Readers question carbon nanotube transistors and brain organoids

Chip off the old carbon block

Scientists built the first microprocessor that uses thousands of carbon nanotube transistors, Maria Temming reported in “A chip made with carbon nanotubes, not silicon, marks a computing milestone” (SN: 9/28/19, p. 7).

Reddit user SchwarzerKaffee asked about the environmental impact of producing carbon-based microprocessors versus standard silicon-based ones.