Slinkey

In the Schrodingers cat argument a phial of poison is triggered by a random atomic event. The argument in this case was would the cat be in a superposition of being alive and dead before we open the box to find out the fate of the cat. Here is a new slant that may have been said already. Let's face it there are plenty of brainier people in this field than me! We create a pair of entangled photons. They are directed along equal paths to the poison phial. In this case the trigger on the poison device is as follows: should the detector find a photon is polarised in the vertical plane the device is completely de-activated. Should it, however, detect a photon is polarised in the horizontal plane it will trigger the device and kill the cat. The experiment is set up such that the pair of entangled photons strike the detector simultaneously. What happens?

And how do you exist in order to do that?

Notably at singularities and at c. In fact there are many issues surrounding black holes that I am not happy about but they are all expressed in anither thread on this forum somewhere so I won't repeat them here. What do you think of the idea of quantized movement?

I'm assuming the maps are as good as ours. ie. we can measure the locations and etimate their distances using similar means as the aliens used to create their map and from this can create 3-D maps that we run on computers to fly us around.

Do you need to go back in time to do that? Sorry. Had to say it! Back on topic now: This all depends on how you view the universe. Is it one time linear universe or is it a many-worlds universe where every quantum choice leads to a new universe where each possibility is played out. David Deutsch argues for a many-worlds scenario. Others do not. Personally, I don't like the many-worlds scenario as I'd like to know where all the enegry comes from for these new universes to be created every time there is a quantum choice made. Maybe there are an infinite number of universe running concurrently with ours and quantum choices make us leap from universe to universe. ie. we don't have a place in any one universe but our choices determine our position within a "multiverse". Within this kind of universe you might be able to go back and kill your father before you were conceived, but it wouldn't neccesarily play out in any universe you find yourself in at any given moment. In a linear universe where there is only one universe and quantum choices do not lead to more universes the situation is somewhat different. You would not be able to go back in time because in your universe there would already be a history that includes your appearance in that history. ie. you would only be fulfilling what actually happened and you certainly didn't kill your dad. I like the second universe myself as it protects my past! No. But then I would say that!

That's not entirely correct I think. They would agree in certain areas but not in others. They would also be able to deduce similarites anywhere the maps over lap. For example, a distant quasar that appears to be directly behind where the commincation came from and some 10bil ly distant from us, would be how far from the source of the alien map? 6bil ly closer?

What about for speeds greater than 300000km/s? The energy equations given above tell us that when v = c we are dividing by zero and it is meaningless. This tells us that relativity is only valid for sub-luminal speeds and breaks down when v = c. The corrolary in GR is the singularity. GR predicts a singularity but cannot tell you anything more about it. Everyone seems to be generally agreed that within GR something else is needed to describe a singularity, but no one seems to be saying this about SR. My thoughts are that SR leads to a kind of ultraviolet catastrophe because it is not quantized. Does anyone disagree that energy comes in packets? I hope not. How does this apply to GR and SR? The golden question, I know, but without it not only is GR incomplete but so is SR. Maybe when we have fused GR and QM we will understand something different about v=c and there might be no requirement for infinite resources to fuel your spaceship up to light speed. My bet is that we end up with a quantized universe where movement is not smooth but trillions of quantum leaps one after the other.

When we look into the night sky we are looking back in time, for we do not see the Universe as it is but as it was. If, for example, we look at the Andromeda Galaxy - I believe it is something like 2.2mil Ly away - the light from Andromeda takes 2.2million years to reach us. Thus we see an apparent universe. Because it takes light time to travel the Andromeda Galaxy may have exploded 1million years ago but we wouldn't know for another 1.2million years. Consider: Six billion years from now we receive a communication from a region of the universe six billion light years away. The communication is a map of the Universe and the apparent distribution of galaxies as seen from the location of the message sender six billion years previously. We go to our databanks and seek out an ancient archive - 6 billion years old - that contains a map of the apparent distribution of galaxies as seen from earth 6 billion years ago. We compare the two maps.... do they match up?

I know. Clearly you didn't read what I wrote.

.....of the ideas and thoughts in my head! This is not a theory but merely me thinking out loud and seeing what thoughts it provokes in other people. The title may not turn out to be relevant but.... well, let's see. The thread "Gravity is Time" got me to thinking about something else I once said to someone - acceleration = gravity. In this case I meant it in the way Einstein meant ie. if you were in a sealed windowless box (that had extraordinarily good vibration dampening) would you be able to tell if the box was simply sitting on the ground and you feel the 1g pull of the Earth or if you were in a rocket accelerating at 1g in a flat spacetime? All things being equal would a clock inside this box clock tick at the same rate in both cases relative to an outside observer? I would assume it would, but it is just that, an assumption as I have not checked the literature. I posed a question in the "Gravity is Time" thread about accelerating a 100kg 1m^3 box to such a speed that it becomes a black hole due to its increasing relativistic mass and decreasing relativistic volume and thus its increasing relativistic(?) gravitational field. Intuition tells me it should be equivalent to light speed and would be so for any object with any given mass. If we were to draw a graph of this what would it look like it we put the relativistic mass on one axis and relativistic gravitational field strength on the other axis? A related question follows: If we have a 1m^3 sphere with a mass of 100kg, how much mass would we have to pack inside this sphere (ignoring real world technical difficulties) in order to make a black hole? If we were to draw a graph showing the gravitational field strength on one axis and the mass on the other axis what would it look like? Final question: Would the two resultant graphs be identical? My problem is that I am an ideas man. Years of reading popular science without doing much of the maths is a real downfall for me but I have a real good visio-spatial mind (I score in the 200 region on visio-spatial IQ tests) and thus get pictures in my mind that I cannot describe mathemtically. What I am trying to ascertain is how close is the similarity between acceleration and gravity. The deeper question I am seeking to find an answer to is whether the time dilation we see when we accelerate particles in a supercollider can be explained by the increase in the particles relativistic mass? Clearly, gravity and acceleration have some deep connection because wherever you find gravitational fields you find acceleration. Does this work the other way? I have read recently about the Higgs field and how it assumed to be the reason things have mass in the universe (ref: The Fabric of the Cosmos by Brian Greene). According to Dr. Greene we are awash in a sea of higgs particles. Could higgs particles be the deeper connection I am looking for? If higgs particles are the reason for mass then when we accelerate an object are we increasing its "higgs field" and where we find a massive object we also find a higgs field and the more massive the object the greater its higgs field? Maybe I'm getting muddled here but it is better I express these ideas and thoughts than have them deluding me without correction. Any ideas people? Am I just rambling:confused: or can you get a feel for what I am trying to decribe and point at:eyebrow:?

And an accelerated clock appears to slow down, right?

I think it was clear enough that you understood what I was saying and could apply labels in the relevant places, and that is sufficient. Indeed. The question still stands however.

The interesting thing I find with accelrating a body is that two distinct things happen. The mass of the accelerated body increases the length of the accelerated body is shortened in the direction of it;s movement If we had a one meter square box (1m^3 volume) that had a mass of 100kg (density 100kg/m^3), at 0.8c it would have a mass of 166.6667kg and a volume of 0.6m^3 (density 277kg/m^3). From the observers perspective this body now has a stronger gravitational field as well. Could you accelerate the body to sufficient sub-liminal speeds for it to become a black hole?

An obscene act with a dog if my eyes don't deceive me....

Don't remember making this a separate thread. Just my comments on another thread in another forum I believe. It was not put forward as a theory (a theory is something that has been tested experimentally in some fashion and shown to have accuracy in it's predictive power) nor even as an hypothesis. It's a speculation. It seems clear that gravity and time (and space) are inextricably linked with each other as shown by the relative time dilation effects that involve the gravitational force. I speculated that they might even be the same thing due to the idea that wherever there is spacetime there is gravity. Bignose, I don't have a mathematical treatise for every off hand comment I make. Sorry. Eric5, I have read one or two books on the subjective experience of time. One thing that is clear is that if you put someone bored in a room with someone having a good time the clock on the wall still ticks and the mood of one or both people will probably change too! Maybe Bignose has a mathematical treatise on the dilation of time relative to mood? kaneda, what do thinking minds call it? In my speculation I was trying to get across that the universe is suffused with the gravitational field and therefore clocks anywhere in the universe are subject to it. As clocks run more slowly in higher gravitational fields relative to the observer it struck me that we cannot describe the universe without gravity. If clocks run faster when they are in lesser gravitational fields than the observer how fast do they run in the absence of a gravitational field? Since Einstein time has become malleable - you can dilate time - but without a defintion of time itself. Events still happen in spacetime but the timing of events are dependent upon the location of the observer. If you and I are watching the same event from different locations we will disagree on timings. These timings will be related through relativity and to a high degree of accuracy, but still no definition of time itself. My thoughts were that maybe we are trying to define something that has already been defined (in whole or in part) within relativity. Why does relativity allow for time dilation? I know Einstein put forward geometrical reasons to show the relationship and his reasoning is sound but it does not show me any mechanism. It simply gives me the tools to relate the effect of the mechanism. Personally I think it is important in science to look at things from as many perspectives as possible even seemingly outlandish ones. Imagine how outlandish Einstein sounded to some when he first put forward SR. How outlandish did Darwin sound when he put forward evolution? How outlandish were Einstein's reactions to his own GR when it demanded an expanding or contracting universe to be right?! I'm not saying my idea might be right because it is outlandish either. It is simply an attempt to inject a new perspective. A speculation with the intent of provoking ideas. bignose, with your obvious grasp of, and delight in, mathematics, can you shed any light on this? Had to correct a word in the last post so if you get it twice please read the edited version.

What is now for me is your past by virtue of the fact that we are distinct entities separated in spacetime. Literally, your "now" is a collection of past events that you perceive at any given moment. Therefore it could be argued that "now" is actually the past.

I wasn't aware of that but I guess that would be the expectation. It is an infinity Maybe the BH is denied by graviton resistence. Watch this space (no pun intended).

Sorry Klaynos, I misunderstood what you meant. That sounds possible, yes.

Photons feel gravity. That was one of the experiments that vindicated GR in the early days. They looked at the apparent position of stars next to the suns surface during a total eclipse. GR said their apparent position would be deflected by the gravitational field of the sun.... they were. No. A graviton only need carry energy away from the BH for it to lose mass, but see DH's reply. But isn't the process in Hawking Radiation a pair of virtual particles that would ordinaruly meet back up but one is sucked into the BH whilst the other is "promoted" to a real particle and moves away from the EH? In my example it would be a virtual graviton being promoted to a real graviton.

Thanks DH for the link however this is more disturbing for me.... Hmmm...hmmmm...hmmmmmmmmm I have to read up on virtual particles again (I like Feynman but it gets so damn complicated! ), but at first glance it looks like the mechanism for Hawking Radiation (HR) is very similar to the mechanism for transmitting the gravitational field. At the EH we cannot have an empty field. Even for gravity. Thus there is a probability that one of a pair of virtual particles gets out into space... but this would mean the BH loses mass simply by gravitating, surely? In this case it would be the bigger it is the quicker it loses mass rather than vice versa with HR. Or am I barking up the wrong tree here entirely?

Some other thoughts that disturb me about Black Holes. BHs have intense gravitational fields. They are objects borne of the classical theory of GR. According to GR gravity propagates at c. It cannot move any faster than this according to the rules of GR. Thus if the sun was to suddenly disappear we wouldn't know about it for over 8 minutes - no signal can reach us at super-luminal speeds to warn us of our impending doom. We have experiments currently trying to detect gravity waves. The idea is to detect gravity waves as they pass us and warp spacetime. I haven't checked the research lately but last time I looked we had not detected any gravity waves. According to QM for every wave there is an associated particle. In the case of gravity it is the graviton. No one has detected one of these but it should exist if gravity waves exist and is therefore detectable in principle. The problem for me is when GR and QM meet at the EH of a BH. According to GR, the gravitational field at the EH is so intense the escape velocity is equal to c. As gravity can only travel at c, whether as wave or particle, how can gravity permeate into the surrounding space of a BH? Shouldn't a BH also be gravitationally black?

This bit caught my eye.... You would've thought that someone falling towards the BH would see more radiation rather than less, or at least, see the radiation coming from the EH as blueshifted, but no. What we see is a BH suddenly frozen by our movement towards it. This can only be as a consequence of the infinite time dilation at the EH im my humble opinion. Indeed. It is both re-assuring to me that I have noticed this problem and it is a known problem within physics, but disturbing that there is such a problem with regard to BHs and that they are widely accepted as existing in reality. I truly belive that BHs will be eradicated once we have a coherent QM/GR theory. I will stick my neck out now and predict that spacetime will become quantized and new rules will be formulated to comprehend incredible densities and their intense gravitational fields.

Hi CPL.Luke How do you out proper math symbols in the forums?! Fair enough. I've not found anything myself except pages that tell you what it is rather than how it would apply in the circumstances I have described. Hence the name event horizon. I understand what it is, yes. It is also a point in space where time dilation is infinite. If it were not then it would not be an event horizon because we would be able, in principle, to detect temporal information. Indeed. Exactly the point I am trying to get across. They will never see anyone cross the EH yet the BH will evaporate given enough time.... I submit that this cannot happen whilst there is a perspective from which a viewer cannot see anything cross the EH of an evaporating BH. These two histories are simply incompatible. It is a vastly different situation to someone sitting on a platform and watching a light being turned on in glass carriaged train moving past us at 0.8c. Ah, but us observers outside the EH do get a result. The result is we never see anything cross the EH. The crux of the issue for me is the ingredient of time. No one knows what it is. Thus we have no theory of time to put into our calculations. Although relativity tells us what happens at sub-luminal speeds and outside singularities it tells us nothing about time except that our theories cannot deal with it at c or BHs. I'm more au fait with SR (I can do and understand some of the math!) than GR so my example is from SR here but it should have a counterpart example in GR. d = sqrt(1 - v^2 / c^2) I once stated in a forum that if v = c then d = 0 therefore time would be at a standstill. I was told in response that this is an assumption, and of course it is. When v=c we simply have no more information about time. The corrollary in GR is that anything beyond the Event Horizon is also an assumption. We can map out an increasing gravitational field but we cannot explain what happens in the temporal direction once the field is strong enough to reduce time to zero for any observer except our hero who is falling towards the EH.

My understanding of the S.Rad. is that it is a volume within which there is enough mass to create a BH. Surely if we can figure out the S.Rad. we can deduce the location of the EH and where it would be relative to us as we fall towards the BH? Rather, we could do the math first and then I fly towards the BH and the time it takes me to reach the center is as we calculated. However, as you hint below, even though we can calculate it only one of us could ever find out if it is correct and never be able to divulge that information to anyone outside the EH. The stationary observer would only have a set of equations and no experimental evidence to support it. He would not see me pass the EH although he could reliably predict what he would see as I approach the EH. The problem is however that GR leads to a point of infinite density which is not only mathematically intractable within GR but non-sensical. I can accept that QM can be far from common-sensical, but GR is a classical theory. It should, as you state above, be able to make sense in any reference frame, yet the very equations of GR lead to a point that does not make sense within GR. Not only this but combined with Hawking Radiation, a QM theory, we get the possibility of dual and contradictory outcomes depending on who is doing the observing. I'm not saying your conclusions are wrong, but from my perspective there is a giant hole here in science (no pun intended) and our only tool to try and fill this hole, QM, leads to absurdities. The absurdities being that from one reference frame an observation could be made of someone falling towards a BH only to emerge alive as the BH has evaporated billions of years in the future of the RF of the observer. Yet, from the perspective of the person falling into the BH he would be crushed into an infinite point and die. For myself, I currently have more faith in QM than I do in relativistic black holes.

I think you probably can, yes. If you are not moving relative to each other and you know your spatial separation it should be calculable. It would just be an arbitrary convention however, rather than a definitive time. What I am trying to get across to the original poster is that we have to take into account spatial separation in our calculations for an object moving relative to us. The first effect is due purely to the fact that light takes time to cross space but is dependent on the direction of movement of the object relative to ourselves (simply put if the object is moving away their clock slows down and if they are moving towards you then their clock will speed up. This is not to be confused with relativistic time dilation which had I more time last night I was going to try to explain. I'm at work right now (on a saturday! ) so really don't have the time now either, but hopefully when I get home tonight I will have time to try and clarify a few things for the original poster.