timo

... especially since the complex answer seems pretty non-saying and is just a collection of keywords. Feel free to elaborate on that, I am sure some people might be interested in an answer beyond "yes".

a) The same time as if it was simply dropped from 1.5 m (note : It might be worthwhile trying to understand why). b) you get that from the time and the horizontal velocity which you can probably assume as constant.

In case the question was meant the other way round: Light not also follows the curvature of space, it also contributes to spacetime-curvature.

Since you were already asking for a reply somewhere else: I wouldn´t have time to go through your post anyways, but if I had, I´d first ask you to make a bit clearer what this is all about. I have the tendency to read the introductionary sentences and then the last sentences first to get an idea of what I have to expect and what the post is all about. However, neither your introductionary sentence which sais "this is a spacetime diagram according to some book you don´t own" nor your last sentence saying "this is consitent with the note 1 above" gives me a hint on what your point is. In short: Perhaps write a short three or four sententence comment on what it´s all about, what you want to tell us (or ask us, I don´t even know that). While making physics claims without any math to back it up might be unprofessional, just throwing out a few calculations without saying what they are supposed to show is confusing.

I have a suspicion who this might have been. You´re not a misbehaved 14 year-old, by chance?

I see a bit of redundancy here. Are these "not pay attention for three days" supposed to be within the three days the user is banned or as an additional three days thereafter? I agree with what you said but I probably don´t agree with what you meant. Not only has the ppd gone down but imho more importantly the scientific content has gone down. And imho the bad habits causing this might be a lazyness not to get involved into scientific discussions. A few reasons for this that might come to my mind (but it´s not that I actively observed it, so take it as an assumption not as an impression or observation) are: - Swaying away user questions with "look it up on google" or "take a look at this wikipedia link". - Ignoring threads that might force you to use your brain. - Staying quiet because someone might know better and show you wrong. - Ignoring replies you don´t understand instead of asking how they were meant or perhaps even thinking about them and ignoring demands to try being a little more precise with what was actually meant in the OP. Even though you´ve switched your user title to resident expert, last time I checked it actually was physics expert. So how about taking a look at this thread http://www.scienceforums.net/showthread.php?t=22846 , trying to figure out what Rajama meant (that´s where the "need to use your brain"-constraint comes in - I openly admit that I was too lazy to do it) and try making a useful discussion out of it? I personally see your energy invested much better there than in threads like this which just fuel unnecessary thoughts on how much was meant as fun, what was meant serious or what you´re trying to achieve here (my suggestion is that you want to live up the place at bit, hence my suggestion on how you could do that a better way).

I nominate Dave in the category "worst chosen thread topic september". Perhaps you have a good spam filter but many people automatically ignore/delete messages titled "Extremely important information".

And not on the quantity, either

You are experimenting with drugs on a 14 year-old ? What would you do with the information above? Imho, the much more important information is: Where do you live? Availability and structure of social, psychic and psychiatric counseling probably varies over the world and maybe even within a country. And the only useful advice I can imagine coming out of this thread would be something like"go to X, you´ll find the adress on www.xyz.ab".

Because both states actively worked on it (http://en.wikipedia.org/wiki/Franco-German_cooperation and http://en.wikipedia.org/wiki/French-German_enmity , in case you want to read up on it), that´s what Iraq and Iran seem to try atm. The delicate democracy of germany did not collapse (ok, the social situation was a bit more stable, admittedly) and I suppose the approach of western germany and france was seen as to make things dangerous to the sowjet block - history showed that we got out of the trouble pretty well. I am aware that one can always see as much or little similarities as one wants (means: Exactly that much or little that supports your position) when making historical comparisons, but spontaneously I found the Germany-France example quite fitting. Also, it´s boring if everyone just presents the "evil arabs try to rule the world"-view.

That would make perfect sense. I suppose the US wants to minimize iranian influence in north america, too. Allow me to see the approach of Iran and Iraq from a non-US standpoint (hey, my nickname already stands for blasphemy, what do you expect ): We have two nations which have had not-so-good relations in the past. Now, a major reason for these not-so-good relations is gone, namely the former leader of the Iraq. I think it is good to see that neighbouring countries which share a bloody not-so-distant history (ok, chemical weapons probably aren´t overly bloody) can approach each other by saying "oh, that was just because of that evil dictator - in reality we are good friends" and maybe develop a sort of partnership. Such things already happened in the past: Take Germany and France. EDIT: While in the OP it doesn´t really become clear (in fact the article tells me next to nothing), the german press (http://www.spiegel.de) actually goes as far as to title "Iran and Iraq approach each other" and claim that both countries pretty much agreed on working together - examples of building a pipeline and making agreements on trade, energy and traffic are given.

Are you already familiar with programming or even object-oriented programming or are you completely new to that stuff ? EDIT: I misunderstood your first question, I think. I use NetBeans for Java stuff. It´s pretty much an all-inclusive solution but I don´t like it that much that I´d recommend it.

Not sure if it is the answer you were looking for: But if you add some kinetic energy to a massive object' date=' it will move faster as a result. However, its velocity will always be <c no matter how much kinetic energy it has. If you look at the velocity of a massless object as a function of the kinetic energy, the velocity will always equal c, regardless of the kinetic energy. Light particles (photons) are massless. The reason why light travels at c is not that there´s something special about light and electromagnetism but simply that photons are massless (admittedly you might see that as being something special, but I hope you see my point here).

Perhaps you should ask Severian if you can use one of his old avatars, then (cow-art) ...

Why are you repeatedly calling the question off-topic? If Newtonian gravity predicted a stable state while GR doesn´t, then that answers MacSwell's 2nd question quite easily with a "no".

On SFN. Otherwise, all pages must drop in rank which isn´t possible. I was not completely serious, though. I doubt that the google pageranking is that good that it sees the keyword "science" and correctly tracks the amount of scientific content. The decreasing scientific traffic also is just my impression but I´ve also heard others saying so. EDIT: But perhaps the number of new posts has decreased overall? I think someone had an eye on the postcount, let´s see if I can find some information ... EDIT2: I found an old post by Martin where he counted the posts from mid-march to beginning of april. He counted an average of 292 posts per day over a period of 25 days. Luckily, he also gave the total number of posts on April, 4th. From April 4th to today, we had an average of 237 posts per day. Since my feeling of declining postnumbers is newer than April, I suppose that we are currently below that 237.

Perhaps google correctly realizes that the amount of new scientific content has tremendously dropped within the last months?

I do not really understand the question because I don´t know what the "momentum of the expansion" is supposed to be. More precisely: I can well imagine what you thought when formulating the question but I do have some doubts that one can properly define something like a momentum of the expansion. I think a mixture of Sisyphus' and Spyman's reply might be a good answer: In cosmology, all matter is supposed to be uniformly distributed and at rest. There is no movement. That´s a point where the good-old rubber-sheet analogon can trick you because seen from the outside, the points on the rubber-sheet seem to move - you are tricked because this analogon only becomes a good visualization if you watch it from outside the rubber-sheet. But usually, an "outside of the universe" point of view is not considered. I don´t know it but I am inclined to say "no". Suppose that the universe has an infinite space-extension, completely uniformly distributed matter and sufficient energy density to recollapse. The infinite extension together with the uniform mass distribution will (in Newtonian gravity) make the whole thing stable -> no collapse.

There´s also the inofficial translation to english: ... the most pedantic one ... Experts have a special subforum where they can whine about people posting crap until a moderator finally can´t stand the whining anymore and reacts. ... will bombard you with arxiv links if they don´t have a clue themselves. Anyone who likes to have a few beer but cannot take as much as Dave. The old recruitment method of simply clubbing down people has been abandoned as only Martin was sufficiently naive to fall for the "hey, come to that dark sidestreet, there´s something interesting I want to show you"-trick. Anyone who even asks for having a blue star tatooed on his forehead must be completely nuts. Rember that WE are the bosses in here (signed: The admins and mods). Help me win the free battlecruiser!

We are making Bradbury´s vision come true and create a world in which no one ever reads a book or thinks for himself but insteads sits at home all the day chatting with people they call friends or family over an interactive medium. Wonder if that will happen in my lifetime ...