Sometime around 3:17 EDT tomorrow, according to my calculations

According to mine this requires direct violation of the FTL limit, Rapaire, which would mean your calculations depend on translating all the molecules of matter between here and there into qubits. Such a transformation would probably mean the collision would pass harmlessly.

I think a few billion years is a more likely estimate. Galaxies are in fact very diffuse—the nearest star to the Sun is in fact almost thirty million solar diameters away from the Earth. (If the sun were scaled to the size of an American quarter, 24.26 mm (0.955 in), the next closest quarter/star would be 700 km [475 miles] away.) If the theory is correct, the stars and gas contained in Andromeda will be visible to a naked-eye viewer in approximately 2 billion years.[4] If the collision occurs, the galaxies will likely merge into one larger galaxy.


While it is known that the Andromeda galaxy is getting closer to the Milky Way by about 120 km/s, there is no way to tell whether it is going to collide or miss. The best indirect estimates of the transverse velocity indicate that it is less than 100 km/s. This suggests that the dark matter halos, although possibly not the actual disks, of the galaxies will collide.

(Data borrowed from WIkipedia)


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