Nathan Myhrvold’s Passion for Snowflakes:
Nathan Myhrvold’s fascination with snowflakes began as a child, admiring their beauty and intricate structures. As a photographer, he became interested in capturing the beauty of snowflakes, recognizing their significance as a source of water and their fleeting nature.

Challenges of Photographing Snowflakes:
Snowflakes are small and fragile, making them difficult to photograph using traditional methods. They are also ephemeral, changing shape and size rapidly due to their growth and sublimation processes.

Myhrvold’s Invention for Snowflake Photography:
To overcome these challenges, Myhrvold collaborated with a specialist to develop a unique device for photographing snowflakes. This device allowed him to capture snowflakes in their natural environment without disturbing them, ensuring high-resolution images.

The Importance of Snowflakes:
Snowflakes play a crucial role in the water cycle, providing a steady supply of water throughout the year. Despite their delicate nature, snowflakes are incredibly diverse, with billions of unique crystals falling during a single snowfall.

Myhrvold’s Selection of Snowflake Photographs:
Myhrvold carefully selected the snowflake photographs to showcase their diversity and beauty. He aimed to capture the intricate patterns, symmetries, and delicate structures of snowflakes, highlighting their unique characteristics.

Snowflake Bentley and Ken Liebrecht:
Snowflake Bentley, a self-taught farmer in Vermont during the 19th century, became famous for his snowflake photography. Ken Liebrecht, a physics professor at Caltech, constructed his own microscope to photograph snowflakes.

Building a High-Resolution Snowflake Microscope:
Nathan Myhrvold set out to create a snowflake microscope with higher resolution than previous models. The microscope’s frame required a very stiff material that would not expand or contract with temperature changes.

The Challenges of Metal Frames:
Metal frames are commonly used in microscope construction, but they are susceptible to thermal expansion and contraction. Even small changes in length due to temperature variations can significantly impact the microscope’s focus and image quality. The use of metal frames can lead to imprecise measurements and blurry images.

Building a Microscope for Snowflake Photography:
Nathan Myhrvold explains that he constructed his microscope’s frame using carbon fiber due to its affordability and ease of use. The frame was designed and built by Myhrvold himself. Working with epoxy during the construction process was messy, and care was taken to ensure that it did not result in permanent adhesion.

Challenges in Photographing Snowflakes:
Snowflakes can be relatively deep, with flattish ones reaching up to 10 microns in depth. This depth creates focusing issues when taking high-resolution photographs, leading to scenarios where only part of the snowflake is in focus.

Developing a Computer-Controlled Photography System:
To address the focusing challenges, Myhrvold spent several years developing a system that utilizes a computer-controlled set of motors to move the camera slightly between each picture. This system allows for precise movement of the camera by as little as one micron, enabling the capture of sharp, fully focused images of snowflakes.

Attaching the Precision Stage to the Carbon Fiber Frame:
Myhrvold faced difficulties in attaching the metal frame of the precision stage to the carbon fiber frame. He collaborated with a Vancouver-based company that had been building these stages for laboratory use. The company conducted tests to assess the stage’s ability to maintain accuracy across a wide temperature range, and it was found to be suitable for snowflake photography.

Capturing Snowflakes for Photography:
Myhrvold uses black foam core boards to capture snowflakes. He either holds them out or props them up in various locations to encourage snowflakes to land on them. For windy conditions, he uses a velvet-covered board, which is more effective in holding onto snowflakes.

Transferring Snowflakes to the Microscope Slide:
Myhrvold employs a tiny size triple zero watercolor brush to pick up snowflakes. The brush is cooled down to ambient temperature before use to minimize the risk of static electricity. Static electricity is often present in the air during snowy conditions, which helps the brush attract and hold the snowflakes. Releasing the snowflakes onto the microscope slide can be challenging. Myhrvold sometimes resorts to bumping his hand or using other methods to encourage the snowflakes to detach from the brush.

Cold Stage Design:
Myhrvold constructed a cold stage to achieve precise temperature control for snowflake photography. The stage features a large copper plate cooled by Peltier coolers, commonly used in camping equipment and CPU cooling. To prevent overheating, a water cooling system, typically used in high-performance gaming PCs, was incorporated. A special antifreeze solution was necessary as regular antifreeze became jello-like at low temperatures.

Artificial Sapphire:
Artificial sapphire, known for its durability and high thermal conductivity, was used as a transparent material for snowflake observation. Sapphire’s thermal properties prevent snowflake melting upon contact, preserving the delicate structures. Sapphire is commonly found in phone screens and high-end watch crystals.

Lighting Innovations:
Conventional lighting can introduce heat, potentially damaging snowflakes. Myhrvold developed a new lighting system to address this issue. Details about the lighting system and the challenges faced during its development are not provided in the given transcript.

Special Pulsed LED Lights:
Nathan Myhrvold faced challenges in capturing snowflakes using continuous LED lighting, as it melted or sublimated the snowflakes too quickly. He discovered a company in Japan that produced pulsed LED lights specifically designed for machine vision in quality control applications.

Advantages of Pulsed LED Lighting:
Pulses lasting microseconds minimize heat transfer, preventing the snowflakes from melting or sublimating. The low average power allows for multiple pulses without overheating the snowflakes. The pulsed lighting freezes motion, eliminating any vibrations in the system.

Collaboration with the Japanese Company:
Myhrvold worked closely with the Japanese company to obtain the necessary technical specifications for the pulsed LED lights and controllers. The company was initially surprised to learn that he was using their lights for snowflake photography, as it was an unconventional application.

Outdoor Setup:
Snowflake photography typically requires an outdoor setup, such as a porch, balcony, or high-rise hotel room with a small balcony. Myhrvold emphasizes the importance of finding a suitable outdoor space for capturing snowflakes.

Snowflake Formation:
Snowflakes form in a temperature-sensitive environment where water molecules arrange themselves into hexagonal crystals. The dendritic growth pattern occurs when initial arms nucleate additional arms, creating a star-shaped structure. The symmetric appearance of snowflakes results from similar growth patterns on each side.

Challenges of Snowflake Photography:
Capturing high-quality snowflake images requires specific conditions, including temperatures around -15°C (5°F). Ski resorts are often too warm for ideal snowflake photography due to the location of accommodations.

Favorite Locations for Snowflake Photography:
Timmins, Ontario: Known for its lake-effect snow, resulting in frequent snowfall. Rental cottages with porches provide convenient access for snowflake observation. Fairbanks, Alaska: Colder temperatures ensure that snow stays on the ground, but snowfall is less frequent. Yellowknife, Northwest Territories: Great Slave Lake contributes to snowfall, but its inland location limits snowfall compared to Timmins.

Gropple:
Gropple refers to tiny spheres of super-cooled water droplets that attach to snowflakes as they fall through a cloud. Excessive gropple coverage can alter the appearance of snowflakes, making them appear less distinct. Gropple formation is more likely in warmer conditions.

Structured Light and DLP:
DLP (Digital Light Processing) is a light projector technology initially developed by Texas Instruments for projection TVs. DLP uses a chip with millions of mirrors to project light patterns. Structured light approaches utilize light beams to create 3D models. DLP is not suitable for snowflake microscopy due to its limitations in focusing. Fan beam lasers offer better focusing capabilities for structured light applications.

Composite Photos and Capturing Thousands of Shots:
Each snowflake photo presented is a composite of 100 to 500 individual shots. During a three or four-day trip to the North for snowflake photography, Nathan Myhrvold and his team typically take around 50,000 shots. This extensive image capture resembles astrophotography techniques, where multiple exposures are stacked to enhance the final image.

Challenges and Learning Curve:
Snowflake photography involves numerous challenges, including cooling equipment and finding the right snowflakes. It takes time and practice to develop the necessary skills and expertise to capture successful snowflake photographs. Ken Lieber, a professor at Caltech, provided feedback to Myhrvold, indicating when he had reached a point where his photography skills were adequate and the limiting factor became finding suitable snowflakes.

Snowflake Variability and Perfect vs. Ordinary Snowflakes:
Snowflakes can change significantly within minutes during a snowstorm. The common notion that no two snowflakes are alike is not entirely accurate. Numerically, most snowflakes are simple hexagonal rods or plates, not the perfect, stellated forms often depicted. However, rare instances of exceptional snowflakes with intricate patterns can occur, prompting photographers to quickly capture these fleeting moments.

Nathan Myhrvold’s Diverse Interests:
Nathan Myhrvold, a polymath, has pursued a wide range of interests, including cooking, planetary science, paleontology, climate science, and quantum theories of gravitation. He finds joy in acquiring new skills and knowledge to explore and understand diverse subjects.

Project-Based Learning and Motivation:
Project-based learning can foster curiosity and encourage the acquisition of skills and knowledge needed to achieve specific goals. Having a clear purpose or mission, such as understanding snowflakes through photography, can provide motivation for learning and experimentation.

Passion for Snowflake Photography:
Myhrvold’s interest in snowflake photography stems from his curiosity and desire to deeply appreciate and understand the intricate beauty of snowflakes. Capturing snowflakes on camera requires focused observation and the use of specialized equipment, making it an engaging and rewarding experience.

Creating a Multi-Gigapixel Mosaic of the Milky Way:
Myhrvold’s current project involves creating a massive mosaic of the Milky Way, requiring thousands of individual photographs. He uses computational photography techniques to combine these images into a single high-resolution mosaic.

Building a Small Multiprocessor System:
To process the large volume of data from his snowflake photography and Milky Way mosaic projects, Myhrvold is building a compact multiprocessor system. This system will enable him to analyze and process the data efficiently while maintaining portability.

Choosing Hardware for the Multiprocessor System:
Initially, Myhrvold planned to use high-end multiprocessor chips, but he encountered software compatibility issues. He shifted to using Intel NUC mini PCs equipped with GPUs, which are more suitable for his specific software requirements.

Conclusion:
Nathan Myhrvold’s insatiable curiosity and diverse interests have led him to make significant contributions across various fields. His passion for understanding and appreciating the world around him, combined with his willingness to learn new skills and experiment, serves as an inspiration for others to explore their own interests and pursue knowledge.

Outro:
Jon Katsir expressed his gratitude to the audience for joining the Tech First podcast. He mentioned that the full transcript of the podcast will be available at his website jonkatsir.com in about a week. Katsir also stated that the full video of the podcast is available on YouTube. He thanked the audience again for joining and concluded the podcast.