Dark Matter: a Wrinkle in Space?

I'll begin with a caveat - I am in no way a particle physicist; nor am I particularly mathematically inclined. This post (as with the rest of them on this site) should be taken as the ramblings of an amateur philosophical astronomer.

It isn’t dark, and it isn’t matter. But it creates 86% of the gravitational pull in the universe – 5 times more than all the matter that exists – and plays a major role in the dynamics of spacetime itself. But what is it?

Astronomer Fritz Zwicky discovered the existence of “missing mass” back in 1934, when he was measuring the rotation of galaxies and seeing that they were spinning much faster (meaning, much more gravity) than their masses (as measured by the amount of starlight) could account for.

A Dark Matter Map

Since then, we’ve gotten more adept at finding and isolating the massive chunks of nearby dark matter by measuring what’s called “gravitational lensing”: light from distant stars bends around dark matter, similar to (but less than) how it’s affected by black holes. Through these measurements, scientists have even been able to map this invisible goo, creating pictures like the one to the left.

Scientists have assumed that the invisible substance was a new form of matter, because that’s the only way we know to have mass, which is the only way we know to create gravity. But my hunch is that this avenue of thought is wrong, and that dark matter doesn’t have mass at all.

See, I get excited when I see the words “the only way we know,” because that immediately implies that there might be other ways to do something. The only way we knew how to get across the Atlantic was in boats, until the 20th century. The only way we knew how to see the moon was from the surface of the earth, until the 1960s. So when I see the only way we know how to create gravity, I start thinking.

I’ll start with what we “know” about Gravity:

1) It’s one of the Fundamental Forces of the Universe. See this post for details.

2) Spacetime warps around it. Instead of a particle exchange, Gravity works when space and time itself are bent, creating an extradimensional dimple that sucks objects toward each other and slows down time.

3) The more massive the object, the stronger its Gravity. There is a relationship between mass and gravity.  For the time being, science believes it's a causal one, wherein Mass creates Gravity.

The last piece of information was the most suspect, and could change in any number of ways (e.g., what if Gravity gives objects their mass in the first place? Or what if mass simply congregates in places with highest gravity?). The relationship is measurable, but the causation is flawed, so I wanted to see what would happen if it were ignored.

Without it, we’re left with this: Gravity is a mysterious, (apparently) particle-free force, around which spacetime warps. It’s very clear that Gravity is a force – that’s immediately measurable. And Einstein’s math regarding the warping of spacetime holds up to the most rigorous challenges, so I’m not gonna touch that with a 39½-foot pole.

So now I’ll take you down the rabbit hole with me, and follow my series of logical explorations and imagination experiments. For these, let’s imagine that the fabric of spacetime is like a huge, 3-dimensional, (frictionless) bed-sheet.

1) What would happen if spacetime were warped without a mass? How would it affect the masses around it? Well, when we wrinkle a bed-sheet, objects on the peak fall toward and congregate in the valleys. Even adding a dimension, there would be a differential between sides of the fold, pulling objects from one place to another. The only word we have for that pull in space is Gravity.

2) What could cause such a wrinkle, other than mass? Based on all our measurements, space itself is expanding, and has been since the Big Bang. This means all the space we now have came from a point smaller than an atom. That’s a lot of space to fit in such a little place – and I don’t know any way to cram something big into something small without wrinkling it…

3) How would a wrinkle in spacetime affect our measurements of the mass of a galaxy? If there’s a wrinkle in spacetime inside a galaxy, it might act as a sort of accelerator, moving objects faster than they would go without it, and refracting light itself.

And now I’ve arrived at my destination – a different, new explanation for “Dark Matter” that seems to fit within the framework of proven physics. Simply switching the causation between Mass and Gravity so that we imagine that Gravity itself pulls Mass together in the first place allows for a whole new pathway of thinking.

So is “Dark Matter” just the old way of saying “Wrinkles in Spacetime?” If it’s true, then soon after the Big Bank, there would be wrinkles at a very high density. Someday, we may be able to measure the gravitational lensing of the light from soon after the Big Bang, and if the faraway light is refracted at a much higher rate than light from closer stars, then this part of the hypothesis might prove sustainable.

As Stephen Hawking said, “Nothing is flat or solid. If you look closely enough at anything you’ll find holes and wrinkles in it. It’s a basic physical principle, and it even applies to time. Even something as smooth as a pool ball has tiny crevices, wrinkles and voids. Now it’s easy to show that this is true in the first three dimensions. But trust me, it’s also true of the fourth dimension.”

P.S. The “Wrinkling” theory also allows for a bit of an explanation for “Dark Energy” – the mysterious power that’s accelerating the expansion of the universe – in that a frictionless substance naturally strives for flatness, so any wrinkles in it would push the substance outward at an ever-increasing rate until it reaches its equilibrium.