Testing a Model for Earth's Magnetic Field

Something that biblical creationists freely admit is that events in the past cannot be observed, tested, or measured. Although secularists want people to believe that Earth is ancient, they have to admit to the same thing about the past. What's a scientist to do? Present an idea and see if it fits the data. Better yet, have a kind of model to go with it.

The age of Earth's magnetic field has been problematic for deep time advocates. One rescuing device is the "dynamo", which is not very promising for them.
Modified from images found at Clker clipart
Biblical creationists have long pointed out that if we take the current decay rate of Earth's magnetic field, it would have been long gone before now, and we'd have nothing to protect us from solar radiation and so forth. If we work backward, the magnetic field would be impossibly strong. Either way, Earth could not be 4-1/2 billion years old. Long age proponents came up with various rescuing devices, the most famous of which seems to be the dynamo model. One model test gave an upper limit of 700 million years, which puts a burr under the saddle of long agers. The problem is their starting assumptions: cosmic evolution leading to an ancient world. If they gave an honest evaluation of biblical creation science models, they wouldn't be having these problems.
What sustains Earth’s magnetic field? Creationists and secularists disagree on the answer, but a recent update from Physics Today seems to lend support to the creationists’ hypothesis that the magnetic field is both recent and decaying.

Magnetic fields naturally decay with time. If Earth were billions of years old, its magnetic field should be gone by now. But it isn’t. This has forced secular scientists to propose a recharging mechanism called a dynamo that supposedly sustained Earth’s magnetic field over billions of years.
I hope you're attracted to reading the rest of the article, click on "Earth's Young Magnetic Field Revisited".