Our technology only lets us hear, speak or detect stuff that's within just a few light years. Our galaxy is tens of thousands of light-years across. In earthly

Our technology only lets us hear, speak or detect stuff that's within just a few light years. Our galaxy is tens of thousands of light-years across. In earthly terms that's like saying "I walked to the end of the street and didn't find any Eskimos. So there's no such people." There could be hundreds, thousands, or even millions of alien planets within our own galaxy but we are unable to detect them, and so they might as well not exist at all.