c:\@Work\Perl\monks>perl -wMstrict -le
"my @ra = (0.000008, -0.000008);
 ;;
 for my $fpn (@ra) {
   my $pfpn = pack 'F', $fpn;
   printf qq{%8s: length when F-packed: %d bytes \n}, $fpn, length $pfpn;
   }
 ;;
 for my $fpn (@ra) {
   my $pfpn = pack 'F', $fpn;
   printf qq{%8s: hex '%s' \n}, $fpn, unpack 'H*', $pfpn;
   }
 ;;
 for my $fpn (@ra) {
   my $pfpn = pack 'F', $fpn;
   printf qq{%8s: bits '%s' \n}, $fpn, unpack 'B*', $pfpn;
   }
"
  8e-006: length when F-packed: 8 bytes
 -8e-006: length when F-packed: 8 bytes
  8e-006: hex '8dedb5a0f7c6e03e'
 -8e-006: hex '8dedb5a0f7c6e0be'
  8e-006: bits '1000110111101101101101011010000011110111110001101110000000111110'
 -8e-006: bits '1000110111101101101101011010000011110111110001101110000010111110'