Danny Hillis (Long Now Foundation Co-founder) – The Trouble with Rockets & Designing for 10,000 years (Oct 2020)


Chapters

00:00:00 Understanding Rocket Efficiency and Limitations for Space Exploration
00:12:16 Spacecraft Propulsion Methods and Limits
00:26:56 Space Propulsion Technologies and Future of Long-Term Space Exploration
00:31:28 Building a 10,000-Year Clock
00:37:42 Engineering Longevity: Constructing the 10,000-Year Clock
00:43:51 Relating Human Timescales to Geological Time
00:49:57 The Clock of the Long Now: Time Beyond Human Scales
00:54:32 Creating Clocks for the Far Future

Abstract

Long-Term Thinking in Space Exploration and the 10,000-Year Clock: Charting Humanity’s Future in the Cosmos and on Earth

The field of space exploration and the ambitious construction of the 10,000-Year Clock by Danny Hillis embody humanity’s quest to transcend temporal and spatial boundaries. This article, rooted in an inverted pyramid style, delves into the intricate relationship between these two monumental endeavors, highlighting the necessity for long-term thinking in both fields and exploring the challenges and possibilities they present.

The Crux of Space Travel: Propulsion and Distance

At the forefront of space exploration lies the challenge of propulsion technology. Chemical rockets, while efficient for reaching Earth’s orbit, fall short in interplanetary travel due to their limited specific impulse (ISP). Although atomic rockets offer higher ISPs, their complexity and environmental risks are significant obstacles. Laser-powered rockets, an emerging technology, promise even higher ISPs, but are still in conceptual stages. Interstellar travel, a distant dream, remains unattainable with current technology.

Delta V and Rocket Efficiency:

To understand propulsion challenges, the concept of delta v, or change in velocity, is vital. Rockets require a specific amount of delta v to reach different orbits and planets, which is determined by the distance between the starting point and the destination. The rocket equation illustrates the relationship between delta v, rocket efficiency, and payload capacity, showing that rockets become exponentially less efficient with increasing delta v.

Chemical Rocket Fuels and Their Limitations:

Chemical rocket fuels, such as gunpowder and jet fuel, have specific impulses ranging from 0.3 to 80 seconds. Solid rockets, like those used in the Apollo program, have specific impulses of just a few minutes. The best chemical rocket fuel, a hydrogen oxygen rocket, has a specific impulse of around 450 seconds, which is used for long-distance space missions.

The 10,000-Year Clock: A Testament to Longevity and Vision

Contrasting the vastness of space, Danny Hillis’ vision for a 10,000-Year Clock encapsulates the essence of long-term thinking on Earth. Inspired by the foresight demonstrated at New College, Oxford, Hillis embarked on creating a timepiece that would endure for millennia. This clock, with its intricate mechanics and astronomical displays, is not just a feat of engineering but a symbol of the possibility of lasting human achievements.

Synergies and Symbolism: Space Exploration and the 10,000-Year Clock

The parallels between long-term space exploration and the 10,000-Year Clock are striking. Both fields demand thinking beyond traditional timeframes, embracing challenges that span generations. The clock, a symbol of a long future, complements the exploration of space – a journey into the vast and unknown. These endeavors also highlight the brevity of human existence against cosmic and geological timescales. Hillis’ clock, with its emphasis on astronomical time units and its portrayal of the zodiacal and solar cycles, resonates with the temporal complexities encountered in space travel, such as time dilation and barycentric time.

The Shrinking Future:

Danny Hillis reflects on how people’s perception of the future has been diminishing over time, with the year 2000 serving as a constant endpoint. This shrinking future prompted Hillis to conceive the idea of a clock that would span a time frame far beyond the scope of individual human lives.

Inspiration Behind the 10,000 Year Clock:

Hillis’ desire to work on a project with a lifespan far beyond his own led to the conception of the 10,000-Year Clock. He envisioned a hidden clock deep within a mountain, accessible through a spiral staircase, revealing the date of the last visit upon winding.

Challenges of Building a 10,000 Year Clock:

Recognizing the limitations of electronics, Hillis focused on simple mechanical mechanisms for the clock’s longevity. Early prototypes, including one with an astronomical display and an orrery, were built and can be seen at the Long Now Foundation in San Francisco.

Site Selection:

Hillis searched for a suitable location and eventually found an isolated area near the Texas-New Mexico border with the right geology and a south-facing cliff. Jeff Bezos, a friend of Hillis, volunteered his land for the clock project and assisted in funding its construction.

Construction Logistics:

Transporting construction equipment and materials to the remote site posed challenges, necessitating the construction of roads and a temporary city for the workers. Plans for building a 40-foot tunnel leading to a chamber were revised for a less ambitious approach due to practical considerations.

Initial Inspiration and Planning:

Hillis’ initial inspiration came from a cave drawing depicting a hidden cave with a clock inside a mountain. The project involved blasting into the mountain, constructing an entrance, and discovering a natural cave aligned with Hillis’s drawing.

Excavation and Construction:

Tunneling began from both the bottom and the top of the mountain, eventually connecting to form a 500-foot shaft. A giant reamer was used to create a four-meter hole extending to the top of the shaft.

Staircase Creation:

A robot with a diamond saw was designed to climb up the shaft and cut a 300-foot staircase as it ascended. Numerical control ensured precision and accuracy in the staircase’s construction.

Mechanism and Material Challenges:

Creating bearings and components that would endure for 10,000 years was a significant challenge. Ceramic bearings and giant quartz lenses were used due to their exceptional longevity.

Clock Chamber and Machinery:

The clock chamber was constructed within the mountain, and machinery was installed within the 500-foot shaft. The intricate mechanism features a spiral staircase, a calendar system, and a weight that drives the clock’s movement.

Bells and Brian Eno’s Contribution:

The clock includes a set of giant cast bells that ring in a different order every time it strikes noon. Composer Brian Eno devised a unique algorithm that allows the bells to ring in a distinct sequence for 10,000 years.

Complexity and Current Status:

The 10,000-Year Clock is considered one of the most intricate mechanical devices ever created. The project experienced delays due to the COVID-19 pandemic but is nearing completion, with an estimated timeframe of years rather than decades. Hillis emphasizes the possibility of engineering structures and mechanisms that can endure for 10,000 years, showcasing the dedication and ingenuity required to create such a remarkable and long-lasting timepiece.

Geological Timescales and Human Civilization:

The 10,000-year time frame, representing human civilization, is short compared to geological timescales. The geological record reveals Earth’s history, including periods of significant ecological changes. The 10,000-year clock had to account for potential changes in the Earth’s rotation due to global warming.

The Earth’s Resiliency:

Earth has experienced major ecological disasters, including the rise of plants and the creation of oxygen. These events drastically altered the Earth’s chemistry and made it uninhabitable for many life forms. The Earth’s resilience to such events highlights the relative brevity of human civilization.

Storytelling and the Clock:

The 10,000-year clock is a story in itself, inspiring other stories and works of art. Neil Stevenson’s book, Anathem, explores an alternative future where 10,000-year clocks are built. The clock serves as a symbol of a long future, a contrast to symbols of the past like Stonehenge and the pyramids.

The Long Now Foundation:

The Long Now Foundation was established to promote thinking about the future and creating a better world. The Interval bar in San Francisco, run by the foundation, showcases pieces of the 10,000-year clock. The foundation’s mission is to encourage people to believe in and work towards a better future.

Concluding Thoughts: Navigating Future Challenges

The journey towards mastering space travel and building structures like the 10,000-Year Clock underscores humanity’s resilience and foresight. While the technical and environmental challenges are daunting, these endeavors encourage us to think creatively and aspire for achievements that outlive generations. The fusion of space exploration and projects like Hillis’ clock not only reflects our current capabilities but also ignites the imagination, pushing us to explore new possibilities in timekeeping and beyond. As we navigate these challenges, the intertwined stories of space exploration and the 10,000-Year Clock serve as reminders of our potential to envision and realize a future that stretches far beyond our present horizons.

Long-Term Timekeeping and Astronomical Cycles

Danny Hillis has explored how to communicate with civilizations thousands or millions of years in the future, considering days, years, and months as consistent units for long-term timekeeping. The 10,000-Year Clock’s face displays these units and connects them to astronomical cycles. The clock also shows the phase of the moon and the zodiacal cycle, which spans 25,000 years. To account for time differences outside of a gravitational field, Hillis experimented with an orrery and has presented a paper exploring various types of time, including barycentric time.

Public Access and Biological Clocks

The 10,000-Year Clock is intended to be open to the public, requiring a full day of hiking for access. It is designed to continue functioning even if neglected and has a manual winding requirement to advance the date. Hillis has considered incorporating life into the clock system, such as a garden with slow-growing plants representing time intervals, or exploring biological clocks and life’s role in timekeeping. The concept of life as a clock, operating on a different scale than human-made clocks, opens up new perspectives on the relationship between time and existence.


Notes by: QuantumQuest