Quiztime — February 28, 2018

Since November 2017 I participate in the daily verification quizzes on the internet. Every day journalists post a photo and the game is to try and locate where the photo was taken (geolocating) and sometimes answer additional questions. This all started early 2017 when Julia Bayer started posting little questions like this:

Over time this gained more and more attention from other people on Twitter and after I read a blog post about this subject on Bellingcat, I joined the club of daily puzzlers: https://www.bellingcat.com/resources/2017/11/13/daily-verification-quizzes/ This has been a great exercise so far and I am very happy more people joined to try and solve these daily quizzes, even though we all try to make them more difficult each time.

We fast forward to the last Wednesday of February 2018 and Philipp Dudek posts a challenge that seemed pretty doable at first glance, especially the geolocating part:

Geolocating the photo

To find out where this photo was taken wasn’t too difficult, especially since the reverse image tool of Yandex was so kind to lead me (and probably others) to a photo of the old city center of Riga in Latvia. It took some time browsing through the hits, but I got there nonetheless. More info on that page showed it belonged to a collection of photos taken in the town of Riga:

Building found, but no information what it is, except for the flag!

It actually took me a bit of time to find the exact street, since I simply didn’t notice the flag of Denmark in the photo I found on Yandex. Only after posting the location I found, I noticed that ZeroQQ pointed out there actually was a Danish flag present on that location:

Well spotted!

And one of the main reasons of a foreign flag in the city of Riga is easy: It might belong to an embassy or consulate. And there we have it, the Danish embassy in Riga, located at Pils iela 11, Centra rajons, Rīga:

The location of the building in Google Maps

Establishing a rough time frame

So far for the easy part! But what about the second question: “When did I take this picture?” At first glance it seemed to be pretty much impossible to find the the year or even the period it was taken. While we started trying to look for clues, Philipp posted a worrying message on Twitter:

Yes, thanks Philipp! But we still like the challenge…

That didn’t hold some of us back to try and answer the second question anyway, so we started collaborating and first looked at the cars that were parked in the photo. ZeroQQ already did some research on it and found out that the Hummer H3 in the photo was actually sold from 2005 on:

Unlike the Netherlands, where license plates can actually be dated to the first registration to an owner by using a chronological coding system, this is unusable in Latvia. I read somewhere that over there it is possible to retain a license plate and transfer it to a different car, so this makes it impossible to attribute the year of registration by just using part of the license plate. And since there was no photo of a Latvian Tuareg at PlatesMania.com, we were left to resort to other methods of trying to close down the time period that this photo was taken.

The current time frame: April 2005 up to the day of the quiz

At that moment I was actually busy looking at security camera’s (more about that later) and right after finding out security camera’s were installed some time before 2010 Philipp actually spoiled the year this photo was taken. And we only just started to drill down to the actual year!

Yes, you can say all you want, but we need verification!

But even though the year was know by then, were we actually able to verify this? And maybe even find out when he made the photo? Join me and the others involved to see what is possible.

Eliminating years

We will now look at the two objects in the street that were eventually used to create a first rough time frame. First we will have a closer look at the security cameras on the building with the pink walls on the left of the photo, and after that a no-parking zone within this street. Both the security camera’s and the location where the street sign is nowadays are accentuated here in the respective colors red and green:

The security camera’s we will investigate accentuated with red, and the location of the street sign with green.

Let’s first try and find out when the security camera’s where placed for the first time. Maybe we can narrow down our lower end of the time frame. After some browsing around I managed to find a photo of October 2006, where the security camera’s on the mentioned building are absent:

At the end of December of 2007 we see that the camera’s have been installed on the walls, as can be seen in this beautiful photo from another Flickr user. So that gives us a 10 month period in which these camera’s were installed:

So now we can refine the earliest moment of the time frame we are trying to establish. Since the camera’s were installed somewhere before December 2007 but after October 2006, we can use the latter date to change it accordingly.

The current time frame: October 2006 up to the day of the quiz

After having a closer look, AitYaakub found out there nowadays is a no-parking zone in this street. I didn’t get his hint at first, but he was on to something extremely useful:

In the photo posted for the challenge, there was no street sign, unlike the present situation. So this gave us a new piece of information regarding the period Philipp took the shot, since that sign was clearly placed some time after taking the photo. Time to spend some more time going through dozens of photographs and we find that in July 2011 the street sign has been put up, as can be seen in this photo on DeviantArt:

When we go back in time a bit more (sorry, I just love posting all these beautiful photos of Riga) we see that the street sign is also visible in July 2010, finally setting the other end of our still pretty rough time frame:

If one would go into Google Street View and turn on the historical data, you can actually go back to August 2011 and can see that exact same street sign placed on the corner. I have tried to find out when the paid parking zone in Pils iela was enforced, but have not been able to find any news article about it so far on the website that is maintained by the city counsel of Riga.

The current time frame: October 2006 up to July 2010

Now let’s quickly cut of another few months of this time frame in an easy way! We can clearly see the yellow leaves on the ground, so we know it is autumn. So finally we have a rough indication when this photo was taken: In the autumn of 2006, 2007, 2008 or 2009. And that’s not bad, knowing that Philipp didn’t even know whether his photo had enough clues to find this out!

But… Can we go even further than this rough estimate? And maybe even find out which month or week he made this photo? When I decided to start doing this write-up, I soon was convinced we had enough information in the photo to actually get really close. So it’s time to do some more serious work and learn a bit more about nature.

Time for some gardening

How do we go from here? We now have four periods of roughly two months within a 3 year period in which this photo is probably taken. How would one go from here to drill even more down to the exact month or maybe week? This is where good gardening is going to help us out.

Two days after the challenge I was really busy gathering lots of information about the weather conditions in those periods, when some new information came in. We received a wonderful lead by MCantow who found out that the common lime tree in the garden of the embassy was pruned at times:

Nice piece of information by MCantow!

I went over some photos and decided this would absolutely help drilling down to the exact year the photo was taken. MCantow’s message translates to:

The key could be with this lime tree: The tree is not pruned every year, but was pruned in the summer of 2008 (see the1 year old branches in March 2009 https://c1.staticflickr.com/4/3543/3346908949_a4b6e4ea56_b.jpg) and in autumn 2010 or spring 2011 (see GMaps). From autumn 2010 I didn’t find a photo.

And it was indeed the key to solving this challenge. I didn’t know it is best to prune lime trees every once in a while, but let’s do some reading up on that. We can read a bit more about the process and the reasons for that for instance this site:

The best time to prune lime trees is early spring or late summer or anytime prior to blooming. Prune lime trees every year or two, which will help keep them from becoming too large.

If we dive into all the photos we can find on Flickr (since they have the oldest photos and is reasonably accurate with the EXIF data as long as people set their time and date correctly!) We find that the lime trees seem to be pruned in 2008 just as MCantow told us:

If we create a small list with all the relevant photos we are able to find, we see the following:

Oct/06 : Full foliage : https://flic.kr/p/ti8PV
May/07 : Full foliage : https://flic.kr/p/62DCmT
Dec/07 : Full foliage : https://flic.kr/p/8KoCSV
May/08 : Pruned : https://flic.kr/p/4YYEi4
Mar/09 : Growing : https://flic.kr/p/66KMqH
Jul/10 : Full foliage : https://flic.kr/p/8kKCWZ
Sep/11 : Full foliage : https://flic.kr/p/anXUTc
May/12 : Pruned : https://flic.kr/p/hwzDme
Oct/13 : Growing : https://flic.kr/p/gzBonS

Since it looks like the leaves on the lime tree are not as thick and fully grown as in September 2011 it seems the photo was taken in in a year it was still developing it’s foliage after pruning. In Philipp’s photo it is not as wide and full as in the photo of September 2011 after growing for three years. We don’t have a photo taken in the autumn in the same year of pruning, but we do have a good comparison of the pruned tree in spring and autumn one year later:

May 2012 (pruned):

October 2013 (growing):

We can clearly see the similarities regarding the thickness of the foliage in Philipp’s photo. So we have to disregard 2006 and 2007 as possible years, since the foliage is much too wide and thick. And since the tree was pruned in 2008, it would never have had foliage that was thick enough later that year to produce the view we see in Philipp’s photo. So we are now left with the only possible year and season that Philipp could have made this photo.

The current time frame: August 2009 up to late October 2009

Let the sun do the talking

Now on to the last part, what week and what time was the photo taken? let’s first have a look at the shadows that are visible in the photograph.

Casting a shadow on the embassy

We see that the sun lights up the south west part of the embassy, and we can distinguish a small shadow on the little balcony of the wall itself, which gives us a very precise indication of the position of the sun during August and September of 2009. The time would have been somewhere around 14:45 to 14:55 CET, which is easy to find out using the website https://www.suncalc.org (the embassy is located in the green circle)

Then we look at the other shadows and we can see the outlines of the church and the little ornaments on the street:

The shadow of the church

We need to find the position of the blue dot, so we can use that to triangulate the length of the shadow. So we go to Google Streets and we plot the spot on the street to get a sense of placement in regards to the building and its surroundings:

The location of the blue dot

The location of the dot is near the edge of the side walk, at roughly 3/4 of the building if we start looking from behind us (since most photos are taken from there). If we go to Bing Maps, we can get a pretty good idea of how long the shadow will be if we measure it from the base of the building. I did not use the satellite image for this picture, simply for clarification, but that too gives you pretty much the same distance: 22 meters.

Now we can go back to Suncalc again, because it can give us accurate information about the length of a shadow that is cast by an object. But before we can do that we need to know how tall the little ornament is on the corner of the church. For that we will have a look in Google Streetview at the front of the church, since that seems to be the same height as the back, but where we are able to use the parked Renault Trafic as a reference. Looking up the specs on the internet gives us a height of 1940cm that we can use as comparison:

Using a Trafic for measurements

I moved some distance away to reduce the influences of perspective and we start measuring the amount of vans we need to stack to get to the top of the ornament:

Time to stack some vans

That seems to be 8 vans in total, and even though this is not super precise, it should be more than enough to solve this quiz. We input the total height as 15.5 meters in Suncalc and we start looking for a date in August to late October 2009 to find a moment in time where we are able to cast a shadow that is about 22 meters long at 14:50 CET in the afternoon. And we come up with the following possible date: 9 or 10 September 2009 at 14:50 CET in the afternoon:

The final answer

One day before posting this write-up the actual date was spoiled by Philipp and without using that knowledge but simply looking at the facts, I was able to get close. The date was actually the 1st of September 2009.

Looking back now it is pretty amazing that it was possible to get within a week of the actual making of the photo. Especially when we realize that neither of us knew whether this was possible at all.

Thank you all for the wonderful collaboration! Because I doubt I would have been able to do this write-up at all without all of your help. So an extremely big thank you to: ZeroQQ, Fiete Stegers, AitYaakub and Lars Wieland for all the collaboration. And of course Philipp Dudek for providing us with one of the most challenging quizzes so far!

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