The Sagan Paradox, Chapter 1: The Golden Record

Introduction and Carl Sagan’s Early Work

Artwork inspired by Linda Salzman Sagan’s design for the Pioneer plaque, commissioned by NASA: click here view the original design

Carl Sagan (1934–1996) was an American astronomer, astrobiologist, and author. After NASA was founded in 1958, Sagan became a consultant for the agency. His first job involved planning the explosion of an atomic bomb on the moon, the A119 project. Highly controversial, to say the least. In 1961, at the age of 27, he published a study on the atmosphere of Venus. In 1970 he researched the conditions that could lead to the emergence of life in the cosmos on distant planets. To achieve this, he exposed frequently occurring elements to the UV radiation of a young sun and observed how amino acids, the building blocks of life, were formed from them. Carl Sagan became a full professor at the astronomy department at Cornell University. Around this time, talk shows began inviting him as a popular guest to discuss the possibility of extraterrestrial life.

Reference: Carl Sagan, Long wavelength ultraviolet photoproduction of amino acids on the primitive Earth

“Hello, Aliens!”: Voyager Probes Get Sagan’s First Broadcast

In 1972 and 1977, Carl Sagan sent the first messages to extraterrestrials into space on the panels of the space probes Pioneer 10 & 11 and the Golden Record of Voyager 1 & 2.

The gold-plated aluminum cover (L) of the Voyager golden record (R) both protects it from micrometeorite bombardment and also provides a key to playing it and deciphering Earth’s location. NASA

It contains greetings and wishes for peace from the people of Earth in 55 languages. Earthlings extend their friendship, wish happiness and health, and express hope to one day meet their cosmic neighbors. They also express the desire for goodwill and harmony among all beings in the universe.

Reference: Golden Record Greetings – NASA Science

Each of the Voyager spacecraft, launched in 1977, carried a golden phonograph record. One of its purposes was to send a message to extraterrestrials who might find the spacecraft as it journeyed through interstellar space.

The greetings are in alphabetical order, from Akkadian (an extinct language for over 2000 years) to Wu Chinese. The inclusion of Akkadian in this earthly record is pretty strange. One day, these transmissions might be intercepted as they pass through space by an alien culture.

Voyager’s ‘Cosmic Map’ Of Earth’s Location Is Hopelessly Wrong

With the help of the included pulsar map, these aliens could potentially find Earth. Pulsars are stars that rhythmically emit radiation, like interstellar lighthouses. We can use them as a cosmic GPS.

Pulsar GPS: Sagan’s Star-Beacon Timecode Reveals 1971 Earth

Over long periods of time, the frequency of a pulsar slows down. Thus the pulsar map designed by scientist Frank Drake and graphic artist Linda Salzman Sagan is not only a determination of the position of our Earth in space, but the map also precisely pinpoints the position of Earth in time: 1971.

What if a prospective alien civilization has or develops the ability to time travel? What would they do with the information provided by our space probes?

Speculation about the subject makes for the greatest sci-fi story ever told. This is particularly true when we consider the included Mesopotamian-language greeting and the Annunaki creation myths—some of which have been popularized by Zecharia Sitchin and others.

Of course, intercepting our space probes is extremely unlikely. It could take millions of years, if at all. But then again, the life expectancy of the Golden Records is 5 billion years.

May 1, 2025May 13, 2025

Could the Voyager spaceprobe make contact with an extraterrestrial intelligence sooner or later, and could the aliens trace it back to Earth?

Artwork inspired by Linda Salzman Sagan’s design for the Pioneer plaque, which aimed to communicate with extraterrestrial intelligence, commissioned by NASA: click here to view the original design

The Ocean of Time

Consider this: The cosmos is an ocean of time, vast and unfathomable. The future and the past may not be fixed shores but fluid horizons, ever-shifting. If time is a river, might there be civilizations advanced enough to navigate its currents? They could potentially voyage upstream against the flow and visit epochs long gone. Suppose such beings exist, they might step into our present, or even our yesterday, with technology that bends the fabric of spacetime itself. We can only speculate if extraterrestrial intelligence might be capable of such feats.

Messengers of Earth

Think of the Voyager probes, those celestial arks launched in 1977. They carry golden records engineered to last 5 billion years, etched with the sounds and stories of Earth. Drifting through the interstellar dark, they are destined to wander for millennia before brushing the icy fringes of the Oort Cloud, possibly to be found by extraterrestrial intelligences in the future.

Pioneers of the Unknown

And what of Pioneer 10 and 11, their plaques engraved with symbols and figures—a map to our tiny blue world? These messengers preceded Voyager by four years. They were charting a path through the unknown, potentially reaching minds skilled in decoding messages intended for extraterrestrial intelligences.

The Cosmic Recursion

Here we drift into a cosmic recursion—a loop of cause and consequence as enigmatic as time itself. Suppose it is not the distant future that answers our call, but the act of calling that creates the future. Could our probes, these fragile artifacts of hope, be both message and catalyst? A whisper that echoes backward through the aeons, compelling beings of tomorrow to seek the source of their own curiosity.

The Search for Answers

If a civilization unbound by time found Voyager or Pioneer adrift in the interstellar void, would they not use the pulsar map to trace its origin back? They could return to the blue-green world that cast it forth. And in doing so, might they not feel compelled to visit the time when it was launched? They might be drawn by the poetry of a planet daring to announce, “Here, we exist,” a statement echoing the hope of encountering extraterrestrial intelligences.

Unearthing Secrets

Imagine this: A civilization, millennia hence, unearths Voyager in the icy depths of the Oort Cloud. They decode its songs and its images of Earth’s shimmering biosphere, and wonder: Who were these beings? Did they survive their adolescence? Such reflections might prompt interaction.

Invitations to Explore

The probes, then, become not just messages but invitations. A handprint on the cave wall of spacetime, saying, “We are here. Come find us.” They serve as signals beckoning extraterrestrial intelligence to respond.

The Gift of Causality

By having declared our presence to the universe, we planted a seed in the garden of causality. Maybe a future civilization, emerging from the same evolutionary currents that shaped us, might trace their own lineage back to this moment. It was a moment when a fledgling species, trembling on the edge of self-destruction, chose instead to reach outward.

Sacred Relics?

To them, the Pioneers and Voyagers might be sacred relics, the genesis of their own yearning to explore. And so they return, pilgrims to their cradle, to ensure the message endures.

The Question of Solitude

And so we are left to wonder: Are we alone, or are we unknowingly surrounded by emissaries from tomorrow? In sending our songs and salutations into the dark, we cast a line not just across space, but through the infinite corridors of time. Who, or when, might one day tug the other end and reveal the existence of extraterrestrial intelligence?

A Silent Witness

Perhaps, even now, the answer is quietly orbiting the Sun or our planet—a silent witness to the audacity of a species. We dared to reach beyond our epoch and into the unknown.

December 20, 2024February 27, 2025

Notes about time travel

The Grandfather Paradox / How Does Time Travel Work? / How to Travel Into the Future / 1. The Waiting Game / 2. Time Dilation / 3. Suspended Animation / 4. Traveling as a Time Tourist / 5. Changing History Through Time Dilation

The Grandfather Paradox

The grandfather paradox raises a troubling question: What would happen if you traveled back in time and killed your grandfather? In that scenario, your grandfather would indeed be dead, just as he would be if you killed him in the present. However, this creates an inconsistency—you would still exist, since you’ve already been born. Essentially, you cannot simply “unborn” yourself. This is a basic question when considering how does time travel work.

How Does Time Travel Work?

To travel back in time, you would need a superluminal vehicle, which is capable of moving faster than the speed of light. To reach your intended destination, you must aim it at specific coordinates in both space and time. It’s important to note that Earth and the solar system are constantly moving at high velocities through the cosmos. Fortunately, superluminal vehicles can match these speeds.

To successfully arrive at your destination without incident, precise timing is essential. As you plan your journey further back in time, the calculations become increasingly complex. To ensure safe arrival, it’s advisable to target the space surrounding Earth rather than the planet itself to avoid collision. Ultimately, you would need to use a smaller ship to land. You would approach Earth from outer space.

How to Travel Into the Future

There are several methods to travel into the future—specifically, five intriguing ways, explaining different aspects of how does time travel work.

1. The Waiting Game

The simplest method is to simply wait. All of us are constantly moving into the future at a steady pace of one second per second. While our mental states can influence how we perceive the passage of time, the rate at which time moves remains consistent for everyone. However, time does flow differently depending on gravitational conditions. For instance, at sea level, time passes more slowly than it does at the top of a mountain, where gravity’s influence is weaker.

2. Time Dilation

Time dilation offers another fascinating approach. If you’re inside a moving object, such as an airplane or a rocket ship, time slows down for you relative to those who remain stationary. If you were to accelerate that rocket ship to the speed of light, time would effectively come to a standstill for the occupants. Upon returning to the launch site after traveling at near-light speed, you would find that everyone left behind has aged significantly. If the journey lasted for many centuries, those back on Earth would have experienced the full passage of that time. Meanwhile, you remained unchanged. This principle is critical in understanding how time travel works in theory.

3. Suspended Animation

Another method involves suspended animation. Our bodies age and progress through time at a constant rate due to our metabolism and the Brownian motion occurring within our cells. By slowing down or halting these processes, one could enter a deep sleep and awaken decades or even centuries later, having aged not a moment.

Returning from Your Past After Time Travel
When it comes to returning to the future after time travel, there are two scenarios to consider, depending on your intentions. One involves traveling as a tourist. The other, aiming to change history.

4. Traveling as a Time Tourist

In this scenario, you commandeer a faster-than-light spacecraft. Direct it toward the approximate position in space where Earth will be after a millennium. Since you can’t perceive where Earth will be in a thousand years—because it hasn’t reached that point yet from your current perspective—you must rely on your knowledge of the timeline. If you traveled to the past using a faster-than-light spacecraft and then returned, you would find that, despite any previous changes, like hypothetically killing your grandfather, the course of history remains remarkably unchanged. Your grandfather would still be alive. You’d walk away with a fascinating story to tell.

5. Changing History Through Time Dilation

5. **Changing History Through Time Dilation**
Conversely, if you choose to travel from your past into the future via the time dilation method—perhaps by orbiting Earth at near-light speed—you would arrive in a timeline drastically altered by your actions. In this case, you might find yourself in a “beta universe” where your grandfather never existed. Consequently, neither would you. While you could observe this altered reality, it doesn’t pose a problem since you hail from a different branch of the multiverse (the “alpha universe”). Thus, even though you have no place in the beta universe, your past experiences in another universe endow you with a unique perspective. It’s a critical aspect when debating how time travel works across different realities.

By understanding and leveraging these methods, the concept of time travel transcends mere science fiction. It invites us to explore the mysteries of our existence and the nature of time itself. This essentially answers the question: how does time travel work?

Quantum time travel: The experiment to ‘send a particle into the past’

Time loops have long been the stuff of science fiction. Now, using the rules of quantum mechanics, we have a way to effectively transport a particle back in time – here’s how