Would someone be kind enough to tell me if I'm getting this correct.(adsbygoogle = window.adsbygoogle || []).push({});

Problem A

A spherical light source is 1 light year away from Point A at point B.

It moves at near light speed in a circumference around Point A to Point C for a distance of 1 light year.

When the light reaches it's destination it turns off.

What does a person at Point A observe?

Answer: Nothing for 1 year and then a light moving in a straight line at a constant speed for about a year before disappearing.

Problem B

A spherical light source is at Point B, 1 light year away from Point A.

It moves to Point C at constant near light speed.

When the light reaches it's destination it turns off.

What does a person at Point A observe?

Answer: Nothing for 1 year and then a light moving in a straight line appearing to decelerate for about a 1.41 years before disappearing.

Problem C

A spherical light source is at Point A.

It moves to point B at constant near light speed.

When the light reaches it's destination it turns off.

What does a person at Point A observe?

Answer: A light moving away from them in a straight line appearing to decelerate for 2 years before switching off.

Problem D

A spherical light source is at Point A along with an observer. They both have atomic stop watches.

As both stop watches start the light moves at a constant near light speed to Point B, then Point C, then Point D, then Point A without resting.

What will the person at Point A observer on each clock at 1, 2, 3 and 4 years (assuming he has a decent telescope)?

Answer:

1 year: Observer clock=1 year, light's clock observed as ~0.5 years

2 year: Observer clock=2 years, light's clock observed as ~1 year

3 year: Observer clock=3 years, light's clock observed as ~1.75 years (???)

4 year: Observer clock=4 years, light's clock observed as ~4 years

I think I'm likely wrong, and if so, please could you explain why?

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# Observing objects moving close to light speed

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