# How would one explain/demonstrate the length of a second/minute/hour to aliens?

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Basically the title. Not much else I can think of adding.
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One second is 9 192 631 770 vibrations of a 133Cs atom transitioning between the two hyperfine levels of its ground state (from the BIPM website).
One minute is 60 seconds.
One hour is 60 minutes.

Edited by Gaarst
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Seconds are currently defined with atomic clocks, so we would just tell the aliens that a second is some number of oscillations of a certain wavelength of radiation from a specific atom (probably cesium).
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Exchange units of distance with one another by means of direct physical or numerical example. Inform them that 1 second is the time it takes for light to traverse 9,324 Linear Gobdorgs to start off, and work from there.

Or just make an LED that blinks every second and show them that.
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fart, then if they can smell explain them it latest that long ... xDr

(if they can't smell reproduce the fart process for another perception + lenght thing, ... yup i do agree and recognize fart is strong to explain duration stuff) Edited by WinkAllKerb''
i told you a not so long time ago in a very far galaxy that fart is science over everything else ... tsss tsss ...
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[quote name='FungusForge']Basically the title. Not much else I can think of adding.[/QUOTE]

Did you look up the definition of a second before posting this?
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[quote name='Gaarst']One second is 9 192 631 770 vibrations of a [SUP]133[/SUP]Cs atom transitioning between the two hyperfine levels of its ground state (from the BIPM website).
One minute is 60 seconds.
One hour is 60 minutes.[/QUOTE]

If you haven't quite gotten to the point where you need to specify standards that well, I'd go with 4.568 * 10 ^14 cycles of the Hydrogen-alpha frequency.

If constraints are even looser, 1.602 * 10^11 cycles of the peak frequency of the cosmic microwave background.

Timing hyperfine level transitions of Cesium -133 requires the building of an atomic clock; Hydrogen-alpha is all over the place, and the Cosmic Microwave Background is everywhere.
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One second is exactly one fifth of the time it takes for food that has been dropped on the floor to no longer be edible.

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One second is 1/86,000 of the length of a day in Universal Standard Time.

I assume they are familiar with Universal standard time after all. Right?

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Well, that depends on how soon after the first contact you need to explain it.

If you already are best buddies and you ran out of more interesting topics to talk about over your pan galactic gargle blaster, then it's a lot easier than if your most basic communications depends on a good, accurate and understandable description of second.

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It depends if you are in New York or not.

Quote

The New York Second (the shortest unit of time in the multiverse) is defined as the period of time between the traffic lights turning green and the cab behind you honking.

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I don't know, but I'd start with an embarrassed apology for how ridiculous it is.

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I would show them a digital clock and a calendar. The clock would cycle through and they would see the pattern of "the fast one goes up to 59 and resets, and every time it resets the next one changes, and that one goes to 59 and resets and the one after that changes, and that one goes up to 12 instead of 59, but oh look, that one cycles exactly twice in one day on the planet. With the calendar, they could see how we keep track of the days, and how we also use the Moon (more or less) to tell longer periods of time.

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Frankly, why bother defining a second?  Just define something consistent as a unit of time, like the transition time of the cesium atoms mentioned above.  Then give every message you want to send a number representing the number of ground state transitions between events.

Similarly, you probably wouldn't bother teaching them base 10 numerals.  You'd use binary, since there are many simple ways to represent 1 and 0, and aliens worth talking to are going to be able to pick up that you mean binary very very easily...

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36 minutes ago, cubinator said:

I would show them a digital clock and a calendar. The clock would cycle through and they would see the pattern of "the fast one goes up to 59 and resets, and every time it resets the next one changes, and that one goes to 59 and resets and the one after that changes, and that one goes up to 12 instead of 59, but oh look, that one cycles exactly twice in one day on the planet. With the calendar, they could see how we keep track of the days, and how we also use the Moon (more or less) to tell longer periods of time.

Good point. The fact that you're already talking to the aliens means that either they're /here/, and you can show them things, or you're communicating with them through radio, at which point, you've already decided on a communications protocol, and can specify things (if you don't want to use any of the other obvious examples) based on the features of your carrier wave.

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Any advanced culture would be familiar with

1 second = e^99.629 in base 2 that would be 1100011 101

e  = 2.71828 = 10 1011....... They could prolly figure the e thing ou if you brought it to enough places all digitally it would be on off pause on off on on ...... long pause. you would have to explain power system and then a video of quantum mechanics. 10 101101 ^ 1100011 101.

or simple by a mickey mouse watch.

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1 hour is 1/24th of the time it takes for our planet to rotate completely around its axis. 1 minute is 1/60th of this time. 1 second is 1/60th of that time.

It's not exact, but it's close enough for communication, and the ostensible phenomena mentioned are much easier to observe than a lot of other possible definitions.

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You can get into the technical details, but that's not necessary. You're communicating with them, so all you need to send is:

The following tone is a period of time we call one 'second'. Beeeeeeeeep. 86400 seconds make one day on our planet.

Change tone for flash, continuous stream of binary 1s, whatever works. Go on to explain time how you like. Any red/blueshift will be insignificant.

From that you can also do distance. During one second, this radio signal travels 300,000,000 'metres'. Adults of our species stand about 2 metres tall. Go on to explain any distances you like. And from that you can explain mass by describing the shape and size of a known mass of a common element.

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With an hourglass.

The old blab about aliens who have no concept of time is science-fiction fluff. Time is an extremely simple concept, which was figured out before the wheel was, mostly because any intelligent organism must instinctively know that it can only survive for a certain amount of TIME before it either eats something or dies.

So, knowing that, all you need is a tool that won't run afoul of language barriers.

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A second? Show them my pulse.

An hour? Take a sundial, divide into two (day/night) then into three and into four

A minute? Take an hour, divide into three and four and five. Also draw a log scale and mark the midpoint between a second and an hour.

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8 hours ago, WedgeAntilles said:

Time is an extremely simple concept

..assuming every sentient species in the universe perceives time in the exact same way we do, and is similarly bound to the one-directionality of it.

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Yup. And that's an assumption I feel perfectly comfortable making.

The basic laws of physics (gee, I seem to say those words a lot!) require that any living thing must consume energy. Which means it has to eat in order to gain energy to consume (though, the concept of "eat" may take very different forms depending on the species!). And anything that eats, can starve. And, anything that can starve, must possess a basic instinctive sense of time or it will starve to death pretty quickly.

As to the one-directionality of time? Time must always go in one direction, for everything. Or you're violating the laws of physics. The reason you don't remember that pile of porcelain fragments leaping off the floor, landing on the table, and assembling themselves neatly into a coffee cup is because that sequence of events runs in the direction in which the entropy of the universe goes DOWN. Not permitted. Except in sci-fi stories, where the laws of physics can be pretty casually handwaved with halfway decent writing and the assistance of the CGI department......

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1 hour ago, WedgeAntilles said:

Time must always go in one direction, for everything. Or you're violating the laws of physics.

I would love to see a proof of that assertion sometime.

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12 hours ago, swjr-swis said:

..assuming every sentient species in the universe perceives time in the exact same way we do, and is similarly bound to the one-directionality of it.

This

20 hours ago, WedgeAntilles said:

Time is an extremely simple concept

This.

Time is a force, just like gravity.

Any alien would be aware of time.

If they are such that time does not affect them, they can observe time's effect on other things. The entire universe is affected by time.

As WedgeAntilles said, "Time must always go in one direction". If by chance the alien can manipulate time as to not go in one direction, then must be the very least be aware of it. Self fulfilling prophecy kind of thing.

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14 hours ago, Pronoes said:

Time is a force, just like gravity.

Interesting statement.

In this (presumably quantum gravity?) model you're using as reference, what particle acts as transport for the force of time-arrowness? Synchrotrons? What does the model predict about the spin, mass and charge of this particle? Does it explain the peculiar asymmetry of it?

14 hours ago, Pronoes said:

Any alien would be aware of time.

If they are such that time does not affect them, they can observe time's effect on other things. The entire universe is affected by time.

As WedgeAntilles said, "Time must always go in one direction". If by chance the alien can manipulate time as to not go in one direction, then must be the very least be aware of it. Self fulfilling prophecy kind of thing.

I am not sure we can say this so categorically. A hypothetical being that is not 'pushed' along the timeline the way we perceive ourselves to be, being free to move in that dimension back and forth as they please, could have a very hard time even understanding what we're talking about.

Unaffected by the arrow of time, time perhaps just being simply one more coordinate in the system, spacetime might be perceived like a 'solid' block, in which nothing 'moves' but simply 'exists' at a set of coordinates (x,y,z,t). There is no separate past, present, or future, all physical things are 4-dimensional 'blobs' that contain all moments in their lifetime, existing... I was gonna say 'simultaneosly', but let's say, 'in the same block'.

Even slicing up the block to examine it in detail, why would such beings even consider that 3D 'moment-things' contained in any one place of that block feel like they are forcibly 'moving' in one of those coordinates? To them, all things are unmoving. Even more wildly for them to understand: that that movement is perceived by moment-things to be at a forced synchronous rate in just one of the four dimensions along with every other moment-thing in the slice? Instead of specs we may all look more like spaghetti to them, composed of tightly-packed 'moment-cells'.

Sure, they would 'see' that everything has a 'timeness', akin to what we call length, width, or thickness, but why would one of the four axes have any special meaning? Think of it as 3D objects to us: they are actually a very densely packed set of 2D 'sheet-things', each of which are located at a specific (and unmoving relative to each other, if integrity is to be kept) coordinate along the 3D body. Imagine a sheet-thing trying to tell us that they actually perceive life and space as evolving from the soles of our feet to the top of our heads, moving at a fixed pace, like browsing through MRI printouts of us. And that to them, their 'start' is actually not the soles of the feet or top of the head as we assumed, but some point at the front left shoulder, progressing towards their 'end' at what to us may look like an arbitrary angle through the 3D body.

A little more in the realm of what KSP players see every time they play the game: not being locked into one moment in time or forced to move along the timeline, they 'see' a 3D spacecraft in orbit as a donut shaped as the trajectory, much like a more solid orbit line like the program draws for us on screen (except... I guess it might be more like a helix, depending at what 'angle' the time axis is set to the others). To affect the craft at any moment in that orbit, they would simply reach 'straight' for that particular section of the solid spaghetti-craft, as simply as us clicking on an arbitrary point along the orbit line to place a maneuver node on one specific moment of the orbit.

Due to their freedom to move along t at their chosen 'speed'... think of KSP time warp, but additionally also 'backwards': how would we explain that a second is always a specific length along that axis? Preferably, without resorting to a 'standard meter/kilogram' type of solution?  Holds up fingers separated by just a bit: "a second is this long" - which if you think about it, is exactly what we're doing when we say that a second is 'the time between transitions of a Cesium 133 atom etc etc' - except to them, atoms are 4D spaghetti that do not seem to change at all.

Enter the Math... and now I need some solid 3D food to untangle the spaghetti in my mind.

Edited by swjr-swis
because quoting quirks

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