What font do you use to read hackernews? Because in Verdana those are exactly the same. Tried some other fonts in inspector but think your thin spaces could be even thinner :)
I'm using the default Verdana font. Here's a screenshot of what the post looks like on my computer (Firefox on Windows).
I guess I should have added a disclaimer to say that the thin space may not always appear correctly depending on the browser/platform/setup etc. :-)
This is because hackernews has font-family: Verdana, Geneva, sans-serif and I have neither of the named fonts installed.
On my system, hackernews is rendered using Dejavu Sans. This is presumably a default for Firefox on linux which I never realised until today.