Related Clues:

• Thermodynamic concern
• Vim and vigor
• Dynamism
• Couch potato's lack
• Vibe
• "E," to Einstein
• ___ bar
• Fuel
• Einstein's ''E''
• E, to Einstein
• Some is psychic
• Part of E=mc2
• Going concern?
• By law, it can't be destroyed - or produced
• What some bars provide