gts@axiom.UUCP (Guy Schafer) (07/24/86)
I received a head injury the other day and I thought of this:
Get a bunch of detectors of all sorts--electromagnetic (video cameras,
thermal detectors, microwave detectors, etc), calibrated clocks,
sniffers (gas and various fluid detectors), microphones, and whatever
other kind you can think of or invent.
Then pick a spot that is durable (won't move very far over the course
of many years) and is PRECISELY known--note it's longitude, lattitude,
measure it from the poles (magnetic and actual) from geosyncronous
sattilites, even from other planets and the sun.
Then pick a time that is also precisely known--use several methods if
possible.
Then widely publicize and permanently store this information (time, place,
types and accuracy of detectors) in many places--especially where physics
research is being done.
At the time chosen, just listen for messages coming in from the future.
If a message comes in, we know that sometime in the future, the stored info
was retrieved and used to send info back in time using technology now
unknown.
If nothing comes in, we know that during the next x years (where x is the
probable durability of the stored information) technology to send info
back in time will not have been invented.
Comments?
>< ...{ decvax!linus | seismo!harvard }!axiom!gts
"Live by the foma that makes you brave
and kind and healthy and happy."
--The Books of Bokonon. 1:5dxm@lanl.ARPA (Douglas Miller) (07/26/86)
> [...suggests a time travel experiment...] > > Comments? > > >< ...{ decvax!linus | seismo!harvard }!axiom!gts There are a lot of good arguments against the possibility of time travel, and since you did ask for comments I'll risk the flames for posting a "not-real-physics" article here. Time travel violates the conservation of mass and energy laws. Consider transporting a 1Kg cube of gold 1 hour back in time. Then in the universe of 1 hour ago, there is this extra 1Kg from nowhere, totally unaccounted for. Similarly in the here and now, we lost 1Kg of mass, poof, just like that. Mass wasn't conserved in our universe. That, as you should well realize, is a big no-no. There are lots of other arguments against it, causality and so forth. I just thought that the point above has the merit of being seldom presented. Doug Miller ....ihnp4!lanl!dxm or dxm@lanl.arpa
brad@looking.UUCP (Brad Templeton) (07/26/86)
In article <289@axiom.UUCP> gts@axiom.UUCP (Guy Schafer) writes: > > > ... advertise big that you're going to listen for time messages from the > future and see what happens ... > >If a message comes in, we know that sometime in the future, the stored info >was retrieved and used to send info back in time using technology now >unknown. > >If nothing comes in, we know that during the next x years (where x is the >probable durability of the stored information) technology to send info >back in time will not have been invented. > >Comments? Not likely you'll get anything. If there is time travel (backwards) then it is probably highly restricted, and messages to the past are no doubt illegal - certainly for frivolous purposes like this. But most of all, it's a paradox. Not only would your intent to listen go in the history books, but so would the results of your experiment. If the books say you received nothing, then they wouldn't bother to send. If they "will have said" that you received something, then the future exists and there is no free will, so why bother with the experiment?
mikes@tekecs.UUCP (Michael Sellers) (07/27/86)
> > [...suggests a time travel experiment...] > > > > Comments? > > > > >< ...{ decvax!linus | seismo!harvard }!axiom!gts > > There are a lot of good arguments against the possibility of time travel, > and since you did ask for comments I'll risk the flames for posting a > "not-real-physics" article here. I think this falls into more of a "could be might be maybe physics" more than "not-real-physics," but who cares. This is one of those topics that is to make the speculative salivaries to overflow :-). > Time travel violates the conservation of mass and energy laws. Consider > transporting a 1Kg cube of gold 1 hour back in time. Then in the universe > of 1 hour ago, there is this extra 1Kg from nowhere, totally unaccounted > for. Similarly in the here and now, we lost 1Kg of mass, poof, just like > that. Mass wasn't conserved in our universe. That, as you should well > realize, is a big no-no. You have made an assumption here that is somewhat "temperocentric," and not necessarily true. You have assumed that the Universe is bound by the same linear time sense that we experience, at least with regard to the mass/energy conservation law. What if it is the case that, while mass and energy must be conserved, they do not have to be conserved with regard to time. That is, I can take a Kg of gold and project it 100 years in the future with no problem because, from the Universal point of view, I haven't gotten rid of it, merely transported it (though through time, not space). Thus it does not matter (in terms of conservation) if I take my gold and "send" it forward or backward in time, because it still exists, just "sometime" else. It would be possible, if this were true, to "rob" the future or past by taking all their gold and holding it here at this point in time. The consequences of this are rather mind-bending, especially in extreme cases (has anyone read the Stainless Steel Rat story where he has to go galavanting through time? there are some awfully interesting circular paths there regarding materials being around because they were sent from the future, so when the characters "get to" the future, they have them on hand to send back to the past...so where did they come from?). And of course just because we've beaten conservation doesn't mean we've gotten rid of the demon of causality. > There are lots of other arguments against it, causality and so forth. > > Doug Miller As for causality, there is always the possibility of multiple futures/pasts, or some even weirder possibilities with multiple universes, etc. Still, the original experiment would almost seem to be a CETI project for time travel ("if it [ever] exists, this is the only way we'll know") with the advantage that we only need to set it up for a few minutes or a day at most. If the spatial and temporal coordinates are recorded and distributed well enough (time capsules, newspapers, libraries, etc, etc), then anyone with time travel capabilities would be able to "send" something/someone back to the window of time during which we were watching. As a collateral question (and possibly too speculative for these august groups :-), if you were the one capable of sending something back, what (or who) would it be? And, if you were around when the watching was done, what do you think the effect on "current" society would be? (This reminds me of the end of the movie "The Time Machine," where we find the hero having gone back to the future (:-) in his machine, taking only three books with him...and we are left wondering which three out of his library he chose to take with him...) -- Mike Sellers UUCP: {...your spinal column here...}!tektronix!tekecs!mikes A path is simply a rut that's going your way.
bhayes@glacier.UUCP (07/27/86)
In article <289@axiom.UUCP> gts@axiom.UUCP (Guy Schafer) writes: >Get a bunch of detectors of all sorts [...] pick a spot [and] >pick a time that is also precisely known [...]. > >At the time chosen, just listen for messages coming in from the future. Good idea. Been done, too. A few years ago a friend of mine got an invitation to a party for time travelers. It was a national mailing [seemed to have been associated with the Church of the Subgenus] and as far as I know no guests of honor showed up.
eugene@ames.UUCP (Eugene Miya) (07/28/86)
> I received a head injury the other day and I thought of this: > > Followed by a descriptions and numerous followup paradoxes. No, but I think you have a great idea for a movie..... From the Rock of Ages Home for Retired Hackers: --eugene miya NASA Ames Research Center com'on do you trust Reply commands with all these different mailers? {hplabs,ihnp4,dual,hao,decwrl,tektronix,allegra}!ames!aurora!eugene eugene@ames-aurora.ARPA
daver@felix.UUCP (Dave Richards) (07/28/86)
In article <289@axiom.UUCP> gts@axiom.UUCP (Guy Schafer) writes: >If a message comes in, we know that sometime in the future, the stored info >was retrieved and used to send info back in time using technology now >unknown. Or the message is from the present and is a hoax or a joke. How do you verify the source of the message? >If nothing comes in, we know that during the next x years (where x is the >probable durability of the stored information) technology to send info >back in time will not have been invented. Or, we know that with that knowlege comes apathy about what has already trans- pired, such that even if someone has the capability to send a message back, they don't. It seems to me that no matter what the outcome, this experiment would tell you nothing. Long ago I theorized that UFO's could be time travelers from our own people in the future. I can think of no benefit to them of making this known to us, how- ever. In fact, contact (and exchange of information) between future people and the present could be very risky to that future. The paradox inherent in this has been debated before, I'm sure. Dave
timothym@tekigm2.UUCP (07/29/86)
Now this is why I read this net. If any of you who read this don't get it, do yourself a favor and read this original article. It is definately worth reading. I also congratulate the original poster for his ingenuity. I hope someone with the influence to make the idea work will perform the experiment. I just hope that the person doing the test is a public organization, and will share the wealth so to speak. Again, read the original article for full information. -- Tim Margeson (206)253-5240 tektronix!tekigm2!timothym @@ 'Who said that?' PO Box 3500 d/s C1-937 Vancouver, WA. 98668
lyang@sun.uucp (Larry Yang) (07/29/86)
In article <5723@lanl.ARPA> dxm@lanl.ARPA (Douglas Miller) writes: >Time travel violates the conservation of mass and energy laws. Consider >transporting a 1Kg cube of gold 1 hour back in time. Then in the universe >of 1 hour ago, there is this extra 1Kg from nowhere, totally unaccounted >for. Similarly in the here and now, we lost 1Kg of mass, poof, just like >that. Mass wasn't conserved in our universe. That, as you should well >realize, is a big no-no. I used to believe this argument, too, 'til I got my brain out of the classical view of the universe. Consider time as an additional dimension. Now just consider time travel as moving mass/energy from one "point" in the space-time to another. Thus , mass/energy is conserved in this new space-time "universe". As an analogy, consider a 2-D universe. Imagine a 1-kg "square" of gold begin translated 1 "hour" perpendicular to this plane. Now our original universe is now 1-kg less, but the overall universe has the same mass. Just a psuedo-technical response from a pseudo-person. Comments/flames welcome. -- Larry Yang
lyang@sun.uucp (Larry Yang) (07/29/86)
In article <1408@felix.UUCP> daver@felix.UUCP (Dave Richards) writes: >In article <289@axiom.UUCP> gts@axiom.UUCP (Guy Schafer) writes: >>If a message comes in, we know that sometime in the future, the stored info >>was retrieved and used to send info back in time using technology now >>unknown. > >Or the message is from the present and is a hoax or a joke. How do you verify >the source of the message? > What could be done is a bunch of scientists secretely set up this equipment for about 60 seconds, then announce to the world the next day that they did this. Thus, in the future when time experiments are being done, they know about this window to shoot for. Of course, they should have heard/recorded something during this session. This way, in order for there to be a joke response, one would have to invent a way to transmit info through time, no? > >Long ago I theorized that UFO's could be time travelers from our own people in >the future. I can think of no benefit to them of making this known to us, how- >ever. In fact, contact (and exchange of information) between future people and >the present could be very risky to that future. The paradox inherent in this >has been debated before, I'm sure. > >Dave How 'bout this theory that I thought of a while ago... Time travellers go back in time to explore the evolution of man and get stranded back there, becoming ancestors to the human race. But then, now we're getting into science fiction and not physics.... -- Larry Yang
sdp@omssw1.UUCP (Scott Peterson) (07/29/86)
In article <5723@lanl.ARPA> dxm@lanl.ARPA (Douglas Miller) writes: >> [...suggests a time travel experiment...] >> >> Comments? >> >> >< ...{ decvax!linus | seismo!harvard }!axiom!gts > >Time travel violates the conservation of mass and energy laws. > >Doug Miller >....ihnp4!lanl!dxm or dxm@lanl.arpa It doesn't violate conservation of mass if all you send is information. I don't know how to send information without influencing the position of something at the destination end (something already there) or causing some kind of radiation, which amounts to sending energy. Scott Peterson, Intel Corp., Hillsboro, OR, ...!tektronix!ogcvax!omssw1!sdp
brian@sequent.UUCP (Brian Godfrey) (07/30/86)
>Get a bunch of detectors of all sorts--electromagnetic (video cameras, >... >Then pick a spot that is durable (won't move very far over the course >of many years) and is PRECISELY known--note it's longitude, lattitude, >measure it from the poles (magnetic and actual) from geosyncronous >sattilites, even from other planets and the sun. >Then pick a time that is also precisely known--use several methods if >possible. >... >Then widely publicize and permanently store this information (time, place, >... >At the time chosen, just listen for messages coming in from the future. Maybe that's what the pyramids are all about. Or stonehenge.... --Brian
jbuck@epimass.UUCP (Joe Buck) (07/30/86)
>In article <5723@lanl.ARPA> dxm@lanl.ARPA (Douglas Miller) writes: >>Time travel violates the conservation of mass and energy laws... In article <5594@sun.uucp> lyang@sun.UUCP (Larry Yang) writes: >I used to believe this argument, too, 'til I got my brain out of the >classical view of the universe. Consider time as an additional dimension. >Now just consider time travel as moving mass/energy from one "point" >in the space-time to another. Thus , mass/energy is conserved in this new >space-time "universe". Sorry, conservation of mass/energy applies at any instant of time, and region of space. It has never been observed that the mass/energy decreases at one instant, and increases at the next, except at the level of elementary particles. The uncertainty principle lets you do this though. Many people are familiar with (delta x)(delta p) >= h but there's also (delta E)(delta t) >= h That is, you can violate the conservation of energy if you do it for a short enough time, since the energy of a system isn't precisely defined unless you measure it forever (t -> infinity). Unfortunately, the time in which you're allowed to have an extra gram of matter around is pretty miniscule. On the other hand, since it's probabilistic, if you wait long enough (10^big-number times the age of the universe) it might happen. In the vacuum, particles and antiparticles are constantly appearing and annihilating each other out of nothing. One way of interpreting this is that the positron is an electron travelling backward in time. So the positron-electron pair is only a single particle, travelling in a little circle in space-time. One could imagine a macroscopic object travelling in a loop in space-time. No microscopic laws would be violated; only the second law of thermodynamics (but this is a statistical law, so if you wait long enough...). An observer in a "normal" space-time path might see this like a pair-production event: suddenly two identical but opposite objects appear, move in some way, collide, and disappear. -- - Joe Buck {ihnp4!pesnta,oliveb,nsc!csi}!epimass!jbuck Entropic Processing, Inc., Cupertino, California
ken@hcrvax.UUCP (07/30/86)
>In article <1408@felix.UUCP> daver@felix.UUCP (Dave Richards) writes: >In article <289@axiom.UUCP> gts@axiom.UUCP (Guy Schafer) writes: >>If a message comes in, we know that sometime in the future, the stored info >>was retrieved and used to send info back in time using technology now >>unknown. > >Or the message is from the present and is a hoax or a joke. How do you verify >the source of the message? TO VERIFY MESSAGE: Set up a random number generator (using atomic decay or something equally uncontrollable, NOT a pseudo-random number generating computer program). Run the test on Friday. On Saturday, generate a 200 digit random number, and publish it along with info about the experiment. With any luck you will already know the number, because the time traveller will have sent it back to you on Friday! Mini-flame to skeptics: You shouldn't use the word "impossible" with regard to these ideas. To be classed impossible, something should have been *proven* impossible (like squaring a circle using only compasses and straight-edge). It is not enough that it be "not possible in light of current *theories*." Especially given the incomplete state of the science of physics. - The universe is not only stranger than we suppose, it is stranger that we can suppose. (Edwin Hubble) -- - Ken Scott [decvax,inhn4]!utzoo!hcr!ken "You say I contradict myself? Very well, I contradict myself. I am large, I contain multitudes."
melnick@unc.UUCP (Alex Melnick) (07/31/86)
In article <7489@tekecs.UUCP> mikes@tekecs.UUCP (Michael Sellers) writes: > As a collateral question (and possibly too speculative for these august >groups :-), if you were the one capable of sending something back, what (or >who) would it be? > > Mike Sellers Another question is: If you were in the future, knew about the experiment, and had the equipment to send some material or information back to the experimenters, WHY WOULD YOU SEND ANYTHING? (Douglas Adams is right: English grammar can't handle time travel.) It seems that in performing the experiment, we're relying on someone in the future not merely to be able to help us, but also to want to help us. Is this a reasonable assumption? Maybe. They might be interested in helping fellow scientists, etc., but on the other hand, what's in it for them? Sounds like a story (or three) in here somewhere. Alex ...!mcnc!unc!melnick (Still looking for M* Right.)
taylor@glasgow.glasgow.UUCP (Jem Taylor) (07/31/86)
In article <289@axiom.UUCP> gts@axiom.UUCP writes: >If a message comes in, we know that sometime in the future, the stored info >was retrieved and used to send info back in time using technology now >unknown. > >If nothing comes in, we know that during the next x years (where x is the >probable durability of the stored information) technology to send info >back in time will not have been invented. Trouble is, a negative response doesn't prove no time travel - 'they' might fail to reply for reasons like "these primitives shouldn't know" (c.f. the time lords in Dr. Who), they might miss the spot when replying - either too soon or in the wrong place, they might not think it worth the trouble, or they might worry about upsetting the course of history ( though I think that the idea of being able to upset history is preposterous - history is HISTORY at least in any particular fork of possibility ) Good idea though; make sure the message you send 'into the future' is in a language, as yet unknown, that they will understand . . . if it *does* work, of course, the experiment should be very famous in the future and therefore well publicised. Jem. -- -------------------------------------------------------------------------------- JANET: ' , ' , ' taylor@uk.ac.glasgow.cs ' ___ , ' USENET: , / | \ , { uk }!cs.glasgow.ac.uk!taylor ' -o| Royal Mail: , ' (J=) ' , J.A.Taylor ~~~~~~~~~~~~~~ Computer Science <>< 17 Lilybank Gardens ><> Jemima GB-GLASGOW G12 8QQ ><> Puddleduck "who says it doesn't rain on the west coast ?"
m128abo@brahms.BERKELEY.EDU (Michael Ellis) (07/31/86)
> Scott Peterson >> Douglas Miller >>Time travel violates the conservation of mass and energy laws. >It doesn't violate conservation of mass if all you send is information. >I don't know how to send information without influencing the position of >something at the destination end (something already there) or causing >some kind of radiation, which amounts to sending energy. Information suddenly appearing out of elsewhen would be equivalent to an increase in negentropy, or a decrease in entropy. Wouldn't that violate the 2nd law of TD? -m128abo
kaufman@nike.uucp (Bill Kaufman) (07/31/86)
In article <7489@tekecs.UUCP> mikes@tekecs.UUCP (Michael Sellers) writes: > As a collateral question (and possibly too speculative for these august >groups :-), if you were the one capable of sending something back, what (or >who) would it be? A nuclear bomb. Something that would, by "appearing" in that time, materialize in my grandfather. A computer & manual, destined for T.A. Edison in Menlo Park, NJ. The plans for "Opertion: Overlord" to die F^uhrer's office (excuse the attempt at an umlaut) in Berlin. In general, anything that would cause an identifiable, unavoidable mistake in time. Great way to verify whether we live in a "parallel" universe, or a "serial" one (cf. "Thrice Upon a Time," by (James P.?) Hogan). In article <83@unc.unc.UUCP> melnick@unc.UUCP (Alex Melnick) writes: >Another question is: If you were in the future, knew about the experiment, >and had the equipment to send some material or information back to the >experimenters, WHY WOULD YOU SEND ANYTHING? (Douglas Adams is right: English >grammar can't handle time travel.) What if the results could be changed by the exeriment (cf. Heisenberg's Un- certainty Principle :-)? BTW: It was Larry Niven who said that. Niven's example went something like: ----- "OK, I'll go back and deal with the dinosaurs. You go to Ford's lab, duplicate the duplicate, come back with the original duplicate, and I'll meet you a million years ago. Got that?" "Ummm,..." (Larry Niven, in one of the "Flight of the Horse" s.s's; and "Theory and Practice of Time Travel", in "All the Myriad Ways".) ----- (If anyone has the original quote, mind emailing it to me? TIA.) -Annoyingly, Bilbo. ___________________________________________________________________________ / DISCLAIMER: If I had an opinion, do you think I'd let my employers know? \ |E-MAIL: kaufman@orion.arpa or kaufman@orion.arc.nasa.gov | |FLAMES: Look, Ma, an asbestos mbox! (Gee, wish *you* had one, huh?) | |QUOTE: "Are you a commie? Good. Don't want no commies in my car. | | No Christians, either!" | +---------------------------------------------------------------------------+
brian@sequent.UUCP (Brian Godfrey) (07/31/86)
I have developed a very important theory in relational physics. It involves the relationship of space and time. This relationship has eluded scientists for many years. We all know that electrons revolve around the nucleus of an atom; Adams revolve around Eves; Eves' credit card accounts revolve around...well, maybe that is subject for another study; the Earth revolves around the sun; and the sun revolves around the center of the Milky Way galaxy. What do the galaxies revolve around? Physicists currently are saying that the galaxies are expanding from some huge explosion. But that violates the pattern demonstrated everywhere else. I contend that the galaxies revolve around time. Now, everybody knows that time flows from left to right unless you are left handed. Just picture a point in the center of that stream with all of the universe revolving at a constant rate around it. That is a simple way to understand the complex interaction of space and time. Amazingly, I discovered the key to this theory while pondering a phenomena familiar to all of us. We all know that in the spring and summer it seems like Friday will never get here - time flows so slow. While in fall and winter the weekend is upon you before you have a chance to get anything done at all - time has sped up. The reason for this is that in the spring and summer months the spacial universe is sweeping downstream. It is moving in the same direction as the flow of time and, thus, is moving at a lesser rate in relation to that current. In the fall and winter the universe is swinging upstream. This causes it to have to move against the flow of time and, so, the current is very rapid in relation to those of us who live in the spacial universe. Now I presume that all of you great physicsts on the net will cogitate on my theory for a while and then (after appropriate experimentation) adopt it as the new space/time model for the known universe. Just remember me when it comes time to name it. (Then name it after someone else.) --Brian
mwg@petrus.UUCP (Mark Garrett) (07/31/86)
++ > > [...suggests a time travel experiment...] > > >< ...{ decvax!linus | seismo!harvard }!axiom!gts > > There are a lot of good arguments against the possibility of time travel... > Consider > transporting a 1Kg cube of gold 1 hour back in time. Then in the universe > of 1 hour ago, there is this extra 1Kg from nowhere, totally unaccounted > for. Similarly in the here and now, we lost 1Kg of mass, poof, just like > that. Mass wasn't conserved in our universe. > Doug Miller Actually that brings to mind an interesting point. Mass *is* conserved but only in the long run: Since you brought the Kg back in time you had *two* for an hour. Then when you send one of them back in time, you are still left with one! If this were possible it would imply that you can duplicate anything but only for finite periods of time. -Mark Garrett
purtill@petrus.UUCP (Mark Purtill) (07/31/86)
In article <289@axiom.UUCP>? Alex <...!mcnc!unc!melnick> writes: > In article <7489@tekecs.UUCP> mikes@tekecs.UUCP (Michael Sellers) writes: > > As a collateral question (and possibly too speculative for these august > >groups :-), if you were the one capable of sending something back, what (or > >who) would it be? > > > > Mike Sellers > > Another question is: If you were in the future, knew about the experiment, > and had the equipment to send some material or information back to the > experimenters, WHY WOULD YOU SEND ANYTHING? Consider a slightly different scenario. You know about the experiment and have a time machine, but *you know the experiment failed* (nothing showed up at the appropriate time). Now, are you willing send soemthing back? I doubt I would.... mark purtill (201) 829-5127 ^.-.^ Arpa: purtill@bellcore.com 435 south st 2H-307 ((")) Uucp: ihnp4!bellcore!purtill morristown nj 07960
andrew@mitisft.UUCP (08/01/86)
In article <5594@sun.uucp>, lyang@sun.uucp (Larry Yang) writes: > In article <5723@lanl.ARPA> dxm@lanl.ARPA (Douglas Miller) writes: > >Time travel violates the conservation of mass and energy laws. Consider > ... > I used to believe this argument, too, 'til I got my brain out of the > classical view of the universe. Consider time as an additional dimension. > ... > As an analogy, consider a 2-D universe. Imagine a 1-kg "square" of gold > begin translated 1 "hour" perpendicular to this plane. Now our original > universe is now 1-kg less, but the overall universe has the same mass. The problem with this is, in a universe with two spatial dimensions, a "2-cube" of gold would not appear to us as a square; rather it would be a square tube -- a 3-d object, since it exists at many different times. If the gold didnt move, it would be a straight tube (prism?). If it moved in space, the tube would wiggle. If it broke into pieces, the tube would branch. What would happen if it were "moved in time"? The tube would be broken off, and the entire "future" part of it would be translated forwards. Thus there would be a gap in the tube. By Heisenberg, this sort of structure is rather unlikely... Andrew Knutsen Convergent Technologies -- hplabs!pyramid!ctnews!andrew I speak for myself only... CT isnt in the time travel business anyway (yet).
jbuck@epimass.UUCP (Joe Buck) (08/01/86)
Michael Ellis writes: > Information suddenly appearing out of elsewhen would be equivalent > to an increase in negentropy, or a decrease in entropy. Wouldn't > that violate the 2nd law of TD? Sure would. The Second Law is the only law that has a time direction associated with it; all other laws are symmetrical in time (though some of the new grand unified-field theories may not be). As I said before, pair production out of the vacuum can be thought of as particles traveling in loops in space-time, but they're random, with no information content. -- - Joe Buck {ihnp4!pesnta,oliveb,nsc!csi}!epimass!jbuck Entropic Processing, Inc., Cupertino, California
jmc@riccb.UUCP (Jeff McQuinn ) (08/01/86)
> Comments?
This is very clever and well thought out. One thing though. The conclusion
that time travel will one day be invented can be drawn if you get an answer.
The converse is not true however. If you DON'T get an answer there are a
number of possible explanations including: Time travel will not be invented;
we don't have the right instrumentation to receive time transmissions (i.e.-
special technology is associated with the receiver as opposed to the sender);
future societies have the technology to talk to us, but chose not to for
social or moral reasons. In fact the old Star Trek reasoning of not contacting
the past must be valid if you assume that future generations must invent time
travel and we have never received a time traveler or message.
Clearly time travel is possible. Why just yesterday I heard on the news that
the Post Office was delivering letters that were mailed in 1940. (Least you
think this funny, it is a time transmission, it's just going the easy way)(-8
Jeff McQuinn just VAXing aroundjmc@riccb.UUCP (Jeff McQuinn ) (08/01/86)
> > Time travel violates the conservation of mass and energy laws. Consider > transporting a 1Kg cube of gold 1 hour back in time. Then in the universe > of 1 hour ago, there is this extra 1Kg from nowhere, totally unaccounted > for. Similarly in the here and now, we lost 1Kg of mass, poof, just like > that. Mass wasn't conserved in our universe. That, as you should well > realize, is a big no-no. > The big question is not whether mass and energy are conserved, they must be, but rather how can time travel take place and still conserve mass and energy. Since time and distance traveled are more or less interchangeable quantities (one can't be expressed without the other) it would seem that in order to back up in in time, the events that occured between leaving the future and arriving in the past would have to "unhappen". The first event to unhappen would be that I tried to move back in time (which may short circuit the attempt). Secondly, since my time is firmly locked together with the rest of the universes time, my events unhappening would need to drag the rest of the universe along (to back up to yesterday I would need the earth to back up one revolution and so on and so on because universal movements were an event that happened during my time). Next, my concept of having this time trip would have to unhappen. So here I somehow am an hour before with no concept of having gotten here, and no idea of whats going to happen. Since my time trip unhappened I didn't do it and since I don't know I didn't do it I couldn't prove that I didn't (-: do it. I would expect a short circuit on the attempt and see no results. The worst case result being that while I'm expending all the energy in the universe to get it to back up, time gets stuck. Jeff McQuinn just VAXing around
ins_apmj@jhunix.UUCP (Patrick M Juola) (08/01/86)
Attention : all physicists Enter suspended-disbelief mode; what you are about to read belongs somewhere between _2001_ and _Conan the Barbarian_; I realize the premises sound absurd. If you must flame me, at least show me *why* they are absurd, merely invoking God, Gauss, or Newton won't work. In article <129@omssw1.UUCP> sdp@omssw1.UUCP (Scott Peterson) writes: >In article <5723@lanl.ARPA> dxm@lanl.ARPA (Douglas Miller) writes: >>> [...suggests a time travel experiment...] >> >>Time travel violates the conservation of mass and energy laws. >>Doug Miller > >It doesn't violate conservation of mass if all you send is information. >I don't know how to send information without influencing the position of >something at the destination end (something already there) or causing >some kind of radiation, which amounts to sending energy. > >Scott Peterson, Intel Corp., Hillsboro, OR, ...!tektronix!ogcvax!omssw1!sdp E == mc^2, or in English, sending energy *is* sending mass.... Why are we assuming that the conservation laws *must* hold in our limited (3d) universe? The fact that we have never observed something appear "from nowhere" might simply mean that not many people are sending things back this far through time. Is there some basis for assuming that the laws we are observing are not a special case of a more general multi-dimensional law? (Absence of evidence != evidence of absence -- the fact that we've never seen fast things get short doesn't mean they don't.) A somewhat related question -- Information theory is a relatively new science, mostly related to thermodynamics. Does information have mass? Or, to put it more specifically, is there some minimum amount of mass/energy required to transmit one bit of information? If so, how is this related to all the other fundamental constants? Obviously, my physics-major girlfriend is not around, else she would have tried to keep me from posting this 8-) -- seismo!umcp-cs \ Pat Juola ihnp4!whuxcc > !jhunix!ins_apmj Hopkins Maths allegra!hopkins / Now accepting applications for a new .signature quote....
tim@sunybcs.UUCP (Timothy Thomas) (08/01/86)
>It seems that in performing the experiment, we're relying on someone in the >future not merely to be able to help us, but also to want to help us. Is >this a reasonable assumption? Think about the logic in that. If we have to rely on somebody in the future to help us, then we will wait forever. If some technology is 'invented' or 'found' because of somebody in the future sending it to us, that would be a contradiction. Ok, fine, we now have some new tecnology. So in the future (since it has already happened), we send it back to ourselves again. Where did it originate??? There is no way any new knowledge from the future can enter into the present or past because of this knowledge must originate someplace, or be found (found meaning discovered on its own or invented, not handed to by some future scientist). -------- ____________ ____/--\____ \______ ___) ( _ ____) "Damn it Jim!, __| |____/ / `--' I'm a programmer not a Doctor!" ) `|=(- \------------' Timothy D. Thomas SUNY/Buffalo Computer Science UUCP: [decvax,dual,rocksanne,watmath,rocksvax]!sunybcs!tim CSnet: tim@buffalo, ARPAnet: tim%buffalo@CSNET-RELAY
jbuck@epimass.UUCP (Joe Buck) (08/03/86)
In article <556@sunybcs.UUCP> tim@gort.UUCP (Timothy Thomas) writes: >Think about the logic in that. If we have to rely on somebody in the >future to help us, then we will wait forever. If some technology >is 'invented' or 'found' because of somebody in the future sending >it to us, that would be a contradiction. >Ok, fine, we now have some new tecnology. So in the future (since it >has already happened), we send it back to ourselves again. Where did >it originate??? There is no way any new knowledge from the future >can enter into the present or past because of this knowledge must >originate someplace, or be found (found meaning discovered on its >own or invented, not handed to by some future scientist). Why would it be a contradiction? Causal loops are certainly strange, but they can be drawn on a Minkowski space-time diagram easily enough. "Contradiction" means that the statements "A" and "not A" are both true. For example, going back in time and killing my (younger) self cause a contradiction, where A is the statement "I exist at time t". But you're stating "knowledge must originate someplace (and time)?" as a postulate; it's not an axiom of logic. It only contradicts intuition. -- - Joe Buck {ihnp4!pesnta,oliveb,nsc!csi}!epimass!jbuck Entropic Processing, Inc., Cupertino, California
franka@mmintl.UUCP (Frank Adams) (08/03/86)
In article <129@omssw1.UUCP> sdp@omssw1.UUCP (Scott Peterson) writes: >In article <5723@lanl.ARPA> dxm@lanl.ARPA (Douglas Miller) writes: >>Time travel violates the conservation of mass and energy laws. > >It doesn't violate conservation of mass if all you send is information. According to current theories, it is impossible to send information without sending energy. Frank Adams ihnp4!philabs!pwa-b!mmintl!franka Multimate International 52 Oakland Ave North E. Hartford, CT 06108
kaufman@nike.uucp (Bill Kaufman) (08/04/86)
[this was, I assume, sent to me accidentally] Date: Fri, 1 Aug 86 21:36:05 cdt From: caip!ihnp4!mmm!cipher (Andre Guirard) Message-Id: <8608020236.AA18362@mmm.SERCNET> To: floyd!caip!nike!kaufman Subject: Re: A Sane Man Proposes A Time Travel Experiment Newsgroups: net.physics,net.sci,net.philosophy,net.sf-lovers In-Reply-To: <451@nike.UUCP> References: <289@axiom.UUCP> <5723@lanl.ARPA> <7489@tekecs.UUCP> <83@unc.unc.UUCP> Organization: 3M Company, St. Paul, Minn. Cc: Status: R In article <451@nike.UUCP> you write: >In article <7489@tekecs.UUCP> mikes@tekecs.UUCP (Michael Sellers) writes: >...If you were the one capable of sending something back, what (or >>who) would it be? > >A nuclear bomb. Something that would, by "appearing" in that time, >materialize in my grandfather. A computer & manual, destined for T.A. Edison >in Menlo Park, NJ. The plans for "Opertion: Overlord" to die F^uhrer's >office (excuse the attempt at an umlaut) in Berlin. >In general, anything that would cause an identifiable, unavoidable mistake >in time. Great way to verify whether we live in a "parallel" universe, or >a "serial" one (cf. "Thrice Upon a Time," by (James P.?) Hogan). It's a good way to tell if you live in a parallel universe, but it's not a good way to tell if you live in a serial one, since the experiment would have a high probability of causing the experimenter never to have existed, or at least never to have conducted the experiment. Better to conduct the experiment on a smaller scale, then you can be sure that you'll be around to see the results. It seems like I've heard a theory to the effect that time travel can't exist not because it's theoretically impossible, but because the invention of time travel makes it possible to modify the past, making time travel never to have been discovered. Knowing how to travel in time is an unstable situation. -- ===+=== Andre Guirard /@ @\ ihnp4!mmm!cipher /_____\ ( @ @ ) My mission: to explore strange new words. \ _ / To seek out and utilize new applications. `-' To shovel snow that snow plows have shoved before. [And now, for the same, low price: a reply! ;-] OK, maybe I was stretching it. Something a little less severe, perhaps. Just so the experimenter will continue to exist--say, kill off someone current and famous. If you're in a serial universe, the event (person, in this case) will simply cease to exist. In other words, if nothing happens, you're in a serial universe! ;-) -Annoyingly, Bilbo. ___________________________________________________________________________ / DISCLAIMER: If I had an opinion, do you think I'd let my employers know? \ |E-MAIL: kaufman@orion.arpa or kaufman@orion.arc.nasa.gov | |FLAMES: Look, Ma, an asbestos mbox! (Gee, wish *you* had one, huh?) | |QUOTE: "Are you a commie? Good. Don't want no commies in my car. | | No Christians, either!" | +---------------------------------------------------------------------------+
dobro@ulowell.UUCP (Gryphon) (08/05/86)
The subject of multiple time lines was put forth in this story.
Short summary: the existance of an additional type of energy (tau) is
discovered. Seems that this energy is created (no comments :-}) whenever
another form of energy is released. This tau energy travels back in time
a distance directly proportional to the amount of energy. SO, these guys
who discovered this (who also happen to be hackers) design a machine to
monitor recption of this type of energy. Then they experiment by sending
forward (sorry, it can go forward or back, distance proportional ...)
and having the future people send messages back.
What they came up with is the idea as follows:
Picture a grid board, with a needle/hook/whatever stuck in at each point.
The 'thread' of relity is strung from point to point.
Now, move the thread in the past and that changes the points is connects
to. But, given enough time (dependend upon the severity of the change),
the 'thread' will head toward its original future. Thus there is an
elasticity to time.
Now, Hogan also came up with what the characters called the 'reset factor'.
This was basically that certain amounts of tau radiation will be consantlt
jumping back and forward and changing things, even as minor as the placement
of a sigle molecule. But, that can have unforseen affects. However, once
a change is made in the past, reality is retroactivley reset to
hav that as its past. Scary thought.
Sorry for length, but I think it was a neat idea. I will leave
all else (this contained no real spoilers to plot) to anyone who
wishes to read it.
Comments?
Gryphon
-------------------------------
Phone : (617) 937-0551
USMail: P.O.Box 8524, Lowell, Ma. 01853
Usenet: ...!{wanginst,masscomp,apollo}!ulowell!dobro
Moderator: mod-psi@ulowell.UUCP
Disclaimer: I am simply a figment of my imagination,
and can therefore not have an opinion.
"Far beyond human ability to classify, or comprehend..."taylor@glasgow.glasgow.UUCP (Jem Taylor) (08/05/86)
In article <451@nike.UUCP> kaufman@orion.UUCP (Bill Kaufman) writes: >In article <7489@tekecs.UUCP> mikes@tekecs.UUCP (Michael Sellers) writes: >> As a collateral question (and possibly too speculative for these august >>groups :-), if you were the one capable of sending something back, what (or >>who) would it be? > >A nuclear bomb. Something that would, by "appearing" in that time, >materialize in my grandfather. A computer & manual, destined for T.A. Edison >in Menlo Park, NJ. The plans for "Opertion: Overlord" to die F^uhrer's >office (excuse the attempt at an umlaut) in Berlin. >In general, anything that would cause an identifiable, unavoidable mistake >in time. Great way to verify whether we live in a "parallel" universe, or >a "serial" one (cf. "Thrice Upon a Time," by (James P.?) Hogan). > But, but, but if we do live in a parallel universes (sic), then you wouldn't notice any difference _in_this_parallel_ since this one is the one where the transmission into the past, failed. If there was a difference, it would be in a different parrallel universe, by definition. So 1) Time travel BACKWARDS into THIS PARALLEL doesn't work If the universe isn't parallels (sic again), no-one would notice the change because it would always have been that way. Ursula Le Guin wrote an excellent book - 'The Lathe of Heaven' ? - which treats this problem, in the context of some-one who can dream reality different. When he wakes up, everyone else has already forgotten the 'real' past, and remembered the 'new' past which is consistent with the new present. Our hero almost goes crazy ... So 2) Time travel DOES WORK but NO-ONE EVER NOTICES ... -Jem. -- -------------------------------------------------------------------------------- JANET: ' , ' , ' taylor@uk.ac.glasgow.cs ' ___ , ' USENET: , / | \ , { uk }!cs.glasgow.ac.uk!taylor ' -o| Royal Mail: , ' (J=) ' , J.A.Taylor ~~~~~~~~~~~~~~ Computer Science <>< 17 Lilybank Gardens ><> Jemima GB-GLASGOW G12 8QQ ><> Puddleduck "who says it doesn't rain on the west coast ?"
kaufman@nike.uucp (Bill Kaufman) (08/05/86)
In article <622@ulowell.UUCP> dobro@ulowell.UUCP (Gryphon) writes: >Short summary: the existance of an additional type of energy (tau) is >discovered. Seems that this energy is created (no comments :-}) whenever >another form of energy is released. This tau energy travels back in time >a distance directly proportional to the amount of energy. SO, these guys >who discovered this (who also happen to be hackers) design a machine to >monitor recption of this type of energy. Then they experiment by sending >forward (sorry, it can go forward or back, distance proportional ...) >and having the future people send messages back. Close enough: The radiation was (in every instance I can remember) sent back in time. Sending it forward in time is: a) No trick (read, "fun") at all. It happens all the time. This posting is going forward in time, and will reach you all at a time later than it was sent. b) Inconclusive. It doesn't show any real change in the universe. Say, in 1941, I send you (here/now) a note saying, "The Japa- nese bomb Pearl Harbor," would you do anything different? c) Impossible in the context of the story, I believe. [FYI, the information is passed as "bleeps", pulses of tau radiation, in a basic serial computer transmission, picked up at the other end by the same computer.] >Now, Hogan also came up with what the characters called the 'reset factor'. >This was basically that certain amounts of tau radiation will be constantly >jumping back and forward and changing things, even as minor as the placement ^^^^^^^ [See above.] >of a single molecule. But, that can have unforseen affects. However, once >a change is made in the past, reality is retroactively reset to >have that as its past. Scary thought. Yeah, but it doesn't happen often (it took the old guy YEARS to prove it even existed), and only interacts on an atomic level. Barely, at that. -Annoyingly, Bilbo. ___________________________________________________________________________ / DISCLAIMER: If I had an opinion, do you think I'd let my employers know? \ |E-MAIL: kaufman@orion.arpa or kaufman@orion.arc.nasa.gov | |FLAMES: Look, Ma, an asbestos mbox! (Gee, wish *you* had one, huh?) | |QUOTE: "Are you a commie? Good. Don't want no commies in my car. | | No Christians, either!" | +---------------------------------------------------------------------------+
cipher@mmm.UUCP (Andre Guirard) (08/05/86)
In article <720@riccb.UUCP> jmc@riccb.UUCP (Jeff McQuinn ) writes: >Since time and distance traveled are more or less interchangeable quantities >(one can't be expressed without the other) it would seem that in order to >back up in in time, the events that occured between leaving the future and >arriving in the past would have to "unhappen". The first event to unhappen >would be that I tried to move back in time (which may short circuit the >attempt). Secondly, since my time is firmly locked together with the rest >of the universes time, my events unhappening would need to drag the rest >of the universe along (to back up to yesterday I would need the earth to back >up one revolution and so on and so on because universal movements were an >event that happened during my time). Next, my concept of having this time >trip would have to unhappen. So here I somehow am an hour before with no >concept of having gotten here, and no idea of whats going to happen. Since >my time trip unhappened I didn't do it and since I don't know I didn't do it >I couldn't prove that I didn't (-: do it. I would expect a short circuit on >the attempt and see no results... But you _could_ prove it! You need a non-deterministic random-number generator, one based on atomic decay for instance. Use this device to generate a random number in the range 0 to 99. Then, if the number is not 42, use your experimental time-machine to reset time to just before the number was generated. Repeat this procedure 10,000 times. If the time-machine works, you will observe that the random-number generator generated the same number, 42, 10,000 times. -- ===+=== Andre Guirard /@ @\ ihnp4!mmm!cipher /_____\ ( @ @ ) My mission: to explore strange new words. \ _ / To seek out and utilize new applications. `-' To shovel snow that snow plows have shoved before.
franka@mmintl.UUCP (Frank Adams) (08/06/86)
In article <3301@jhunix.UUCP> ins_apmj@jhunix.ARPA (Patrick M Juola) writes: >Absence of evidence != evidence of absence. Actually, absence of evidence *is* evidence of absence. It isn't, and can never be, proof of absence; but it is evidence. The harder you looked for the evidence, the better the evidence of absence. Frank Adams ihnp4!philabs!pwa-b!mmintl!franka Multimate International 52 Oakland Ave North E. Hartford, CT 06108
franka@mmintl.UUCP (Frank Adams) (08/06/86)
>From: caip!ihnp4!mmm!cipher (Andre Guirard) >It seems like I've heard a theory to the effect that time travel can't >exist not because it's theoretically impossible, but because the >invention of time travel makes it possible to modify the past, making >time travel never to have been discovered. Knowing how to travel in >time is an unstable situation. I believe this suggestion is due to Larry Niven. Frank Adams ihnp4!philabs!pwa-b!mmintl!franka Multimate International 52 Oakland Ave North E. Hartford, CT 06108
jmc@riccb.UUCP (Jeff McQuinn ) (08/07/86)
> > The first event to unhappen > >would be that I tried to move back in time (which may short circuit the > >attempt). Secondly, since my time is firmly locked together with the rest > >of the universes time, my events unhappening would need to drag the rest > >of the universe along (to back up to yesterday I would need the earth to back > >up one revolution and so on and so on because universal movements were an > >event that happened during my time). Next, my concept of having this time > >trip would have to unhappen. So here I somehow am an hour before with no > >concept of having gotten here, and no idea of whats going to happen. Since > >my time trip unhappened I didn't do it and since I don't know I didn't do it > >I couldn't prove that I didn't (-: do it. I would expect a short circuit on > >the attempt and see no results... > > But you _could_ prove it! You need a non-deterministic random-number > generator, one based on atomic decay for instance. Use this device to > generate a random number in the range 0 to 99. Then, if the number is > not 42, use your experimental time-machine to reset time to just before > the number was generated. Repeat this procedure 10,000 times. If the > time-machine works, you will observe that the random-number generator > generated the same number, 42, 10,000 times. > No, I can't prove it, if backing up in time causes things to "unhappen". If I can back up without short circuiting time I would lose knowledge of the fact that I did it. Granted it would look like I hit 42 every time but I will never know I tried to back up in time and thus would not be able to prove that time travel was responsible for the radom number generator getting stuck. In fact since every attempt to back up in time "unhappens" it could be argued that successful attempts at time travel were never made. But they were never made because they were successful! What I'm advocating here is that time travel cannot change the structure of the time traveled to. If you travel back to a time before your birth and you actually show up then, the structure of the time you show up in has changed and isn't really the same as it was (because you are there) so it can't be the same time that it was. If you travel to the time of your birth then you must show up as a new born baby. Time is a measure of the passage of events. To back up in time you must pass those events in reverse. Like a movie where the film stops and then starts running in reverse. The pictures on the film don't change, and new characters don't appear, and the hero still doesn't know whodunit. Since the events of the future have not yet happened, their time has not been created, there is no future "time" to travel to. The best you can do is travel at the speed of light so that time on Earth passes more quickly then yours. Not really time travel just a different perspective. Jeff McQuinn just VAXing around
aka@cbrma.UUCP (Andy Kashyap) (08/07/86)
>In article <720@riccb.UUCP> jmc@riccb.UUCP (Jeff McQuinn ) writes: >>... So here I somehow am an hour before with no >>concept of having gotten here, and no idea of whats going to happen. Since >>my time trip unhappened I didn't do it and since I don't know I didn't do it >>I couldn't prove that I didn't (-: do it. I would expect a short circuit on >>the attempt and see no results... > In article <1037@mmm.UUCP> cipher@mmm.UUCP (Andre Guirard) writes: >But you _could_ prove it! You need a non-deterministic random-number >generator, one based on atomic decay for instance. Use this device to >generate a random number in the range 0 to 99. Then, if the number is >not 42, use your experimental time-machine to reset time to just before >the number was generated. Repeat this procedure 10,000 times. If the >time-machine works, you will observe that the random-number generator >generated the same number, 42, 10,000 times. But how would you know it did? Every time you back in time you 'erase' any previous records of anything. Is there any way to store records such that when you go back in time that you recognize the records as being left there in a previous time trip? If there is, is some logical conflicts developing. Disclaimer: This discussion of time travel rests upon the idea of 'sliding' back in one's own world-line. Arguments of time travel through time warps or worm holes (and the such) do not apply here. - andy kashyap -- +---------------------------------------------------------------------------+ : Jim, what's the value of Pi? : Andy Kashyap : : About 3.14159. Why do you ask, Doctor? : AT&T Bell Labs : : Actually, Captain, the exact value is 3.1415926535...: Columbus OH : : Kirk & McCoy: Shut Up, Spock!!! : ..!cbosgd!cbrma!aka: +---------------------------------------------------------------------------+
cipher@mmm.UUCP (Andre Guirard) (08/08/86)
In article <722@riccb.UUCP> jmc@riccb.UUCP (Jeff McQuinn ) writes: >>>My concept of having this time >>>trip would have to unhappen. So here I somehow am an hour before with no >>>concept of having gotten here, and no idea of whats going to happen. Since >>>my time trip unhappened I didn't do it and since I don't know I >>>didn't do it I couldn't prove that I didn't (-: do it. I would >>>expect a short circuit on the attempt and see no results... >> >> But you _could_ prove it! You need a non-deterministic random-number >> generator, one based on atomic decay for instance. Use this device to >> generate a random number in the range 0 to 99. Then, if the number is >> not 42, use your experimental time-machine to reset time to just before >> the number was generated. Repeat this procedure 10,000 times. If the >> time-machine works, you will observe that the random-number generator >> generated the same number, 42, 10,000 times. > >No, I can't prove it, if backing up in time causes things to >"unhappen". If I can back up without short circuiting time I would >lose knowledge of the fact that I did it. But if you back up to a time after you _decided_ to back up you will still remember _deciding_ to do it. Your subsequent inability to activate the time-machine should tell you something. Incidentally, deciding to activate the time machine no matter what is very dangerous, since in order to get past that point in time something catasrophic has to happen to either you or the machine. > Granted it would look like I >hit 42 every time but I will never know I tried to back up in time and >thus would not be able to prove that time travel was responsible for >the random number generator getting stuck. Not if you mean with 100% certainty, but with a much higher degree of certainty than most other scientific "facts" are known. You want to try to eliminate other factors (such as a malfunction in the RNG) by repeating the experiment and running control experiments with no time machine. >In fact since every attempt >to back up in time "unhappens" it could be argued that successful >attempts at time travel were never made. But they were never made >because they were successful! If that's true, there would appear to be two "levels" of time. The "base level" which we are accustomed to, and the "meta-level" in which the base level may appear to change as time-travel takes place. The event of a successful experiment never appears in the final configuration of base level, but a meta-level observer could remember the experiment taking place. >Since the events of the future have not yet happened, their time has not been >created, there is no future "time" to travel to. Is there experimental evidence that would tend to confirm or refute this position? Anyone? I think it's silly to believe things without evidence. -- /''`\ 500cr REWARD!!! Andre Guirard ([]-[]) For information leading to the capture ihnp4!mmm!cipher \ ) / of Silas Thornby, alias the Line Eater. la plej bela ^sultro `-' Contact: Vid. Arthune, 09DART-447243 Terra
ins_apmj@jhunix.UUCP (Patrick M Juola) (08/10/86)
In article <1692@mmintl.UUCP> franka@mmintl.UUCP (Frank Adams) writes: >In article <3301@jhunix.UUCP> I write: >>Absence of evidence != evidence of absence. > >Actually, absence of evidence *is* evidence of absence. It isn't, and can >never be, proof of absence; but it is evidence. The harder you looked for >the evidence, the better the evidence of absence. I stand corrected. -- seismo!umcp-cs \ Pat Juola ihnp4!whuxcc > !jhunix!ins_apmj Hopkins Maths allegra!hopkins / Now accepting applications for a new .signature quote....
markb@sdcrdcf.UUCP (Mark Biggar) (08/11/86)
In article <1693@mmintl.UUCP> franka@mmintl.UUCP (Frank Adams) writes: >>From: caip!ihnp4!mmm!cipher (Andre Guirard) >>It seems like I've heard a theory to the effect that time travel can't >>exist not because it's theoretically impossible, but because the >>invention of time travel makes it possible to modify the past, making >>time travel never to have been discovered. Knowing how to travel in >>time is an unstable situation. > >I believe this suggestion is due to Larry Niven. I call this the "Fixed Point" theory of why there are no time travelers. The universe recurses until it reachs a fixed point (i.e., a universe where one one gets around to inventing a time machine) Mark Biggar {allegra,burdvax,cbosgd,hplabs,ihnp4,akgua,sdcsvax}!sdcrdcf!markb
davidsen@steinmetz.UUCP (Davidsen) (08/12/86)
In article <1037@mmm.UUCP> cipher@mmm.UUCP (Andre Guirard) writes: >But you _could_ prove it! You need a non-deterministic random-number >generator, one based on atomic decay for instance. Use this device to >generate a random number in the range 0 to 99. Then, if the number is >not 42, use your experimental time-machine to reset time to just before >the number was generated. Repeat this procedure 10,000 times. If the >time-machine works, you will observe that the random-number generator >generated the same number, 42, 10,000 times. I'm missing somthing? If you "reset time" to just before the number is generated, don't you reset the conditions too? Wouldn't you get the same number every time (and decide to reset time, and ... DON'T!). If you do what I think you mean, events will happen the same way, since you have changed nothing, including the next number to come out of the atomic generator. -- -bill davidsen ihnp4!seismo!rochester!steinmetz!--\ \ unirot ------------->---> crdos1!davidsen chinet ------/ sixhub ---------------------/ (davidsen@ge-crd.ARPA) "Stupidity, like virtue, is its own reward"
simon@einode.UUCP (Simon Kenyon) (08/12/86)
my own thoughts on time travel go like this: if time travel is possible AND you can alter the course of history THEN time travel will never be discovered. my reasoning is that if you can alter the past then one day someone will screw up and the discovery of time travel will be deleted from history. in a small puff of smoke the whole of time disappears up its own rear end :-) the possibility of time travel with NO history alteration implies that effect on YOUR past have no effect on YOUR future. time lines and parallel universes and all that. one thing i could never understand at university was why when time was just another coordinate in 4-space, could you not move in a negative direction. probably just my lousy maths ability :-) (don't listen tcdmath) -- Simon Kenyon The National Software Centre, Dublin, IRELAND simon@einode.UUCP +353-1-716255 EEEK /dev/mouse escaped (Glad to see my competition went down well at USENIX)
rickheit@ulowell.UUCP (Erich W Rickheit) (08/14/86)
[Is that a line-eater? Hey, you are you a li<*>]
I have a (half-wriiten) story along these lines. Some mad professor or
other develops a time machine that can go no further than a half-hour either
way (for mathematical reasons that our hero doesn't understand and so never
appear in the story--SF plot device #1233) Several days later, in the empty
lab, there is the characteristic blue light of the time-traveller, and a
dark figure appears with a pistol in hand. He places it in a desk drawer,
and exits the lab. Some twenty minutes later, one of the lab assistants (a
lovely young lass) enters arguing with a familiar dark figure. Angrily, he
pulls the gun out of the drawer, and shoots her dead. He then goes to the
time machine, and transports himself back a half-hour. There is the
characteristic blue light of the time-traveller, and the dark figure
appears with the pistol in his hand. He places it in a desk drawer, and
exits the lab.
An hour later, the police arrive on the scene, and find the body. There
are plenty of suspects (the girl was an obnoxious bith who made herself a
lot of enemies) but the murder weapon is untraceable. Our hero, a police
detective, must find the killer, and a murder weapon which does not
logically exist!
I have plenty of holes to iron out, of course (such as, who loads the
pistol?) but that, avoid the character development, was the base of the
plot. The possibilities of a nonexistant item appearing within a time loop
though, are staggering. What else could you do with this? Am I the only one
to have ever thought of such a thing?
--
a lesser Power of Darkness
This is indeed an opinion; whose fault it is, I don't know.
UUCP: ...wanginst!ulowell!rickheit
USnail: Erich Rickheit
85 Gershom Ave, #2
Lowell, MA 01854
Phone: (617) 453-1753jim@ism780c.UUCP (Jim Balter) (08/18/86)
In article <646@ulowell.UUCP> rickheit@ulowell.UUCP (Erich W Rickheit) writes: > I have plenty of holes to iron out, of course (such as, who loads the >pistol?) but that, avoid the character development, was the base of the >plot. The possibilities of a nonexistant item appearing within a time loop >though, are staggering. What else could you do with this? Am I the only one >to have ever thought of such a thing? I think Heinlein has been there before you. Consider the character(s) in "All You Zombies" who is his/her own parents, and who drafts himself into the Time Service. And while the dictionary in "By His Bootstraps" does not appear via a time loop, the information in it does. Your mechanism strikes me strongly as Deus Ex Machina, unless you can explain why the character should expect to find a gun in the drawer when he opens it to shoot his victim, since he has not yet planted the gun at that point, nor why he should expect the drawer to be empty when he goes back to plant the gun; there is no way for him to know that his action was the cause of the gun being there. Heinlein's treatment of the dictionary is much more subtle. And in both his classic stories, the character never expects any of what happens, until he reaches a point where he already knows that it was his own future actions that set things into motion, and acts accordingly. -- -- Jim Balter ({sdcrdcf!ism780c,ima}!jim)
public@wheaton (Joe Public) (08/21/86)
In article <646@ulowell.UUCP> rickheit@ulowell.UUCP (Erich W Rickheit) writes: > I have a (half-wriiten) story along these lines. Some mad professor or >[Description of plot involving murderer transporting himself back in time >to place a murder weapon where he can reach it "later" (or is that >"earlier"?).] >... > I have plenty of holes to iron out, of course (such as, who loads the >pistol?) but that, avoid the character development, was the base of the >plot. The possibilities of a nonexistant item appearing within a time loop >though, are staggering. What else could you do with this? Am I the only one >to have ever thought of such a thing? > > UUCP: ...wanginst!ulowell!rickheit > USnail: Erich Rickheit > 85 Gershom Ave, #2 > Lowell, MA 01854 > Phone: (617) 453-1753 But isn't the murderer himself stuck in the same time loop as the gun? --calvin richter--
tainter@ihlpg.UUCP (Tainter) (08/26/86)
> Your mechanism strikes me strongly as Deus Ex Machina, unless you can explain > why the character should expect to find a gun in the drawer when he opens it > to shoot his victim, since he has not yet planted the gun at that point, > nor why he should expect the drawer to be empty when he goes back to plant > the gun; there is no way for him to know that his action was the cause of > the gun being there. > -- Jim Balter ({sdcrdcf!ism780c,ima}!jim) There is a story about a time/travel parallel universe society. In this story a group has extracted historical individuals from some timelines (Khan, Catherine, Ivan, Hitler, etc) as infants and raised them in alternative universes as laborers and average people. The scientist who developed the time/space/universe doorways they use to move around finally objects to the exploitive behavior of the group but they get control of the devices to open these doorways and trap him in a particular time line. To get out of it he decides he will come back to save himself through some particular doorway and then proceeds to be rescued by himself, which he then sets out to do. He actually shows up as 6 of himself together and 6 of a friend (one of the relocated) also trapped with him. I can't remember who wrote it or what it was called but it struck me as very good reading when I read it many years ago. --j.a.tainter