
The Size of the Human Radio-Broadcast Bubble in the Milky Way Galaxy - thegrossman
http://blog.jackadam.net/2011/the-tiny-humanity-bubble/
======
johnohara
_This makes me feel small, sad, and alone._

One man's opinion.

For me, I am grateful I live in a time when I can use a human invention to
view images, taken by another human invention, of galaxies 13.5 billion light
years away that probably no longer exist and be educated enough to sit down
and calculate in terms of miles just how far those specks of light have
traveled.

Aristotle, Caesar, DaVinci, Newton, Kepler, Napoleon, Faraday and Einstein
never saw what I have seen from my desktop.

Sad? No. Privileged.

~~~
51Cards
I agree... but it also makes me yearn for what will be seen after I am gone. I
constantly wish I could be frozen and woken up every 1000 years to see what
else we have learned about the universe. The fact my glimpse into the cosmos
is so fleeting does disappoint me.

~~~
Eliezer
<http://alcor.org/AboutCryonics/index.html>

------
mechanical_fish
"Space... is big. Really big. You just won't believe how vastly, hugely,
mindbogglingly big it is."

[http://en.wikiquote.org/wiki/The_Hitchhikers_Guide_to_the_Ga...](http://en.wikiquote.org/wiki/The_Hitchhikers_Guide_to_the_Galaxy)

And, really, this picture is just a fraction of a fraction of the down payment
on the concept of _big_ : This is merely an illustration of how big one galaxy
is. _There are eighty billion galaxies._ [1]

<http://en.wikipedia.org/wiki/Observable_universe>

\---

[1] Tune in tomorrow for a new estimate, of course.

~~~
AngryParsley
I find that reading huge numbers doesn't get the true scale across. It helps
to bring the relative scale down to human terms. There are 63,360 inches in a
mile. There are about 63,240 AUs in a light-year. So if the Earth was one inch
from the Sun, Alpha Centauri would be 4 miles away. In this miniature model,
the speed of light is around 7 inches per hour, or 1 mile per year, and our
fastest probes take 100 days to move an inch.

The galaxy sounds big at first, but only because our lives are so short. If we
built Von Neumann probes we could take over the galaxy in a mere million
years. That's nothing on a geologic time scale. The fact that the solar system
has sat around for 4 billion years without being eaten by Von Neumann machines
makes me pretty certain that we're alone.

~~~
CamperBob
_The fact that the solar system has sat around for 4 billion years without
being eaten by Von Neumann machines makes me pretty certain that we're alone._

That's quite a leap you're making. One very strong counterargument boils down
to simple economics: where's the profit motive in building a fleet of von
Neumann probes to 'eat' every solar system in the galaxy? Who is going to pay
for this effort, and what returns do they expect?

If it takes a million years to colonize a galaxy, then unless you plan to live
for _two_ million years you aren't going to see the full fruits of your
effort.

As a race our attention span seems to be narrowing. As far as I can tell,
despite or perhaps because of recent advances in applied science, we're
actually losing our propensity to engage in multidecade R&D projects. The next
LHC-scale project is going to be an almost impossible thing to sell to the
governments that will have to agree to finance it, and it would take years for
us to return to the Moon if our survival depended on it. We are most
definitely _not_ moving in a direction that will lead to the sort of
expansionism you're talking about.

Edit: here's another thing, with regard to the absence of 'radio bubbles' from
other civilizations. It's really, really dumb, from a technical perspective,
to transmit RF signals that are distinguishable from background noise. It
means you're wasting power and throwing away channel capacity.

Look at an HDTV transmitter on a classical spectrum analyzer sometime, and you
won't see much in the way of coherent structure -- you'll just see a pedestal
where the noise floor seems a bit higher than usual. This means that the
'radio bubble' is not a bubble, but two nested spheres with only about 100
light years of space between them. To observe emissions from an advanced
civilization, we need to look at just the right time, between the development
of RF technology and information theory. Otherwise we won't hear a thing.

~~~
AngryParsley
I guess the inferential distance between us is too great. A world in which we
colonize the stars is a world where we've fixed some of the problems today
(aging, death, existential risks from various technologies). I assume humanity
will change substrates to something that lasts a little longer than our
current bodies.

 _where's the profit motive in building a fleet of von Neumann probes to 'eat'
every solar system in the galaxy? Who is going to pay for this effort, and
what returns do they expect?_

You only have to build one Von Neumann probe, and there's a massive benefit to
taking over your light cone: You make sure nobody else does.

Even if million-year life spans are out of our reach, why does one have to
live to see the full fruits of one's effort? The world doesn't cease to exist
when you die.

~~~
CamperBob
_You only have to build one Von Neumann probe, and there's a massive benefit
to taking over your light cone: You make sure nobody else does._

So this hypothetical civilization has conquered aging, death, and the drive
for rapid gratification, but fails at elementary game theory?

~~~
AngryParsley
There's no game theory involved. A million years is a blink of an eye on an
evolutionary timescale. When the first civilization has Von Neumann machines,
their closest competitor is most likely primordial goo. See
<http://andabien.com/html/evolution-timeline.htm> to get an idea of how long
it takes for life to evolve.

Even if there were multiple civilizations in a galaxy, a single "defector"
civilization would have vastly more matter under its control than
civilizations that did not use Von Neumann probes to expand. With such a huge
advantage, they would quickly destroy all competitors.

~~~
CamperBob
_With such a huge advantage, they would quickly destroy all competitors._

Sorry, but I'm still not getting the 'advantage'. This strikes me as one of
those games where the only winning move is not to play.

~~~
AngryParsley
You don't understand how controlling a significant fraction of a galaxy's
matter is advantageous?

~~~
CamperBob
No, but then I don't understand the imperial incentive, even here on Earth.
I'm a fairly self-centered individual, and a lazy one at that... and as far as
I can see, running an empire _always_ seems to be more trouble than it's
worth. The whole history of the twentieth century can be written in terms of
the world's great powers discovering this little tidbit of truth. I believe
the first few decades of the twenty-first will see the US experiencing the
same global comedown that Russia, Germany, and Britain have already undergone.

Fortunately, the loss of its empire is a process that always seems to leave
the nation in question better off, at least in modern times. As I see it the
only possible justification for total galactic conquest is self-defense: do
unto others before they can do unto you, more or less as you put it. Any
advanced civilization that _doesn't_ see that as a self-defeating
justification is so different from my way of thinking that I couldn't possibly
deal with them on any terms, offensive or otherwise.

Basically, what you're saying is that the only way to survive and prosper in
the Universe is to be a murderous, psychopathic douchebag on a galactic scale.
Not down with that, sorry.

~~~
AngryParsley
Either you don't understand what I'm saying or you are purposely misconstruing
my words so you can have a convenient strawman to take apart.

~~~
CamperBob
_The fact that the solar system has sat around for 4 billion years without
being eaten by Von Neumann machines makes me pretty certain that we're alone_

Were these your words, or not?

You're projecting human flaws and attributes on an advanced race that would,
by necessity, be almost nothing like humans. It simply does not follow that
because the solar system has not (yet) been turned into grey goo, we must be
alone in the galaxy.

------
zoomzoom
"Two things fill the mind with ever new and increasing admiration and awe, the
more often and more steadily we reflect on them; the starry heavens above and
moral law within. . . The former view of a countless multitude of worlds
annihilates, as it were, my importance as an animal creature, which must give
back to the planet (a mere speck in the universe) the matter from which it
came, the matter which is for a little time provided with vital force, we know
not how. The latter on the contrary, infinitely raises my worth as that of an
intelligence by my personality, in which the moral law reveals a life
independent of all animality and even of the whole world of sense--at least so
far as it may be inferred from the purposive destination assigned to my
existence by this law, a destination which is not restricted to the conditions
and limits of this life but reaches into the infinite." (Kant, Critique of
Practical Reason, 1788)

------
JonnieCache
Try this if you want to feel really small AND really big at the same time:
<http://htwins.net/scale/>

WARNING: You may become nauseous, dizzy and afraid if you sit playing with
this for too long.

~~~
ceejayoz
The really amazing thing about that link is how much empty space we're made up
of on an atomic and subatomic level.

~~~
ars
On a subatomic (and subnucleonic) scale it's 100% empty space.

Fundamental particles are true point particles and no spatial extent has ever
been found for them.

So it's not just a lot of empty space - it's nothing except empty space.

------
ecaron
Am I the only one that sits and thinks "wait, I can barely get my local AM
station to come in clear enough to be understood - how could any signal
possibly be distinguishable beyond 1 lightyear?"

~~~
Udo
No, and you're absolutely right, too. The human radiosphere might technically
be 200 light years across, but that doesn't mean a meaningful amount of data
could be extracted from it. Yes, we are putting out a steady hum of energy,
but it's hardly announcing our presence. Were it not for high energy radar
systems deployed on Earth, we could not even detect a civilization down here
from any point in our own solar system, much less decipher any of the data
being transferred. And as our civilization matures, the amount of energy
radiated into space is actually shrinking.

That said, 200 light years is an enormous size. Everything that is large
enough to take up more than one pixel on the map of our galaxy if freaking
huge! People may disagree about the factual relevance of the radio bubble, but
it's still immensely cool that we managed to project something this big out
there into the world. Looking at this beautiful image of the Milky Way and
seeing the unstable little flicker centered on our humble home, I can't help
but wonder how many other radiospheres are out there and when they might
finally overlap with ours (if they haven't already).

~~~
jdelanoy
An intelligent race which knows anything about stars would note that Sol has a
disproportionately large output in the radio spectrum. This would likely
attract considerable attention and debate as to the cause. Careful analysis
would reveal a very precise and regular Doppler shift lasting approximately
365.25 days...

------
yuvadam
This kind of stuff always blows my mind away.

How insignificant we all are, in the grand scheme of things.

(Then my mind overflows when I ask myself the question of "what the hell _is_
the universe?")

~~~
jamesbressi
I can practically give myself an aneurism thinking the following when
contemplating how it all began:

Try and put religious arguments aside (while this will have some overtones)
for a moment and work with me here and not throw the notion of time having no
beginning or end which is equally frustrating to comprehend.

Reverse the creation story and you wind up at the beginning with light and
darkness. Before light there was darkness or nothing.

But what was before the "darkness" or nothingness? The religious will say God
whom has no beginning or no end, but how did God or energy pop into to
existence if there was nothing?

Then, put yourself in God or energy's place... You are in a "space" with
nothing around you... everything is void... Then where did "you" come from?

I know this is linear thought and time and the universe should not be
considered in this way many in the field of science and mathematics explain...
I understand the many dimensions that are possible and how time should be
viewed, but it still doesn't answer the question of how something, anything
came of nothing...

~~~
Retric
That's a limited viewpoint.

One idea is that time and space started with the big bang. So asking what
happened before the big bang is somewhat pointless because causality did not
exist. Things could happen without cause or consequence.

PS: Our preconception of how reality operates break down on the vary large,
the vary fast, and the vary small. Trying think how things operate without
matter, energy, space, or time is something of a fool's errand IMO.

~~~
makmanalp
Could you expand upon how causality can cease to exist or what would cause
(heh heh) such a thing?

~~~
mey
There is the concept of the heat death of the universe.
<http://en.wikipedia.org/wiki/Heat_death_of_the_universe>

Essentially, as particles expand and spread out, the universe will reach a
point where there is not enough energy localized in one area to support
anything.

Of course this is just one theory. etc etc

------
Swizec
Pale blue dot feels like an apt comparison -->
<http://en.wikipedia.org/wiki/File:Pale_Blue_Dot.png>

If you don't know yet, that's what earth looks like from just beyond Pluto's
orbit.

Also interesting to note in these discussions is the Hubble deep field image.
These 3000-ish galaxies are covered by a quarter at arm's length when you look
into the sky --> <http://en.wikipedia.org/wiki/File:HubbleDeepField.800px.jpg>

We are indeed small and insignificant, but alone? Doubtful at best.

~~~
pbhjpbhj
>We are indeed small and insignificant, but alone? Doubtful at best.

If we're the only (or even just one of few) intelligent beings (!) in the
Universe then our significance is huge.

~~~
Vivtek
If we're the only intelligent beings in the Universe, then I argue that
intelligence is overrated, thus our significance (except to ourselves) is
negligible. Unless you go the route of arguing that without intelligence,
there is no significance, and thus our self-significance is all the
significance there is, in which case you're right - it's huge.

------
robotomir
"...there is an ever-expanding bubble announcing Humanity’s presence to anyone
listening in the Milky Way."

This 200ly sphere does not equal detectable radio signals from Earth. SETI is
looking for radio signals from the stars, yes, but they are looking for a
focused and high-energy attempt from ETs to contact someone by beaming at
specific stars. Radio "leaked" from regular transmissions typically does not
carry a signal over interstellar distances.

~~~
spiralganglion
That's something I want to know. With the amount of energy given to our
broadcasts, they surely would decay long before traveling any noteworthy
distance. I'm curious as to what our most powerful broadcasts have been, and
how far they'd travel before becoming unnoticeable. Especially, when compared
to the amount of EMR released by neutron stars, pulsars, background noise,
etcetera.

~~~
robotomir
From the SETI FAQ: "Detection of broadband signals from Earth such as AM
radio, FM radio, and television picture and sound would be extremely difficult
even at a fraction of a light-year distant from the Sun. For example, a TV
picture having 5 MHz of bandwidth and 5 MWatts of power could not be detected
beyond the solar system even with a radio telescope with 100 times the
sensitivity of the 305 meter diameter Arecibo telescope."

Now, the Arecibo message should carry over a couple of hundred light years
easily, but it was transmitted for three minutes only, and if you miss it, you
miss it.

~~~
meric
Not if you have faster-than-light travel!

If they don't, it would seem pointless to contact aliens, by the time they
send their ambassador on a multi-generational ship to Earth we humans may have
already been extinct.

~~~
btipling
FTL is probably not ever possible no matter how technologically advanced a
society may be as it would allow for the violation of causality.

~~~
ceejayoz
You're assuming we already know everything there is to know about causality.
It wasn't long ago that some people thought the sound barrier was
insurmountable, or that trains would kill their occupants by going too fast.

~~~
AngryParsley
FTL is equivalent to time travel into the past. If you have one you have the
other.

People thought humans wouldn't break the sound barrier for engineering
reasons, not because the laws of physics prevented it. And just because people
in the past thought something was impossible doesn't mean it will one day be
possible. 100 years ago, physicists thought perpetual motion machines were
impossible.

~~~
khafra
Thanks for saying what I wanted to. Everybody who knows nothing about physics
always brings up the "humans can't possibly travel faster than 25mph" thing
when someone who does know talks about violating causality, but as far as I've
seen it was only printed in a newspaper or two, not espoused by physicists.
The speed of light limitation is a necessary part of one of the most precise
and thoroughly tested theories of all time.

------
pohl
I'd like to see this plotted on two dimensions, where the horizontal axis is
the year, starting when radio emissions began, and the vertical axis is the
number of non-sol star systems that are within the bubble at that time. Binary
or trinary systems would count as 1 system, not 2 or 3. This function would
obviously be monotonically nondereasing.

I wonder if wolfram alpha could rise to the challenge.

~~~
spullara
Using the NStED database of stars I find that there are 11,384 cataloged stars
within a 200 light year bubble. I thought that it would probably follow an r^3
function but it appears that it follows something closer to an r^2 function -
perhaps that is explained by the flatness of the galaxy or just noise? For
example, within 20 light years there are only 77.

Stars by Distance: <http://dl.dropbox.com/u/3924269/plot_10956.jpg>

NStED: <http://nsted.ipac.caltech.edu/>

~~~
ars
Yah, the galaxy is very flat. Depending on how you define the thickness (do
you go by majority of stars, or include all outliers) proportionally the
galaxy is flatter than a sheet of paper.

~~~
AngryParsley
I don't think that's true. Other galaxies don't appear as thin or as flat as
paper. (Examples: <http://apod.nasa.gov/apod/ap031008.html>
<http://apod.nasa.gov/apod/ap020703.html>
<http://apod.nasa.gov/apod/ap060612.html>) Typically they're about 100x wider
than they are thick.

~~~
ars
<http://www.astronomycafe.net/qadir/q546.html>

"....the thickness of the Milky Way is 50/100000 or 5/10000 of its maximum
size making it flatter than a sheet of writing paper."

You can not calculate how flat something is by estimating from such a photo!

~~~
AngryParsley
Wikipedia says the stellar disc of the Milky Way is 1,000 light-years thick
and cites
[http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980317b....](http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980317b.html)
. The core is thicker. Even the image on the page you linked to shows an
object that is much thicker than a piece of paper.

~~~
ars
Did you miss the part where I said: "Depending on how you define the
thickness" ?

The milky way does not have a clear cut end, so you need some kind of
definition on where to stop, and there are many ways to do so.

And you should stop estimating thickness by looking at photos. Brightness
often masquerades as thickness in photos.

~~~
gjm11
Yes, there are many definitions. None of them, however, gives the result that
the Milky Way is flatter than a piece of paper. Not even the (rather silly)
one used by the author of the web page you quoted; his numbers are wrong.

------
meric
Is the milky way really large or is 200 years a really short time?

Galileo was born only about 164000 days ( ~ 4 million hours ) ago.

And that's already over twice as long as 200 years.

It makes me sad when I think about how a life time is a mere thousand months.

------
teaspoon
Even more discouraging than the size of the bubble is what the bubble's cross-
section looks like:

[http://www.smbc-comics.com/index.php?db=comics&id=2004#c...](http://www.smbc-
comics.com/index.php?db=comics&id=2004#comic)

------
ck2
But maybe, just maybe, our industrial and scientific development is producing
an occasional side-effect of some kind of as yet-unknown faster-than-light
wave which has made it much further out, and significantly more advanced
civilizations have the ability to detect it.

Sort of how an archaeologist can look at the surface of earth in a sat. photo
and determine there was once human activity in a location based on ground
disturbances, etc.

~~~
jasamer
Of course, such a wave would be pretty bad news for a certain theory proposed
by a certain Albert.

------
rdamico
It would be interesting to know how much of the Milky Way SETI has scanned so
far. In other words, if someone else out there was running their own version
of SETI, how long before they would be likely to find our little radio
broadcast bubble?

------
tow8ie
This reminds me of the opening scene of “Contact” (1997), the movie adaptation
of Carl Sagan’s novel by Robert Zemeckis:

<http://www.youtube.com/watch?v=vGyq7d62oPQ>

------
pessimist
To put the blue dot in perspective, its unimaginably beyond the scope of our
current technology to travel that far. Pluto by comparison is 13 light-HOURS
away and it takes about 10 years to get there. At that rate, it would take
approximately 150000 YEARS to reach the same distance to reach the perimeter
of that blue bubble. And blue bubble is almost insignificant in relation to
our galaxy, which is one of about 100 billion galaxies!

------
iwwr
Sadly, it would not be possible to discern manmade radio transmissions from
further than a few light-days/weeks.

Also, as communication capacities increase, more and more of that is moving
into cables and not radio transmitters. High-power Earth-Satellite and Earth-
Earth transmitters are being replaced with low-power point-to-point wireless
links. The power of radio traffic leaking off the Earth is not growing very
much, if at all.

------
evo_9
To me this is really inspiring.

I look at that and think 'Wow, our presence is already felt that far/wide and
we've barely started to walk'. Incredible.

------
Jach
Oh, it's a blog entry! There really should be a noscript warning, I thought it
was something like <http://www.phrenopolis.com/perspective/atom/> at first.

------
aufreak3
Cool! .. and all this discussion reminds of a line from Calvin and Hobbes -
"Sometimes I think the surest sign that intelligent life exists elsewhere in
the universe is that none of it has tried to contact us."

------
dhughes
It's odd how you look at that and go "hunh" but then realize, wait a minute
who took the picture of the Milky Way Galaxy?

It's a graphic of course but still you forget what you're looking at and how
far away and how big it is.

------
ogrisel
You should cheer up that we are living in the Slow Zone. That should make us
unaffected by the "Straumli Perversion" and other Powers from the Transcend
and messing with the Beyond for quite some time.

------
athom
Sure-fire way to feel small, sad, and alone: typekit.com

Seriously, the page was completely empty until I unblocked that scripts on
that and his main site.

------
gaius
Ugh, what is that horrible font? Whatever typekit.com is trying to do (in
Firefox 3.6 on Windows 7) isn't very working...

------
jaekwon
This makes me more hopeful of getting a response from other beings. Perhaps
we're not so alone after all.

Relax, it's PhysEx.

------
malkia
Some alien might think - hmmm.... Human Spam again :)

~~~
iwwr
Spiced human ham would likely be incompatible with any alien metabolism.

------
VB6_Forever
Curiosity apart what good could it do us to discover or be discovered by
aliens?

~~~
hydrazine
All in the name of technology..

Assuming no ETs exist within our 200ly bubble, if ETs somehow discovered our
signal and made contact, our level of knowledge would jump a few centuries at
least.

~~~
ars
If there are no ETs within the bubble how can they discover the signal?

~~~
hydrazine
Sorry, I meant discover as in through our bubble's reaching them in the future
(ensuring they're at least 100ly away).

------
derleth
Ha. So, we don't even rate a single pixel on the blank, white screen that is
the Universe? Sounds about right.

