Monday, March 28, 2011

Gravity Sucks

It's a travesty that Suction (or Pressure, its inverse) isn't considered one of the 4 fundamental forces of the Universe.  After all, without Pressure, the Universe wouldn't be nearly the same as it is:

  • The sun would collapse without the pressure from its heated core;
  • Our atmosphere would come crashing to the ground without the pressure of heated air and the suction of the vacuum of space;
  • The Earth's crust wouldn't drift without the pressure from the expanding magma, meaning our planet would be as flat as the moon;
  • Planes and helicopters would be forever grounded without the low-pressure area above the wing/blade sucking the machine into the sky.
There are many, many more instances of how pressure has literally shaped space.  But in a lot of these instances, the force has even more dramatic consequences because of its battle with Gravity.  On the sun, gravity and pressure balance to create a stable (for now) ball of flaming gas.  On earth, gravity holds the atmosphere in balance, creates the heat that presses the surface above the oceans, and prevents airplanes from being sucked into space.

In fact, Gravity has more in common with suction than we give it credit for.  As Einstein explained, Gravity itself stretches spacetime toward the source of the gravity, like a 4-dimensional bowling ball stretching a 3-dimensional trampoline.


This creates a cavity in space toward which things are attracted.  Anything not moving fast enough (even light) will be caught in the Gravity well, and affected accordingly.


Now imagine a ping-pong ball flying quickly by the end of a vacuum in a straight line.  As the ball passes the source of the low pressure, its course will be altered forever.

Just like air, as spacetime stretches, its density gets lower and lower.  And, just like wind, objects rush toward the lowest density.  Every day, we're sucked toward the center of the Earth, that place of lowest spacetime density.

Monday, March 14, 2011

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.

Tuesday, March 8, 2011

The 5th Force

In High School Physics, we learned that there are four Fundamental Forces in Science: Gravity, Strong Interaction, Weak Interaction, and Electromagnetism.  But it hasn't always been that way.

In 1686, scientists (or "Natural Philosophers," as they were called then) knew nothing of any of these.  It was just a fact of life that we could only jump so high, and would always come back down.  Isaac Newton changed it all the next year, publishing his theory of Universal Gravitation, and opening the floodgates for the study of gravity that culminated in Einstein's Theory of General Relativity.

Like Gravity, Electricity and Magnetism have been used for thousands of years but misunderstood (and kept separate) until 1873.  The Strong & Weak forces, which work only between subatomic particles, weren't even imagined until the 20th century!

We're slowly learning more and more about how these work - some we know more than others.  Electromagnetism exerts force via photons, gluons are the particles that create the bonds of the Strong force, and "intermediate vector bosons" cause the Weak force to operate.  But Gravity, the first of the four forces to be truly understood,  is still a mystery, wrapped in a riddle, inside an enigma.

So what?

I suspect that as the years go by, we'll discover more and more forces that bring things together, especially when it comes to Life itself.

After all, what is the particle that attracts one human being to another?  What is it that makes a person put themselves into harm's way to help someone else?  What makes our chests ache when we break a deep relationship?  What is the "electricity" that zaps you when a loved one touches your skin?


What I'm asking is this: what if we're not done learning all that the Universe has to offer?  What if the world's religions know something Science does not?  What if our explanations (and understanding) of God is at the same level as Newton's explanations (and understanding) of Gravity?

Monday, January 31, 2011

God and Science

A pretty dicy topic to write about, you know?  I have family that believe with every fiber of their souls in the Word of God, which does not allow for Evolution.  I have friends that believe with every fiber of their beings in the non-existence of God, which only allows for Evolution.

As for me?  I'm somewhere in the middle.  I have a very personal, and very real relationship with God, yet do not deny the existence of things which, to me, are incontrovertible proof of Evolution.  And believing in both at the same time doesn't bother me; on the contrary, it inspires me even more than either would on its own.

The Light Horizon

No, I'm not talking about Event Horizon, that super-creepy movie from the 1997. I'm not even talking about the event horizon, the edge of a black hole past which there's no escaping its gravity no matter how fast you're going. I'm talking about something much, much bigger than that, something I'd never heard of until recently.  And it's trippy.

Spacetime

This discovery, of the most distant object ever seen, finally got me understanding why space and time are inextricably related...

As you know, when we talk of astronomical distances, we talk of time. We talk in "light years" and "light seconds," not "miles" or "gigameters" or anything like that. And there's a simple reason for it - as most of us have known since elementary school, when we see something that's 1 light year away, we're actually seeing it as it was 1 year AGO.

My breakthrough came in realizing that there's a marked difference between what something was a year ago and what it is today. And thus, since we can only see what other spatial bodies USED to be, they only exist, for us, in that past state.