michel123456

_I was not aware of the Sagnac effect. Quite interesting BTW that the effect was interpretated by Sagnac as a proval for the existence of the luminiferous aether. (conclusion in which I disagree completely but that is another subject) _Obviously, the difference between "constant" and "absolute" is not clear. Vuquta understands, because he talked about the ballistic theory, and I thank him a lot for that. I am really happy when i learn something. _"constant" means the measurement is the same. The same as a horizon. If you stand at rest at sea level the horizon on Earth is at about 11km from you. If you walk toward the horizon, it is still at 11 km. If you take your car or a train, the measurement is the same. And it will be the same for all the observators around the globe (at sea level, it is only an analogy). The distance from the observator to the horizon is something that the observator carries with him, it depends from the observator (its height) in relation with the curvature of the globe. Physically, and astronomically, the distance 11km means nothing. In this case it is not an absolute, it is just a constant. _"absolute" would mean the horizon for each observator is at 11km. When the observator takes a car to get to the horizon , the speed of the car influences space, which expands, and the car will never reach the horizon. And of course, it is impossible to get to the horizon. In this last case, 11km is an absolute of the universe and means something very important both physically ans astronomically. That was only a silly analogy. Meaning to explain the difference between "constant" & "absolute".

Master Benjamin has humor. First, he should learn about communicating vessels http://en.wikipedia.org/wiki/Communicating_vessels (since Benjamin is french-speaking and there is no wiki page in french for this article he can go to http://www.ac-grenoble.fr/stendhal/francais/travaux/phys9899/18vases.htm). Maybe he has to really build his mechanism to see that water won't flow, and that turbines in point 12 will stand still. Secondly, he uses living elements to extract energy from his system. In practice, things may go like that because you are using energy from the sun which is external to your system. And not exactly, because plants and fish are not nourishing themselves from pure clear water, but from other elements you have to put into the water. If he likes thinking that way, he could get more energy from a cow without making his mechanism at all. Merged post follows: Consecutive posts mergedBenjamin, don't be frustrated if your thread has moved to the "speculations" entity. I didn't do that, someone else did, because from a physical point of vue, it it has been demonstrated that perpetual motion is not working. But from an engineering point of vue, it is an exercise as another, since you can use other available free energy sources, like the sun, the wind, tides,etc. I don't know how old you are, but I think you have good engineering potential. In order to exploit this potential, you have, between many other disciplines, to learn physics.

Hum, I agree. When a chef coq tries making mayonnaise sauce, his goal is to make something coherent. When the ingredients agglomerate, the sauce is a failure. The whole universe may be a failure after all, who knows? We are so used to consider our universe admirable because we are part of it and we are admirable. Maybe we should take a step back and look at things more objectively. On the other hand, the current model of the universe presents a single creation. The entire universe is a single entity that was created at a single moment in time. I am not sure this is correct. I think your ideas should be suitable for a multiple creation model, in which "creation" does not happen once but many times and in many places. Of course in this case the concept "creation" loses some of its strength, but if it is compatible with observation, why not.

Interesting. The question arises from the fact that we are observing BH very very far from us, in the very early universe. At first sight it is curious, because for creating a BH, you need sufficient time. You don't have enough time in the early universe. There are 4 possibilities: 1. we are interpreting in a wrong sense the data.We have to redo our maths. 2. the BH are created very quickly. We have to redo our maths. 3. the BH are inherent structural elements of the universe, they have been there all the time. We have to redo our maths. 4. the BH are not created quickly. What we are observing so far from us is not the very early universe. Paradoxally, we don't have to redo our maths.

Inertial Frame Of Reference

AJB, there is no doubt Relativity is correct. As it seems I am the one who has misinterpretated Relativity. Back. If I understand well what you are all saying here, C is a constant for each IFOR, and that's all. C is not a constant of the Universe (an absolute, I have no other word to express the concept, banana is not suitable).

My point is those analogies do not help. People who are enough interested in the BBT are not dumb. They may be ignorant or uneducated, but most of them can use their brain. Don't be surprised if your explanation is not always well received when using such analogies. It is much better without analogies at all. For example, you said Good. And enough to be understandable, you are talking about gravity. Because if you haid to choose an analogy to " an attractive force (...) that diminishes with distance.", be my guest. What would you choose? An elastic rubber band attached between the ants? No, the force is augmenting with distance. What analogy would you choose?

Whatever is well conceived is clearly said and the words to say it flow with ease.(Ce qui se conçoit bien s'énonce clairement et les mots pour le dire viennent aisément.) Boileau (1636-1711) Merged post follows: Consecutive posts merged If it is a trap, yes, I am trapped.

I used to be a supporter of the BBT. Now I fell into serious doubts. I have no other theory to propose, so I am just asking. For example: about the balloon analogy. 1.Most of balloons analogies don't use ants. They say: draw some spots upon the balloon, inflate the balloon and see how the spots are getting away from each other. _problem: the spots are growing exactly as the balloon does. It is a wonderful analogy to explain the scale factor, because everything grows, but not good for the BBT . Basically it is not a problem to me since I could accept easily that I am part of the expansion as anything else around me. But that is not the mainstream point of vue. We are not growing with the universe: we have stable dimensions. So we have to improve the analogy. 2.Instead of spots, we put ants upon the balloon. The balloon grows, the ants don't. But ants do observe their world growing (as we do), but everywhere, no matter the distance. _problem: we have been told that it is not the case. We are not observing the Earth expanding, the solar system is not expanding, the Milky Way is not expanding, even the local cluster in not expanding. Only the distance between the galaxy clusters is growing. So that to remain consitent with the analogy, the ant must be a galaxy cluster. 3.the balloon inflates. _problem: there is a center, we can draw a vector from the ant to the center. In the analogy, the inflation has a direction, that is not the case in the BBT. 4.the balloon inflates. _problem: where is the clown who inflates the balloon? A balloon does not inflate from his own resources, there is need for "deus ex machina". The raisin cake is better, no clown necessity. 5. The balloon inflates at an increasing rate (as the BBT), so the ant feels a force (an acceleration). _problem: we do not feel such a force in real world. Actually, in real world we do feel a force (gravitation) but it is assumed it has nothing to do with the subject. 6. The balloon has a surface, an inside and an outside. Nothing of such in the BBT. 7. The ant lives upon the surface of the balloon, the limit between inside and outside. Nothing of such in the BBT. We should have put the ants flying inside the balloon, but that makes the whole analogy collapse, because the inflation of the balloon has no effect at all about the flying ants. Their distance do not increase anymore and since they went out the surface they live in 3d world, not in a 2d world as presented in the analogy. So we take the raisin cake analogy, much better. Definitly IMO the balloon analogy is not good.

Oach, I was a bad guy writing this kind of comments. It was not on my agenda at first, but it became quite quickly after a few reading of the linked article. So Martin is right. I don't know if any of you can understand that this kind of article is only suitable for convincing the already convinced. The non-convinced will have in his mind similar thoughts as those I writed down (with very bad preconceptions (parti-pris) from my part as you may have notice). The BBT is not a simple theory. If you want to explain this theory to an ignorant that is not completely stupid, you encounter some problems. An origin that has no center, an expansion of something that do not exist (no aether) into nothing. No border also. A distance that is not a "real" distance (the expansion of space). Receding speed faster than light compatible with Relativity, organisation into an explosion, negative gravity, a.s.o., all maybe explainable phenomenas for well educated men, but difficult to grasp at-once from a layman. My intervention is not intended to demonstrate that the BBT is wrong or right, it is intended to show that the BBT is not easy to explain, and difficult to accept.

Bob has showed a kitchen experiment, I will do the same. This is small old video (sorry for the poor quality) of my casserole with cold water an reluctance of boiled salad (Greek speciality "horta"). Here we are: a small galaxy formation in my casserole. Stupid, isn't it? Only that here we have deceleration, instead of the observed universe which accelerates. Bad analogy or something goes wrong?

You seem to forget the human factor. _you forgot to welcome our new friend _you treat him as an ennemy before listening to his arguments (maybe he has not any, let's see) _you throwed his thread out of Science at once (we are now in the section labeled "Non-science topics that frequently come under discussion") _you are arguing as if we were still in the Science section. _you are discouraging our friend of learning science, like teachers shouting at pupils that they are too stupid & lazy to learn anything. That is not the right method IMO. _four against one is not fair. I would propose to listen. You still have the power to condamn the whole thread and throw it down to the waste basket.

Why horizon: A horizon is a kind of observational limit that anyone carries with him. Since C is a constant for each observator, c could be considered as a kind of horizon: as far as you go, at any speed, your measurement of your horizon will stay constant. In this case, c is an observational limit. The word constant is ok when considered from one IFOR. It means that the observator's speed will not influence his measurement. When the word constant is used by many observers in different IFOR, it is transformed in absolute (all observers making the same measurement) from which the sentence "nothing can travel faster than C" arises. These are different concepts IMHO.

http://www.scientificamerican.com/article.cfm?id=air-cavity-system http://www.teknologiportalen.dk/EN/Teknologi/Transportation+and+Logistics/Ships+-+Maritime+technology/070711_aircavitysystem.htm

_I don't think it has anything to do with QM. _The cup's center of gravity is decentered due to the cup's hand. The horizontal motion is exactly in the hand's opposite direction because when the cup raises, the air pressure is decentered. The second cup makes a turn before sliding, I suppose due to the lack of perfect horizontality. _funny experiment. Some ships are based on such a principle. They input the exhaust gases into a concave part of the hull (carene), creating an air layer between the water and the ship. They reduce by this way a large amount of the ship's friction. I'll see if I can find a link about this technology.

Well, IMO, that shouldn't be called an absolute. That should be called a horizon.

Guess: there is thin air layer between the cup and the table because the cup's bottom is not flat. When you put hot water into the cup, the air expands and tend to rise the cup which moves along the slippery surface (because the water from the humid cup is acting both as a sealing material and as a slippery surface).

cancelling wrong comment of mine

Bob posed 3 empty cups (mugs) upon a counter top. When he pours boiling water, the cups slide freely for about 20 cm, like skating on ice. _the counter top is not perfectly level.(as Bob stated) _there is water upon the counter top. _the cups are not dry (he just washed the cups with cold water) _one of the cup missed moving before even the boiling water was poured. _the counter top seems to be made of light laminate (like a side table top), not a regular kitchen counter top. C'est juste Vladi?

This is not a stupid theory. It is Le Sage theory. http://en.wikipedia.org/wiki/Le_Sage%27s_theory_of_gravitation Annus Domini 1748

Since AJB mentioned C, I'd like to take the opportunity of asking some question. The general accepted concept is that Speed Of Light is absolute. AJB understands there is subtility in here, it is not a simple statement. And I have to admit I am confused most of the times in its interpretation. So: _an observator A in an inertial FOR, will measure a photon traveling at speed=C _another observator B in his own inertial FOR, will measure a photon traveling at speed=C _an observator C in an inertial FOR, will measure a photon traveling at speed=C _same for observator D,E, etc. Is that what we mean when saying "C is absolute"?

As I said before, only calculations will tell. The good & more interesting question is what the guy will see looking back. He will see the Earth moving at 99,99% C. And he would assume intuitively that people on Earth are experiencing weird phenomenas such as the impossibility to speed up. Which we know is not the case. So, where is the catch? _You could assume that Relativity tells that the guy near a black hole would actually know that he is moving at speed near C, because he will experience some phenomena (the impossibility of speeding up) so that he could measure his own speed. Wrong, because his own time will change also, so that he will not experience anything weird, and not be able to measure his own speed. But in this case, there would be no impossibility for him to speed up (accelerate), as there is no impossibility for us to speed up. Which looks contrary to intuition, but not contrary to Relativity. Because the guy's new speed (after acceleration) as measured from his point of vue (FOR) would be only a fraction of C (0,00000000000000000000000........1) of C as measured from Earth. The point is that our guy would experience nothing weird due to his speed. Merged post follows: Consecutive posts mergedBut he would experience something due to the fact a BH is a gravitational well. http://en.wikipedia.org/wiki/Gravitational_well That means our guy at the BH proximity would be in a state of free fall in a huge gravitational well. Instead of walking on the Moon, where his body wheights less than on Earth due to the lower gravity on the Moon, in the BH case the human body would turn into billions & billions of tons. Knowing that the human body can stand acceleration only a few g's ("a constant 16 g for a minute, however, may be deadly. from http://en.wikipedia.org/wiki/G-force#Human_tolerance_of_g-force), I suppose our guy would be dead before reaching the BH event horizon. Or am I wrong somewhere?

It reminds that the BBT is a creationist theory introduced by a priest (Monsignor Georges Henri Joseph Édouard Lemaître ) in 1927. It is quite funny that most of atheists are supporting the BBT instead of fighting it. They haven't even figure it is a creationist theory, and if you tell them (as I do) they will refuse to listen, believing the BBT is "their" materialist theory. It is not. BBT belongs to creatonism. http://en.wikipedia.org/wiki/Georges_Lema%C3%AEtre