h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Traveller in Time not convinced it does something
"How should a magnet mounted on the copper waterpipe reduce the calcium in tap water ? "

it doesn't. it's a device designed to get money out of your pocket into the local shopkeepers pocket

Traveller in Time collecting magnets
"I know, just what can be the idea behind it. I can not imagine all these people buying a thing just to sponsor the local hardware shop "

well.. history is all about people giving life, love or goods for a story if told in a convincing way. paying a few pennies for a magnet is relatively harmless

I reckon it's supposed to ionise the calcium atoms or something to stop them clumping and forming limescale. Doesn't actually remove it. No idea whether it actually works; in fact I'm not sure a weak magnetic field could ionise anything on its own.

Calcium ions are already ionised by definition. There certainly isn't lumps of calcium metal floating about in water

The theory, I assume, is that a negative magnetic pole will attract positive ions (cations like Ca2+). This is true, they will be attracted to magnet of the correct pole. But the effect would be miniscule and any kind of flow of water (as is quite likely in a pipe ) would overcome this weak concentration of calcium (and other cations) leading to the overall effect of the magnet being diddly squat.


I also imagine that in a static situation - i.e. no flow of water - that the calcium ions (which are actually hydrated calcium ions - ie. Ca2+ with a coordination sphere of associated water molecules) could lose protons rather easily if they were to concentrate too much in one area of solution and so neutralise the hydrated calcium ion species so that they would drift away into solution again.
You would therefore reach a dynamic equilibrium of some calcium ions being somewhere near a magnetic pole. So what? To get them out of the water you'd need to precipitate them somehow.

Incidentally. If this magnet did actually work. Wouldn't it just block your pipe after a while with the lime build up around it?

No no no no no!
All magnits, because of their close connection to ancient lay lines and primorvial brimstone and volcanic action, contain magical powers derived from the ancient twin BoBs of earth beer and water the ancient, mystical healing powers of magnets which are well documented can be harnised to positively enpower water by encircling a copper pipe.
Copper, as everyone knows is the most ancient of metals used for centuarys by mystics and in the rituals of druids, through harnishing its special relationship with Bod the ancient lord of spitting, and water, the magnets around the pipe embibe and encorce mystical powers on the water that flows through the pipe.
By teh combined effect of the copper and the magnets, lay lines are alighed through the water as it flows and the postive energy this distills into teh water can produce measurable beniical health effects in those that do drinket he water yeh... like coudln't help myself there

What was I thinking. 2legs has got it to a tee!

I think 2leg has the most realistic explanation of .. ... .... the effects of .. magnets? copper pipes? things in general

(oh, and magnetic fields are not really known to have much effects on ions in a solution anyway..)

They must be attractive to persons though. I've often heard people say he's got a magnetic personality.

So my fantastic invention for an ultra quick clothes drying device, based on a giant electro-magnet, which would 'suck/atrtact' all teh water molecules to it and hence off the clothes, leaving them perfectly dry, that wouldn't work?
What about my other invention; Vacuum room painting device?: where you seel the room entirely, create a total vacuum in it by sucking out all the air, and the pot of pain left in the middle of the floor then all the paint comes out of the can and evenly paints the walls? well I thought they were good inventions Actually, talking of giant magnets I was inside one a few weeks back; twenty mins or so inside a MRI scan with the big magnet wizzing about me they even took the precaution of X-raying my head before hand as I coudln't remember if I had any metal pins, plates or other metal things left inside my head And you do definately get a 'strange feeling' when its wizzing about you.... Weather that is actually the affect of the magnatism on molecules inside the body.... I don't know

Orcus, I don't think ions are inherently atracted to magnetic poles ... unless the ion is in a high total angular momentum state, anyway.

As Bob Park (physicist U Maryland) likes to point out, most of the magnets sold for these kind of gimmicks are like fridge magnets - alternating strips of north and south poles packed closely together. The net result of this structure is a stronger field closer to the magnet (and greater sticking ability) but with a much weaker field further away. If that's the case then the magnetic field won't even penetrate the pipe...

But as you said, any effect would negligible compared to the solution forces of the surrounding water molecules.

I was being highly generous to the magnet. I didn't really think anything would happen at all. A kind of best case scenario for it is what I was painting. Sorry if I didn't make that clear.

Of course there are positive and negative ions in a salt crystal and no attraction at all to a static magnetic field. This is because associated negative and positive ions cancel each other's fields out on anything more than a few nanometres from the individual ions. The same is going to be true of a liquid.

Your confusing positive magnetic pole and positive electric charge. A positive electric charge will attract a negative one, but a positive magnetic pole won't attract a negative electric charge. If the charge is stationary, it won't have any effect on it at all. If the charge is moving, the magnetic field would cause it to circle, but not to go to the edge of the pipe.

ions are magnetically charged as well as positively charged.

electrically charged rather

And you can fling them around with magnetic fields, it's what mass spectrometry is all about.

or at least one form of mass charge separation is done using magnets in mass spectrometers.

Sorry that was posted in haste earlier as I was trying to rush to a meeting. Clearly it's codswallop.

They are, though, as I said affected by magnetic fields.
http://en.wikipedia.org/wiki/Image:Mass_spectrometer_schematics.png

Only if moving though, in which case they generate a magnetic field of their own.

Traveller in Time coming to the confusion point
"And that is exactly what they do in a waterpipe.

Granted, they are affected very little, the magnetic force is very weak, just the net outcome could be something is really happening; as long as the ions are in the magnetic field. "