In the New Testament the book of John begins with In the beginning was the word. Whether a poetic reflection on philosophy or a declaration of belief, it embodies an idea that has been around for a long time. If the cosmos had been created either by advanced aliens or by a divine creator, could that architect have buried a message in the universe? Absolute evidence of deliberate design.
The message doesn't have to be profound. It could be as simple as Kilroy was here, or as Douglas Adams suggested: Sorry for the inconvenience. But it would have to be extraordinarily clear and buried in a way that it would be impossible for mere mortal civilizations to forge.
Looking for a message from space. Photo credit: UCLA SETI Group / Yuri Beletsky
Carl Sagan suggested mathematics as a possibility. In Contact he described how a message could be buried deep in the digits of pi. Others have suggested that the evidence lies within the physical constants of the universe, arguing that some sort of anthropic principle points to a cosmic designer. Another idea is to look for a message in the light of creation itself, the cosmic microwave background.
The idea was first suggested in 2006 with an article published in Modern Physics Letters. In the work, the authors showed how a clear message can be planted in the cosmic microwave background by optimizing the cosmic initial state using the so-called basic Lagrangian. The idea was later popularized in the television series Stargate Universe, in which the old Stargate builders refer to the message as "the fate of all things".
Astronomers have long searched for structures within the CMB. Whether it is unusual cold spots or statistical anomalies, the CMB structure could be indicative of both new physics and evidence of parallel universes. So far these studies have yielded nothing, but that hasn't stopped a new study from specifically looking for a message in the cosmic background.
If you're looking for a message, you might find a fake one. Credit: Know Your Meme
It is one thing to argue that a sufficiently advanced civilization could bring a message to the CMB. Trying to find this message is something entirely different. One of the biggest problems with finding patterns is that you often see them even when they aren't there. So this new work is proceeding very carefully. Instead of looking for a specific message, it checks whether the hypothetical message differs from the random one. The author takes data from the WMAP and Planck surveys and expresses temperature fluctuations as a range of services. This is a common way to study the extent of CMB variability. Using an average value as a limit value, the fluctuations can be translated into a sequence of binary numbers.
The author then argues that if this string of roughly 1,000 bits contains a message, it should at least deviate from purely random noise. Testing the string for randomness using statistical rounds of testing shows neither a pattern nor a comparison with mathematical constants such as pi or phi. The cosmic microwave background is apparently random noise.
So if the first ones left a message in the CMB, they hid it really well. Or they don't exist and the only messages the universe can deliver are the answers to scientific questions we raise.
Reference: Hsu, Steven and Anthony Zee. "Message in the sky." Modern Physics Letters A 21.19 (2006): 1495-1500.
Reference: Michael Hippke. "Looking for a message in the angular power spectrum of the cosmic microwave background." arXiv preprint arXiv: 2011.14435 (2020).
Hat tip to Moiya McTier.