# Hawking's theories... **URL:** \ **Category:** Great Debates\ **Created:** [March 13, 2003, 3:30pm UTC](https://boards.straightdope.com/t/hawkings-theories/161111 "2003-03-13T15:30:05Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![minega](https://avatars.discourse-cdn.com/v4/letter/m/ac91a4/32.png) [@minega](https://boards.straightdope.com/u/minega)\ **Post date:** [March 13, 2003, 3:30pm UTC](https://boards.straightdope.com/t/hawkings-theories/161111/1 "2003-03-13T15:30:05Z")
I have been reading up on Hawking’s theories because they fascinate me so much (although i can barely understnd Jack shit, i guess its mainly to impress the girls)However one of his theories has fascinated me most: He says ‘Why do we remember the past and not the future’ What does he mean? ---
**Author:** ![MC\_Master\_of\_Ceremonies](https://avatars.discourse-cdn.com/v4/letter/m/bb73d2/32.png) [@MC\_Master\_of\_Ceremonies](https://boards.straightdope.com/u/MC_Master_of_Ceremonies)\ **Post date:** [March 13, 2003, 3:38pm UTC](https://boards.straightdope.com/t/hawkings-theories/161111/2 "2003-03-13T15:38:43Z")
minega, I’ve never heard this from Hawking but it is an area I have looked into: What he means given that most of the fundamental laws of nature are time-symetric, how come we have more information on what happened in the past than what will happen in the future. Here is one take on it (I belive the writer of the article is a psycologist: [http://www.goertzel.org/dynapsyc/1995/EGOANDTI.html](http://www.goertzel.org/dynapsyc/1995/EGOANDTI.html) Here’s a slightly different version (posted for someone else on a different board): > [@](#): > > Why does time move forward? > > Firstly you have to realize that the fundamental laws of nature (i.e. quantum physics and general relativity) are time-symetric, which means that they do not distinguish between past and future (i.e. any classification of the two is arbitary). Clearly the world that we live in is not time-symetric, this is due to the second law of thermodynamics which states that entropy always increases in a closed system (the universe is a closed system), or, to put in a more relevant form, the future always has more entropy than the past. > > In human terms what distinguishes the past from the future? The answer to this is our memories. Another way of putting your question might of been, given that the laws of nature are time-symetric, “why can’t we remember the future like we remember the past?”. The answer to this is that to a certain extent we do remember the future, this ‘memory’ of the future is our ability to predict events (our memory after all is nothing but a prediction of how past events played out) and I don’t mean in the psychic sense, but in the way that, for example, if someone throws a ball up in the air you will be able to predict where it lands with at least some degree of accuracy. However, what is clear from this is that out ‘memory’ of the future is nowhere as good as our memory of the past or, put differently, our ability to predict how past events played out is better than our ability of how future events will play out. > > This inbalance between knowledge of the future and knowledge of the past must be connected to the second law of thermodynamics.The second law of thermodynamics is a result of the way that particles are organized in the universe, if the universe was in a completely uniform state it would not operate. > > The thing about systems in a low state of entropy is that they can be described more accurately using less amounts of bits (a bit is the smallest possible piece of information) than a system in a high state of entropy, this is because they are more ordered. So therefore it takes less room to store information in our brains about the past than the future (because the observation of past -future is systems going from a low to a high state of entropy). ---
**Author:** ![minega](https://avatars.discourse-cdn.com/v4/letter/m/ac91a4/32.png) [@minega](https://boards.straightdope.com/u/minega)\ **Post date:** [March 13, 2003, 3:47pm UTC](https://boards.straightdope.com/t/hawkings-theories/161111/3 "2003-03-13T15:47:43Z")
But here you are talking about PREDICTING the future while we have already experienced the past. Can the two really be compared? Can you remember something that never happened? ---
**Author:** ![minega](https://avatars.discourse-cdn.com/v4/letter/m/ac91a4/32.png) [@minega](https://boards.straightdope.com/u/minega)\ **Post date:** [March 13, 2003, 3:49pm UTC](https://boards.straightdope.com/t/hawkings-theories/161111/4 "2003-03-13T15:49:56Z")
Oh…you mean ‘to a certain extent’ i think… ---
**Author:** ![MC\_Master\_of\_Ceremonies](https://avatars.discourse-cdn.com/v4/letter/m/bb73d2/32.png) [@MC\_Master\_of\_Ceremonies](https://boards.straightdope.com/u/MC_Master_of_Ceremonies)\ **Post date:** [March 13, 2003, 3:54pm UTC](https://boards.straightdope.com/t/hawkings-theories/161111/5 "2003-03-13T15:54:38Z")
But as stated above our memory is nothing more than a predication of the past. Memories aren’t and cannot be perfect. At a certain point in time your mind has a set of information contained in it. This set of information can be used to find out what happened in the past and what will happen in the future, from this information you cannot find out either with perfect accuracy. ---
**Author:** ![MC\_Master\_of\_Ceremonies](https://avatars.discourse-cdn.com/v4/letter/m/bb73d2/32.png) [@MC\_Master\_of\_Ceremonies](https://boards.straightdope.com/u/MC_Master_of_Ceremonies)\ **Post date:** [March 13, 2003, 3:58pm UTC](https://boards.straightdope.com/t/hawkings-theories/161111/6 "2003-03-13T15:58:08Z")
Obviously, you can find out what hapened in the past, better than you can find out what will happen in the future and Hawking’s question can be restated as: “why is there this inbalance?”. ---
**Author:** ![MC\_Master\_of\_Ceremonies](https://avatars.discourse-cdn.com/v4/letter/m/bb73d2/32.png) [@MC\_Master\_of\_Ceremonies](https://boards.straightdope.com/u/MC_Master_of_Ceremonies)\ **Post date:** [March 13, 2003, 4:00pm UTC](https://boards.straightdope.com/t/hawkings-theories/161111/7 "2003-03-13T16:00:49Z")
An important admission from the quoted section, is about the formation of information and how that relates to entropy. As a result of the laws of entropy, information can only be formed in the past to future direction and not in the future to past direction. ---
**Author:** ![MC\_Master\_of\_Ceremonies](https://avatars.discourse-cdn.com/v4/letter/m/bb73d2/32.png) [@MC\_Master\_of\_Ceremonies](https://boards.straightdope.com/u/MC_Master_of_Ceremonies)\ **Post date:** [March 13, 2003, 4:02pm UTC](https://boards.straightdope.com/t/hawkings-theories/161111/8 "2003-03-13T16:02:10Z")
Sorry not admission, omission. ---
**Author:** ![blowero](https://avatars.discourse-cdn.com/v4/letter/b/41988e/32.png) [@blowero](https://boards.straightdope.com/u/blowero)\ **Post date:** [March 13, 2003, 7:24pm UTC](https://boards.straightdope.com/t/hawkings-theories/161111/9 "2003-03-13T19:24:11Z")
> [@](#): > > \*Originally posted by minega \* > \*\*But here you are talking about PREDICTING the future while we have already experienced the past. Can the two really be compared? Can you remember something that never happened? \*\* But what do you mean by “never happened”? The future exists; we just don’t happen to be there right now. From what I understand, mathematically speaking, the past and future are symmetrical. They are just different points in the time/space continuum. From that perspective, to say that the future “never happened” is similar to saying that if I am standing in San Francisco, that St. Louis doesn’t exist. Does St. Louis only exist if I get in a plane and fly there? By the way, if that kind of stuff interests you, I read a great book that describes many different theories about the nature of time and why we experience it directionally. I don’t know how dated it is, since I read it years ago - but it was enjoyable reading. _ABOUT TIME: Einstein’s Unfinished Revolution_ by P. C. W. Davies. [http://www.amazon.com/exec/obidos/tg/detail/-/0684818221/qid=1047583136/sr=1-3/ref=sr\_1\_3/104-3537307-4496768?v=glance&s=books](http://www.amazon.com/exec/obidos/tg/detail/-/0684818221/qid=1047583136/sr=1-3/ref=sr_1_3/104-3537307-4496768?v=glance&s=books) ---
**Author:** ![Florentine\_Pogen\_1](https://avatars.discourse-cdn.com/v4/letter/f/9e8a1a/32.png) [@Florentine\_Pogen\_1](https://boards.straightdope.com/u/Florentine_Pogen_1)\ **Post date:** [March 13, 2003, 10:26pm UTC](https://boards.straightdope.com/t/hawkings-theories/161111/10 "2003-03-13T22:26:52Z")
In that case, we _do_ remember the future. Think of say, driving to a party, thinking what it’s going to be like. Our memory of the future just tends to be less accurate than or memory of the past. ---
**Author:** ![blowero](https://avatars.discourse-cdn.com/v4/letter/b/41988e/32.png) [@blowero](https://boards.straightdope.com/u/blowero)\ **Post date:** [March 13, 2003, 10:48pm UTC](https://boards.straightdope.com/t/hawkings-theories/161111/11 "2003-03-13T22:48:24Z")
I knew you were gonna say that.😉 ---
**Author:** ![tracer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tracer/32/20578_2.png) [@tracer](https://boards.straightdope.com/u/tracer)\ **Post date:** [March 14, 2003, 12:31am UTC](https://boards.straightdope.com/t/hawkings-theories/161111/12 "2003-03-14T00:31:52Z")
> [@](#): > > \*Originally posted by Florentine Pogen \* > **In that case, we _do_ remember the future. Think of say, driving to a party, thinking what it’s going to be like.** Yeah, and every time I do, my “memory” of this future party is that it’s always the bestest party _ever!_ (My memory of past parties is always more disappointing, for some reason.) ---
**Author:** ![Alien2022](https://avatars.discourse-cdn.com/v4/letter/a/e19adc/32.png) [@Alien2022](https://boards.straightdope.com/u/Alien2022)\ **Post date:** [March 14, 2003, 1:03am UTC](https://boards.straightdope.com/t/hawkings-theories/161111/13 "2003-03-14T01:03:07Z")
Or maybe Deja Vu is us remembering the future? Maybe it is just a latent power that we have no access to? ---
**Author:** ![eburacum45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eburacum45/32/8690_2.png) [@eburacum45](https://boards.straightdope.com/u/eburacum45)\ **Post date:** [March 14, 2003, 1:45am UTC](https://boards.straightdope.com/t/hawkings-theories/161111/14 "2003-03-14T01:45:12Z")
Hawking and a lot of cosmologists have historically been concerned about the symmetry of the universe over time- he has said that at one time it was believed that the expanding universe would stop expanding and start contracting, and that during the contraction phase time would run backwards— well that certainly doesn’t look like being the case, a recent theory says that the universe will expand faster and faster until our bodies and the Earth itself explodes. No symmetry there I’m afraid. ---
**Author:** ![tracer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tracer/32/20578_2.png) [@tracer](https://boards.straightdope.com/u/tracer)\ **Post date:** [March 15, 2003, 3:02am UTC](https://boards.straightdope.com/t/hawkings-theories/161111/15 "2003-03-15T03:02:36Z")
When was time supposed to run in the imaginary (+i or -i) direction? ---
**Author:** ![Shaolinrabbit](https://avatars.discourse-cdn.com/v4/letter/s/e0b2c6/32.png) [@Shaolinrabbit](https://boards.straightdope.com/u/Shaolinrabbit)\ **Post date:** [March 15, 2003, 3:13am UTC](https://boards.straightdope.com/t/hawkings-theories/161111/16 "2003-03-15T03:13:03Z")
I just started reading _A brief history of time_, so presumably I can post here on the subject in either a brief moment or after a long eternity. I can report, however, that I don’t remember that post yet, so Hawking is off to a good start. ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [March 15, 2003, 4:58am UTC](https://boards.straightdope.com/t/hawkings-theories/161111/17 "2003-03-15T04:58:42Z")
> [@](#): > > \*Originally posted by Florentine Pogen \* > In that case, we _do_ remember the future. Think of say, driving to a party, thinking what it’s going to be like. Our memory of the future just tends to be less accurate than or memory of the past. \*\* Generally, my memory after a party is usually a lot less accurate:D ---
**Author:** ![FranticMad](https://avatars.discourse-cdn.com/v4/letter/f/c68b51/32.png) [@FranticMad](https://boards.straightdope.com/u/FranticMad)\ **Post date:** [March 15, 2003, 5:04am UTC](https://boards.straightdope.com/t/hawkings-theories/161111/18 "2003-03-15T05:04:05Z")
What you’re all going to say next has really pissed me off. ---
**Author:** ![Spiritus\_Mundi](https://avatars.discourse-cdn.com/v4/letter/s/c68b51/32.png) [@Spiritus\_Mundi](https://boards.straightdope.com/u/Spiritus_Mundi)\ **Post date:** [March 15, 2003, 5:12am UTC](https://boards.straightdope.com/t/hawkings-theories/161111/19 "2003-03-15T05:12:07Z")
Well, it is correct to say that the equations of both classical physics and quantum mechanics treat time as a symmetric variable, but that does not mean there is no diffreence between past and future. It just means that neither model is complete. For the record, most physicists accept CPT (charge-parity-time) symmetry as an absolute law. Both experimental results and current cosmological theories, however, argue that the individual elements of that trinity are not symmetric. T assymetry (and hence CP assymetry) have been demonstrated experimentally for neutral kaons. So far as I know it has not yet been verified experimentally, but violation of CP (and hence T) symmetry for baryons is at the heart of current big-bang cosmology, since it is the mechanism used to account for the fact that there is more matter than antimatter in the observed Universe. So, I’m afraid the premise in the OP is simply mistaken. While time is modeled as a symmetric variable in the mathematics of physics, it is not symmetric in the real world. ---
**Author:** ![MC\_Master\_of\_Ceremonies](https://avatars.discourse-cdn.com/v4/letter/m/bb73d2/32.png) [@MC\_Master\_of\_Ceremonies](https://boards.straightdope.com/u/MC_Master_of_Ceremonies)\ **Post date:** [March 15, 2003, 1:42pm UTC](https://boards.straightdope.com/t/hawkings-theories/161111/20 "2003-03-15T13:42:43Z")
Yes spiritus Mundi but the time-symmetry violations you describe could not account for the amount of time-asymmetry in the macroscopic world. But however they could account for the arrangment of matter in the universe that is itself responsible for time-asymmetry. If the universe was in total thermal equilibrium there would be, excepting the cases you described, time-symmetry. It is the nonuniformity of the universe that is responsible for macroscopic time-asymmetry. [Next page](https://boards.straightdope.com/t/hawkings-theories/161111.md?page=2)