An Exercise in Knowing You

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Across
  1. 2. Mass times acceleration, culturally sanctioned
  2. 4. Double prime that once lived on his back (2 words)
  3. 5. Amateur gastronome with professional enthusiasm
  4. 8. Rebrand that rings true and takes flight (4 words)
  5. 9. System in which omission is not absence, but efficiency
Down
  1. 1. Birthday weekend soundtrack provider
  2. 3. Technically outdated, sentimentally permanent
  3. 6. Interface between optics and interpretation
  4. 7. Cartoons, but say it in a way that starts arguments