Yes, it's found a wealth of evidence that there aren't currently alien radio signals being beamed at us. At least, in the directions we've looked, at the freque

Yes, it's found a wealth of evidence that there aren't currently alien radio signals being beamed at us. At least, in the directions we've looked, at the frequencies we've checked, within our feeble human understanding of what a signal should look like, we haven't seen any signals. That's useful information. But the returns rapidly diminish. The first thirty seconds you use checking to see if your car keys are under the couch is time well spent. But if you're still looking under your couch two hours later... well, it's possible your car keys ain't there.