Just a quick one tonight.

At Dragon*Con (which I won’t mention again until next summer) some fascinatingly misguided person suggested that ghosts are made of Dark Matter. Dark matter is the missing 22% of the stuff the universe is made of. This is stuff – it is just stuff that doesn’t interact with the electromagnetic force in a noticeable way. This means it does not obscure light (like dust), it does not give off light (like stars), it does not chemically interact, or in fact it does not do anything other than move stuff with its mass via gravity. This means that if you can see something, it is not Dark Matter. This means that if you can detect something as a cold spot (which implies something happened to the heat energy in that spot), and if you can measure something via some electromagnetic something (changes in inductance, conductance, etc of air), it cannot be dark matter.

I do not believe ghosts have been proven to exist.

That said, the folks trying to prove they exist have “results” based on stuff that requires ghosts interact via the electromagnetic force.

If dark matter was as visible as they claim ghosts are, my job would be a whole lot easier. Dark Matter can only be detected via gravity. Ghosts cannot be made of dark matter based on any of the “Observables” ghost hunters tote out.

One more point: if you try and claim ghosts use gravity to move stuff around, then they couldn’t selectively move things because they’d need HUGE amounts of mass to move a small chair, and in the process they’d probably bend walls and collapse ceilings. They could not simply push or pull on the chair because without the electromagnetic force at play, dark matter pretty much just passes straight through normal matter (like chairs).

In case you missed it, ghosts are not made out of Dark Matter.

Try again, and please stay out of astronomy next time.