The first screen I look at every morning

Part of my morning ritual when I wake up and sit down at my iMac nowadays is to open up this particular screen on our SaaS dashboard:

This shows me all the users who are logged on to my HR SaaS application over the past few hours. This screen always gives me pause to think.

I remember when my startup was just in its infancy, and we only had a few dozen users around the world. When I look at this stack of pins in this real time map, I am reminded that this is no longer a side business or just a hobby business any more. We are now providing a real time critical service for people in all corners of the world (at time of writing, 1685 customers in 73 different countries).

It is a sobering thought, and I keep that in the back of my mind when I make any changes to our system now, to be sure that I don’t do anything that will result in downtime or errors.

This is also motivation for me to one day visit a lot of these countries and get to talk to our users face to face!

(BTW, this real time map widget was built using RethinkDB, Segment, MapBox and VueJS - I may do a separate blog post on the technical aspect of building this, which only took a couple of hours).

On Racism...

#BlackLivesMatter protesters in Darwin (photo courtesy of ABC News Darwin)

The massive groundswell of the ‘Black Lives Matter’ protest has resonated around the world. Even to my sleepy little hometown of Darwin right here in Northern Australia. As great as things are here, we do have problems with Aboriginal deaths in custody, as well as a disproportionally large number of Aboriginal people being detained or incarcerated in our country. Things must improve, and I hope that the awareness and motivation generated by this recent movement will mean real changes and improvements to the lot of non-white people here and across the world.

Personally, I consider myself quite lucky. Whilst I am a “sub continental punter” (as Whoopie, a charismatic team member from my cricketing days used to affectionally call me), I have experienced very little overt racism during my time here in Australia.

One reason why I really love this country. Everyone seems very open and curious and non judgemental when you come across them. Sure there may be some rare occasion of undercurrents of racism - being made to wait longer in a line at the bar or store for no reason while other ‘whiter’ customers are given priority, or not getting calls or emails returned if I use my full name when introducing myself (and getting better responses when I don’t include my name) etc., but by and large, these do not really concern me at all.

Probably the worst case was in school in Year 12. I was in a boarding school, and the Year 12 boarders got the privilege of living in actual houses surrounding the school. These were beautiful old Adelaide architectural domains, and the one I shared with about 8 other kids had a disused cellar that we converted into a little hangout to get away from the stresses of exams or school life.

When the cellar was outfitted with all the mod cons necessary for high school kid life, I went to go in there one night after a particular hard study session only to find the door locked. I knocked and asked to enter, only to hear the voice of the guy who was actually the boarding house captain (let’s call him Arthur) say “Sorry, you can’t come it. This area is for whites only”. This was mostly puzzling, rather than offensive to me at the time, and I simply wandered off and went to bed.

Next morning James, another close friend of mine who had been in the room came up to me with tears in his eyes while I ate breakfast. He apologies profusely for what was said to me and said that he was repulsed by it and that it was wrong. I was grateful to James for his honest and emotional short speech (and he went on to be one of my best men at my wedding).

Many years later, at a 30 year reunion of our boarding house, I came across Arthur again at the party. He greeted me warmly and chatted away as if nothing had happened. He probably didn’t even remember the incident at all. In truth, he probably wasn’t even a racist, but just didn’t ‘get’ me for some reason back in the day, and just used the bigotry angle as a way to needle me at the time.

I chose to just forgive him at that point and to focus on talking and reconnecting with the 99 other friends in the room whom I shared great moments with during my school years.

Dambusters - on triangulations and forgotten boffins

Last week was the 77th anniversary of the famous “Dambusters” raid on German dams in the Ruhr valley. There are many sources of stories online describing Barnes Wallis’ innovative ‘bouncing bombs’, and the bravery of Wing Commander Guy Gibson and his 617 squadron crew. However, I wanted to shine the spotlight (pun intended) on the unnamed ground crew who had to prepare the Lancaster bombers for these crucial missions.

As you might know, in order for Wallis’ bombs to ‘bounce’ properly on the surface of the dam waters, they had to be dropped precisely from an altitude of 60 feet above the smooth body of liquid.

Early attempts used a low level altimeter from EMI, but that proved to be unreliable and not accurate enough for the purpose.

Legend has it that Guy Gibson himself (or one of his crew) had a brainwave to use two beams of light to triangulate the altitude of the bomber above the water. If you watch the famous black and white movie from the 50’s, it shows an aircrew member being inspired by going to a West End show and observing the two spotlights on either side of the stage focusing on the performer.

However research shows us that it was Benjamin Lockspeiser, the Deputy Director of Scientific Research at the Ministry of Aircraft Production who designed the actual light fitting for the bombers. Unlike Wallis and Gibson, his name is a little more shrouded in the history books, as most of the ‘boffins’ working in the labs often were. Here are his plans for the lighting system installation on the Lancasters:

Image courtesy of RAF Museum

The idea was that there would be two Aldis lights mounted on the nose and midships under the bomber. They would both shine a narrow beam spotlight downwards and off to the right of the aircraft. The two beams would meet at an exact point 60 feet below (and to the side of) the aircraft.

The navigator of the bomber, could look out of his blister window on the starboard (right hand) side of the aircraft towards the surface of the water in order to ascertain height. From this, he would simply convey the verbal instructions “Down, down, down” to the pilot until the beams met at a single point of light. The pilot then had to maintain a steady 232 knots and hold the aircraft level until the bomb aimer released the rotating drum bomb (and that method of judging the release point is another exercise in clever triangulation that I might discuss in another post).

Using my dimly remembered high school trigonometry to work out some details, I tried the following calculations.

The two beams were shone down from points underneath the bomber, and from the rough sketch above, it looks like the light under nose (X) was shone down at a right angle with respect to the airframe. The second light (Y) was mounted just ahead of the bomb bay about a third of the way along the aircraft and was angled to meet the forward beam at a distance of 60 feet. Because a Lancaster is just over 100 feet long, my estimations were that these two light were approximately 25 feet apart.

This gives us some starting points for a right angled triangle. We know the distance between X and Y is 25 feet, we know that the distance from X to Z, which is the point on the water surface is 60 feet, and that X is a right angle, so we have enough information to work out the angle α at Y.

Well - nearly enough. We need to find out the length of the hypotenuse of the triangle. The distance from the light at Y to the surface of the water at Z. Let’s call this length h. Using simple trig given X-Y (25 feet) and X-Z (60 feet):

This gives us a result of 65 feet for the beam length from Y to Z. And from this, we can use an arcsign function to find the angle α of the light at Y:

This gives us an angle of 67.38° that the light needs to be mounted at in relation to the body of the aircraft

But wait! We have said that the lights had to be canted sideways as well, to enable the navigator to see them on the surface of the water. From pictures (and illustrations) I’ve seen, it looks like the beams meet in line with the inboard engine on the starboard side. A rough approximation from Avro Lancaster schematics shows me that this is approximately 15 feet from the fuselage centreline.

Hence the actual distance from X to Z is slightly longer than 60 feet, and we need to find the new distance to the surface of the water based on this offset.

Based on the same formulas above, I get that the new distance to the water h will be:

which gives me 61.85 feet beam length to the water. Both of these lights will also have to be canted 14.04° from the centreline of the aircraft.

So plugging all that back into the top two equations, we get:

Which gives us a rear light angle of almost exactly 68° - that is more than 1.5 degrees difference from our original, based purely on canting the light towards the side a little.

And here is the thing - for every 1 degree that the light is out, this will translate to a nearly 3 feet of difference in the convergence point. For instance, if the rear light was inadvertently set at 70°, then the beams would converge at 68.7 feet - more that the height of even the tallest crewman (in terms of difference from the required 60 feet).

For this reason, the mounting and calibrating of these lights have to be absolutely precise. They would have to be mounted at a set 90 degrees and 68 degrees, PLUS both be angled sideways at 14 degrees. If the sideways angling was not the same, then the two beams would not meet at all!

Sir Benjamin Lockspeiser

All this on a pair of lights on flimsy metal brackets, exposed to the whipping slipstream and turbulence and the jolts of heavy landings and incoming enemy fire.

I could not find any photos of the mounting brackets or adjusting mechanism for these lights, but it is all hats off to those anonymous ground crewmen who spent possibly many back breaking hours ensuring that the light were set perfectly before each mission. If not for these forgotten guys, Wallis’ bouncing bombs would have either sailed well over the dam walls, or not travelled enough length to reach them.

Finally, all credit to Sir Ben Lockspeiser (1891-1990), for inventing the lighting altimeter system, and who later went on to become the first President of CERN, which is home to the Large Hadron Collider today, and continues to push the bounds of human research.

Hitting 1000

Every morning, one of the first things I do when I sit down in front of my PC is to check out the dashboard on my HR SaaS app to see what the overnight activity is. A couple of days ago, I noticed this in the top right of the dashboard:

I won’t lie, I actually had tears of emotion well up when I looked at that. It says “1000 subscribed companies”. That means ONE THOUSAND companies out there that have actually paid money to subscribe to my app.

That is something that I find surreal and have to pinch myself often. This is an app that was formulated entirely out of my head. I have written 99.9% of all the lines of code in it. Designed up almost every screen and field and prompt in the system. I find it hard to grasp that something that literally was just ideas floating around in my head is now in use by thousands of people around the world to help them to manage their teams.

Later on that day, Sarah from our team also posted this in our Slack channel:

And that is another thing that also astounds me. That we are now a growing team, with people working in the team who are also passionate and excited about getting our app to the world.

What started as ‘me’, is now bigger than just me.

I am eternally grateful to my family for their constant, untiring support. I am also grateful to my co-founder for sharing the load with me and for her great marketing skills that have got us to this level. I am grateful for my team and colleagues and friends who have been avid supporters and have stuck with me through tough times.

Onwards and upwards.