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Now I’ve done it. I’ve put the dreaded “God Particle” title on my blog after railing against it in the past. (And yes, I really did write that, even though my identity has been expunged. Another story. Better to be published without credit than to not be published at all, I suppose.)
Here’s my excuse. In his book Smashing Physics, which I just finished listening to, English (very English) physicist Jon Butterworth makes the following statement about the Higgs boson and the Brout-Englert-Higgs (BEH) field that gives mass to matter particles:
If you think this BEH mechanism is correct, then every time you measure the mass of something, you are seeing evidence for it. On the other hand, this becomes simply a matter of interpretation, since the BEH theory has explained the mass, but has made no unique prediction for any new phenomena that you can test experimentally. Maybe some other theory could also explain the mass. In fact, this is pretty much why the draft of Peter Higgs’ second paper on the matter was initially rejected by the journal Physics Letters. He then went and added an equation that essentially says something along the lines of, ‘Well, if this field is there, you can also make waves in it, and this will appear as a new scalar, i.e. spinless, particle . . .’
That is the famous Higgs boson, and that is why we have to see whether it’s there or not. It was this prediction that made it possible to demonstrate whether the BEH mechanism was just a neat piece of mathematics, or whether it really operates in nature.
It struck me the contrast between this statement and the ubiquitous proof of God given by believers. God, they say, is everywhere. Everything is evidence of Him.
What they fail to consider is that, as in the case of the BEH field theory, some other theory might explain the world just as well as the God theory. What testable prediction does the God theory make?
William Lane Craig, who is supposedly the best the apologists can put up, presents a version of the “evidence for God is everywhere” argument on his web site:
1. The fine-tuning of the universe is due to either physical necessity, chance, or design.
2. It is not due to physical necessity or chance.
3. Therefore, it is due to design.
How does Craig reach point 2, the key point in his argument? I’ll let you read it, but it essentially comes down to, “no one has yet thought of any argument that convinces me. Therefore, design.” That’s just an argument from ignorance, a God of the gaps. I can’t think of anything else, therefore God.
It’s fine to be skeptical of the multiverse, of inflationary cosmology, of the 10^500 possible worlds of String Theory. I certainly am.
Maybe the fine tuning is a physical necessity. Maybe it is chance. Maybe it’s something else, something we haven’t yet considered, including the idea that maybe the fine tuning is an illusion, caused by our incomplete understanding. The best current answer to the fine-tuning problem is, ‘we don’t know yet.”
Yet nowhere does Craig put his concept of God under the same skeptical microscope. And that’s the point I’m making here.
Note the key difference between physicists like Butterworth and theologians like Craig. Physicists are open to the idea they may be wrong. They devise tests that are vulnerable to failure. They don’t make their pet theory the default position.
Imagine if instead the physicists had taken Craig’s angle. They might have said:
1. Particle properties are caused by either the BEH mechanism, or by something else.
2. No one’s offered a “something else” that I find compelling.
3. Therefore, particle properties are caused by the BEH mechanism. Done!
But this isn’t what happened. Instead, physicists came up with an idea, then put that idea to the test. First, physicists crafted the BEH mechanism, an idea that fit the known data. But they didn’t stop there. Next they found real-world implications of their theory (the Higgs boson). Then they they devised tests. And finally, at the Large Hadron Collider, they performed these tests and examined the outcome.
This is what is so impressive about the discovery of the Higgs. The BEH prediction could have failed. The physicists could have been wrong. At any point the data might have pointed in a different direction. But it didn’t. The Higgs is really there, the BEH field is an accurate representation of reality. We humans have glimpsed something true, and real, and right about the universe. That is what science can do. God particle 1, God (still) 0.
I was recently in Hitchcock Hall at The Ohio State University with my daughter. Displayed in the lobby is a jet engine used in the Boeing 737.
To the left and the right of the jet engine were two mounted flatscreen monitors giving information about the engine and its operation. We started talking about these two inventions, which both in their own ways changed the world. My daughter made the point that in fact the flatscreen and everything it represents might be a more important invention than the jet engine, because it is the flatscreen and the explosion of information technology that has truly opened the world. It’s a good point. They’re both such amazing inventions, though, that I wanted to write a little about each of them.
How does a jet engine work?
What I’ll write here completely ignores the most important parts of a jet engine – the control systems, the sensors, the subtle ways in which we humans get the engine to do our bidding. Just as Wilbur and Orville Wright’s great contribution was not the physics of flight but the control of the airplane, the thing that makes a jet engine work is the way we monitor and control it. But I don’t know nearly enough to write anything about that.
What I do know is the basic physics of the engine. Much like your car’s engine, the jet engine burns fuel. As the fuel burns, heat is released, and gases expand. Unlike your car’s engine, though, the expanding gases in a jet engine don’t push on a piston. Instead, they push on the blades of a turbine, causing the turbine to spin around 1o,000 times a minute. The turbine is connected via a shaft to the huge fan at the front of the engine. This spinning fan pulls in air. Some of this air is compressed and pushed into the combustion chamber to support the burning fuel. Most of it, though, bypasses the combustion chamber and comes flying out the back of the engine, producing most of the engine’s thrust.
Here’s an animation from NASA showing the key pieces:
This air, mixed with burned fuel and air from the combustion chamber, flies out the back of the engine. That’s the action. The reaction is that the engine (and the aircraft it’s attached to) moves forward, into even more air. And the world flies.
OK, what about the flatscreen?
The same caveats apply. Ask me to build, or even fix, a flatscreen, and I’m lost. The true genius of modern flatscreen monitors lies not in the basic physics, but in the control, the logic, the functionality of the screen. And of these details I’m painfully unaware. Again, what I know is the physics.
Not long ago, televisions were electron guns. Electrons produced at the back of the television flew through a tube (the cathode ray tube) and struck the phosphors at the front of the screen, producing light. The technology worked, but the tubes were heavy, expensive, and used a lot of energy.
Today’s flatscreens depend on two technologies that sound similar but are in fact quite different. The light energy emitted from a flatscreen into your eye originates with light-emitting diodes, LEDs. The particular colors produced by the screen come from liquid crystal displays, or LCDs. Here’s a little about each.
LEDs are light bulbs that don’t use a filament. Instead, they use a sort of cliff, over which electrons fall. When electrons move from one material to another inside the LED, they fall into a lower energy state. You can imagine the electrons jumping off a cliff, shouting “cowabunga” or something as they fall, except the “shout” comes out as a piece of light, a photon. The difference in energy between the beginning material and the ending material determines the type of photon released. Phosphors in the LED turn those photons, usually of a very specific type, into a wide spectrum that our eyes see as white light.
LCDs are completely different. These in a sense reverse the action of the phosphor inside the LED. By absorbing photons of many colors and emitting photons of just one color, each liquid crystal can make a single dot of a single color on the screen.
The amazing thing, though, is that each color cell in the screen can be (and is) turned on and off very quickly with just a small electric signal, allowing each tiny piece of the screen to produce a particular color at a particular time. When added together, all these on and off signals add up to the picture. And the world sees.
Two world-changing technologies on display side by side. Ain’t science grand?