From Ian McKinley
Peter Tredgett is clearly correct – 1013 lasers for one year is much more sensible than one laser for 1013 years for transmuting a tiny fragment of iodine-129 into iodine-128 (11 October, p 31). The tricky bit, however, is organising the 1013 power stations needed to drive these beasts.
Villigen, Switzerland
