imatfaal

Liquid nitrogen is cheap. In a vacuum the top speed is pretty much unlimited until you start getting relativistic and I do not want to be on the same continent as a 25kg slug travelling at relativistic speeds wrto the earth. But you are right the OP needs to provide far more info or maybe search the net for some of the presently operating rail guns etc (the US Navy has a doozy that was featured here a year or so ago) BTW Railguns - tbomk - are not simple linear accelerators and rely on the slug forming an electrical contact with both rails, the (huge) current flowing in this circuit causes magnetic fields, and with currents flowing in magnetic field you get force

Agree - cloud chambers are excellent. Basic electronics kits are very useful for learning stuff you will reuse for the rest of your life - both in academic pursuits and at home/work. At your age I had a deep distrust of other people's results and just didn't believe canonical experiments - one summer project was redoing Young's work on materials; when I related this to a teacher he commented that next year I should look at the rest of his work and do the double slits experiment so I did. This was quantitative work in which I found it more important to get consistent data than discover or prove anything. So many of the experiments we did in class were frankly rubbish - they were poorly thought out and even worse in the execution; so a bit of discipline and trying to achieve a good data set was a challenge and fascinating

You are assuming a certain sort of collision and other things. The deceleration is related to both the change in velocity [m/s] (which you have partially covered) and the time [s^-1]in which that change occurs giving an acceleration [m/s^-2]; this is one of the (lesser) reasons why we have crumple zones - you must lose velocity but it is safer to do so over a longer period of time and importantly with greater control. The collision could also be elastic or inelastic or anywhere in between - momentum is always conserved without an outside force - but in some collisions (perfectly elastic) all kinetic energy is conserved, in others no kinetic energy is conserved (perfectly inelastic). You have to consider vectors and scalars (at odds to recent posting in speculations) momenta (as vectors) can cancel but energy has to go somewhere. Perfectly elastic collisions will have very different accelerations (final velocities will not be zero)

! Moderator Note Clarification regarding crashing cars (at real world speeds) has been split off to allow discussion. http://www.scienceforums.net/topic/95595-actual-relative-velocities-and-real-world-scenarios/

! Moderator Note The lack of science and continual assertion of unproven / unprovable ideas is just unacceptable for the main fora. B John Jones. Whilst you will find many places in RL and on the internet that allow you to make unchallenged affirmations (many of which are clearly inspired by your faith) this is not one of them. We insist on a minimum level of debate which you are consistently failing to reach across multiple threads. Please also refrain from making any personal comments about members - especially impugning one of our most active and respected experts - I will make known here that Arete has taught me a huge amount here on this forum and I believe he is a superb communicator and educator. I am locking this thread as the argument has run down to a base level with no real input from one side.

! Moderator Note Hijack regarding the moon split off to the trash ! Moderator Note B John Jones. Such arrant nonsense is not tolerated in any of the fora - you do not get to make counter-factual assertions and spout mystical claptrap. This is doubly so as your contributions were a hijack to the OPs thread. Do not hijack threads and remember this is a science forum in which we expect argument to be grounded in evidence. Do not respond to this moderation within the thread.

! Moderator Note Thread locked - failed to comply with moderation. In essence - you need to get a grounding in science before you start asserting that bits of it are wrong.

! Moderator Note I will lock this thread unless the OP starts to listen to criticism, stops asserting made-up nonsense, and tries to work within current physics. Do not respond to this moderation

"relieved" that he wasn't shot for thanking someone? FFS - that is some screwed up value system

! Moderator Note I think we can call a halt to any more unsubstantiated and scurrilous imputations regarding Princeton and the University Press. Do not respond to this moderation.

! Moderator Note Let's keep the topic on the historical reality or not of Abraham and not stray into lex talionis etc.

Agreed. Done [mp][/mp] I would really recommend watching the discussion - great find Sunshaker

Yes. Done

Perhaps the iq bit is being able to distinguish between all the possible and unlikely to discern the most likely in the setter's eyes - just sayin; IQ tests as Empathic Quotient tests. I was a bit disappointed when given my score that the most obvious part of the webpage was an advert was for "Chakra Testing"

First question on first google response to "iq test" 1. Which one of the five is least like the other four? Dog Mouse Lion Snake Elephant That is a resounding Yes

But not maths, not philosophy either; just sloppy phrasing. Might not even work in some languages in which numbers and questions about number vary depending on what you are counting (ie containers versus foodstuff). A mathematical or philosophical problem cannot depend at root on bad phrasing and sloppy use of language

Has gravity ever be demonstrated or observed on a non-composite boson other than the photon? Or at short range? If we are wildly speculating (which this thread is) about changing relationships at the most fundamental level then that which has not be empirically verified is up for grabs

In my generation most children had leashes - although my parents called them reins (basically a mini-climbing harness with 2-3 metre straps). My Mum and Dad had 4 inquisitive boys to look after and the youngest (me) was tethered to either Mum, Dad, or a Bigger Brother. I don't know of any lasting damage to me - but then I suppose through the nature of oppression I wouldn't would I? I know that I was once pulled back up a cliff by my reins, and Jeremy the next eldest was pulled from quicksand by them - I suppose they gave my parents the ability to go to interesting places and still maintain safe control. Unfortunately children are not the best arbiters of their own safety - this is practically definitional; once you can be trusted to do the sensible thing you are no longer a child. It is great to give children freedom and they have to be allowed to make bad decisions in order to learn how to make decisions at all - but if freedom is only given at the cost of making the environment safe and hazard-free or avoiding those places which are not as such then I think the the price is too high.

We can do very sophisticated modelling on the Strong - and that goes from being attractive to repulsive at shortening distances. But in the case of the strong we have experimental data to guide our hand - in the case of pure supposition there are so many variables that any modelling has very limited value. You could maybe think of it like this; gravity is always attractive at very low distances you start getting fermionic exclusion which, for example, is manifest through degeneracy pressure in neutron stars. Are you saying that pauli exclusion is actually gravitic - or that it can be better modelled as such?

http://www.astro.ex.ac.uk/people/hatchell/rinr/candles.pdf Of Course it may be that you are getting mixed up with Cephid Variables - with them it is completely the case. Their luminosity is in a strict relationship with the period of their cycle edit - I see you have a much better link. Will read up on yours above.

Those press releases are too often written by the PRO or at least heavily edited. I will check up as I thought it could be absolute - they are all the same sort of progenitor which pop at exactly the same mass therefore the process is the same time and time again [mp][/mp] From the same source - HubbleSite - so possibly with the same error but it bears out my memory and the Press Release http://hubblesite.org/hubble_discoveries/dark_energy/de-type_ia_supernovae.php

Definitely agree - "hiccough" in my title was deliberately provocative. The more we learn, the greater the quantity of data, and the deeper our understand of those data then the closer to a good solution. Bit more commentary - still not found the meat tho http://www.theregister.co.uk/2016/06/02/universe_expanding_faster/ And because you cannot have enough photographs/images/illustrations from Nasa/Hubble http://hubblesite.org/newscenter/archive/releases/2016/17/image/b/ Got it http://hubblesite.org/pubinfo/pdf/2016/17/pdf.pdf BTW - Perlmutter's, Schmidt's and Reiss's lectures at the Nobel Prizegiving are worthy of a good watch. http://www.nobelprize.org/nobel_prizes/physics/laureates/2011/ this was for the initial accelerated expansion.

http://hubblesite.org/newscenter/archive/releases/2016/17/text/ https://www.theguardian.com/science/2016/jun/03/universe-is-expanding-up-to-9-faster-than-we-thought-say-scientists On the Search for more details. ! Moderator Note BTW this thread is for discussing the NEWS - if you want to query the underlying theory or question accelerated expansion then the main forum is where to ask questions and the speculations forum is the place to pose alternatives.

! Moderator Note Mike Stick to the OP or the thread gets locked. You have been told this too many times to count - this is not your blog and not a fitting place for a rambling exposition of whatever comes into your head. Keep the thread focussed on a single topic or it gets closed down. Do not respond to this moderation.

As a guess I would say no - not quite. KE is not necessarily lost energy; KE would be lost when for instance two particle collide and scatter off each other, this causes a rapid change of direction - a deceleration, charged particles under deceleration give of a special and fascinating form of radiation called bremsstrahlung. The photons of bremsstrahlung will be well under the energy needed to continue creating pairs - and in effect remove energy from the creation/annihilation system https://en.wikipedia.org/wiki/Bremsstrahlung