December 1st, 2010


[links] Link salad wonders where the warmth went

Better Book Titles — Literary humor at its lowest. Snerk. (Via Language Log, in a slightly NSFW post.)

Bad sex award goes to novelist Rowan Somerville — A literary honor to which most of us likely do not aspire. (Snurched from Scrivener's Error.)

Khirbat en-Nahas — Ancient copper mine and fortress photographed from orbit.

Martian Moon Phobos from Mars Express — Oh, Ghu, this APOD photo just gives me the chills. The good kind.

Why people should learn statistics — Hahaha. Humans really are very bad at risk assessment.

Used aircraft carrier, anyone? — (Via danjite.)

My Unemployed Life: The Forgotten Woman — What this woman needs is more tax cuts for the wealthy. (Via lt260.)

?otD: Ever read Eugene Sue's The Wandering Jew?

Writing time yesterday: 0.0 hours (post-novel ennui)
Body movement: 30 minute stationary bike ride
Hours slept: 6.75 hours (solid)
This morning's weigh-in: n/a
Yesterday's chemo/post-op stress index: 3/10 (peripheral neuropathy, emotional distress)
Currently reading: Between books


[help] Special relativity, reference frames and timekeeping

So I'm noodling a bit more of special relativity into my poor, ageing, liberal arts educated brain, via (among other things), posts such as this one. (The first few dozen comments are excellent, btw. After that the thread starts breaking down.)

What got me rattling down this track was the problem of timekeeping across astronomical distances. Since reference frame is a critical concept, is it reasonable to have your clock so far away that it stands outside significantly enlarges your reference frame?

For example, let us posit a pulsar 30,000 light years distant. Let us further posit that its periodicity is slowly lengthening, by a degree both measurable and predictable. Say that I know from a certain zero point, say, Earth on a given day and time, what the periodicity is. Then, some arbitrary amount of time later, having moved at relativistic or supraluminal speeds to an astronomical distance, I measure my beacon star's periodicity again. I then calculate backwards (or, potentially forwards) from my known zero point reference.

Have I in my new, arbitrary location now established the time at my zero point? Ie, have I synchronized my clocks?

I am absolutely certain there is at least one serious error here, but I can't see it yet. I'd appreciate comments that might correct this idea, or references to more successful examples of this kind of thinking.