A small clarification: 1h MACD is still positive, just the divergence went negative.
MACD is a lagging indicator, the divergence is less lagging. This term confusion happens a lot in these forums.
Possible way to explain it to someone with physics/math background:
TA math physics
price function coordinates
MACD first derivative speed
histogram second derivative acceleration
Edit: replaced "divergence" to "histogram", as more correct.