Talk:2920: Survey Marker

"datums." JohnHawkinson (talk) 14:38, 16 April 2024 (UTC)

FWIW, there is a marker at the end of my street, and I have seen others. I know "in the ground" is a figure of speech; all I have seen were set in rock (often with molten Lead/Zinc) so they didn't travel. My road we have boulders nobody is likely to move. Other places like Appalachian Trail, set in the mountain stone. In sandy South Jersey they set a couple tons of concrete and set the marker in that. --PRR (talk) 23:41, 16 April 2024 (UTC)

I like to think our myriad calendars & leap days & time zones & daylight savings time & mapping coordinate offsets, are all orchestrated specifically to complicate time travel. Have fun materializing halfway into the ground, or entirely out of the ecliptic, time travel wankers. ProphetZarquon (talk) 06:30, 17 April 2024 (UTC)

A fairly old 'time travel failure' trope is a time machine that only travels in time. If you go back (or forward) six months, you find yourself in space in exactly opposite the Earth (which is now half way round its orbit).

Yes, there's also solar-galactic motion and galactic-extragalactic, and tends to date back to an era where a universal/local æther was predominant as 'the one true frame of reference'. But even a more arbitrary-frame 'locking' isn't movement-free. H.G. Wells's traveler in time apparently sat still in his location, but seems to ignore/handwave all kinds of issues of long-term soil accumulation/weathering, tectonics, etc. Or the very basic (but vital) acknowledgement that only in freefall can you not be in a continually revised 'frame', as merely standing still under gravity you're accelerating.

However much detail there is, in the source material, there's pretty much always a fudge in a object-type time-machine (as opposed to a portal-style, which will have its own 'rules') that also gives it a "necessary secondary supwerpower" of space-movement, even if only to stay (apparently) in the same place and not then try to merge its atoms with whatever solid things (gases, even liquids, generally being already handwaved as inconsequential!) might happen to be in the 'landing zone'.

It's gross failures (or 'exact word' strictness) in the space-travelling element that can cause plot-driving surprises to the protagonist(s) involved. (Perhaps I'm here at least in part harking back to the 'retro-canon-crossover' work that was The Space Machine.) 172.69.43.164 09:47, 17 April 2024 (UTC)

This reminds me of the prime meridian that's laid out on the ground at the Greenwich Royal Observatory for tourists to stand on. Unfortunately, it uses an old datum and the actual prime meridian under WGS84 is about 100 metres to the East. Fortunately, the British Isles are moving slowly North East so the two meridians will coincide at some point. Jeremyp (talk) 09:09, 17 April 2024 (UTC)