Baby photos (by alaric)

From an old family photo album, some pictures of me as a newborn have appeared, on a visit to The Mill:

They're dated April 1979, so would be less than a month after my April birth.

Who'd have thought, then, that one day I'd be bringing up my own baby in this place? 🙂

EmDrive (by alaric)

A British chappy claims to have built an reactionless engine, the EmDrive - I just read about it in New Scientist today, so threw up the Wikipedia page about it.

Any physicists around here who are able to do the maths and see if his claim (that a truncated-conical resonant cavity full of microwaves will experience an asymmetric photon pressure due to the group velocity of the waves changing as the local diameter of the tube varies, thanks to some relativistic effects) holds water?

And if it does, what becomes of conservation of momentum?

Cleaning Agents in the Rain (by sarah)

Jean's highchair has non-removable straps which had abviously started their live as white but where a darkish brown instead. I had tried to clean them with just a wipe down but this failed, I put ace one them - this removed maybe 2 % of the staining. Then I moved on to carpet cleaners and then things like vanish oxi which I mixed into a paste applied and left for ages. Then to the shower for a thouror rinsing (we didnt want any nasty chemicals on Jean). This last one removed about 50% of the brown colouring but the straps still looked discoloured.

It had taken months to get this far as I have to weight until Fridays when Jeans in nursery and I have nothing else todo. To my dispair the straps still looked festy even though I know they probably weren't - we decided to give up.

Then the highchair got left outside after the party and it rained and rained and rained - when we bought it in again to our suprise the straps were gleaming white! There is still some brown staining around the seams and stitching but thats it! Of course as soon as Jean eats a bannana they will revert I'm sure 🙂

The thing is this is a bit scary cos I ran loads of water over the straps in the shower and it didnt remove the stain so surely its not just the movement of the water on the straps? Ok so rain water is a lot finer than the shower so maybe it pemeated the material better? But still it would suggest to me that some thing in the rain was acting as a cleaning or bleaching agent - I am left wondering about acid rain - carbonic acid, sulphuric acid? Hmmmmm.....

Accessing a Domino server from Java (by alaric)

For a project, I'm having to write some Java code to talk to a Domino server.

Finding any references on how to do this is a BIG pain, so for posterity, here is what I've found.

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Lead-free soldering (by alaric)

In the UK right now, just about every electronic component, PCB, or whatnot is being labelled RoHS Compliant.

In particular, this means that Maplin, the only local place I can just drive to to pick up electronic components and tools, is now only selling lead-free solder.

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