Tuesday, August 20, 2019

Today's Big Number

The mass of the Milky Way Galaxy is about 1.5 trillion solar masses. It contains about 100 billion stars. The matter we can see accounts for only 16 percent of the mass, with the rest being "dark matter."


G. Verloren said...

I know intuition is often at odds with the scientific evidence, but I've never been able to shake the feeling that it seems far more likely that we simply can't see everything that's out there from our single limited viewpoint, than that most of the universe is made up of some bizarre mystery substance that couldn't be detected even from a different vantage point.

If I sat you down on a sofa in the living room of a random house, you'd only be able to see certain parts of the whole structure directly. But you'd still be able to tell from indirect observations that there is more of the building out there, unable to be seen. You might hear water moving through pipes, or road traffic on one side of the house but not on another, or you might hear what sounds like a party being held in what presumably is a very large room of the house. You can't see it, but you have every reason to believe it is there.

Now imagine the same situation, but you are only the size of an ant, and you're struggling just to see beyond the tasseled and fringe-trimmed sofa cushion you're resting upon. There's a whole room all around you, but the sofa itself is blocking out a huge portion of what would otherwise be visible. That's more akin to our current vantage point of the cosmos.

We need a far broader sampling of observations. We need readings taken from different parts of the galaxy. We need parallax on a cosmic scale before we can begin to understand much of anything, and we're still insanely far off from that.

"Dark Matter" is a useful way to categorize the "Known Unknowns" of the universe, but I balk at the idea that it's some fundamentally new and different thing. Our ignorance does not equate to a fundamental shift in the physical universe.

Shadow said...

Flubber. This is why the universe is expanding. Okay! Okay! Dark Flubber.