SETI and Alien Quantum Communications

TL;DR

SETI may be missing alien communications because signals can be transient, extremely weak, spread across billions of radio channels, or based on quantum technology rather than familiar classical radio. A transmission that repeats only every thousand years could appear to be a meaningless one-off, while current searches cannot monitor everything continuously. Read on to see how signal timing, targeted searches, radar, and quantum communications shape the search.

Transcript

Within the history of SETI there has always been the question of whether we’d actually be able to identify an alien signal of some type, whatever that may be, even with a simple radio signal. This is a problem on multiple counts. After all, even with just a radio signal that repeats, how do you know what an alien’s timescale is for repeating? We ma... Read More

Key Insights

• 👾 Identifying alien signals is challenging due to uncertainties in repeating patterns and the vastness of space.
• 👨‍🔬 The electromagnetic spectrum has billions of channels, making the search for narrowband technological stations difficult.
• 😒 The use of targeted searches and monitoring periods poses limitations in detecting alien signals.
• 😒 The potential use of quantum communications by advanced civilizations could explain the lack of detected signals and offer better possibilities for detection.
• 👽 Quantum communications offer advantages in security, computation, information transfer, and could be a potential communication method for advanced alien civilizations.
• 🥺 Current SETI searches focus on classical radio communications, but technological advancements may lead to new forms of communication.
• 👽 Monitoring technologies may need to evolve to detect and decipher potential alien quantum communications.

Questions & Answers

Q: Why might SETI fail to detect alien communications?

Alien signals may be weak, transient, aimed elsewhere, or transmitted in an unfamiliar form. SETI must search billions of radio channels and cannot monitor every part of the sky continuously, so even a genuine signal could be missed or dismissed as a one-off.

Q: Why is it difficult to identify a repeating alien radio signal?

Researchers do not know the timescale an alien civilization might use. A signal that repeats every 100, 200, or thousand years would probably appear only once during human observations and might not meet the criteria for an interesting signal.

Q: How does the Wow signal illustrate the problem of transient signals?

The Wow signal was detected but never observed repeating. Since 1977, observations of its area have added up to only about a month across four decades, so a signal with a long or unknown repetition period could easily escape detection.

Q: Why do billions of radio channels make SETI searches difficult?

The electromagnetic spectrum can be divided into billions of channels, each representing a frequency where a narrowband technological signal might appear. Searching them is especially difficult across light-years because signals weaken as they travel through space.

Q: How do targeted SETI searches work?

Targeted searches point observations directly at a star system and check for detectable signals. This approach addresses the vast search space, but nothing has been found so far, and brief observations can miss intermittent transmissions.

Q: Why might advanced aliens continue using radio and radar?

The transcript argues that useful technologies can persist, comparing radio with humanity's continued use of fire. Radar works well over large scales, and the former Arecibo telescope used powerful radar pulses to map asteroids economically.

Q: Why could alien radar signals still be hard to detect?

Radar can produce signals far stronger than ordinary communications, but individual uses may never repeat. The radar pulses used to map particular asteroids, for example, were sent once, so an observer would have only a brief opportunity to detect them.

Q: Why should SETI consider alien quantum communications?

SETI has primarily searched for classical communications resembling the radio signals humans produce. Quantum communications offer advantages in security, computation, and information transfer, so advanced civilizations might use them; monitoring technology may therefore need to evolve to detect and decipher such signals.

Summary & Key Takeaways

• The ability to identify alien signals, even with simple radio signals, is challenging due to uncertainties in their repeating patterns and our limited ability to monitor the vastness of space.

• Targeted searches have been the focus, but the weak signals and the vastness of space make it difficult to detect anything.

• The potential use of quantum communications by advanced alien civilizations could explain the lack of detected signals, and there is potential to detect these signals in the future.