Wednesday, 1 August 2012

the condensing universe

Have you ever fried vinegar?

I don't know why I tried it, but if you try it you'll notice at least three things.

1. the vinegar drops shrink as the water in them evaporates
2. they become darker as the percentage of vinegar increases to 100%
3. they skate across the pan due to the Leidenfrost effect

I wondered about how this would look if you could stand on one of those vinegar drops.

From this relative perspective the other drops would appear to be moving further away.

Then I wondered, how would the universe look, if viewed externally.

Could it be like frying vinegar?

What if the size of the universe was fixed, and it was the matter that was shrinking?

What would that tell us about how the laws of physics would need to change so that we, the inhabitants, wouldn't notice?

At the very least, some physical constants would need to change:
1. the speed of light
2. how mass warps space
3. (add more constants here)

The one thing that couldn't be hidden by all this is quantum physics.

In quantum physics matter and energy are converted to each other with no loss.

Atoms are formed from protons and neutrons and the equations balance out perfectly.

It's fundamentally at odds with our everyday experience - where putting something together or taking something apart involves work, effort, energy.

What if the quantum world were no different from our world, except that quantum particles get their energy from the condensing universe?


Isn't technology great?

I have a vision of the future.

It's a hot summer night in (a place near you).

Everyone who wants to see and/or be seen is entering that new great night club.

After paying the price of a cinema ticket (it's a posh place, no riff-raff) each attendee is handed some Google glasses, earphones and a little box to drive them, with a neck strap or belt attachment, depending on attire.

With the glasses and earphones on, attendees enjoy an augmented reality experience.

Those black 16 foot by 9 foot rectangles that looked really odd now show videos thanks to those Google glasses, accompanied by the music being pumped through the earphones.

A hand gesture conjures a mid-air menu.

One of the options is "I'm feeling friendly".

Now your view of the people around you becomes augmented with talk balloons like you see in comics when people are talking.

In the balloon you see various statistics from which you can determine if they would be nice to talk to, as well as their status.

Now to the subject of the post.

The music you're listening to is from a YouTube video, and that video on the wall is from the same video.

According to the YouTube copyright terms of use, you're watching it personally, and because you're seeing the video through those Google glasses you were handed, it's a private viewing.

The fact that everyone around you is dancing to the same beat might lead you to suspect that they can see the same video and hear the same music, but that's just coincidence.

If it were true then this would be a public viewing, wouldn't it?

Saturday, 23 June 2012

WiFi bargain hunting

I recently had occasion to buy a TP-Link TL-WR702N from ebay.
The transaction itself went smoothly enough, but when I tried to use the thing, that's when the problems started.

The box it came in had a lot of Chinese writing on it - I could still see the product name, the company name, and TP-LINK in English.

I was slightly concerned when the documentation included were all in Chinese - I've upgraded the firmware for routers before, and I could download the English manuals from TP-Links web site, so I figured I could "upgrade" it with an English firmware file.

That's where the fun began.

To help you, dear reader, to appreciate the following content, let's talk probabilities. Imagine that each customer, having received the router, considers it 100% likely that they can use the router. For each hurdle some will fail.

Chance for success: 1.0

TP-Links own documentation mentioned that uploading firmware required selecting a ".bin" file from the routers web interface - a file upload - simple enough, I thought - that's how most routers do it.

Unfortunately I couldn't access the routers web interface, from Debian Linux or Windows 7 (I added Debian and Ubuntu to my Samsung laptop).

By chance I happened across another blog that told me how - by using a network cable and setting the ethernet port on my PC to

That hurdle would probably have caused 90% of customers to fail, or 1 in 10 to pass.

Chance for success: 0.1

Then I discovered that the web pages were in Chinese too.

It took a bit of trial and error network wizardry to be able to connect to the internet using WiFi and to the router via the ethernet cable, so that I could translate the web pages to English with Google translate.

That's where the fun really began.

The web pages the router served told me that I had to set up a TFTP server to provide the firmware upgrade.

Since setting up a TFTP server to deliver a file isn't a trivial undertaking, and since the TFTP server configuration varies widely depending on who/what you're serving files to, that's another severe hurdle, causing 90% of customers to fail at this step.

Chance for success: 0.01

The (translated) router web page indicated that there were 5 ways to use the router - the "repeater" mode seemed the best.

In repeater mode, the router acts as a repeater for your "main" router, plus you can connect equipment to the same network using it and and an ethernet cable.

Unfortunately, I couldn't get it to work.

Chance for success: 0.001

It was only after deciding to send it back, telling others about the problems I had, and the delay involved in trying to raise this problem with ebay, trying to cancel the transaction in Paypal (causing a server error, no less) that I tried to set up the router as a client - the way wifi dongles work, but with a network cable instead of a USB port.

It worked, as long as you remembered to set the IP address of whatever device you connect to it.

Chance for success: 0.0001

When I contacted the seller about this I was told that I didn't need a TFTP server. Incorrect.

When I contacted TP-Link about this, I was told that I could only upgrade/convert the router to English if its web pages showed traditional Chinese - routers showing simplified Chinese couldn't be "converted" to English.

Guess which one I had.

I even managed to upload updated (Chinese) firmware to it, using tftpd-hpa-5.2-2 in Debian by running the server in the same directory as the firmware upgrade.
Here's the command you need to run as root to serve that file (bye bye Windows users)
in.tftpd -4 -L -v -s --permissive $PWD
If this command completes straight away it means that it couldn't start (no error message).

You have to stop the running tftpd with

        /etc/init.d/tftpd-hpa stop


Chance for success: 0.000001

The upgraded firmware still needs a TFTP server to work, and no, it wouldn't accept the English firmware file from TP-Links web site.

I considered that a lot of customers (almost including myself) might find that the time and trouble required to enjoy this product may be more than most are willing to commit, and that ebay should take some steps to prevent this happening to other unsuspecting English speaking users, maybe by getting someone fluent in Chinese to talk to TP-Link about this.

They recommended I follow the steps they gave me to get the sellers telephone number to try speaking to him, so that we might come to some amicable arrangement.

Chance for success: 0.0000001

The sweetest thing about all this is that if I'd bought a TL-WR703N I could have just installed OpenWrt!

Some disorganized notes

There's no point trying to lay these out - I'd need to know all the possible failure routes.


Configuration changes sometimes don't take effect right away.

Try (as root) "ip neigh show", and "ip route list cache"

You can also try to see if "ip route flush cache" and "ip neigh flush dev eth0" can unwedge the system.

After a flush, "ip neigh show" and "ip route list cache" should return very few, if any, entries.

Web pages translated
See my separate blog post.

Error codes translated

Error code: 18000
Upgrade is unsuccessful, please check if you open the TFTP server and upload files in the appropriate directory.

Error code: 18001
Upload the file length error, please check the file and try again.
Error code: 18005
Version of the uploaded file does not match with the models.

Saturday, 3 March 2012


The term "anti-work" is one of those terms that makes you do a double-take.
How can something be anti-work?
From the definition of work as "the amount of effort applied to produce a deliverable or to accomplish a task", it follows that
Anti-work is the work done to make the production of a deliverable or the accomplishment of a task more difficult.
So what does that mean in our everyday lives?

1. Learning curves
If a learning curve is made more steep, so that learning a new skill is more difficult than it otherwise might be, this is anti-work in action.

Sometimes this is justified as "intellectual property protection".
You may notice this when you buy a gadget and discover that there are no visible screws or means to open or examine the device.

Sure, there are good reasons not to mess with electrical equipment, for example. But this wouldn't stop one of the manufacturers competitors from opening it - they'd use a hack-saw and be done with it.

2. Officialdom
It takes a certain level of skill to put something moderately complex together.
If you can give it smooth curves or a two-tone plastic case, it conveys the impression that it was made by a corporation, and that tweaking it is "discouraged".

3. The "Oubliant"
This is a French term that originates from the word "forget" but here it's used as a noun that means "a place to send someone to forget about them".
In the context of anti-work, this means a labrynth.
A good example of this is the world wide web.
If you use the right search term and there are one or more sites that feature that term then you're in luck.
Veer of the beaten path and you're in for errors misconceptions, copies out of date references etc.

To remove these entries from the web would be a great service to humanity, but that in itself constitutes another form of anti-work:

4. Work that appears to achieve no result
Another way of putting it is "work that helps you discover all the wrong ways of doing something".
You meant to ask for the right way, but didn't have the language, the grasp of terminology or the experience to pose the question correctly.

This happens a lot in software development, even in cases where buying a book on the subject is not an option, simply due to what's called "shop blindness".
This is where a group of individuals become so immersed in a subject that they unconsciously begin to use every-day terms with specific meaning not apparent to an outsider. Result: anti-work.

5. One vs many
If you're trying to "stay ahead of the field" you can either be ahead of the field, or make the field more difficult, using anti-work.
Of course your ability to encourage others to follow your anti-work path indicates that you're already prominent in that field, so why do it?
Possible answers are: officialdom, in the public interest (e.g. risk or hazard concerns), branding (where the tone used is consistent within professionals in the field).

6. Bureaucracy
The incidences of bizarre procedures where a simpler friendlier and ultimately more efficient alternative exists are too depressing to list.

7. Gamesmanship
When an otherwise simple career path is steeped in dodgy dealings/characters/situations.
See <insert country here>'s next top model to see what people get up to in the business of wearing clothes.

8. Bottle-necks
Just like a bottle, the flow is restricted at the neck, unlike a glass or cup.
This is where the supply/production/application process needs to be handled by an elite group of individuals.
Rather than train others to share the load, these talented individuals are far too busy catering to demand. If only there was more time!

9. The blind leading the blind
No offense is meant towards the visually impaired here.
In this context the "blind" leaders many be amateurs, enthusiasts or those who otherwise manage their audiences expectations of their ability.
If there's a problem, they "have an idea" as to what's wrong.
If they fix it, it'll "probably be OK".
They may ask the real experts but don't tell you otherwise you wouldn't need them.
The wonderful thing about this class of anti-workers is that we can all claim our free membership pass with subjects we're learning or that are a bit beyond us.
I think that's the job description of a parent.

10. It was like that when I got here
The possibility that this was really the case implies the existence of some unknown individual/entity who's in a better position to know how things really work than the people responsible, and that asking too many questions might offend this unknown deity.
Religions have started over this kind of hearsay and rumor.
Then again some people duck and dive responsibility for a living.

11. The "stall"
You have a requirement, and you look around for the tool, service or product to solve it, but none of them fit exactly, or need further investigation.
"OK there are problems with version 0.5, wait until you see version 0.6, it will knock your socks off."
So you start looking into their offering and indeed the possibility exists that one day it could possibly do what you want.
A few days/weeks of learning how to use it you discover you need to buy a book.
Then a DVD.
Then a training course.
Then the next version.
And another training course.
There are more expensive offerings available, but you thought you'd save money be allying with an impertinent start-up or open source alternative.
It's bound to be cheaper than doing it yourself, won't it?
Then they change direction entirely and guess what, there are books, DVDs and training courses for that version too.
Who would have thought they were in the book/DVD/training course business.
Then you find out that the thing you wanted to do could be done with the product, and 250 people.

12. Fashion
Yes, fashion even gets in here too. See also culture, tradition and religion.

13. Psychological projection
See here for more on this.

14. Competition
Anti-work is a tool, and if you can keep a competitor too busy to compete effectively, then that could make the difference.

15. Jobs
It's a sad fact that the importance of some management positions is measured by the number of people that position manages.
Like the emperors new clothes, this can run away with itself.
We should all have more free time by now, not keeping each other busy.

I encourage you to note anti-work wherever you go and whatever you do.

It may help you distinguish between real work and a performance.

I wouldn't describe myself as a "save the planet" type, but most damning of all is the fact that anti-work is just wasteful.

If even one such problem could be solved or its effects reduced by one person spending one hour of their time, to save thousands of other people spending hours or days of their time trying to solve, then we would have a more efficient society.

That's a good thing, isn't it?

Thursday, 9 February 2012

3D printing PCBs

Solder (see this for an example) has a melting point of 270C.
PET has a melting point of 250C.

If you could form 0.1mm cubes of each and arrange them in rows, then the "printing" process becomes a process of arranging row after row and layer upon layer into a finished (rectangular) shape - like a circuit board.

Subject the finished item to 240C and the solder and plastic will become soft enough to sinter to themselves while holding their relative shape.

The finished PCB won't be as tough as a regular PCB, but it would be possible to reuse them as they will separate with a sustained heat of 270C because of their different densities.

You obviously couldn't solder items to this PCB - they would need a mechanical contact to the solder.

Just make sure you have adequate ventilation!

Tuesday, 7 February 2012

the moist maker

I had an idea about how to connect a memory chip to the Broadcom BCM2835 for the Raspberry PI without the need to solder the connection.
The original comment is here and the blog entry is here.
I called it the "moist maker" because in the TV series "friends" that's the name Ross gave to the extra slice of bread soaked in meat sauce that went in the middle of the sandwich - a triple-decker.
I saw two chips and a plastic layer that goes between them - I thought that calling it a "moist maker" makes it easy to identify and reference.

I now realize that the scope of this idea is much greater than this one specific application.

Imagine circuit boards where most components are surface mount - through holes would only be needed where the increased pin density would require more precise component alignment.

Next, imagine a thin plastic electrically insulating sheet with conductive plastic pillars in it that conduct electricity from the component connector above to the circuit board below - the moist maker.

Finally a rigid transparent cover sheet that's molded or 3D printed so that it lightly presses the components onto the moist maker and holds them in place so they can't move and the electrical connection between them, the moist maker and the PCB is good.

The cover is held in place with clips on the edge of the PCB.

No need for soldering and if you no longer need the circuit, just unhook the cover and you can reuse the components.

The memory->CPU->PCB that started off the idea has more precise alignment requirements than other components and this would be possible by adding rectangular pillar into which the CPU, another moist maker and the memory chip fit. It would need to have pins that fit into slits/slots in the PCB to achieve the required alignment precision.

The other alternative to conductive plastic pillars is an insulating sheet saturated with carbon nano-tubes orientated perpendicular to the sheet surface.

As long as enough of them connect the item above to the item below without them shorting out adjacent pins or each other, it should work.

Once 3D printing takes off, the possibility of printing the multi-layer PCB complete with soft conductive component connections would open this up to hobbyists.

2013-11-07 update
You can now do a web search for "vertical conductive cloth tape adhesive" - let me google that for you:

I won't publish them here as there doesn't seem to be a manufacturers link available yet, but would it work for this application???