Sorcerer

Surely you get linear momentum as well as angular. I agree, the OP needs a better explanation, but it seems some of the posters also need better reading comprehension and also fail where the OP does. Anyway answered my question about a solar panel/sail hybrid. http://wiki.solarsails.info/index.php/IKAROS Here's how angular momentum is used for existing sail designs. http://wiki.solarsails.info/index.php/Category:Spin_Stabilized

I think the main difference is that letting go of the weights allows for rapid course changes. While you could change course by angling a traditional sail , this could only be done effectively within the solar system and take time. Why doesn't the magnetic bearing he mentioned prevent the craft from spinning? Why does it matter if the craft spins too, in fact wouldn't some kind of centrifugal artificial gravity be a good thing? Why not put a sail as well as a rotor? Kind of offtopic: could you make a solar sail from solar panels, or is a mirror most efficient. Is the only loss in efficiency equal to energy gained in electricity, sinice a mirror could be behind the panels? Seems he's a few decades late http://wiki.solarsails.info/index.php/Heliogyro

It's doubtful anyone will use this in the patents life time, so for money making purposes, no. But like all ideas it has value. It seems reasonably practical to me to, I don't see the relevance of the objections raised here. (Not that that means they might not be valid.

I'm trying to convince someone without insulting them. But damn I laughed hard at that last paragraph. They brought this up: https://www.sciencedaily.com/releases/2015/05/150527103110.htm Am I wrong in trying to explain that thoughts and perception are only given through action. And energy is needed for thought, not all thought is? I began by referencing this : http://profmattstrassler.com/articles-and-posts/particle-physics-basics/mass-energy-matter-etc/matter-and-energy-a-false-dichotomy/ But that didn't convince them

Would hawking radiation preferentially select the opposite charged particle of a pair and gradually reduce the charge of the rare case of a charged black hole to neutral? For instance a positive black hole would preferentially emit positrons and consume electrons, and vice versa. Conversely could a statistical imbalance of absorption of electrons, since each pair creation event is an independent trial, lead to rather than black hole evaporation, black hole growth and the change over time from a non charged black hole to a negative black hole? Or would the law of large numbers forbid this? Isn't there still a possibility, given that there are probably billions upon billions of black holes, that one somewhere might do this? Would the exact same effect in the initial question prevent this?

So..... is it far as in opposed to close? What's close then? That made little sense to me. Let's say the distance between the event A the gravitational wave emerges from a collision of black holes and B the same gravitational wave passes through a planet. What distance between those two events is far?

well said

Being pressed for time, I won't read the paper right now. If you know however, what distance does he mean by "far"? I'm hoping he means galactic scales, because that's exactly what I was proposing, the wave initially separates a lot of particle pairs - in this region matter is dense and the vast majority annihilate/reunite with the gravitational source, this essentially cancels out any extra gravitational effects, making gravity behave as predicted. But in the mid range/interstellar range there is a prolonged excitation/increase in mass which essentially acts as an extension of the gravitational field. At longer distances however the wave has lost some of its energy and doesn't produce any/or very little additional mass. It is the medium range increase, that could account for dark matter. Especially if we sum over all the gravitational waves in a galaxy, not just those we can observe from super massive encounters.

Well, I just blew a brain gasket visualizing the set of all sets, which contains itself ad infinitum. The set never reaches a conclusive boundary, since infinite progression would end in the creation of a set which is included in the set of all sets. WTF you mentioned a link in another thread on the topic, showing this set doesn't exist, I'll try to find it later, but maybe you could find it first? studiot : I'm actually just getting my head around sets, I glanced over this topic at high school and always considered it to be childish, I remember doing set diagrams at primary school and putting counting blocks in them, it never really seemed to be of any deeper level than that. I'm not actually going to attempt to do any kind of maths with sets and I don't see myself ever using them practically. So I don't have a collection or a want. I'm just playing with ideas and learning. Actually this other thread, maybe you could show me how to use sets here, I guess it starts with the collection of every possible concept. http://www.scienceforums.net/topic/89662-question-about-nothing/?p=905563

I'm learning a little about set theory at the moment, particularly ZFC, but I just glanced at category theory too. Set theory shows how sets are the basis for numbers, and as the basis of all sets is the empty set, this seems to me to be a very good candidate for a definition of nothing. Considering all physics used to model the universe requires math, and all math can be built from an empty set, then there is a logical progression from the empty set (nothing) to everything we have now. However this requires that we assume mathematics isn't an approximation of reality and rather that reality can be exactly described by mathematics. It also requires that there is at least one other abstract entity, some function. The concept of a set and the addition of a function make it necessary to ask whether an abstract mathematical concept is something or nothing. This is dependent on whether you define something to be only measurable and tangible substances in the universe, or you extend the definition to include abstract mathematical concepts, or even further, everything. Paradoxically, extending the definition in either of these ways means that all the things you define as something would then include the concept of nothing, since nothing itself is an abstract mathematical concept. Nothing therefore becomes something, so the logical choice would be to define something as only measurable and tangible substances in the universe (I could probably find a more concise way to say that). The prior assumption that maths and reality are one and the same also point to nothing being something. However it is possible to avoid this problem is we exclude nothing as a mathematical entity and instead only use 0. The problem arises then, how can we from processes which require the use of something come to perceive of a concept of nothing which could reasonably be assumed to be correct. Without our concept, does nothing still not exist - it seems we created it just to torture our heads. Wiki goes over some of the philosophical problems with this idea here: We'll all have an opinion I guess, I'm not totally convinced myself.

If ZFC doesn't allow a set of all sets, is there an alternative which does. I find this quite important considering if this is the leading theory on which all subsequent math is based and we use that math to model reality. It seems that since a set of all sets is a possible thing, that we must begin with a theory which can include it. If we exclude the possible or subsequent descriptions of reality may also exclude crucial prices. By removing the paradoxes in naive set theory, and introducing a restriction on the existence of a universal set, we still leave a problem, is there another step to fix this, or did we step the wrong way before?

How long would it take for the anti particle of the pair to encounter a particle and annihilate if say the pair were separated in interstellar space? If this process was repeated regularly with the same probability on each successive wave front so as to maintain VPs in the vicinity, how long after the wave passes would normality return? Why isn't the temporal redistribution of mass from the high density center of the galaxy to the edges, effectively extending the gravitational range of the most massive object able to account for DM? What fraction of DM might it contribute to? Are there any long lasting sources of gravitational waves? Would say a binary black hole system in a stable orbit, say lasting billions of years, 1 be possible and 2 generate gravitational waves at regular intervals? Is there a minimum requirement for production? Shouldn't all gravitational interactions cause waves, isn't it only the big events that are needed because detection is difficult, so we look for the biggest? Surely even the earth causes a wave, as it rolls around the distortion of space caused by the sun it too locally distorts space as it moves forward it bends space in front and the space behind snaps back to its prior shape, shouldn't each moment be sending a tiny outward ripple from this constant orbital warping outwards?

True, I guess, an ocean wave is bound by gravity, a buoyant object effected by surface tension and air resistance, so it's not a very good model. Of course a pair of balls would slip apart when caught either side of the crest, due to gravity. And of course one would be carried up the wave to the crest and the other fall into the trough, that's again surface tension and kinetic energy being greater than gravity at one point and less at another. So it's not the best analogy. Maybe a better analogy/model would be a wave travelling through a liquid kept in micro gravity. The two balls representing the particles would be of neutral buoyancy and suspended in the liquid. Various ratios of the size of the balls to the size of the wavelength and amplitude could be tested to see how the relative flattening of the wave crest (just like the earths curvature appears flat to us), would effect the frequency of separation. There would be problems in this model though when the size of the balls became too small, Brownian motion would interfere with results. I'm guessing instead of an actual experiment this could be just modeled on a computer. ____________________________________________________________ Now assuming this is possible, it lead me to a thought, could gravitational waves, near their source, while still powerful, lend their energy to the creation of enough matter that it could account for some of the missing mass/dark matter? Wouldn't doing this extend the range of gravitys influence? If gravity can lend its energy to create mass, and that mass has a gravitational distortion on space itself, rather than gravity diminishing over distance from these events approximate to the inverse square law, some of its effect is replenished. (i'm having difficulty wording this, and also I am trying not to violate the conservation of energy). OK, so as the gravitational wave begins, this is when the VP's are most likely to be separated, without knowing the formulas, just to roughly show this, lets say 1 unit of gravity is borrowed to separate the VP pair, The VP pair has gained energy and since it has it's own mass has it's own gravity, in order for there to not be a violation of conservation, 1/2 a unit of gravity is used to separate the pair and the each of the pair has 1/4 gravity each. This could be 0.1 to 0.45 and 0.45 or anything I don't know. Most of this created mass however is so close to the source of the waves that it doesn't take long for it to be reunited as the highest probability for a future path here is a common direction towards the massive object, but some does escape. So a prediction, a massive object becomes even more massive, in an anomalous way, shortly after the production of gravitational waves. As the wave moves out a bit further away from the super massive objects, where the curvature of space is less significant, more of the VP's separated can drift freely and have more possible futures. The wave produces behind itself mass, it has effectively carried mass away from the event that created it and spread it more evenly. The effect being that, without the wave the mass would be concentrated at the event and gravity weaker at a long distance, but because of the wave gravity's range of effect is stretched out a bit further. This increase in range could also be mistaken for hidden mass. This range increase could help prevent the outer edges of galaxy's from separating and remove the need for dark matter. Eventually, the wave lends more and more of its gravitational energy to the creation and separation of VP pairs, lending this energy influences the properties of the wave. As frequency reduces so does the frequency of possible events which separate VP pairs. As the amplitude decreases and the wavelength increase past a critical value the gravitational waves no longer appear steep enough (have enough energy) (the scale factor, the wave is flat) for the VP pairs to separate. Thus there is only a boosted gravitational influence over the short and medium range of the wave. At long range it just coasts on appearing to do as we predict currently. It's thought LIGO detected a wave from 1.8 billion light years away, under my assumed model, it wouldn't be surprising if this effect no longer occurs at this distance. Modelling it might tell us what kind of range we could expect. But I really am getting ahead of myself, I need someone first to clarify if this is even a possibility. I attempted some research to see if any similar ideas had been proposed, however trying to google anything with "gravitational waves" in it right now will give you a clusterf*ck of news stories, regardless of other key words. Anyway, this is as close as I got to a similar idea..... and it's really completely different. http://phys.org/news/2011-11-quantum-vacuum-dark.html

I wonder if it's a question of wavelength, gravitational waves might need to have very small wavelengths to do this. Visualizing this a large wave length would be to smooth to change anything. However on second thought if the interaction was with the wave where one VP was above the x axis (or horizontal line of symmetry) and the other just below, the two may be carried in opposite directions. It could also be the case for the crest of the wave, the other axis of symmetry. Or am I seeing that wrong? Surely place 2 floating balls tied togther by a string in a wave tank, the least likely position they'd assume is touching and the string at maximum slack no matter what their size.

I'm going to have to learn that language of logic one day. However I can refute that with words only. The set which contains every possible set contains itself and is not contained in any other set. However because it is the ultimate set doesn't mean it is defined purely on predicates, it is actually the set which is reliant on the most sets in order to form its definition. So since that's not right, how about the opposite, the empty set? Well in order for the empty set to be meaningful it is necessary to exist atleast one non empty set.

Is it possible for a gravitational wave to assist in the seperation of a virtual particle pair? Let's say our control model is of a VP produced in very flat space a long way from any strong gravitational field. In this case the 2 virtual particles quickly come in contact with their partner and annihilate. Now, what if instead during that same series of events a gravitational wave crossed that part of space, could it be timed/positioned so that space expands, pulling the particles away from each other at the crucial moment and upon the following contraction the particles no longer align, preventing their annihilation. Could successive wavelengths as they pass increase this effect? Would it be necessary for the wave to lose energy , ie transfer it to the new arrangement of the VP pair? If this occurs, and drains the wave of energy, does it impose a maximum range on gravitational waves? Is that range where the amplitude drops to 0?

From wiki: "ZFC does not assume that, for every property, there is a set of all things satisfying that property. Rather, it asserts that given any set X, any subset of X definable using first-order logic exists. The object R discussed above cannot be constructed in this fashion, and is therefore not a ZFC set. In some extensions of ZFC, objects like R are called proper classes." I was running through possible sets without subsets and started to think of sets containing only explicitly unique objects. The definition of an explicitly unique object being an object which does not share the same value of its properties with any other object. I then thought about quantifiable properties which define objects uniqueness and eliminated the explicitly unique objects with infinite quantifiable properties from the set and then again eliminated all but the set of explicitly unique objects with only 1 quantifiable property. I then specified a quantifiable property, grams. All other possible quantifiable properties have a value of 0. I then considered the size of the set of all explicitly unique objects with 1 quantifiable property, grams, which weighs 1 gram. This set can only contain 1 object. Let's call it #1. What is its subset? The quote seemed to say ZFC insists it has one. I considered it might contain an empty set as a subset, but there is no quantifiable property of an empty set. Is 0 a quantity? A set lacking objects cannot also have an object with the property of weighing 1 gram. An empty set has no object to weigh one gram. If absence of something 0 is a quantity and all properties are said to be a definition of an object, but with 0 value. Then there can be an infinite amount of empty sets but none are explicity unique, 0 = 0. If an empty set can be defined by no quantity with no properties, we can then add to the definition of #1 having all other possibilities for properties, but with 0 unit value. Comparing 2 or more empty sets shows they all have 0 quantity and 0 value for all properties, thus all identical and not explicity unique, so unable to be the subset. If however 0 value properties make no sense, my definition of the set of unique objects doesn't allow for the empty set to be included as it has no quantifiable property. Is there no subset of this set because it isn't definable using first order logic? Is this set an indivisible unit, part of an infinite series of concentric sets? The problem seems to lie with the dependence of the existence of a quantifiable property on the existence of an object. By insisting objects to be unique it limits the options to only 1 possible object. I can't quite see an error. Is only allowing positive integers restricting ZFC? I'm off to read more, hopefully it's explained later. Thinking of fractional subsets and allowing them as objects, how can half of #1 also weigh 1 gram?

Couldn't the initial rate of expansion be reduced by having it spend that energy on the creation of matter and then further countered by matter pulling together under gravity? Do these models attempt to input a balance like this into the equation, or simply just let matter creation occur at the same time as being ripped apart ? Couldn't there be an area which collapses away from the rest of the universe, 1 order of magnitude dropping out of the other 120.

Sounds about right. I know it's probably a slip, but gravity isn't a force. ________________________________________________________ My brain got speculating a bit: As gravity waves propagate they disperse and become smaller, what if over short to medium distances they followed an inverse square law as Newtonian gravity indicates. At these distances they predominantly interact with matter (because they happen to form near dense clusters of matter) and their interaction with Zero Point Energy (ZPE) is of minor consequence. As the wave propagates out into areas more dominated by voids, the interaction with ZPE plays a larger part. Normally in the void it would be expected the wave wouldn't slow, but its interaction with ZPE by lending and regaining energy quickly as it excites the vacuum and creates VP pairs which annihilate, slows the wave slightly, but maintains its total energy. This gradual decrease in the speed of propagation, without a decrease in strength has the property of allowing the wave to interact for longer with medium range areas of the vacuum. Some of the VP's it excites into existence are split away before annihilation. During the mechanism that aids this one half of the VP appears on the front of the wave crest and another is left behind in the trough. This reduction in energy modifies the inverse square law very slightly at medium distances, so gravity is slightly weaker here than normal, it also lessens the waves chance of continuing to excite VPs into existence from ZPE. Finally the wave reaches a third stage, where it is very weak and distant, just as expected by the inverse square law, only with a slight reduction. But, it is at this point that the VP pairs previously created have their highest probability of decaying back into the vacuum. This borrowed energy is returned to the gravity wave and it is strengthened to just the right amount so that gravity's range of effect has an energy spike at its farthest reaches. This extension of gravity at long range may be enough to hold galaxies together and be a plausible candidate for Dark Matter.

Thanks, I'm wondering if current experiments looking for gravitational waves assume they will propagate at exactly c? And if they assume so, but the waves propagate slower, how would that effect their measurements. Wouldn't this mean lower energy waves, perhaps even more difficult to detect than currently thought? Since they'd be dissipating some energy interacting more strongly with the vacuum. If gravity waves interact with the vacuum, could they somehow be altered by it, what if interaction with vacuum energy and virtual particles lessened gravity's effect at middle distances, but lent back energy and strengthened it over larger distances? Would this work as a suitable alternative for dark matter?

The area we were in was quite dense with matter, the region the became our galaxy and local clusters was surrounded by a shroud of matter in all directions, only select portions of the CMB were projected by lensing around us. There wouldn't need to be all directions, in fact two hemispheres would provide the best chance of a matching smoothness. It does seem a bit contrived, but is actually quite simple when compared to inflation.

The link is right there..... I can cut and paste the text, but there's some interesting diagrams too. They represent space in 2D and make the 3rd dimension time so it's easier to visualise, it's just that the assumption of an eternal black hole ruins it all. http://www.einstein-online.info/spotlights/changing_places I guess the last bit says it,

I worded that carefully, glad you spotted it. Do you think it'd be funnier if they were both naked and bald?

This didn't really answer the question, I was particularly asking why. Light/photons as far as I'm aware actually tend to travel slightly less than the speed of light unless travelling through a perfect vacuum, which because of the virtual particle, vacuum energy, doesn't exist. What are gravitational waves "made" from, and why don't they interact to slow down slightly too, like light. Since gravity waves carry information, how is it encoded, if it is simply encoded in the shape of space-time, is it then only able to be decoded by observing the interaction with space-time of particles. Shouldn't this then be viewed as the transmission of information between particles?