The average life span in the United States is about 70 years. Does this mean that it is impossible for an average person to travel a distance greater than 70 light years away from the Earth? (A light year is the distance that light travels in a year.) This is not a yes or no answer. Explain your reasoning.

for the people of the Earth traveling they last much more than 70 years

Explanation:

In order to answer this answer we must place ourselves in the context of special relativity, which are the expressions for time and displacement since the speed of light has a finite speed that is the same for all observers.

 The life time of the person is 70 years in a fixed reference system in the person this time we will call their own time (t₀), when the person is placed in a ship that moves at high speed, very close to the speed of the light the time or that an observer measures on Earth, the expression for this time is

              t = t₀ 1 / √(1 - (v / c)²)

We see that if the speed of the ship is very close to the speed of light the  

the value of the root of the denominator is very high, for which for the person on Earth it measures a very large time even when the person on the ship travels has a time within its 70 years of life

In concussion, for the people of the Earth traveling they last much more than 70 years

i don't understand. explain it clearly

molecules are free to separate from each other and will take on the shape of the container. molecules move completely at random and high speeds. they vibrate in a fixed position and do not move around much. molecules expand to the edge of their container.