# Want to Know What Time Is?

I do not con­sider my­self to be smart enough to an­swer a ques­tion that re­mains unan­swered since thou­sands of years:

What is time?

Nev­er­the­less I will an­swer that ques­tion now. I am ask­ing ev­ery per­son smarter than me to ex­plain to me, why my an­swer must be wrong. More so: There may even be some very ba­sic math­e­mat­ics be­low. I am very keen to find out why this math­e­mat­ics is ei­ther wrong or ir­rele­vant – or sim­ply stupid. It sure is!

I define time as the amount of in­for­ma­tion available for a given phe­nomenon.

If there is a lot of in­for­ma­tion, then the phe­nomenon is con­sid­ered to ex­ist for a very long time. If only lit­tle in­for­ma­tion is available, the phe­nomenon is con­sid­ered to ex­ist for a very short time only.

For ex­am­ple, if a guy called Join Doe is trav­el­ing from Ber­lin to Moscow, there might be at least two bits of in­for­ma­tion about this:

• John Doe is in Berlin

• John Doe is in Moscow

If there is no other in­for­ma­tion available, then the phe­nomenon is very short lived, mean­ing John was trav­el­ing at max­i­mum speed. That could be the speed of light.

But there might be more in­for­ma­tion available: John might take a stop in Minsk, be­cause he loves a most beau­tiful Be­larus girl at that place. It just means, that his travel speed is much slower. Far from the speed of light in this very case! So there is more time be­tween his de­par­ture in Ber­lin and his ar­rival. It might even hap­pen, be­cause he is so very much in love with this girl, that he will never ar­rive in Moscow. In that case, the amount of time be­tween de­par­ture and ar­rival is in­finite.

Time `T`can thus be seen as func­tion of the dis­crete amount `N `of available in­for­ma­tion: `T(N)` We know that for any `N_1,N_2` with `N_2 > N_1`there will always be `T(N_2) > T(N_1)`.

(But apart from that I do not re­ally know a lot about the func­tion `T(N)`.)

Please note that by this defi­ni­tion there is no di­rec­tion as­so­ci­ated with time! So, time does not re­ally tell us if Johnny starts his jour­ney in Ber­lin or in Moscow. We can only be sure that he was in Minsk, and that he was hav­ing a great time there, wish­ing to stay for ever with the girl. (Maybe she also re­ally cares a lot about him!)

Things are get­ting more in­ter­est­ing, if we – for ex­am­ple – con­sider a black hole. As we know by the the­ory of rel­a­tivity, time “is slow­ing down” a bit, the nearer you get to a black hole. Now, let us look at John Doe again: Imag­ine this guy is get­ting re­ally close to a black hole. (There is no rea­son what­so­ever to com­pare his re­la­tion­ship with his girl to a black hole or find any other similar­i­ties or even more vul­gar com­par­i­sons re­lated to her.) Just imag­ine that John is at­tracted to the black hole just as he is at­tracted to his girl friend. The nearer he is get­ting to the black hole, the lesser are his chances to es­cape. A black hole squeezes a lot of mat­ter into a tiny space, in­creas­ing its grav­i­ta­tional field and de­creas­ing time in com­par­i­son to other peo­ple lucky enough to stay farer away from the black hole. (Still, please no com­par­i­sons to the girl friend!)

If John fi­nally reaches the cen­ter of the black hole, there will be no more doubt about his very lo­ca­tion. No longer will he be in Ber­lin! He will not be in Moscow, nor in Minsk. No mat­ter how of­ten we would re­quest his po­si­tion, we will always be sure that we could find him in the cen­ter of the black hole. Thus the amount of available in­for­ma­tion about his po­si­tion has reached in­finity, the un­cer­tainty about his where­abouts has reached `0`, and thus time will now longer flow. Time will stand still, and there will be no time at all at the cen­ter of a black hole.

As you can see, we can ex­plain the be­hav­iors of time in a very strong grav­i­ta­tional field, even with­out the nasty com­plex­ity of gen­eral rel­a­tivity.

Let me give you an­other ex­am­ple: The dou­ble-slit ex­per­i­ment, seen from the view­point of quan­tum the­ory. As we know, get­ting in­for­ma­tion about a quan­tum sys­tem always im­plies do­ing an ex­per­i­ment, and the re­sults will vary de­pend­ing on their prob­a­bil­ities. The more ex­per­i­ments we do, the more in­for­ma­tion we will get about the lo­ca­tion of a par­ti­cle. Some very smart peo­ple would most likely say, that the Schröd­inger equa­tion col­lapses with each ex­per­i­ment, mean­ing that a prob­a­bil­ity wave will turn into some (triv­ial) in­for­ma­tion about some­thing. What­ever that means, it is ob­vi­ous to us that in­for­ma­tion pops up in ex­change of a cer­tain amount of un­cer­tainty that we are loos­ing on the way.

We con­sider time to be just the sum of all the in­for­ma­tion gath­ered dur­ing ex­per­i­ments.

In par­ti­cle physics, the path of a par­ti­cle is some­what in­de­ter­mi­nate. No mat­ter how many ex­per­i­ments we do, we will only end up with an ap­prox­i­mate path of the par­ti­cle. OK. But if we re­peat the ex­per­i­ment un­der the ex­act same con­di­tions, we might end up with a com­pletely differ­ent path, only de­pend­ing on some prob­a­bil­is­tic rules de­ter­mined by the maths of quan­tum physics.

But with our un­der­stand­ing of time that does not re­ally bother us any longer. There is no or­der in time. Time does not flow from 0 to `in­finity`, always in the same di­rec­tion. It is just the sum of all the in­for­ma­tion that we can gather. And that does not need to be the same all the time!

Now you know what time is!

• Wel­come to LessWrong!

The cen­tral is­sue I see with this ar­gu­ment is that it seems to as­sume time in the setup to the ex­am­ples, or im­plic­itly in the equa­tion. For ex­am­ple:

For ex­am­ple, if a guy called Join Doe is trav­el­ing from Ber­lin to Moscow, there might be at least two bits of in­for­ma­tion about this:
John Doe is in Berlin
John Doe is in Moscow

How do we dis­t­in­guish be­tween the Ber­lin to Moscow case, and the Moscow to Ber­lin case? You men­tion this point later:

time does not re­ally tell us if Johnny starts his jour­ney in Ber­lin or in Moscow.

So I can ac­cept the ar­gu­ment that Ber­lin,Moscow and Moscow,Ber­lin are the same amount of time—it stands to rea­son that do­ing the same thing in re­verse or­der should take the same amount of time, which the in­for­ma­tion rule seems to cap­ture. But this doesn’t seem to square with the Minsk ex­am­ple:

it might even hap­pen, be­cause he is so very much in love with this girl, that he will never ar­rive in Moscow. In that case, the amount of time be­tween de­par­ture and ar­rival is in­finite.

Based on the pre­vi­ous ex­am­ple I would ex­pect Ber­lin,Minsk,Moscow to be the same as Moscow,Minsk,Ber­lin, and this seems to hold up—but it doesn’t seem con­sis­tent that Ber­lin,Minsk,Moscow is more time than just Ber­lin,Moscow and yet Ber­lin,Minsk is in­finite.

It also looks to me like we have a prob­lem with try­ing to in­te­grate new kinds of in­for­ma­tion. For ex­am­ple, un­der this rule Ber­lin,Minsk,Moscow and Ber­lin,Paris,Moscow are the same amount of time—but when we look at the map we see Paris is farther away from Moscow than Ber­lin is. How do we ac­count for this, un­der the rule?

• How does this the­ory dis­t­in­guish time from space? If I look at ever wider and wider re­gions of space, I can ob­tain more and more in­for­ma­tion. Similarly with scale… look­ing at things in finer de­tail makes more in­for­ma­tion available.

• As a few thresh­old con­sid­er­a­tions:

How do you de­ter­mine what “in­for­ma­tion” is rele­vant? And at what level of de­tail? I could zoom in on any num­ber of ar­eas of in­quiry about John’s origi­nal “in­stan­ta­neous” jour­ney and come up with ad­di­tional in­for­ma­tion un­til the cows come home. In do­ing so, it seems that the “time” con­clu­sion would change based in what in­for­ma­tion I deem rele­vant.

As an­other big is­sue, I would ask what qual­ifies in­for­ma­tion as be­ing “available”. In other words, available to who?

It seems to me that your pro­posal gives ad hoc an­swers to these ques­tions which fit your de­sired out­come.

More gen­er­ally speak­ing, I think you need to fold a whole lot more sub­jec­tivity into a con­cep­tion of time. In my view, time it­self is a quale.

• The first po­ten­tial prob­lem I see is that “in­for­ma­tion available” should be rel­a­tive to an in­for­ma­tion-stor­age de­vice like a hu­man brain, whereas time in (my limited un­der­stand­ing of) physics is rel­a­tive to a rock or other phys­i­cal frame of refer­ence. Those seem differ­ent.

If we try to re­move that prob­lem then we get a new one (which might ex­ist any­way in a less acute form). When we take as our “given phe­nomenon” some­thing large in spa­tial area, like ‘the Earth at ex­actly 4:40 am EST in this frame of refer­ence,’ we find vastly more available in­for­ma­tion than we could have—even in prin­ci­ple, I would think—for many phe­nom­ena we would con­sider to take more time. So this defi­ni­tion doesn’t seem to match the word.

• It doesn’t match a cer­tain way of defin­ing “in­for­ma­tion”. But some peo­ple are quite happy with no­tions of in­for­ma­tion that aren’t tied to a sub­ject. You can rec­on­cile the two by say­ing that ob­jec­tive in­for­ma­tion is po­ten­tial sub­jec­tive in­for­ma­tion.

• If I study his­tory with this view I would be mov­ing events in time. There seems to be a lot of im­plicit as­sum­tions that could go mul­ti­ple ways needed to make it com­pat­i­ble with or­di­nary time phe­nom­ena.

There seems to be similar­ity with Zeno’s ar­rows in that if each state is con­sid­ered sep­a­rately no move­ment oc­curs. Is this just a restate­ment of that view?

• Thanks very much for won­der­ful replies! There are not many places in the net where such ar­ti­cles can be pub­lished and are read! I am con­fi­dent that my thoughts can only get less wrong, if they re­ceived some feed­back. So you guys make me happy!

@ryan_b Do not look at maps or watches to un­der­stand time! It did not help in two mil­le­ni­ums. Since Ein­stein we live in space-time, and it does not make sense to talk about time with­out con­text. Imag­ine there were con­sid­er­ably more mass con­cen­trated in Paris, then in Ber­lin. Very, very, very fat peo­ple for ex­am­ple! That would bend space-time, clocks would be slower in Paris, and Paris could in­deed be nearer to Moscow than Ber­lin, con­sid­er­ing all pos­si­ble mea­sure­ments.

@Slider Yes! It is a “playful” con­cept, full of de­tails that needed to be ironed out. For now, I find it very in­ter­est­ing to ig­nore the fact that we ex­pe­rience time as di­rected. I tried to start with a new con­cept, com­pletely in­de­pen­dent of ever­day’s ex­pe­rience. How we ex­pe­rience time might be mis­lead­ing. The whole phe­nomenon might be an illu­sion.

@et­sim Yes, in­deed! Sub­jec­tivity! Since Ein­stein, time de­pends on the rel­a­tive speed you have com­pared to some­body else. – What in­for­ma­tion is rele­vant? When I wrote the ar­ti­cle, I dared con­cen­trat­ing on the in­for­ma­tion about speed and po­si­tion of “some­thing”, say a par­ti­cle. But that is plain physics, and I am not the right guy for such stuff. But I know about the un­cer­tainty prin­ci­ple: Speed and lo­ca­tion can­not be de­ter­mined with the same ac­cu­racy at the same time. There is always un­cer­tainty in­volved. Miss­ing in­for­ma­tion? A miss­ing un­der­stand­ing? I find these things very, very in­ter­est­ing and fas­ci­nat­ing.

• What an in­spiring thought. I love ideas like yours, mainly be­cause I was taught philos­o­phy at UCL in Lon­don UK. At the time Arnold Zuboff was a lec­turer there and his ideas were as in­ter­est­ing as yours. I was there some time around 1992 or 3, I last spoke to him around 2004 maybe 2006. UCL may be able to put you in touch with him, as they did that for me. He is very good at dis­cussing ideas such as yours in emails and on sites such as this. Let me as­sure you, Zuboff is a ge­nius. Here is a pa­per he wrote re­gard­ing time and self iden­tity https://​​philpa­pers.org/​​rec/​​ZUBMUA

I am fairly cer­tain, and I hope I’m not wrong or em­bar­rass­ing my­self or him in some way but se­ri­ously, get his advice