Episode 6 min
0:00 in our galaxy alone there are an estimated 400,000,000,000 stars the latest data suggests most of them have planets mhmm so a conservative guess puts the number of potentially habitable earth like planets in the milky way in the tens of billions it's funny last week we talked about the hard problem of consciousness that deep internal0:29 mystery and now we're staring out at this cosmic scale and finding another kind of profound silence the great silence that's what some call it it's the paradox that enrico fermi supposedly blurted out over lunch in 1950 where is everybody right because with those numbers the universe should be teeming with0:58 civilizations some of them should be millions of years older than us their technology would be like magic we should see something radio signals dyson spheres probes you should see the artifacts you should see the evidence of engineering on a galactic scale and we have pointed our best instruments at the sky for decades and have found nothing an1:27 unnerving statistically improbable quiet so what are the leading theories i mean how do you solve where is everybody oh there's a whole cottage industry of solutions they fall into a few buckets the first and maybe most famous is the great filter the idea that there's some barrier that stops life from reaching our stage or a stage beyond1:54 us exactly a hurdle so high that almost no one ever makes it over it could be behind us like the jump from single cell to multicell life was just astronomically rare or and this is the unsettling part the filter could be ahead of us like climate change or nuclear war or some technology we haven't invented yet that2:22 always always leads to self destruction precisely in that scenario the silence isn't empty it's a graveyard okay but what if the filter isn't some universal law what if it's just us the rare earth hypothesis that the specific conditions here our moon our jupiter our plate tectonics are a2:52 galactic fluke that's another popular one it's comforting in a way it makes us special but it feels a little pre copernican doesn't it every time we've assumed we were the center of the universe we've been wrong why should this be any different so you don't buy it i think it's plausible all of these are plausible that's what3:19 makes this so maddening there's also the zoo hypothesis that they're out there but they're deliberately hiding from us a cosmic prime directive don't interfere with the primitives right or the more sinister version the dark forest hypothesis the idea that the universe is a dangerous place and the first rule of survival is to never ever announce your presence3:46 because something else something older and more powerful might hear you in that case the silence is a sign of intelligence everyone is holding their breath wow so every potential solution is kind of terrifying we're either alone or doomed or in a zoo or we're hiding from monsters you see the problem every answer just creates a more profound4:13 and frankly more unsettling question it reminds me of the search for things in physics like for decades the standard model predicted the higgs boson and for a long time the absence of a discovery was the biggest story the silence in the data was shaping the entire field that's a perfect analogy but here's where it breaks down with4:37 the higgs we knew exactly what we were looking for and where to build the machine to find it here we don't even know what the signal would look like are we listening for radio waves when they're communicating with something we can't even conceive of more like an isolated tribe on an island listening for drumbeats while the sky4:57 above is full of satellite signals we can't detect exactly and that for me is where this moves beyond a simple scientific problem after you exhaust the plausible solutions you're left with the silence itself you have to take it on its own terms so after all the years thinking about this where do you land i don't i mean5:23 that's the point i think we have a deep seated need for answers for closure but some questions are powerful because they resist answers this paradox forces us to confront the scale of the universe and our potential place in it or our lack of a place so the value is in the asking the value is in the listening5:53 in sitting with the immense profound quiet and trying to understand what it might be telling us this is one of those areas where science touches something older a sense of awe and frankly a sense of dread the answers all feel small next to the scale of the question what if the silence isn't an absence of an answer6:23 what if the silence is the answer
