Coffeebreak links 240409

Psychologically profile your blog!


Typealyzer parses the content of your blog and gives you a Myers-Briggs style result as to the ‘personality’ of your blog. P&C comes out as INTJ scientist type. What jolly good fun.

Think you know topology? Try to get your head around this:

How to turn a sphere inside out
(via The truth makes me fret)

Because ‘Women in STEM’ sounds so last century….

The nerd girls and their amusing website:

Lowering the magnet assembly

After installing some magnetic shielding, and reinstalling the superconducting magnet, I thought I’d put a picture of the entire dilution fridge assembly being lowered into the dewar, as it looked quite impressive.


At the bottom you can just see the top of the outer mu-metal shield. It’s actually quite a lot longer than this, I’d already lowered it a fair way into the dewar. Inside this shield is a second, inner one, and inside that is the superconducting magnet (solenoid). Inside the bore of the solenoid is the IVC, inside which is the sample box, and inside that the Josephson junction is mounted. Which makes it sounds a bit like one of those childrens’ pop-up books or interactive posters where you ‘look under’ parts (I should really make one of those, it would be cool to show to visitors).

I’m thinking of adding a third mu-metal shield. I do have one that will fit, but it will involve some ‘fridge modification’ (aka a hacksaw to the Lambda coil) so I think I’ll see how it does with 2 layers for now.

Addition of the magnet allows the critical current of the Josephson junctions to be changed in persistent mode (with less flux noise from the magnet itself) and the shields should help attenuate external magnetic interference.

So we’re ready to rock!

Circuit diagrams of real neural systems


How to Map Neural Circuits With an Electron Microscope


“This giant, and potentially revolutionary, task requires custom software, electron microscopes and an incredibly sharp knife. If everything goes right, the team may be the first to create a circuit diagram that explains how mammals see.”

Photo Credit: Marc Lab / Moran Eye Institute

This is just too cool for words.

I’m reading permutation city by Greg Egan at the moment – which paints a picture of a world where the human nervous system has been sufficiently ‘mapped’ to such an extent that simulations of the brain can be run resulting in artificial (or actual – you decide) intelligence. Strong AI for the win! *ahem*

How far away is this technology? If we can map neural pathways by taking slices, scanning them with an SEM/TEM, and and automatically reconstructing the 3D original using clever software.. then all you need to do is bring it to life digitally using a wetware-friendly circuit simulator – I’m not sure such a thing exists… If not, lets develop one and call it MeatSPICE 🙂

Seriously, I have a colleague who does work on electrical models of the nervous system. You can essentially model neurons and axons as electrochemical transmission lines with inductance, capacitance and resistance. It’s a good way for physicists, biologists and biochemists to collaborate.

I also have a slight penchant for this kind of thing seeing as I love using the SEM as an imaging tool. In addition, I recall spending a couple of weeks once doing some work experience at the histopathology department of my local hospital; watching how you actually make those waxy slices and observing them under an optical microscope. (Although we were looking for cancer cells in that particular case and musing over how you could automate such a task).

I’d love to put a load of these ideas together into something tangible to research (as an aside to my already busy schedule!), but it’s a wide, diverse assembly of proto-thoughts (of which I have far too many), requiring quite a large collaboration from different fields.

On a slightly different note, WIRED has now been released as a magazine version in the UK. Which means all my pocket money is belong to them 😦

An Inconvenient Truth

I’ve recently watched the film AN INCONVENIENT TRUTH, directed by Davis Guggenheim, featuring Al Gore.

inconvenienttruthI’d highly recommend watching this film. I found it really moving. Here is the Wikipedia entry for the film, including quite a few opinions from film critics. Trying to normalise away any potential political spin here, Al Gore seems like a nice guy who actually cares. And indeed one who knows his stuff.

A few film critics accuse the movie of skewing the data, however I’ve attended several seminars on climate change recently, and the results reported in those seem to agree with what was presented in the film. They all seem to paint a similar picture.

‘Nine errors’ have been pointed out in the film, points used for impact which are unsupported by current scientific studies. This news report gives a good summary. The film is allowed to be shown in schools as long as ‘guidelines’ documenting and explaining these errors are included.

The film gives some useful information and tips at the end, and believe me even if you *think* you’re being green, you could probably improve on it tenfold. The film has seriously made me consider buying a hybrid car.

On a slightly unrelated note, the film also demonstrates how to essentially make a movie out of a seminar consisting of a slide-show presentation. It works really well and keeps the audience attentive. I think this is generally a good way of presenting physics/scientific ideas.

Reporting on the Blogosphere

Here is a link via Hake’s EdStuff:

“Over two-hundred education & science blogs”

A nice report mainly consisting of a compilation of educational blogs, with notes about advantages and problems arising from the use of the growing blogosphere as a tool for the dissemination of scientific knowledge. Each listed blog has a blurb, a weblink, and a Technorati and Blogger rating (where available).

Matryoshka mumetal shields and superconducting magnets

Fun with magnetic shielding:


Mu-metal shields help screen the experiment from magnetic fields, both varying (such as from local sources of interference) and static (e.g. the earth’s field). Nesting them increases their effectiveness. Mu-metal workings by ‘sucking’ in field lines – they prefer to go through the high permeability material than through air (or free space), so they are diverted around a sensitive sample in the middle.

Magnetic field affects the Josephson Junction by altering its critical current, Ic. The experiment I am performing involves precise measurement of Ic. Ironically, in the middle of all these shields a magnet will be fitted (in the picture this is the smallest item at the right hand side of the line-up). The magnet allows Ic to be changed in a controlled manner when necessary.

The magnet is superconducting so that it can be operated in persistent current mode. This is where the current supply is isolated from the magnet’s superconducting coil using a special switch and the current flowing in the coil then just carries on going round forever. This is good news as it means the field is extremely stable.

At the moment the experiment only has 1 magnetic shield, which is not shown in the picture. Now that I have these new shields, I will nest 3 of them (note I can’t nest them all due to both geometry and space reasons) to improve the experiment. I will assemble the shields inside the dewar (the big blue thing in the background) housing the liquid helium which cools the Josephson junction experiments.

Savoie experimental superconducting electronics workshop

At the moment I’m attending an S-Pulse superconducting electronics (SCE) workshop at the University of Savoie in Chambery, France.


So far we’ve had talks about single photon detectors, hot electron bolometers, junction measurements, ballistic readout of qubits, Terahertz imaging, modelling inductances and superconducting circuits, cryocooling and cryopackaging, and plenty of RSFQ related information.

Yesterday morning we had an invited talk given by Hideo Suzuki from ISTEC, Japan, entitled ‘Progress of the interface circuit and cryopackaging techniques for SFQ circuits’. The Japanese progress on RSFQ technology is very impressive, the presented results demonstrated some very high speeds with very low Bit Error Rates (BER).

The weather is lovely and the food is delicious which always helps 🙂


Part of the idea of S-Pulse is to get people involved in the RSFQ/SCE scene, and to disseminate information about superconducting digital electronics and why it is useful. So if you are interested in attending or contributing to a workshop, you can check out the S-PULSE website for information. So far people are meeting and networking within this European project from Germany, France, UK, Sweden, South Africa, The Netherlands and Italy, to establish the position of Europe in the field of SCE and to promote the European superconducting device foundry. Note: People from outside Europe are also encouraged to attend.

Also, there is a postdoc position and a couple of PhD positions currently available in RSFQ. More information can be found here.

Potential science funding policy review

This is slightly worrying:

“Funding of science must be reviewed, say Tories”

The basic idea is that the Haldane principle needs reviewing. This is the idea that researchers and scientists themselves decide what research should be funded, as opposed to a higher (governmental) system. The Haldane principle seems like a sensible idea to me. The fact that it has been around since the start of the last century doesn’t necessarily make it outdated.

Whilst I agree that issues like climate change and green energy need to be addressed, allowing politicians to become more involved in decisions about research, especially fundamental research, cannot be a good thing. I believe (or perhaps naively like to think) that researchers (even those at the top of the funding hieracy) are on average more motivated by their curiosity towards scientific discovery, rather than what will make them the greatest profit or keep them in government. And besides, do politicians really want to spend their days discussing detailed scientific issues in which they are neither qualified nor interested?

As a final point, the government (or shadow cabinet in this case) should really stop riling scientists like this. We’re paid lousily for our contribution to society, and there’s precious little money invested in fundamental research as it is. At least let us keep the right to choose what we want to research.

Right – that’s my political rant over for the year 🙂