# You'll be all alone!

Assume that the nearest galaxy to us is separated from us by $$10^{20}$$ m. If we wait long enough, in $$t$$ years we won't be able to see any other galaxy from ours. If this time is written as $$a \times 10^{n}$$, where $$1 < a < 10$$, what is the value of $$n$$?

Details and Assumptions:

• Take the Hubble constant $$H = 10^{-18}$$ $$s^{-1}$$
• Assume the speed of light $$c = 3 \times 10^{8}\text{ m/s}$$.
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