* Posts by Stooriefit

6 publicly visible posts • joined 1 Nov 2013

Free space optics gets shiny new snake-oil paint job


Forget direct line of sight - what you need is a PBG fibre; check out:


You get the speed of light in air coupled to the convenience, security and backwards compatibility of old fashioned optical fibre.

Investors throw cash at affordable 3D scanner


Re: Oh dear, 3D selfies...

I was at a trade show in Brum about 5 years ago when a representative from a well known American metrology company used one of their laser scanners to surreptitiously measured the rear end of one of the models unreconstructed engineering companies still employ to staff booths. She didn't realise for quite a while that the 3d surface rendering on all the 42" plasma screens was her arse.

She wasn't pleased.

Cheap 3D printer works with steel


Re: Settle down

Sorry can't find a magic link - check out Prof Stewart Williams' publications at Cranfield. There is stuff on welding dissimilar metals and doing additive manufacturing using arcs in fancy alloys.

You could also check out AILU's list of active research groups http://www.ailu.org.uk/assets/document/randreport/091205table2.pdf

It is a bit out of date and the field is moving fast - there is more activity at Liverpool and Heriot Watt as well as Cambridge than that disclosed here.

There is also a NSF report on Additive Manufacturing in Europe but I can't paste it because of a little IT difficulty I'm encountering...

Thumb Down

Settle down

Nothing to see here.

If you have ever seen the parts these things produce you wouldn't imagine making a gun from one. They have a finish quality similar to a constipated dragon's stool. You would have to post machine it to get any kind of fit or function' in which case why not start with stock bar? You could use your FOS lathe.

This work is positively last century - at team at Cranfield did this years ago, and have been doing much more impressive stuff of late, welding steel to aluminium and seven other impossible things before breakfast etc.

Only the mention of open source firearms (which is patently bobbins) has garnered any press for this at all.

Stephen Hawking: 'Boring' Higgs Boson discovery cost me $100


I don't understand...

...but then that was never likely. The particular bit that doesn't smell right though, is:

""These multiple universes can arise naturally from physical law," he said. "Each universe has many possible histories and many possible states at later times, that is, at times like the present, long after their creation.

"Most of these states will be quite unlike the universe we observe, and quite unsuitable for the existence of any form of life. Only a very few would allow creatures like us to exist.""

It is the use of the words "many" and "a few"... If a universe comes about for every possible state, how many are there at any given time, given the number of states of matter there are within a region (I'm not saying the whole of everything, because for all I know there may be some way of partitioning up regions so that they act independently...) and the range of values for the various physical constants which might be self selected by fine tuning. I'm guessing, given the factorial involved, that the fine tuning which would be required is pretty fine indeed to get back down to "a few" when we are making the filter criterion "creatures like us".

Why wouldn't that fine tuning get us back down to just one universe again? Why a few? It is like the mass - gravity - inertia equivalence ... I've never had the reason for it explained to me, but it is too much of a coincidence.

On another note Neal Stephenson's Anathem is a ripping yarn on this theme, but again, the numbers don't feel right.

Can someone who understands physics point me in the direction of a convincing exposition on this stuff?

A post-Snowden US had better not SQUEAL about Chinese cyber-spying



All this talk of 'Merkin hypocrisy is perfectly fair, and I'm not one of these "let he who is without sin cast the first stone types" but we in the 51st state should remember that dear Winston handed out Enigma machines after the war to our friends in developing countries so that they had secure means of communication. That's one of the reasons the Bletchley operation was so secret for so long - we didn't want our poor relations to know we could see their dirty knickers.