字幕表 動画を再生する 英語字幕をプリント If you've watched any of our videos about the James Webb space telescope, you've probably noticed the eye catching massive gold mirrors. The primary and secondary mirrors are covered in 48 g of gold, about the same mass as a golf ball. But the gold coating is not just about Web looking dazzling and epic from space, it actually serves an important purpose. Gold is highly reflective of infrared wavelengths, which will help Web focus light from distant objects into its instruments, tap the link to learn more about the James Webb space telescope.