Last week, our team was deep in the trenches, working on a multi-DC event-driven system designed to power booking searches.

As part of the process, I was testing replication delays between our data centers in Hong Kong and Ashburn. The dashboard proudly displayed a maximum delay of 17ms.

Cue one of our lead engineers chiming in: "Anything under 100ms is physically impossible."

My confident response? "Trust me, bro." 😅

Then came the mic-drop moment from my director:

"I trust the speed of light more than you."

Big facepalm moment.

Let's Do the Math

The distance between Hong Kong and Ashburn is about 13,100 km.

Light travels at 300,000 km/s.

In theory (vacuum conditions), it would take roughly 45ms for light to cover that distance.

Distance: 13,100 km Speed of light: 300,000 km/s Theoretical minimum: 13,100 ÷ 300,000 = 0.044 seconds = 44ms

Add in real-world factors (fiber-optic cables, signal processing delays, and the absence of a magic vacuum tube), and even 45ms is optimistic.

The Reality Check

So, yeah... that 17ms? Either our dashboard is defying the laws of physics, or we've just rewritten them. (I'll let you guess which.) 😅