Archive for the ‘Uncategorized’ Category
Today is my brothers birthday but, as is traditional between the two of us, I completely forgot to send him a card. There is little point in sending it now as it would turn up very late – he lives in America and I am in England you see.
So..I hope you’ll all join me in wishing my little brother a very happy birthday.
Cheers bro – hope to see you soon,
Mike
I can’t beleive I missed this one! I knew that Mathworks were ditching Maple in favour of MuPad for their symbolic toolbox but I didn’t realise that they liked it so much that they bought the company. I wonder how this is going to affect other products, such as Mathcad and Scientific Workplace, that have adopted MuPad as a symbolic engine? Will Mathworks continue to license the technology to their competitors or will the likes of Mathcad have to find an alternative?
Sorry about the recent downtime – we encountered some problems while upgrading to the latest version of WordPress. Normal service has been resumed.
I like VirtualBox and find myself using it more and more often but had a little problem with it this morning that took me a few minutes to solve. This post is essentially a note to self. It would be a bonus if it turned out to help someone else too (please let me know if it does).
So I am using version 1.5.6 of VirtualBox on Ubuntu 8.04 (hardy Heron) and I wanted to clone a vdi image to save me from having to go through the Operating System installation from scratch for a particular virtual machine. I navigated to the directory containing the vdi images and issued the command
VBoxManage clonevdi ./clean_machine.vdi ./copy_of_cleanmachine.vdi
which resulted in the error
Text = Could not access hard disk image ‘/home/mike/.VirtualBox/clean_machine.vdi’ (VERR_FILE_NOT_FOUND)
The file definitely was there so this confused me for a bit. It turns out that you need to provide the full path to your vdi files – not just the relative path. Something like
VBoxManage clonevdi /home/mike/.VirtualBox/VDI/clean_machine.vdi /home/mike/.VirtualBox/VDI/copy_of_cleanmachine.vdi
did the trick.
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In my attic there is an ancient computer desktop that is long past its sell by date and it is time to take it to the tip to be recycled. Before I do this though, I want to ensure that all of the data is securely removed from the hard drive. As many people know, just deleting the files is not enough as they will still be on the hard drive – your operating system will just pretend that they are not.
So what to do? Well, my solution was to use a Ubuntu Live CD to boot into Linux, open a terminal and issue the following command
shred -v -z /dev/hda
This wrote random data to the entire hard drive 25 times and then finished with a set of zeros. That’s pretty deleted!
I have heard that even with this level of ‘shredding’ it would still be possible for someone with suitable equipment (such as an AFM) and sufficient determination to get access to at least some of your old files but I am betting that such equipment is expensive and hard to obtain. I also can’t imagine why anyone would go to such lengths to view my old data – its not THAT interesting!
Essentially all I am trying to do here is stop the casual snooper from easily finding out what was on that hard disk and I think that the shred command does exactly that!
The 30th Carnival of Mathematics has been posted over at The Number Warrior. Topics include visualizing Ageev’s squaregraph, a selection of math fallacies and much more.
One of my favourite web-comics is xkcd and while flicking through it recently I came across the following strip. I was planning on posting more but I can’t stop thinking about the problem.
During a routine google search I hit upon the following website http://nostalgia.wikipedia.org/wiki/HomePage which is a snapshot of Wikipedia taken in December 2001. For better or worse, the wiki is used by millions of people today and I think it’s fascinating to see what it looked like back in the early days.
Life has been very hectic for me recently so I didn’t get chance to mention this at the correct time. The 18th Carnival of Mathematics was published on October 6th including over 50 maths-related posts. Ten days later and I still haven’t had chance to read them all!
The 19th Carnival will be up very soon over at Good Math, Bad Math.
I have just returned home from a wonderful holiday in the south of France (The village of Valbonne to be precise) and while I was there I re-discovered a stunning looking vegetable called a Romanesco. I stumbled across these for the first time last year at an organic farmers market where I bored my wife to tears explaining how this was the perfect example of a fractal. I liked the look of them so much that I bought several and so it was very lucky that they happen to taste good as well.
At the time of writing if you google for ‘Fractal Food’ then the top search result is the following great website which includes the above picture along with some of the mathematics of fractals. It also has a couple of recipes (which is unusual for a site about mathematics).