Sciencespeaking topic
The total energy of the universe may be zero. The positive energy of matter might be exactly balanced by the negative energy of gravity. If so, is the whole universe a 'free lunch'?
— zero-energy universe hypothesis
practice with this topic
Set the timer (5-30 min), take 20 seconds of prep if you like, start talking. Jot your thoughts onto the sticky-note board.
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