(Sidney San Martín)

I explore life and technology. I fix computers and write code at DeepTech, Inc. in NYC. On the side, I guide development at DISTRO.fm. I’m taking three months off to do batch[2] of Hacker School. You can find me on GitHub and Twitter, among other places.

March 14th, 2012

Am I more or less likely to cancel if you make it easy to do so?

Here’s a message I just sent to a big-name credit monitoring service as part of a we’re-sorry-you-cancelled survey:

I was still in the trial period — when I first signed up I looked around the website to find out how I could cancel, if I wanted to, and I didn’t find anything. There was no button in my account settings, there was nothing in the FAQs or the help section about how to do it. I searched around online and found out (from other websites) that I had to call in and talk to someone during business hours.

Products that make it so much more difficult to cancel than to start using them make me uncomfortable.

I like paying for stuff online. I think that when I know I can cancel a subscription service really, really easily I stick with it longer — the option’s always there, any hour of the day.

But that’s a huge guess. I wonder if there’s an accepted answer?

Tagged

February 19th, 2012

Subject: Signing gnupg keys

Got this email out of the blue and I have no idea what to make of it. I asked in the #gnupg IRC channel on Freenode and got little insight. Not being at all familiar with Spain’s ID card system doesn’t help.

Hi…

I’m looking for people who sign my gnupg key. It’s a hard job, but i found a method to make Virtual Keysigning Party. Here at Spain we have an ID Card with a x509 certificate inside, this certificate is provided by my goverment with the control of the police, so this certificate is full legal and it’s like handmade signature.

I would ask you if you may sign my public key with this legal proof. If you agree i send you a PDF file with my asc pubkey inside signed with my legal ID Card.

Do you agree to sign my pubkey with this method?

Feel free to delete this mail or answer no.

Thank you.

I’m very curious whether this guy’s intentions are pure and, if not, what he’s trying to do.

November 27th, 2011

Bookshelf perspective

I just finished putting all the books I want on my bookshelf back on my bookshelf, and I decided that I should take a picture of it. It’ll be cool to look at it in a few years and see which new books have showed up, and which old ones I’ve finally gotten rid of.

But, there’s a problem: you never look at a bookshelf from only one spot! You step back and stand on the tips of your toes to look at the high shelves, and you bend down to look at the low ones. It’s nicest to look at each book straight on.

So, how do you take one picture of a bookshelf? You could get very far away from it. But, my room isn’t nearly big enough — if you take a picture from the opposite wall, you’re still clearly looking up at the top shelf, and down at the bottom shelf.

A scanner has many image sensors across its width, and by moving (scanning!) the paper, or the sensors, down its length. As a result, a picture taken by a scanner has no perspective. It sees everything straight-on! But, I don’t have a giant flatbed scanner.

You could get the same effect by taking many pictures with one scanner and stitching them together — that would take a lot of work, and I wanted something a little bit quicker. So, instead, I took a few pictures of my bookshelf with a regular camera. I got as far away from it as I could, set my camera up on a tiny tripod, pointed straight at the bottom shelf, and took a picture. Then I switched to a bigger tripod, raised it up, and took a picture from slightly higher. I did this a few more times, raising the camera up all the way to the ceiling. Then I stitched them all together in my computer.

The result is pretty cool — a picture with normal perspective in the horizontal direction (you can see the inner sides of the left and right walls of the bookshelf) but with very little in the vertical direction (and the perspective is strange — you’re clearly looking up at some the books on the left side of the bottom shelf, but you can see the tops of the books on the top shelf!).

June 29th, 2011

Bugs everywhere