How to find planet with earthlike day/night cycle?

[Morbad]

Is there an explanation for why Earth's day/night cycle doesn't match reality? You can look down from orbit on your current real-life location and the time of day/amount of daylight will be completely different than what it is in the real world.

I haven't really paid much attention to this, but are you taking into account the almost 1300 year time differential? Is universal/galactic time still tightly coupled to UTC? Calendars haven't been allowed to drift?

We have numerous leap (insert time unit here) to continually correct out calendar, but if these lapsed for any protracted period of time, it wouldn't be hard for there to be perceptible drift after a millennium. For example, Ceasar had to make 46 BC 445 days long to realign the Roman calendar with the solar one.

I am curious now though.

 

[Ned Flandalorian]

I haven't really paid much attention to this, but are you taking into account the almost 1300 year time differential? Is universal/galactic time still tightly coupled to UTC? Calendars haven't been allowed to drift?

We have numerous leap (insert time unit here) to continually correct out calendar, but if these lapsed for any protracted period of time, it wouldn't be hard for there to be perceptible drift after a millennium. For example, Ceasar had to make 46 BC 445 days long to realign the Roman calendar with the solar one.

I am curious now though.

I'm assuming it's been accounted for since all in-game references to time still use (what appears to be) UTC and the same calendar.
But mostly it just seems odd, that they would go to the effort of things like calculating where the voyager probes should be 1300 years from now but not match physical Earth's day/night cycle.

 

[varonica]

Is there an explanation for why Earth's day/night cycle doesn't match reality? You can look down from orbit on your current real-life location and the time of day/amount of daylight will be completely different than what it is in the real world.

Because it's the year 3,000+ and the day (full rotation of earth) is not exactly 24 hours long, 23 hours and 56 minutes in fact, so over thousands of years it will change considerably. In fact over one year that's 23 hours, so it's not surprising the earth time of day 3000+ years in the future is not exactly the same as it is today. The sidereal day, the amount of time it takes the earth to rotate is not the same as the 24 hour day.

 

[thistle]

Because it's the year 3,000+ and the day is not exactly 24 hours long, 23 hours and 56 minutes in fact, so over thousands of years it will change considerably. In fact over one year that's 23 hours, so it's not surprising the earth time of day 3000+ years in the future is not exactly the same as it is today. The sidereal day, the amount of time it takes the earth to rotate is not the same as the 24 hour day.

That might be the reason, but I seem to have a vague recollection of visiting Earth years ago - probably pre Beyond - and the sun position was correct as far as I could tell for my actual location. The couple of times I've been there recently - before EDO - it's been 'wrong'. But I may just be misremembering.

Similarly one of the crashed Thargoid scout sites used to be locked in position with a dramatic skyline of a (I think) ringed gas giant over a mountain range. I remember MalicVR on stream being disappointed to find it wasn't there after an update, pre Odyssey I think, it was as if the planet/moon had been rotated compared to its original locked position relative to the ringed giant.

What I'm saying is based on that I'm not sure it's right

 

[Ned Flandalorian]

Because it's the year 3,000+ and the day is not exactly 24 hours long, 23 hours and 56 minutes in fact, so over thousands of years it will change considerably. In fact over one year that's 23 hours, so it's not surprising the earth time of day 3000+ years in the future is not exactly the same as it is today

No, because the difference between 24 hours and the time the Earth takes to complete a full rotation is accounted for by the distance the Earth moves along its orbit during that time.
If the Earth's rotation was getting misaligned with the current time by 23 hours every year, we would be spending nearly half the year eating our lunches at midnight instead of midday.
We're not talking about thousandS of years, we're only talking about 1300 years from now which is less time than between now and the beginning of our current calendar system.

 

[varonica]

No, because the difference between 24 hours and the time the Earth takes to complete a full rotation is accounted for by the distance the Earth moves along its orbit during that time.
We're not talking about thousandS of years, we're only talking about 1300 years from now which is less time than between now and the beginning of our current calendar system.

The calender year isn't the same length as the earths orbit, this is why we have leap years every 4 years, it should be also pointed out that the speed of the earths rotation isn't fixed, which is why we sometimes add leap seconds every few years and why we sometimes skip adding leap seconds, there are a lot of factors at work here that will change the day/night cycle.

 

[rootsrat]

I've sat through a few sunrises and sunsets in both the old volcanic sites and bio sites, watching the fumaroles and vents slowly start activating as the ice heats up with the rising of the sun is quite an experience, and sitting in the mists of a Brain Tree site as the sun slowly pushes it's way through, well they were fun days, I must try that on atmospheric worlds one day!

Wait, the geological activity is dependent on the temperature of the surroundings?

 

[Ian Doncaster]

We know the calendar has changed since the present day, since the leap years are in a different place - February 29 3308 would have existed under the Gregorian system but doesn't in Elite Dangerous; February 29 3306 existed instead.

There is a general effect where the rotational period of the Earth is very gradually slowing due to the influence of the moon. Over a period of millennia this can lead to a substantial divergence between where the sun is and where a naive extrapolation of UTC would place it - historic measures of the times and places where solar eclipses were recorded thousands of years ago can be used to get a fairly precise idea of how significant this is. Over the last few decades we've sometimes tried to correct for this with leap seconds; once we move from "Earth time" to "bubble-spanning-civilisation time" inserting leap seconds just to keep one planet's rotation in sync with what it was a few hundred years ago is going to feel silly (they're already controversial even with just one planet!)

Whether the divergence shown in Elite Dangerous is accurate to current best scientific predictions of how the Earth's rotation will continue to slow over the next 1300 years or not? I have no idea. Probably not other than by coincidence, but you can pretend it is.

 

[Screemonster]

Because it's the year 3,000+ and the day (full rotation of earth) is not exactly 24 hours long, 23 hours and 56 minutes in fact, so over thousands of years it will change considerably. In fact over one year that's 23 hours, so it's not surprising the earth time of day 3000+ years in the future is not exactly the same as it is today. The sidereal day, the amount of time it takes the earth to rotate is not the same as the 24 hour day.

Isn't that because the earth going around the sun adds an extra "rotation" relative to the solar position, compared to its rotation relative to more distant objects that it isn't orbiting?

 

[varonica]

Isn't that because the earth going around the sun adds an extra "rotation" relative to the solar position, compared to its rotation relative to more distant objects that it isn't orbiting?

That does account for most of it, but the moment we defined the exact length of the second it separated people time from earth time, earth time changes, people time doesn't, it used to when people set watches for noon when the sun was directly overhead, but not anymore. For instance we add a leap second every couple of years to account for this discrepancy, in fact around every 21 months give or take, so lets say 2 years. Over 120 years that moves the time line by 1 hour, 240 years 2 hours, 480 years 4 hours and by the time we have 1,000 years the time on a given spot on the earth will be 8 hours different than it is now, so areas that are noon now will be night-time in 1000 years. That's if that's the only factor we take into account, I am sure the are others that will also affect what areas are day and night over 1,000 years, but 1,000 years is quite enough to account for the difference we see in game and real life.

 

[Florenus]

Universal Galactic Time in game is based on Coordinated Universal Time on Earth.
If it's 12:00 UTC on Earth, it shouldn't be middle of the night over Europe no matter how many years in the future, because it's constantly adjusted (includes leap seconds f.ex.). It's basis of time zones after all.

 

[varonica]

Universal Galactic Time in game is based on Coordinated Universal Time on Earth.
If it's 12:00 UTC on Earth, it shouldn't be middle of the night over Europe no matter how many years in the future, because it's constantly adjusted (includes leap seconds f.ex.). It's basis of time zones after all.

People are looking out of the window and wondering why it's light where they are but dark in game in the same location, it's got nothing to do with what time the clocks say, I thought that was obvious from the very beginning of the thread.

 

[Ned Flandalorian]

That does account for most of it, but the moment we defined the exact length of the second it separated people time from earth time, earth time changes, people time doesn't, it used to when people set watches for noon when the sun was directly overhead, but not anymore. For instance we add a leap second every couple of years to account for this discrepancy, in fact around every 21 months give or take, so lets say 2 years. Over 120 years that moves the time line by 1 hour, 240 years 2 hours, 480 years 4 hours and by the time we have 1,000 years the time on a given spot on the earth will be 8 hours different than it is now, so areas that are noon now will be night-time in 1000 years. That's if that's the only factor we take into account, I am sure the are others that will also affect what areas are day and night over 1,000 years, but 1,000 years is quite enough to account for the difference we see in game and real life.

Leap seconds are applied as needed, not according to a fixed schedule. They are used to account for unpredictable changes in Earth's rotation (such as earthquakes) so they can not be used to explain a difference between our real world and the game's simulation.

 

[Florenus]

People are looking out of the window and wondering why it's light where they are but dark in game in the same location, it's got nothing to do with what time the clocks say, I thought that was obvious from the very beginning of the thread.

Really?
If you live in London for example and check Earth in game at noon UTC in RL and in game and in game it's middle of the night over Britain, then something's wrong, because universal Galactic Time should be the same as UTC.
Sure Universal Galactic time and our RL UTC are the same for practical purposes, but the fact that it doesn't correspond with in game Earth locations can be viewed as some kind of oversight, even if in reality time zones would move considerably over a thousand years if not adjusted - after all now we have in game UTC and time zones that move around. It would be better to just mirror Earth's RL rotational position, since we're using RL time.

 

[varonica]

Leap seconds are applied as needed, not according to a fixed schedule. They are used to account for unpredictable changes in Earth's rotation (such as earthquakes) so they can not be used to explain a difference between our real world and the game's simulation.

I should point out that leap seconds are added, never subtracted, since 1972 27 leap seconds have been added to UTC, certainly they can be irregular, for instance they skipped the last one, but they are never subtracted.

 

[Ian Doncaster]

because universal Galactic Time should be the same as UTC

I'm not sure that follows. Once you stop being bound to a single planet, and especially a single star system or a political system ruled from it, continuing to sync UGT to UTC by adding the same leap seconds stops making sense. Why should systems independent of Earth have to go through the inconvenience of processing leap seconds when it makes no difference to them anyway? Everyone else has to do UGT->local planetary time conversions, why shouldn't Earth too?

So UTC on Earth may well be synced to the rotation, but UGT won't.

 

[Florenus]

let's forget it

 

[Ned Flandalorian]

Then explain why UGT adjusts to summer and winter time?

It doesn't. The clock in Elite never gains or loses an hour.

 

[Florenus]

It doesn't.

Then I'm going to sleep. That was giant brainfart if I ever had one. Sorry.

 

[Ydiss]

Here's the first few around Sol, should be landable. Quite surprising we still have CMDRs who've never noticed locations being different on different landings, and never seen a sunrise / sunset ...

name | rotational_period | from_sol --------------------------------+-------------------+---------- Major's Mine | 1.00465 | 11 Groombridge 34 A 9 a | 0.991104 | 12 SPF-LF 1 6 a | 0.991863 | 12 Flousop A 4 | 0.997196 | 17 Ross 671 AB 3 a | 1.00699 | 22 WISE 0713-2917 2 | 1.00939 | 23 RR Caeli C 5 a | 1.00435 | 27 RR Caeli C 2 c | 1.00572 | 27 LHS 149 8 | 0.994029 | 30 G 14-6 A 7 d | 0.998828 | 34 LTT 8181 B 2 a | 1.00423 | 35 Blest 5 a | 1.00643 | 39 LHS 6427 B 5 d | 0.994078 | 40 Core Sys Sector CB-O a6-0 2 | 0.993337 | 40 LFT 142 1 e | 0.994985 | 40 Hambula B 1 | 1.00789 | 40 Edenapel C 1 a | 0.994068 | 40 LP 5-88 3 a | 0.991739 | 41 Dala A 1 a | 0.999891 | 42 Athra C 6 | 1.00672 | 42 Hoko 2 d | 0.990694 | 42

I've noticed it. Oh yes I have.

Trying to find day locations to film a specific scenario that can change at any moment and 95% of the locations you find that are perfect but.... Night time.

Grr.