michel123456

All that we can observe lie in the past. When we are considering positive time, it is the past. When we are considering (positive) space, it is space in the past. In order to get an idea of what we are discussing, we need a space-time diagram. Merged post follows: Consecutive posts merged The past is the low green triangle. It is (as commonly believed) what we can observe, i.e. the observable universe. It is what we are considering as positive. The future is the upper pink triangle. It is not observable. The negative sign on the diagram is an assumption. The "real" Universe lies entirely into 3D space and belongs to present time (the horizontal line on the diagram). It is not observable.

Zetetics, the Art of Doubt. "- An extraordinary allegation needs a more than ordinary proof." http://www.unice.fr/zetetique/anglais/a_enseignement.html#facets

Woaw. So you agree that positive distance in Space is related to positive time...in Time. Sorry. Again. So you agree that positive distance in Space is related to positive duration in Time.

Right. Except spelling. But You said "you can move in space in every direction you wan`t, but in time only foreward never backwards", which is the regular way to think. Because I am not a "regular thinker", I will dare to ask the question "why aren't there negative distances?" Space is considered exactly as Time i.e. Space is positive. Negative Space do not exist, exactly as negative Time do not exist. When a lot of people is actually asking and assembling more or less fallacious theories about negative time, when you can discuss seriously for hours about negative time, discussion about negative space is not even considered. It is so evident that space is always positive that its definition does not even mention it. see http://en.wikipedia.org/wiki/Space Time is exactly as Space: always positive. (I hope my spelling O.K.)

I suppose you mean "uniform motion", not "any movement".

I am glad that the discussion could last so long discussing such a weird thing as negative time, which has never been observed. Time is a scalar. Negative time mean negative scalar. Using negative time in equations gives strange results from the basics. For example :Speed [math] V = \frac{x}{t} [/math] Introducing negative T, you obtain negative speed (which is a scalar too), very weird. In this little "game", negative scalars are blowing out from everywhere. So, IMO, there are 2 alternatives: _either you refuse to introduce negative scalars in the first place, assuming it is pure nonsense. _either accept that negative scalars can be used, and offer the theoretical possibility that ANY scalar can become negative, independently of what intuition drives to reject at first sight.

Well I found the solution. At the question "Can you work out how the codes can be calculated and explain the method used to determine the combination lock code of Box J 6383 ? The answer is "no." Merged post follows: Consecutive posts mergedBack. "Can you work out how the codes can be calculated and explain the method used to determine the combination lock code of Box J 6383 ?" What is the difference between "work out how the codes can be calculated" and "explain the method used to determine the combination lock code". why the question is not simply "find the code" (without s). i mean "code" not "codes". Bizarre. Also, no 2 boxes have the same number (for example there is no H 6709 to parallel with J 6709). It's an indication that the letter, as you said, is not involved in calculation. It is probably an indication of category. The clue that "only digits used for the code will be 1 , 2 , 3 , 4 and 5." is very important too. It makes mathematical approach more difficult: how do you manage your result to be digits from 1 to 5 only? And there is a huge amount of data. Note again that the question is not " find the code(s)", but "work out". Bizarre.

In the meanwhile I found this: _"In 1942 he proposed the interpretation of the positron as a negative energy electron traveling backward in time." from the wiki article http://en.wikipedia.org/wiki/Ernst_Stueckelberg And "By considering the propagation of the negative energy modes of the electron field backward in time, Ernst Stueckelberg reached a pictorial understanding of the fact that the particle and antiparticle have equal mass m and spin J but opposite charges q." under "The Feynman-Stueckelberg interpretation" section in http://en.wikipedia.org/wiki/Antiparticle. Thus nothing new. So, as a resume, under time reversal the once broken cup of tea (that jumps from the floor) is probably made of antimatter, we don' t know for sure wether the particles of the cup are bounded together through the attractive strong force, and Michel still doubts that gravity keeps its attractive properties between the cup and the Earth. Maybe this could be considered more than a simple "movie reversal".

_ IMO the problem is software. _Maybe you should try to run a malware removal program (such as Adaware, free available, or other). _you may also disable some automatic upgrade feature from some program running in the background each time you are starting your browser. If the upgrade cannot run completely (maybe some old program running on a new system), you may experience the same delay each time.

No no, my suggestion is entirely different. I cannot propose anything of it and certainly not here (it should be posted under the "speculations" entity at least, after some introduction). For the moment I just want to gather information I cannot find on the Web. I am not an expert in any field I try to discuss, and I supposed people on this forum would maybe give some clue, some information or reference. The question of the strong force comes naturally because IMO physical nature is a whole. When you change something, it must obligatory have some influence somewhere else. Call that CPT symmetry, equilibrium, law of conservation,or wathever. For me the meaning is the same. So we talked about graviy, about electromagnetism, and about the weak force (considered as the electro-weak). I still don't know about the strong force.

I have some idea about it, but it is highly speculative, not suitable for this thread. I supposed that the question could be answered independently from the peculiar consequences. In any case, intuition will be a very bad adviser.

You have got all the meaning of this thread, in some sense. Yes, I agree when you write " (...) if you "reverse time" and end up with a sequence of events that is something other than the "forward" events in reverse order, that just shows you've done something wrong." That is the reason I believe that the "reverse movie" is not enough. When you reverse the movie, the world becomes weird. Broken objects distributed at random on the floor stick together and become a cup. The milk separates spontanously from coffee and jumps into the bottle, and so on. Endless descriptions. I think that those descriptions are weird because they are incomplete. That was the reason of my first question: (in other words) when time goes backwards, what are the following physical consequences. From the discussion, it appears that turning back time may also involve a transformation of the charge. Antimatter is described as matter of reversed charge (electron/positron, wrong?), so I believe that we could accept antimatter as regular matter travelling backwards in time, which is quite the same as giving the definition of antimatter as matter travelling backwards in time. I know that is a little bit too much of an interpretation, but I believe that it complies with the laws of physics. Of course I have not the knowledge to confirm anything of it. Otherwise, i wouldn't be here. And still, still, I cannot get what is happening to the strong force. As much as I know, the Strong force is always attractive. Do this force become repulsive through time reversal?

In order to show that the diagram complies with existing theories, here is the way the Big Bang can be represented, following the expanding universe theory: graph.7 On the left (into the past), the red lines converge. At the meeting point, Bang. On the right, the red lines intersect the white bold line which represents Space at present time. The intervals between points 1-2 is smaller than 2-3: the space is expanding. Because there are some problems regarding the converting point, BB theory had to be corrected a little bit, through the Inflation Theory. That gives something like the following graph: graph.8 End of the monologue (I hope so). Now, if I had to see graph. 7 in a science book, I surely would have shouted: I know this kind of configuration, it is so evident: Space is not expanding! So, please, tell me graph. 7 is wrong. Otherwise you will have to endure another monologue. Thank you.

This thread was not intended to speak about time travel. It was more intended to clarify the influence of time upon physical events. As I wrote above, I think that "turning time backwards" is more than "turning the reversal sequence" (looking at the reverse movie). For example: your cup of tea falls down from the table and breaks. The reversal movie will show the broken pieces stick together and jump from the floor to the table. That looks completely weird, and you can find in the litterature a lot of discussions on similar themes, involving entropy etc. But I think that in real physics you cannot simply assume that "reverse the movie" = "reverse time". In "real" physics (can we say that?), the broken pieces and the jumping cup of tea are made of anti-matter. This anti-matter is subjected to attractive gravitation (following the comments on this thread), something that I have not personnally clarified yet (the jumping from the ground still bothers me). Inside this anti-matter cup of tea, the strong (attractive) force that binds quarks into hadrons becomes ...?

I made a try that may work: First of all, the code of 4 digits is made from 5 numbers. It looks quite difficult to make a mathematical formula that reduces the result to 5 numbers only (12345). I think you can replace the 5 numbers 12345 with 5 letters ABCDE or wathever other symbol. I used ABCDE. The codes for J become : J 0023 = ABAE J 1853 = ECBB J 6242 = CEDE J 6709 = ECEE J 6519 = AEBE J 5362 = EECE J 5264 = DEBD That is only to make things a little bit clearer in my mind. Numbers are good as well as symbols. After that, make a square matrix of 10 digits (0123456789) in abscisse and ordinate. 9 - - - - - - - - - - 8 - - - - - - - - - - 7 - - - - - - - - - - 7 - - - - - - - - - - 5 - - - - - - - - - - 4 - - - - - - - - - - 3 - - - - - - - - - - 2 - - - - - - - - - - 1 - - - - - - - - - - 0 - - - - - - - - - - 0 1 2 3 4 5 6 7 8 9 to convert J 0023 into ABAE: _the first and fourth digits make the fourth letter (0 absciss, 3 ordinate = E) _the first and third digits make the third letter (0 absciss, 2 ordinate = A) _the first and 2nd digits make the 2nd letter (0 absciss, 0 ordinate = B) _the third and fourth digits make the 1st letter (2 absciss, 3 ordinate = A) which gives the following: 9 - - - - - - - - - - 8 - - - - - - - - - - 7 - - - - - - - - - - 7 - - - - - - - - - - 5 - - - - - - - - - - 4 - - - - - - - - - - 3 E - A - - - - - - - 2 A - - - - - - - - - 1 - - - - - - - - - - 0 B - - - - - - - - - 0 1 2 3 4 5 6 7 8 9 You can go on with this system for all the J serie. It works. It does not work for the other series. I suppose the order of operation must change. I had no courage to spend more time on this and to check if it goes right. The purpose is to fulfill the matrix, which gives the final code. I went until this, then I gave up. 9 E A - - - - E - - - 8 - C - - - - - - - - 7 - - - - - - C - - - 6 - - - - - E - - - - 5 - B - - - - E - - - 4 - - - - - D D - - - 3 E B A - - E - - - - 2 A - - - C E E - - - 1 - - - - - - B - E - 0 B - - - - - E - - - 0 1 2 3 4 5 6 7 8 9 Hoping not having commited any mistake in transcription. Michel.

I would be proud if I could understand 10% of your last post. You wrote "If [math] \theta \neq 0 [/math] then the vacuum state is complex and time reversal invariance is violated" and you also wrote that [math] \theta [/math] is never zero. So, in two words, what happens to the Strong Interaction under time reversal ?

What about strong interaction?

The supposition in my question is that physical laws are maintained under time reversal. Otherwise the dicussion is out of meaning.

Basically, that was the question in the first place. Running a movie backwards do not change the nature of matter into anti-matter, as Mr Skeptic coined. The only thing that changes is the sequence of events ( the order in which events happen). I am not sure that it is a good representation of the full "backwards in time" situation. Simple intuition is not enough here. For example, when time turns back, do the charge of electron / proton change?

This comment of yours goes against what I thought I knew. I am not sure you are right. I am not sure I am right either. Have to think about. Do you have any more information, any reference?

The reversal of Newton's second law shows that intensity is the same. It says nothing about direction i.e. attractive or repulsive. Merged post follows: Consecutive posts mergedAt time 1, the apple is on the tree. At time 2, it falls down to earth (and not upon Isaac's head) Attraction between the apple and the Earth. reverse: At time 1, the apple is on the ground. at time 2, the apple is ejected upon the tree. Repulsion between the apple and the Earth. Now, I never thought about associating a repulsive force and an orbit. Quite interesting comment. Have to think about it.

This is a question I could not get a clear answer yet. When you theoretically turn time backwards, the attractive force of gravitation becomes repulsive. (I hope it is evident) What happen to the 2 other interactions? (the electroweak & the strong).

Sorry That was not intended to frustrate the english language. But you must know that articles in Wiki are not translated from one language to another. Each language has its own article. usually, english Wiki is the best. Articles are more developped and more readible. The sentence from english Wiki is " When a Foucault pendulum is suspended on the equator, the plane of oscillation remains fixed relative to Earth." You are right. i will be more carefull in the future.

That's what I used to believe too. but , after some thinking, it must be somehow different. The right answer is contained in "Draw light cones originating of the points A,...., G. See what cones contain the origin." Speed Of Light © is constant. It is the corner-stone of Relativity. That means that Light cannot travel faster than C, but cannot travel slower than C either (of course we are speaking about SOL through empty space). It follows that if you draw a ray of light from point D, this line will have the same slope (or angle C in the diagram), and will not intersect with the observator. Point D cannot be observed. In other words, the observator's light-cone is empty. Only points (events) upon the surface of the light-cone are observable. insane_alien wrote "B and F are on the very edge of observability". No, B and F are observable, simply. Or yes, then all observable objects are on the edge of observability. I think this simple observation has some importance on the way we represent the observable universe, on the way we use to represent what we call "reality". I'll try to explain it in some other thread, maybe. But for the moment, just go back and have a look at the diagram again. Say that points A,B...F are galaxies in the universe, and we can only see some of them. The others are hidden from our sight. And also, make attention to point D. It represents our own past, and point D is not observable. This simple diagram explains why we canot see our own past. Reduce the scale of the diagram, and say that points A,B,..etc are events a few milliseconds ago. Still, you cannot observe yourself as he was a few milliseconds ago. But you friend next to you can. Any objection welcome. Merged post follows: Consecutive posts mergedWhat is that for a forum ? Is there anybody ? With any sense ? Anyway..... Here is another space-time diagram: the Expanding Universe as commonly represented (the basic image comes from the Web). It is a space-time diagram, like the first one i presented, rotaded 90 degrees clockwise. Past is on the left, Future on the right, Present is where the WMAP sattelite is represented. the yellow lines (added by me) represent the light-cone. Each elliptic slice represents a circle surface: Space (or 3D space reduced in 2D surface) at a certain time in Universe's history. Same question: which of points A,B,C, X are observable? Merged post follows: Consecutive posts mergedThis thread ressembles more a presentation than a discussion. I am sorry for that. ........ Point A is invisible. It is a point standing at present time at a distance of a few billions light-years from us. Point B is invisible. Point X is invisible too. X is an event at the place of space where we stand, but a few billions years ago. We cannot see it. only point C is visible. Now look at the following diagram: Merged post follows: Consecutive posts mergedFor those it may concern, this is not a regular representation anymore. following our beliefs (sorry, our knowledge), the light-cone is only a naive representation. Accounting space expansion, the light-cone becomes curved, something like the diagram here below, where the light-cone is represented by the blue lines: Is there anybody? ............ ............ Continuing. Merged post follows: Consecutive posts mergedLet's suppose that we know nothing about the Expanding Space Theory, and examine only what we are observing from scratch. Indeed, what are we observing? We are observing something like the diagram below: All observable events lie in the Earth's past light-cone. The observable universe is collated upon the surface of the (naive) light-cone. The light-cone is empty. Emptyness also outside the light-cone. The slope of the light-cone (the angle with the horizontal) represents C, the Speed Of Light. The farest observable events (galaxies) lie at about 13.7 billions light-years from us. We are measuring galaxies receding from us. The receding speed is represented as an angle with the horizontal. These are the red lines on the graph. As much we look far away, as much receding speed increases.It is Hubble's Law. THAT is what we are actually observing. Merged post follows: Consecutive posts mergedFor those who are not familiar with those diagrams, maybe a 2D projection is more comprehensible, in order to make clear that all the above is not speculation, only interpretation of what mainstream science (do not) presents.

O.K. for your last post. Digestion will take time for the rest. I think you have to make a search in another direction, in reality, the same direction: try to prove that the notion of mass (rest mass) is time dependent. I do not use the term "frame dependent", because we know that rest mass is not frame dependent. When we accept, as posed in wikipedia, that "For a system of particles going off in different directions, the invariant mass of the system is the analog of the rest mass, and is the same for all observers", we are speaking of observers in the same time (the present), observers in the past & observers in the future, traveling smoothly in Time. Time is considered as invariable. Let's suppose it is not: maybe you will see negative mass rise from the equations. Merged post follows: Consecutive posts mergedBack to the topic. Icarus wrote:"II-2. Negative mass cannot form the structure greater than atom." What makes you think that?