As the sun went down last Friday, nerdiness-fuelled distraction at work came in the form of blinding intensity of the reflection coming off Auckland’s newest glass-wrapped skyscraper.
It was really bright. A colleague pulls out an iPhone and fires up their light-intensity-app.
![](https://i0.wp.com/floatingintheclouds.com/wp-content/uploads/2019/05/IMG_20190508_165349-1.jpg?resize=480%2C640&ssl=1)
I get home and have this text conversation:
![](https://i0.wp.com/floatingintheclouds.com/wp-content/uploads/2019/05/Screenshot_20190509-181529.png?resize=300%2C533&ssl=1)
Glass optical and thermal properties are something I get involved with at work, and so I resolved to try and use theory to get the same illuminance as the iPhone sensor was indicating.