glucose
is that you can put two glucose molecules side by side,
link them up and you create a new sugar called maltose.
Maltose is the main sugar that you get from barley.
Put another glucose molecule there, now we've got another sugar, maltotriose.
And you can keep this linking process going on and on and on
and create very long strands of glucose molecules.
This is what we call starches.
Moving on, we have proteins
which have what we call mouthfeel to beer.
So whether a beer has a rich and full body
or whether it's thin and watery
is mainly down to proteins.
We have esters which have fruity flavors and aromas,
typically find ales have esters but not so much in lagers.
We have the bittering compounds that come from the hops
give us the bitterness in beer as well as some preservative qualities.
In addition to all those groups, I wanted to mention
four molecules of particular interest to beer flavor.
The first one is dimethyl sulfide, or DMS for short.
In very low concentrations, it has quite a pleasant, sweet smell and flavor,
somewhat reminiscent of cooked corn.
Then we have methyl mercaptan which again is quite pleasant
in low concentrations. But in high concentrations,
it's actually is the ingredient mainly in bad breath and asparagus pee.
(Laughter)
You're probably wondering,
"Why would you want these chemicals anywhere near a beer?"
They are actually very important flavor characteristics of beer,
in very low quantities.
But obviously we don't want them in high quantities,
so any brewer that's worth their salt,
will know how to very carefully control these things.
The next one is acetaldehyde
which has an aroma similar to freshly cut green apples,
or freshly mowed lawn for that matter.
It's actually a molecule that's produced by the yeast
as it takes the sugars and converts it into ethanol.
So if you smell this stuff in beer, it's a typical indicator
that your fermentation hasn't quite finished yet;
you need to be a little bit more patient.
The last one is diacetyl
which has a pronounced butter or butterscotch aroma and flavor to it.
It's actually the chemical that is used to flavor butter popcorn.
In very low concentrations,
it adds a distinctive sweet, creamy, malty flavor to beer.
But in high concentrations, once again you don't want this stuff in your beer
because nobody likes to drink a pint of butter.
So that's the whole lot that goes into beer.
You can look at this as a shopping list, if you will.
So now we want to go out in Space and see if we can find these things.
The first question is where do we look in Space to find these molecules?
It turns out the best place to look is within our galaxy at the places
where the biggest stars are being created.
So let me explain a little bit about that process.
You start off with a cloud of gas and dust
some places within that cloud are a little bit denser than others.
And those dense bits contract together under the influence of gravity
to create these well-defined blobs.
Now if you look deep inside one of these blobs,
you'll find a disc structure like this.
Obviously eventually this is where the planets will form.
The disc itself is very dense in the middle,
not so dense on the outside,
and as more and more material are piling onto the disc
and through the middle of the disc all the time,
so the center of the disc gets denser and denser and hotter and hotter
until eventually a star is born.
Now this star itself continues to grow and gets brighter and hotter.
And it in turn heats up its surroundings a little bit.
Now sometimes after this,
there is a powerful stellar wind that turns on around this star,
and it physically pushes material away from the star.
And this little bubble that's created very quickly expands,
and it goes right through the disc right through the surrounding envelope.
until you got nothing left but just the star sitting there on its own.
This pretty picture here is one of my favorite regions in the sky
with somewhat subdued name, G305.
(Laughter)
If you're curious to know where G305 sits,
here's a picture of the Southern Cross,
G305 is right down there,
just on the edge of this star patch that we call the Cossack.
A really good things about G305
is it shows this star formation process very nicely.
So the starting part of the process, the Cold Dark Clouds,
this is where you've got the density coming together
but before any star has formed.
Unfortunately we can't see much in this particular image
because they're cold and dark.
But one thing says that you get these little red fuzzy guys like this one here
which is Warm Cloud,
so, now we got a star in the middle,
it's heated up and it's starting to heat up its surroundings,
but before the powerful stellar wind turns on.
When that happens, you get these cute little young bubbles forming.
The one on the left there, you should be able to see,
is a very small shell-like structure with a very bright star in the middle.
And of course this picture shows a very nice example of an old bubble
which is this very large circular hole here.
Now thinking about the chemistry, how does that fit into this process?
When in the earliest stages with the Cold Dark Clouds,
the chemistry is very very simple and somewhat boring.
But where all the action is is when you have the Warm Clouds
because the extra bit of heat allows chemical reactions to proceed
and it gets a whole lot more interesting.
By the time the stellar winds turn on, things get a little bit boring again
because these winds effectively destroy all the complex molecules.
If you look in these earliest stages,
these are the most common molecules that you'll find out there;
quite simple 2, 3, 4, maybe 5 atoms.
But what you'll see in the middle there
is two of the molecules that we need for beer:
we've got water and carbon dioxide,
So we can make fizzy water.
When we go to the Warm Cloud phase, then it gets quite a bit more interesting,
a little bit more organic and larger chemicals.
And again in the middle here, we've got two of the molecules we need.
We've got the green apples and we've got asparagus pee.
(Laughter)
If you're wondering how we find these molecules out in Space,
we use a radio telescope like this: this is the Mopra Radio Telescope.
It lives in New South Wales, but a really cool thing about this telescope
is that I can sit in my office here in Perth
and can control this thing directly over the Internet.
Anyway, a radio telescope operates on a similar principle
to the radio in your car except that we don't have a tuning knob,
so you can't pick out a specific frequency for specific radio station.
In fact you get all frequencies in a spectrum like this.
So all those peaks that you see there
are kind of like radio stations at specific frequencies,
but instead of being radio stations, they come from molecules in Space.
If you know the frequencies of the molecules
from doing experiments on Earth, then you can match up the frequencies
you see them in Space and identify these peaks.
If you look very closely at these identifications,
the second-in from the left and the second-in from the right,
you'll see EtOh which is shorthand for ethanol, that's the good alcohol,
so we got alcohol out of Space.
Here's an entire list of all the molecules that we know about out in Space,
as of a few weeks ago, there're a bit over 170 of them.
The ones in white there are all the ones that we find in beer.
So there's a good overlap between the two of them.
So, let's go back to our shopping list and see which ones we can tick off.
As I said all along, there's plenty of water out in Space.
If you look at just one of these Warm Clouds,
and put all of the water together, there would be enough water
to fill up the volume of a full planet, the size of Jupiter.
So plenty out there.
And ethanol, yes, we have ethanols, I've shown you, how much?
A lot of ethanol out in Space.
Again, average Warm Cloud just one of these guys,
take all of that ethanol, make a standard-strength beer out of it,
there'll be enough beer to fill up the Swan River with beer,
20 times over, for each and every individual on the planet.
(Laughter)
So we are not going to run out of this stuff.
(Laughter)
There's a lot of carbon dioxide out in Space as well,
and we do see sugars out in Space.
We have this glycolaldehyde, but as I said the important one in beer
is glucose which we haven't seen yet.
Unfortunately we don't have any in the groups of proteins, esters
or bittering compounds.
Simplistically put, this is because the larger the molecules are,
the more difficult they are for us to detect.
This is humulone, the main molecule that gives the bitterness in beer.
You can see it's quite a bit bigger than all the other molecules
that we've been detecting so far.
And looking down on the bottom line there,
the 4 molecules of particular interest I've shown you, we've got two of those,
but we don't yet have dimethyl sulfide
and we don't yet have the buttered popcorn.
Now I want to impress on you
that it doesn't mean that none of these molecules are out there in Space.
There's actually really really good reasons
to assume that they are out in Space,
and it's just that we haven't been able to detect them yet.
If you remember from this spectrum, this is how we detect the molecules.
But the way that you match up these peaks
is you have to know the frequencies for the molecules on Earth.
And the only way you can do that is go up to the chemist's
and be really nice to them, and say,
"Study this molecule very carefully in your lab,
then do some detailed calculations,
and then tell us exactly which frequencies they are,
and then we're going to look for them out in Space."
Out of all those molecules that we're missing at the moment,
we have no information on where their peaks are.
So they could well be in a spectrum like this.
If you look really closely at this spectrum,
you see there are indeed various places
where there are little peaks, and we have no idea
which molecules are responsible for them,
so it certainly could be molecules that we're missing.
So, as I'm finishing up here, I'd just like to take a step back.
We started off by asking a very simple question:
can we make beer in Space?
Some people might consider this a rather absurd question,
but what it does is it provides a very nice demonstration
of how science works.
We've asked a very simple question,
and in the process of trying to come up with an answer to that question,
we've managed to bring together two apparently unrelated areas of science:
astronomy and chemistry.
Now I don't pretend
that the only pursuit for astrochemistry is to find beer molecules in Space.
(Laughter)
But this question does provide a relevant and tangible link
between these two subjects.
As I've shown you already, astrochemistry is showing us
a rich complexity to the universe that we never thought existed before.
And of course astrochemistry brings us one step closer
to that ultimate, most noble of goals: finding beer in Space.
(Laughter)
Thank you.
(Applause)