C perhaps slight doubt with my knowledge
Answer:
a quarter of the former gravitational force.
Explanation:
This change in gravitational force is not instantaneous. To understand this one must know about gravitational waves. The relation between gravity and gravitational wave is analogous to the relationship between EM waves and EM force. Gravitational wave as EM waves travel with speed of light. Nothing can exceed this limit. i.e.- 3,00,000 km/sec.
Even light takes approx. 8 mins to reach Earth and so does gravity (or gravitational waves). One famous question based on this is if our sun vanished instantly would it affect Earth immediately like thrown out of orbit or there would be no light !? The answer will be that people of Earth wouldn't know that our sun has vanished until 8 minutes have passed. Then it may be thrown out due to absence of gravity but in those 8 min we won't feel any difference.
Now coming to your question if the distance is doubled instantly by some mean (mostly impossible and theoretical) then the change in light or gravity will take double the time. So the new gravitational force or the brightness change will be felt by us after 16 min approx.
They are different because a forensic chemist studies and tests chemicals and drugs and a forensic toxicologist studies poisons with criminal justice cases
A Precambrian the Canadian shield dates back almost 4 billion years ago about the same time as the Precambrian eon.
