gravity
Every particle in the universe is gravitationally affected.
The only way the solar system can be curving through space at this rate would be because of being gravitationally affected by another very large mass.
As the Universe expands and gets colder, the gravitationally accumulated matter undergoes stabilization.
The space around the object contains pieces that have been decoupled physically, but not gravitationally, from its surface.

SMART Vocabulary: related words and phrases

Physics: energy, force & power
animal magnetism
anti-gravity
atmospheric pressure
attract
attraction
ballistic
entropic
entropically
equilibrant
erg
excited
geothermal
inertia
propulsive
radiant energy
self-propulsion
sine curve
sinusoid
the sound barrier
thermodynamics