michel123456

Yes. Thick lines. We have 3 possibilities: A. Lines If you give thickness to the lines, it corresponds to Iggy's point of vue. That means there is mass in the past. At each infinitely small slice of time corresponds a quantity of matter. A huuuuuge quantity of matter from which we can observe directly only a little slice. That small little quantity is the one used in all equations of physics. The rest is ignored. B. moving dots#1 If you don't give thickness to the lines, but give thickness to the dot, it is Spyman's (I guess) point of vue. There is no mass in the past: what we are observing is accurately what it is. Point. C. moving dots#2 The moving dot interpretation is exactly the same as motion in space: when mass leaves a coordinates for another, the new coordinate is occupied, the old one is empty. Empty means that leaves place for another (hypothetical) mass. Which in this case is not observable. So that there is full room in spacetime for unobservable hypothetical mass. Not allowed in the Line concept, because in the line concept the coordinate is already occupied. To speak frankly, the line concept looks to me outrageously wrong. I cannot understand how mass magicaly duplicates at each infinitely small frame of time. It looks to me like creation of energy from nowhere, just due to the flow of time. Totally unacceptable.

No. Just get rid of religion at school. BTW are you an academic?

Again. Where is the mass? I made an attempt some posts ago:

I think in this matter, the key word is tolerance. It is absolutely impossible IMO to make everybody believe the same thing. It is a wrong and devastating goal. Moral codes have the purpose to make people live together. So, why can't we live together? Each one with his own belief, peacefully. After all "Death is vigilant enough, she needs no one to help her take the scythe"* *poor traduction from the words of G.Brassens from the song "Dying for ideas" Untranslatable....

Iggy, you have drawned the fish.* *french slang. You have put too much (correct) information. You wrote I suppose it is thus not a big deal to draw mass upon your spacetime diagram. Can you do that? ------------------------------------- From the site you provided, I see the moving dot, don't you see it? Maybe it is still confusing, because the past trajectory of the dot is showed as a bold line (a LINE you will say, I hear your voice from the other side of the Atlantic Ocean, or is it coming from East?) And here are 2 moving dots Here there is no bold line for the past. from http://casa.colorado.edu/~ajsh/sr/simultaneous.html P.S., don't forget my question. Thanks Merged post follows: Consecutive posts merged Shame on you.

How reliable is that Journalofcosmology ?

It is the idea of the "click", based on comic strip of Milo Manara. I will not put the link because in the story the thing has been implanted in a woman's brain (not a dangerous terrorist) and its all about erotica. Morality is screwed by all means.

Hm. So when we estimate the mass of an object (the quantity of matter), are we estimating the amount of matter distributed along the black line ?

Sorry, your question combined with your avatar misleaded me.

yes. The spacetime diagram will do. Since you say that the object is a line, can you show where is the mass of object Black?

The senior can split the money equally between 4 people (the ones he likes), and nothing (zero) to the three last ones. He would have gathered 4 votes against three, and win. Quite unfair, but 250.000 in his pocket. At least, no one is fired.

Icarus, don't forget this part of the lecture is called by Dr. Guth "Miracle Of Physics"... Gravitational repulsion is "Miracle #1" Negative energy of gravitational field is "Miracle #2"

Iggy. We have touched a sensible point. As you proposed, lets go right from the beginning. You have posted the following diagram: Could you please make another such diagram, representing the same situation adding time only in the graphic (without motion). Thanks.

there is a mention on this point in Dr Allan Guth's lecture at MIT

That is what I mean (BTW I don't understand what is the meaning of "time B" .There is only one time. The labelling on the time axis must correspond to the elapsing time as mentioned above, only ~2,5 sec have elapsed (following the labelling), not 5 sec. The diagram is presented in slow motion but that is not so important. The result is great) (editing) My feeling is that books are unable to present animated gif, that's the reason why you will find your static diagram in 100% of litterature. Basically, both diagrams represent the same thing. The gif is closer to reality IMO. (end of edit) Yes. I agree that different reference frames have a different hypersurface of their present. I don't understand this part.

Excellent Spyman. Iggy, your turn.

Our ouroborous friend wants to talk about 108 http://en.wikipedia.org/wiki/108_(number) 108 is also the next Peugeot model. And my trousers don't fall due to the miraculous power of a belt exactly 108 cm long.

Lets slightly disagree on this:-). We are constantly interacting with past event. The entire observable universe is made of past events. What you mean is that we (today on Earth) cannot affect Neil Armstrong walking on the Moon, when you say "I can't affect Neil Armstrong walking on the moon." But another star far away is interacting with N.A. walking on the Moon. A star we can see today. We cannot interact with N.A. because, as you said, "(...)an event inside our past light cone then, no, it may not be directly observable." Speaking for events. You believe that: I am messing events with objects. I believe that: You are messing trajectories with objects. Can we, at least agree on something, which was the idea of this thread: the events placed in the inside part of the light-cone are not directly observable.

It is quite funny that after such disagreement, we agree on one thing: As for the rest In my diagram the red & black dots are different objects. And about Cleopatra, I can't say, but about Tutankhamun, he still belongs to present. You can go to Egypt tomorrow and see his body is there, not in the past only. He travelled through time. like the Earth, he cannot be duplicated in present & in the past. There is only one. I guess you agree with me on that. I could never imagine someone could represent the flow of time as a lined-object. I though it was quite an evidence that we are "moving" through time, since time is considered as "something of the same nature with space". Space & time are made of the same "stuff". The idea that we are travelling was so evident to me that I was totaly surprised with your objections at the beginning of this thread. Maybe due to surprise, I am still unconvinced. It is difficult for me to accept that an object "still exist in the past". But I'll think about it again... On the other hand I agree that the "moving dot" concept is like inserting time twice: it is "motion inside time". And motion has the concept of time already in, so it must be redundant. Having no other argument to provide I will temporarily agree with the line concept. So you say and Both statements don't seem to be coherent. Explaining: if the coordinates (0,0,0,1) are taken, there you are. And there you are in the present reading this post. So I understand that there are two Iggies, one in the past at coordinates (0,0,0,1), and another one at coordinates (0,0,0,t), in your coordinate system.

I don't think it is the right meaning of Swaha's intervention. You must see the human race as a whole, not as individuals. If you consider yourself part of the living beings, you may notice that your body is made of elements of your parents, and of elements of your surroundings. Without that, you are either not born, or dying. You will pass some of those elements to your childs, they will look frightently like you, they will be "you" (horror), and life will continue. By this process, you are in a sense, immortal. The problem is your "soul" is not transmitable.

It means that Genesis is the story of a tribe, not the story of human kind. If it were, where are our black and chinese brothers, american natives and others. Strontidog wrote Here is the answer: God created man in his own image.- ...........................................-After, man evoluted. God, we don't know. From the fabulous belgian Philippe Geluck.

Excellent. ------------------------ I have to read it several times more, but I think your model don't need the Big Bang anymore. The scaling factor is a totally different concept.

That was a very interesting discussion. I have to admit Iggy has strong arguments. Now I am more balanced than ever. But: _ I don't know if it is correct to use a spacetime diagram in such a way Iggy presented it. A spacetime diagram is relative to the observer, it is not an absolute representation. If cleopatra were to make her spacetime diagram, it would not be different from ours, the event "sun" would be at the same position on her diagram, and for her the sun would be travelling through time with her, as it is for us. Does that mean that the sun actually "exist" in the past, that's the question, IMO still unanswered. Nowadays, Iggy made a point and his diagram is clear enough to make me think again (& again). _ Nowhere in the links provided by Iggy there is the sentence "an object is a line". All I read can be interpretated as a trajectory as well. I don't think the concept of trajectory can be confused with the object itself. _you could resume simply the question by a simple statement: the trajectory of an object through time IS (or IS NOT) the object. _at least, the first question of this thread has been answered several times. Can we see it? the answer is: NO. ----------------------------------------- ----------------------------------------- Iggy your last diagram was tricky. You have inserted half of your argumentation into mine to prove I am wrong. Explaining: In the moving dot interpretation, there is only ONE dot moving through time. There is no other dot behind with Cleopatra. The second and third dots are part of your interpretation as still "existing in the past". In the moving dot interpretation, we cannot observe if there is a second hypothetical dot behind us, and if there is such a thing, it is not the Earth but something else.