Photograph credits

• Sjschen, CC BY-SA 4.0
• Battlesnake1, CC0
• Toby Oxborrow from Kowloon, Hong Kong, CC BY-SA 2.0
• Nadav Spiegelman, CC BY-SA 4.0
• cyclonebill from Copenhagen, Denmark, CC BY-SA 2.0
• Haneburger, Public domain
• Difference engine, CC BY-SA 4.0
• Zantastik, CC BY-SA 3.0
• John Gillespie from New York, USA, CC BY-SA 2.0
• Battlesnake1, CC0
• Laitr Keiows, CC BY-SA 3.0
• Namayasai LLP, CC BY-SA 3.0
• ShakataGaNai, CC BY-SA 3.0
• Guilhem Vellut from Annecy, France, CC BY 2.0