Science Doesn't Even Know What It Doesn't Know

What if scientists already knew they could be deceived about the foundational nature of the universe? Do you think that would inject a bit of humility into a scientific worldview, particularly when it purports to speak about things that no human directly deserved?

Read below a jaw-dropping admission from a reputable physicist, professor Brian Greene of Columbia University, delivered in a 2012 TED Talk. (A bit of background: In 1929 Edwin Hubble realized that universe was expanding, not static. In 1998 two teams of scientists discovered that, contrary to what everyone believed, the expansion of the universe isn't slowing down over time. It's actually speeding up.)

Here's what Greene said:

Because the expansion [of the universe] is speeding up, in the very far future those galaxies will rush away so far and so fast that we won't be able to see them—not because of technological limitations, but because of the laws of physics. The light those galaxies emit—even traveling at the fastest speed, the speed of light—will not be able to overcome the ever-widening gulf between us. 

So astronomers in the far future, looking out into deep space, will see nothing but an endless stretch of static, inky, black stillness. And they will conclude that the universe is static and unchanging, and populated by a single central oasis of matter that they inhabit—a picture of the cosmos that we definitively know to be wrong. 

Now, maybe those future astronomers will have records handed down from an earlier era like ours, attesting to an expanding cosmos teeming with galaxies. But would those future astronomers believe such "ancient knowledge," or would they believe in the black, static, empty universe that their own state-of-the-art observations reveal? 

I suspect the latter.

Now, if you delivered that talk, what would be the next words out of your mouth? Would you immediately conclude that we stand at a unique moment in history when our knowledge it near its zenith? Or would you raise this question: What might we think we know with absolute, incontrovertible certainty, that may not be true at all? Of what factors are we oblivious that would turn our conclusions on their heads? What do we not even know that we don't know?

To find out what Dr. Greene had to say, you'll have to watch the end of the TED Talk embedded below.

But I bet you can guess.