• KneeTitts@lemmy.world
    link
    fedilink
    English
    arrow-up
    2
    ·
    edit-2
    2 小时前

    200 light years radius is for radio signals to reach someone. 100 years radius for possibly receiving a signal back

    So I have more bad news, the strength of our radio signals is not very strong either so by about 20ly, they fade into background noise so no one would be able to pick them up at all. (could be a lot less than 20ly too, possibly 5 ly depending on the signal)