Related Clues:

• Gossip about retired medic? Forget it!
• Just as shiny as before, but that's all right
• What is there in a vacuum? Never mind!
• New team not beginning to react? It makes no difference
• Gas, including oxygen, beginning to materialise? It's not important
• It makes no difference
• Feature of vacuum that's unimportant
• 'Don't sweat it!'
• Definition of a vacuum?
• 'Let's not worry about it'
• Gossip involves retired medic? It isn't important
• "Oh, it's fine"
• Talk idly, accepting award? It's not important
• It's not important why one can't see The Invisible Man
• "Same difference"