What would be the effect of the day permanently becoming 25 hours?

Ah, the DST change to Standard Time. Set your clocks back!

Today is the one day a year that’s 25 hours long, sort of. I like it; you get an extra hour.

But I was wondering; what would happen if the Earth’s rotation slowed, and the day was 25 hours long all the time? Assume this slowing happens over the course of the next month, and then stops when the Earth’s day is precisely 25 hours long, so it’s not something anyone or anything is used to but it happens slowly enough we’re not all violently pitched to the East.

Huge Tsunamis?

Everyone would suddenly have a circadian rhythm disorder.

It might have some interesting effects on weather patterns. It would get a little bit hotter during the day and a little bit cooler at night.

Assuming, as you say, that the process is gradual enough to avoid overt damage to the planet …

The change is about 4% (1/24). Not huge, but enough to be above the noise floor of any delicately balanced system.

In terms of pure physics, the days & nights will both be longer. This ought to lead to greater diurnal temperature variation. That could drive more fog in areas prone to fog, and more and harder freezes earlier in the fall.

On a biological level, it could mess up many animals who’s behavior is strongly circadian-driven. Plants in areas with little seasonal variation, e.g. those growing below about 30 degrees latitude, may have more trouble with the creater diurnal variation.

On the scienctific level, we would need to add some conversion factors to metrology & astronomy, but they already deal with the fact the Earth rotational day is neither constant, nor 24.0000000… hours long.

On a gross human society level, we’d have a lot of rejiggering to do. Do we stick with a 40 hour work week and everybody gets an extra hour off? Or do we work 9 instead of 8? Or do we decide the simplest way is to redefine the size of an “hour” so there are 24 of them in the new rotational period?

Lotsa confusion & wrangling, but not much else.

You guys are a little confused. The Earth’s rotation is only 24 hours long because we puny humans have decided that “Hour = 1/24 Day”. I don’t know exactly why 24, except it’s easily divisible by 2, 3, 4, 6, 8, and 12. (Babylon did this, right?)

If we wanted one Earth-day to be 25 hrs long, all we need to do is redefine “Hour” as “1/25 Day”. It’s that simple.

Do I get a medal? :smiley:

No, because that’s not what the OP was asking at all.

Economically, there would be a massive hit, and much more than there would have been a century ago. Think about how many time-based automated systems we rely on, right from the suburban homeowner’s lawn sprinkler and setback thermostat up to huge industrial control systems. We have to retool ALL of that, and use manual procedures in the meantime. Lots of temporary jobs consisting of going around turning things on and off or up and down at the right time. I would think about investing in the Taiwanese fab outfits that have to make all the updated controllers. They’d have order backlogs into the next decade.

Would they? I’ve been told by my sleep doctor, as well as seen it float around this board a few times, that most humans don’t have a 24-hour circadian cycle, but it’s closer to 25-hours…

I think that’s only if you sleep 8 hours a night. If you sleep 7 or 7.5, I think it’s 24 hours?

I thought so too, but wiki says that’s been disproven. Something about sloppy research establishing the 25 hours thing. http://en.wikipedia.org/wiki/Circadian_rythm#The_myth_of_the_25-hour_day

Clock manufacturers would be rubbing their hands raw with glee.
Sorry, that’s all I’ve got.

I can give only anecdotal evidence. Over Christmas vacation one year, more years ago than I can contemplate, my wife and I, perpetually short of sleep, decided we would do 25 hour days for 24 days. Didn’t work. We stayed up later and later and slept later and later but we were draggy and one night suddenly our internal clocks moved ahead 10 hours or so and suddenly we were back on regular time.

Some years after that, we took a ship from Montreal to Europe (it went eventually to Leningrad, being a Russian ship–the Pushkin). The trip took nine days and the first five they advanced the ship’s clock one hour every day to put us on London time. It sounded like a fine idea–five 25 hour days instead of one massive 5 hour time change. It wasn’t. We were eventually getting up at 3AM and so were our children (which were not there the first time we tried it). So I think the main mass of humanity would have an enormously hard time adjusting.

Wow, didn’t think of that. Factories, computers, timers, clocks…everything.

Well, the earth’s rotation is slowing, so if you just sit tight for a while, you can find out yourself.

:smiley: