For more than 60 years astronomers have been drawing a
rough sketch of a great future event that will transform the world: a
day when astronomers with their radio telescopes will receive a radio
message from extraterrestrials on some planet revolving around a
distant star. Based on the way such an event is imagined, you might
think of it as some kind of revelation of great clarity in which
suddenly our place on the cosmic totem pole is made crystal clear.
But it is all but certain that we will never receive any
message anything like this:
Greetings,
cosmic brothers! We speak to you from a distant planet 10,500
light-years away. We are members of a technical civilization
2,460,000 years more advanced than yours. Let us show you some of
our dazzling accomplishments, which will probably cause your puny
race to become sick with envy.
The reason we will almost certainly never receive a
message like that is because it is written in English. We could get
a message in English only under a very improbable scenario. It could
be that there was some extraterrestrial civilization relatively close
to ours – say, 25 light-years away. Such a civilization might have
picked up a radio signal transmitted from Earth after 1950. From such
a signal, that civilization might have figured out the rules of
English; and it might then have sent a radio message back to our
planet.
But this scenario is very unlikely. For one thing,
radio signals from Earth would be so weakened after traveling
light-years that it would be doubtful that any other civilization
could pick them up. For another thing, if intelligent life in our
galaxy was so common that there are civilizations only about 25
light-years away, we probably would have already received radio
signals from extraterrestrials; but we have not. For another thing,
it is very doubtful that anyone could figure out how to write a
message in English merely from receiving some radio signals in
English.
So in all likelihood if we get a radio signal from
extraterrestrials, it will not be in English. There's another
possibility often considered: we will get a radio message in some
extraterrestrial language; then scientists will figure out how to
translate that message into English, and the message will become
crystal clear. But it seems most unlikely that we could ever figure
out the meaning of some message written in some language that
originated on another planet. Such a language might have linguistic
rules and semantic complications that totally baffled us.
Another idea often discussed is that an extraterrestrial
radio message would not be written in the native language of its
authors, but would instead be a kind of pictogram. A pictogram can be transmitted by radio, using a system
in which an instant of non-transmission represents a white pixel, and
an instant of transmission represents a dark pixel. For an example of
such a pictogram, we can look at the plaque that was put on the
Pioneer space probe:
The image here attempts to transmit three main items of
information: a visual showing what humans look like, a depiction of
the solar system, and an indication of the position of Earth in our
galaxy. The method used to depict Earth's position in the galaxy is a
rather dubious one, involving listing relative distances from pulsars
and the position of the Earth. There would be a large chance that
anyone analyzing this message would fail to interpret this part of
the message correctly. One reason is that there are more than a
billion pulsars in our galaxy, so it would be hard to figure out
which pulsars the message was referring to.
Another example of a pictogram message is shown here.
The message is supposed to show a DNA molecule, a depiction of a
human, a depiction of some important chemicals, and a depiction of
the transmitting telescope.
Let us assume that an extraterrestrial radio message
would be some type of pictogram. Once the message had been received,
would any of these things be crystal clear:
- Would we know for sure the exact location where the message had come from?
- Would we know that the message had actually come from extraterrestrial life forms?
- Would we know how much older than us such extraterrestrial life forms were?
It seems that these things would be very much in
dispute, even after such a message had been received. For one thing,
there is the very general fact that a radio signal resembling a
signal from extraterrestrials can very easily be faked. One way to
do that would be to have a satellite or space probe transmit a radio
signal that was designed to look like an extraterrestrial radio
signal. The possibility of such mischief can hardly be dismissed in
light of the Russian interference in the United States 2016 election.
We know that Russia spent millions of dollars in an influence campaign that often resorted to
misinformation. Given that reality, there would always
be the possibility that a radio signal that we thought was coming
from another planet was actually coming from somewhere else in our
solar system, perhaps from one of the satellites or probes of China
or Russia or some other nation. There might be any number of reasons why a nation might
resort to such a trick. One reason is that such a ruse might be used
to create a distraction diverting public attention from some scandal
involving that nation. Or if a nation were planning on launching a
surprise attack or doing a military buildup, it might create illusory
“radio messages from extraterrestrials” to get the world's
attention focused on such a matter, and away from threatening troop
movements or weapons deployments the nation was starting to make.
Another reason for doubting the source of a message
claimed as coming from extraterrestrials is that such a message might
crop up as a result of computer hacking. The radio telescopes
scanning for extraterrestrial signals are linked up to computers and
software needed to analyze the signals. Such computers and software
might be subject to computer hacking. Hackers might download a fake
signal fooling astronomers into thinking they had received a message
from the stars. If this sounds too far-fetched, consider all the
shenanigans that went on during the 2016 election, in which quite a
few supposedly secure systems were broken into and tampered with.
Then there is the fact that religious theorists might
interpret any unnatural radio signal as a message from a divine
source, not a message from beings on some other planet. It is
interesting that the first movie made about the reception of
non-human radio signals was not the 1997 Jodie Foster movie Contact,
about the reception of extraterrestrial radio signals. It was
instead the 1950 movie The Next Voice You Hear, about humans
getting radio messages from God. If some apparently non-human radio
signal was received by astronomers, religious theorists would
probably jump in with speculations that this message was some kind of
revelation from some divine being. It would be hard to rule out such
a possibility, given the difficulty of determining exactly who sent
some message, particularly if such a message was some kind of
abstract or baffling pictogram.
Even if the message had some type of indication of a
particular location in the galaxy, this would not prove that the
message had been transmitted by extraterrestrials from such a
location. Religious theorists might speculate that the depicted
location was a special planet, and that the message was a message
about that planet – perhaps something telling us to search at that
location, or a message telling us about some special blessed
location that was particularly sacred or important.
There would also be theorists who might speculate that
the message was coming not from extraterrestrials but from some other
dimension – perhaps some kind of Other Side that is an afterlife
realm. If you object that no one would ever try to link a mysterious
radio signal with life after death, I may note that people have
already being making such a link for decades. For decades there has
been a phenomenon called Electronic Voice Phenomenon, in which people
report getting mysterious electronic messages, which may be either radio signals or words that appear unaccountably while recording in a quiet place. The people getting these
messages often claim that they are messages from some afterlife
realm. There is an Italian researcher named Marcello Bacci who
claimed to have received radio messages from some afterlife realm
for many years. People supportive of these claims might claim that
any new radio message of a non-human origin was another radio message
from some spiritual realm.
There might also be multiverse theorists who might
speculate that the mysterious radio message was not a message from
extraterrestrials but a message from some other universe. Conspiracy theorists might claim that the radio message was faked by some group of scientists looking for glory or more government funding. If the radio message was a one-shot affair, and not a repeating message, it would be hard to prove otherwise.
It seems hard to imagine any way that a pictogram
message could convey some of the basic facts about senders of a
message, such as how much more advanced than us the sender was. Such
a message might include a number listing how many years passed since
the civilization had started to develop technology. But we wouldn't
know what that number meant. The “year” used to state the age of
the civilization would presumably be the time it took the home planet
to revolve around its star, but that might be anywhere between one
tenth of a year and 100 years, leaving the age of the radio-transmitting civilization very uncertain.
If the radio message was some type of pictogram, there would probably be multiple ways to interpret each of the representations in the message. The multiple possibilities for interpretation would help lead to a long or permanent controversy. If the message was written in an alien language, there would be endless debates over whether a particular translation was correct.
If the radio message was some type of pictogram, there would probably be multiple ways to interpret each of the representations in the message. The multiple possibilities for interpretation would help lead to a long or permanent controversy. If the message was written in an alien language, there would be endless debates over whether a particular translation was correct.
A radio message of apparently artificial origin would be
comparable to a message in the clouds, in that it would be
interpreted by people in different ways, according to their
philosophical inclinations. For example, let us imagine that clouds
were to form a message in the sky, one stating: you are
being watched, so do not act badly. Such a message would be the start of a great
controversy. Theists would say that it was a message from God. The
non-religious would claim that it was a message from visiting
extraterrestrials, and that “do not act badly” was referring to
things such as “fighting too many wars” or “creating too much
global warming pollution.” Others would say the message had been
produced by humans. If only one such message was received, the
controversy would probably never end.
Similarly, a single radio message from a non-human source would probably be the start of an interpretation controversy which might never end, with an endless debate about whether the message was from extraterrestrials, hackers, a foreign disinformation squad, a divine being, an afterlife realm, or transmitters in another dimension or another universe.
Similarly, a single radio message from a non-human source would probably be the start of an interpretation controversy which might never end, with an endless debate about whether the message was from extraterrestrials, hackers, a foreign disinformation squad, a divine being, an afterlife realm, or transmitters in another dimension or another universe.