Mr Reid's Blog

There's a lovely building at North Greenwich which is Penrose'd. http://wordpress.mrreid.org/2011/02/26/penrose-tiling/ http://www.bdonline.co.uk/foa%E2%80%99s-peninsula-patterns-for-ravensb…

http://wordpress.mrreid.org/wp-content/uploads/2014/06/atmosphere-comp… the density is low though observe that where Helium becomes a significant percentage, there is also Hydrogen and (monoatomic) Oxygen. if one were driven by purism or vanity for stoichiometric exactness, then at a height of 1000 km theres 2 Hydrogens per Oxygen atom, so this could be reacted to water, and the energy used to power compression of the Helium, the water would freeze. without this vanity, helium becomes a significant fraction at much lower heights... and thus higher densities. The energy to compress becomes nearly insignificant at low pressures. if humanity ever builds space elevators, this will be one of many benefits of having space elevators.

You can’t have standard seconds with solar time though (or minutes or hours), unless you live at the equator [0]. So it will be interesting to calculate at what local time your CI build is expected to complete, or if you have enough time to watch that 120-minute movie before whatever the equivalent of 10 o’clock would be in solar time. Or alternatively, each day would have to end at a different time, but then 12 o’clock wouldn’t be solar noon (or midnight). [0] http://wordpress.mrreid.org/2014/10/19/rate-of-change-of-day-length-wi…

There used to be a site that listed everything that the Daily Mail (a low-quality British newspaper) had claimed could cause or prevent cancer (and often both): http://wordpress.mrreid.org/2009/09/07/kill-or-cure/ Now all I can find is this partial list: https://www.anorak.co.uk/288298/tabloids/the-daily-mails-list-of-thing…

http://wordpress.mrreid.org/2011/08/06/hacking-qr-codes/ Reminds me of this blog on redirecting qr code links with cleverly made transparent overlays to change a few blocks in the code.

That would be a... double-whoosh? http://wordpress.mrreid.org/2015/04/18/the-nuclear-double-flash/

In 2011 I remember reading about “QR phishing”, where a transparency is overlaid on a QR code to completely change the data while barely modifying the representation. http://wordpress.mrreid.org/2011/08/06/hacking-qr-codes/

This phenomenon is referred to as a "double flash": http://wordpress.mrreid.org/2015/04/18/the-nuclear-double-flash/

Crazy, USA needs higher voltage AC, not DC... People in the 240V world get to pull 3KW from their wall sockets, I'm jealous. http://wordpress.mrreid.org/2012/04/16/why-kettles-boil-slowly-in-the-…

> It’s confusing because the latitude line 66° south looks like a straight line on a globe. On the contrary, latitude 66° on a globe looks to me like a fairly tight circle. http://wordpress.mrreid.org/wp-content/uploads/2011/07/antarctic-circl…

It may be a good model, but that is not what the poster claimed. The poster claimed that is was an aspect of a real, physical reality. There is no evidence of that. In fact, there is a good argument that 0k is unachievable [0]. [0] http://wordpress.mrreid.org/2014/07/03/why-cant-we-get-to-absolute-zer…

The authors of the blog don't say, but here's one approach: http://wordpress.mrreid.org/moviebarcode/ A discussion using mplayer for faster output is also attached at http://projects.metafilter.com/2996/Make-your-own-Movie-Barcodes

You have clearly never lived in North America, continent of pathetic kettles. It's hard enough to find one here that's electric in the first place, it seems people prefer to balance their kettles on the tops of stoves, like peasants. On the odd occasion you do find one that plugs into a wall, often it's like it was designed in the dark ages before they were cordless, and of course the cord is only about 6 inches long, so you have to unplug it to move it to the tap for a refill, then plug it in again. My current apartment's kettle doesn't even have a lid or a button, you have to fill it through the spout and it starts boiling immediately when you plug it in. After all that, it still takes about 27 minutes to make a cup of tea. Forget all these fancy lime scale filters and temperature controls, just finding a £5 one that actually worked would be a dream. Rant aside, apparently a large part of the problem is because North America uses 110v at the wall. Quick explanation here[0]. As mentioned in the linked article, many houses here also have a separate high voltage line for washing machines. Perhaps they should have a high voltage kettle line. [0] http://wordpress.mrreid.org/2012/04/16/why-kettles-boil-slowly-in-the-…

Radiation Hardening. Space Sicence Missions are analyzed from a perspective of risk, when designing the hardware specifications. The CPU specifically, is called a RAD750. It is essentially PowerPC 750 Architecture, with radiation hardening. http://wordpress.mrreid.org/2012/08/25/curiositys-rad750-radiation-har… The key risk vector in semiconductors in a space environment is things like bitflips. So, when a high energy particle collides with your transistor in DRAM and a 0 becomes a 1, that is a problem. There are deep architecture changes made to the RAD 750 specific to deep space missions, for example SRAM is used instead of DRAM, as SRAm is less succesptable to bitflips from high energy particles. There are other alternative RAD CPUs, such as the Leon. But ultimatley, a space vehicle does not need a lot of compute to have a successful mission. It runs VxWorks, a real time operating system. And a far, far, high risk of failure comes from bit flips, rather than having a bunch of compute for no reason

Why is the resolution so much fixed to the number of mics? Shouldn't 3 mics be somewhat sufficient for intermediate values as well? More mics => more redundancy => clearer image of the waves, but why do the pixels/blobs "snap" to a microphone? edit: ah, he does not use timing (at 10fps obviously not) but needs continuous sound to see the wave pattern across the array... edit 2: so do these gunfire locators¹ only time stamp impulses? Or do they do continuous analysis? With natural, irregular sound, it should be possible to match and measure the delay between mics, no? edit 3: the gunfire locators would need to analyze for gunfire characteristics anyways, to weed out false positives, but that could be separated from the locating. edit x: oh cool, if you zoom out of the final picture so it's smaller on screen, you can even see some parallax effect happening: http://206hwf3fj4w52u3br03fi242.wpengine.netdna-cdn.com/wp-content/upl… ¹ http://wordpress.mrreid.org/wp-content/uploads/2013/06/boomerang-mount…