Nothing But Love :: golf blogger

Flying Cars Revisited

Troops are still fighting and dying in Afghanistan. Troops are still targets in Iraq. Health care for everyone who needs it is an idea whose time has not yet come. The economy still sucks.

But there is good news! The Toyota Yaris with the Peace and The Who stickers on the rear bumper has not been recalled. If you have seen a Toyota Yaris, one of the inexpensive cars on the market, you know why it has not been recalled for problems with the gas pedal and/or brakes.

And I don't like our tax money being spent on lasers zapping missiles, but how far off can flying cars be if we are shooting missiles with laser beams?

Flying cars. Anti-gravity.

It's really very simple. Here it is, straight from the High Field Magnetic Laboratory at the Radboud University Nijmegen:

Whether an object will or will not levitate in a magnetic field B is defined by the balance between the magnetic force F = M∇B and gravity mg = ρV g where ρ is the material density, V is the volume and g = 9.8m/s². The magnetic moment M = (χ/ µ₀)VB so that F = (χ/µ₀)BV∇B = (χ/2µ₀)V∇B². Therefore, the vertical field gradient ∇ B² required for levitation has to be larger than 2µ0ρg/χ. Molecular susceptibilities χ are typically 10^-5 for diamagnetics and 10^-3 for paramagnetic materials and, since ρ is most often a few g/cm³, their magnetic levitation requires field gradients ~1000 and 10 T²/m, respectively. Taking l = 10cm as a typical size of high-field magnets and ∇B² ~ B²/l as an estimate, we find that fields of the order of 1 and 10T are sufficient to cause levitation of para- and diamagnetics. This result should not come as a surprise because, as we know, magnetic fields of less than 0.1T can levitate a superconductor (χ= -1) and, from the formulas above, the magnetic force increases as B².

Now, get to work; and make me a flying car! My feet hurt.

Posted by Bill at February 15, 2010 06:13 PM