geordief

Is there a formula for the relative speed of two objects which takes into account their mass and so tends to c as mass decreases to zero in the limit? I mean ,from a standing start. If we have two objects and ,just using the energetic resources internally available use these resources to accelerate apart is there such a formula which gives their relative velocity (in a vacuum of course) and has their masses as a variable in the equation?

I may have been told this before ,but you are clearly saying that c is not just the speed of light. Would you remind me again what c is derived from? (not from the Maxwell equations surely since light is just a form of electromagnetic radiation.. and those equations ,if I am right give a figure for the speed of em radiation.)

How would one calculate the momentum of a particular quantity of light if one is not using the formula involving mass and velocity? (not being argumentative ,I genuinely have not studied this)

Yes ,that is interesting. The inter brain communication which in normally ** mediated by the vocal/motor output of one brain and the sensory input (plus "integration" )of the second brain is replicated in a very rudimentary way by signals moving across an internet connection. I don't know if anyone was supposing that this signal was able to reach its destination without great degradation (allowing only for snippets to be picked out seemingly ) but that potential achievement ,whilst extremely sexy may be an entirely unreasonable prospect at any time in the future (it might indeed herald an era of "thought control" or "mind fusion" ) ** ie everyday routine communication such as two people talking about the weather or films- anything at all,in other words.

I am fairly certain this is impossible to do. Not sure if anyone in this thread is seriously suggesting some kind of a direct feedback mechanism. If they are I would very much like that idea to be backed up somehow. . I am not even sure if it is theoretically possible at some time in the future. It would imply that the brain was able to treat a brainwave pattern as an external stimulus that was immediately (re-?) incorporated as a thought or mentation. Bio-feedback works by the subject attempting to "move" his or her brainwave patterns in real time but I feel this has zero connection to what seems to have been brought up earlier in the thread.# Aside from that , I am not quite sure what this research actually has . It could be a powerful tool ,but quite what for I don't know.

I was going to suggest that he only felt right in Spring (so it was Stravinski,then ?)

Does he anything like this fella? http://serincini.blogspot.ie/2015/06/iosis-totes-igor-squirrel.html

W What was the incident you remembered? Here is one I dug up quite easily but I don't think it is the same one. http://www.dailystar.co.uk/news/latest-news/637595/Brittany-Carter-male-taxi-driver-raped-ohio-jailed From the article the police was reported to have been mystified as to why she performed fellatio on the taxi driver as he was being held at knifepoint by her male accomplice.

So ,if a male mentally dominates a woman with a view to sexual intercourse that can be called rape? Is buying presents or meals a tool of the rapist? Flattery too?

Does "charity begin at home"? First be kind to yourself and ,on that basis your treatment of others will be similarly characterized. This behaviour may propagate in widening circles of "influence" ,passing through friends,colleagues ,family etc ,extending to other creatures at the end of the road.(even objects). Like all rules this would exist to be broken and adapted to circumstance.

I wonder how useful this website is? It is supposed to be a UK spellchecker .I haven't used it. http://www.spellcheck.net/english_united_kingdom_spell_checker.html Seems to prefer magnetise....

Yes pedantry will certainly be required if we are ever to establish a firm footing in P Centauri

The Plasma drive only does 100,00 mph (kph? ) according to that programme. So only about 5 times faster than present day speeds. Here is something I found (that I cannot vouch for) They are discussing the Plasma Drive. https://www.universetoday.com/15403/how-long-would-it-take-to-travel-to-the-nearest-star/ "But adjusted for a one-way journey to Proxima Centauri, a nuclear rocket would still take centuries to accelerate to the point where it was flying a fraction of the speed of light. It would then require several decades of travel time, followed by many more centuries of deceleration before reaching it destination. All told, were still talking about 1000 yearsbefore it reaches its destination. Good for interplanetary missions, not so good for interstellar ones."

Yes I wan't sure of the name of the star (but I think we all know that I was referring to our nearest star that may have a planet around it in the Goldilocks zone) Arriving at P Centauri in any acceptable(?) timeframe will require relativistic speeds imo and how can such a craft be decelerated in order in make a landing? Any idea at all? The plasma drive would take an absurd 20,000 years (as I recall ) and so the question of deceleration/landing does not even arise.

If lifeboats ever became remotely feasible the danger might perhaps that they will only be for a few and policies might be followed which effectively set the Earth adrift as the motivation for making the hard choices on "terra firma" would be undermined. But I cannot see "lifeboats" ever becoming realistic (in a relevant timeframe) and I think if we do not manage our shrinking world we may all go down with the ship one way or the other. That discussion reminds me of the so called technological fixes to climate change that supposedly allow us to pollute the planet and emerge consequence free.

I have just been watching a documentary on BBC2 "The Search for a New Earth" http://www.tvguide.co.uk/detail/2790044/131126240/the-search-for-a-new-earth about the possibilities of sending a manned mission to Alpha Centauri ( can I say "don't laugh" ?) Along with Hawkin's warnings that many of us are no doubt familiar (in my case sympathetically so) with, the subjects of possible suitable destinations and methods of transport were addressed. I was left dissatisfied since ,although it appears technically possible to cut the time of journey to Alpha Centauri and its posited Goldolocks zone planet (all 4 light years distant from Earth) by means of ground based laser propulsion the crucial question of how to land on a planet was not addressed. If a theoretical manned craft can be sent to the neighbourhood of Alpha Centaur by accelerating it to relativistic speeds (10-20% of the speed of light by the looks of it) how can this craft be decelerated? A fly past is of no use whatsoever (not a problem for a fleet of mini craft equipped with sensing tools but useless for a manned expedition) I cannot see the point of a programme like this that does not address this point. And I cannot really see the point of even discussing this putative manned mission /colonization of Alpha Centauri unless there is consideration given to this (it seems to me) intractable problem. Has anyone a clue as to how any craft can be decelerated from such high speeds? Are there any possible methods?

I was happy with the "all the universe applying force to a neutrino" as a kind of limit. It means there is a limit of some kind (I wonder if the expansion/evolution of the Universe means that the force available to cause an acceleration in a part of it implies an increase in the force available or whether the greater distances involved mean that more work is required for this hypothetical task)

Feels like you answered the question. It also feels as if "infinity"as a word should be extirpated from the English dictionary if it was practical. It seems to be an entirely negative concept (dreamt up by some foreigner no doubt) It seems like shorthand for a process rather than an actual thing in its own right. And the force available to a finite system is also finite.....

Yes Gabriel's Horn does seem to show an infinite quantity enclosing a finite quantity.I think in my scenario the boundary is expanding infinitely and enclosing a finite (4D?) volume. At T^-42 SECONDS the Universe was inflating or expanding (I think). Was it finite or infinite then (is that a valid question?) If it was finite then (or perhaps just a finite times greater than earlier) how is that moment in the development of the Universe any different to say T^ +100 seconds? Can it be expanding infinitely but finitely measurable at any "instant" (I think "instant" must be a loose term)

But for a given mass the available force (sourced from within the system) would be finite and a function perhaps of the mass of the system. So would there be a limit then? Can the Universe be bounded but infinite? (is there such a thing as a dynamic boundary that might apply? )

(posted in this subforum as I couldn't see where else it might fit) I have searched around on the net and see that this is a question that has been asked often before and the answer is invariably that ; "no,there is no theoretical limit to the rate of acceleration that can be achieved." (not real quotes) If we take a unit mass (is there such a thing? If not can we set mass at a randomly chosen constant ?) can we say that this mass is then subject to a maximum rate of acceleration? Since I imagine that mass may be a term that applies to a system rather than any one particular object then I guess I am asking whether a given system with a given mass contains within it a maximum rate of acceleration. Could I also ask (possibly for the second time ) if there is a theoretical mass of the whole universe? (does this mass tend to zero in a "heat death" scenario? )

Sure,by "everywhere" I just meant everywhere in our Universe at that time of development. If multiverses ever become a testable theory then I might have to rephrase the question.....

I keep hearing that the "Big Bang" happened everywhere and was not an explosion but an inflation or expansion. Well ,it is not claimed that the Big Bang Theory accounts for the 10^43 second prior to its applicability . If the "Big Bang" happened "everywhere" does this not imply that at 10^43 seconds "everything" was in the same place? Does this not also imply that the "volume" of everything at that time had zero extent? (no top or bottom or left or right) If there was "extent" then would not some areas of the observable Universe differ from other areas in that they originated from different areas of the Big Bang ? Or was the "extent" small enough to make these differences zero? Second question about the "non explosion"...Is this explained by the fact that explosions need an external containment of some kind and this is not part of the BB Theory?

They are different expressions.I can imagine circumstances where "where it's at" might be appropriate (if "it" referred to a point on a journey for example)

:Mummy, for why did you put that book the which I was going to be read to out of up for? If "where it's at" is dated ,could it be a Dylanologism? (it comes in "Like a Rolling Stone" )