Read this, and weep, and call your mother.

NPR Weekend Edition host Scott Simon is at his mother’s bedside in the ICU — and he’s tweeting.

Some will contend that this is exactly what we feared Twitter would lead to — what sounds precariously like a present absence in one of the most wrenchingly personal of circumstances — but what else do you do in the terrible waiting? These are not minute-by-minute updates. They’re moments stolen out of a string of moments. He tweets when buying his mother’s favorite floss — “waste of time? act of faith” — or after she falls asleep. He tweets her thoughts and wisdom. He’s not absenting himself from the room so much as bringing us into it.

There is something remarkable going on here in the camaraderie of strangers and of distant friends who in ordinary circumstances would never have picked up the phone or written — the dark matter of solidarity in the online world.

It’s a poignant vigil. Tune in now, while you can. It’s turning the adjective “live now” into the commandment “live now!” and it’s immensely powerful.

Maybe this is what Twitter, social media, all these vast flimsy webs of Internet “connection” are supposed to do.There is something about holding a vigil on Twitter that makes perfect sense. Twitter is words written in hot water. It’s all about the fragility of the “is” — these are the moments when you can speak about this in the present tense, this person, this happening, this unfolding — and they are as fleeting and fragile as phosphorescent bubbles. Read it the next morning and you’ve missed it. Right now we are all together in the “is” — but tune in any other time, and you will be on the outside of the glass, gazing in. The past tense will intrude. We are all passing into was together. Read it now. Call your mother.