# Large bodies of mass and their effects on apparent time

• NWH
In summary, the conversation discusses the concept of time dilation in the context of a black hole and two observers, one far from the gravitational forces and one being pulled into the black hole. The question is raised about the rate at which time appears to slow down for the observer being pulled into the black hole and whether this would be representative of the rate of further time dilation. A resource is shared for further information on this topic.

#### NWH

I'd like to expand on the example Dweirdo set in his thread and ask a few different questions. I didn't want to hijack his thread as I thought it would keep info more organised if I separated the discussion.

So, let's take the example that we have a black hole and two observers, one (A) far out safe from any gravitational forces, the other (B) trapped in the black holes gravity being pulled into it. At what kind of rate would time appear to slow down for observer B, when compared to observer A's watch? Starting from the point which it entered the gravitational field, all the way through it's journey into the center of the black hole? Would the experience from observer B's frame of reference make observer A appear to be in a state of constant acceleration and would that be representative to the rate at which further time dilation is occurring?

Looks interesting, I'll check it out, thanks...

## 1. What is the concept of time dilation?

Time dilation is a phenomenon in which time appears to pass slower for an object moving at high speeds or near a large mass. This is due to Einstein's theory of relativity, which states that the passage of time is relative to the observer's frame of reference. As an object's speed or proximity to a large mass increases, the flow of time for that object slows down compared to a stationary observer.

## 2. How does the mass of an object affect time?

The mass of an object has a direct effect on time dilation. According to Einstein's theory of general relativity, objects with larger masses have a greater gravitational pull, causing time to flow slower in their vicinity. This is why time on Earth appears to pass slower than time on the moon, as Earth has a larger mass and therefore a stronger gravitational pull.

## 3. Can time be affected by black holes?

Yes, black holes have an incredibly strong gravitational pull due to their immense mass. This causes time to slow down significantly near the event horizon (the point of no return). As an object gets closer to the event horizon, time appears to pass slower and eventually comes to a complete stop at the singularity, the center of a black hole.

## 4. How do large bodies of mass affect the measurement of time?

Large bodies of mass can affect the measurement of time in several ways. As mentioned before, time dilation near these objects causes time to appear to pass slower. Additionally, the gravitational pull of these objects can also affect the accuracy of timekeeping devices such as clocks and watches. This is because the pull of gravity can change the frequency of the device, causing it to run slower or faster depending on its proximity to the mass.

## 5. Is time affected by the expansion of the universe?

Yes, the expansion of the universe does have an effect on time. As the universe expands, the space between objects increases, causing them to move further apart. This results in a decrease in the gravitational pull between these objects, leading to a slower passage of time. This effect is small and is only noticeable on a large scale, such as the expansion of the entire universe.