But accurately working out Mathilde's volume (necessary because density is the ratio of mass to volume) was harder.

ECONOMIST: Asteroids

Double your vegetable intake and reduce fat -- Both of these changes will significantly decrease the calorie density of your diet without decreasing the volume of food that you consume.

CNN: How can I maintain my energy level for sports while on a diet?

Power density refers to the energy flow that can be harnessed from a given unit of volume, area or mass.

FORBES: Magazine Article

Energy density refers to the quantity of energy that can be contained in a given unit of volume, area, or mass.

FORBES: Magazine Article