4 ms·
This is what happens when your data structures declare year zero like pol pot. Unfortunately if we wanted to be scientific we'd probably need something like 300
by jart 6y ago
This is what happens when your data structures declare year zero like pol pot. Unfortunately if we wanted to be scientific we'd probably need something like 3000 bit timestamps to do planck time until heat death of the universe. XFS could have lasted the better part of the stelliferous era if they had chosen struct timespec, but even that has the problematic nanosecond granularity limitation. It's not the stone age and seconds have a very clear definition these days in terms of the number of hyperfine transitions of caesium, so I would have hoped new data structures would at least choose that.
- mhh__ 6y ago> planck time We can't even get close to a planck time tick so that's not really necessary
- withinboredom 6y ago> We can't even get close to a planck time IIRC, Windows can't get a higher resolution than time % 10ms, should we not allow getting the time at millisecond resolution? Just because it's not necessary, doesn't mean it isn't useful. In this case, I can't really see it being useful either... would love to hear a non-niche use-case for it.
- jart 6y agoWindows NT measures time at hectonanosecond (100ns) granularity and declares its epoch as modernity (~1600) so it does better than UNIX but unfortunately still limited by arbitrary traditional thinking.
- dundarious 6y agoI think the point is that the entire human race is not able to get close to a planck time, by any reasonable definition of "get". See this recent discussion: https://news.ycombinator.com/item?id=24804624 https://news.ycombinator.com/item?id=24804624
- mhh__ 6y agoI heard a Keysight engineer saying they have NDA-ed tech to achieve picosecond synchronization over the network, so there is a case for precise ticks but the planck time is about 20 orders of magnitude shorter than cutting edge research that is a one shot experiment in a laboratory.
- dmurray 6y agoFor most applications, 500 years and nanosecond granularity is not "problematic". The handful that need greater range or precision (or unlikely, both) can roll their own data structures or use a specialised one rather than needing to cater for that in the default. You can always use floating point representations. It will give you great range and great precision, though not both at the same time (you can't refer to a specific picosecond on a specific day 100,000 years from now).
- Dylan16807 6y agoNanosecond timestamps are fine for their purpose. Just measuring something from an observation point a few inches different will shift your numbers by a nanosecond. If you need ultra-precise records from some kind of equipment then it needs to use a specialized local clock anyway, and it's probably better if it's hard to convert those records back and forth with normal timestamps. > This is what happens when your data structures declare year zero like pol pot. Picking an arbitrary zero point is the only way to make timestamps work. If we started counting with the big bang then all our clocks would be plus or minus millions of years.
- zelly 6y ago3000 bits for every inode. Academic excellence.