I'm new to the study of SR and GR. I have a question that I have not been able to find any discussion about.(adsbygoogle = window.adsbygoogle || []).push({});

In the case of two frames of reference where we are comparing events from the point of view between a 'stationary frame' (inertial) to an excelerating frame like the twin paradox is the scenario I'm using as a thought excerise.

Say the excelerating frame is approaching the speed of light, like 90%. Then the traveller shines a flashlight toward a mass in the distance that is in the same frame as the inertial frame. If the distance to the object is for example 100 light years away, then it will take the light 100 years to reach that object.

Now, since the traveller is going .9/speed light, it stands to reason that the traveller will reach the object in 90 light years from the travellers frame of reference.

My question is, what would the observer in the stationary frame see relative to the traveller? i.e. the observer would measure the speed of light as 186,000 mi sec and the traveller at 167,400 mi sec, but would the observer see the traveller arrive after 9 years? That would not seem to be the case based on time dialation and length contraction so I'm a little confused here.

Any help with the math to calculate this and explanations would be greatly appreciated.

Please help me correct any inaccurate terminology if you would. Thanks.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# SR Inertial Frame Scenario Confusion

**Physics Forums | Science Articles, Homework Help, Discussion**