Robittybob1

Well if I look at the context of the first quote: That is like saying: "Since you are such a good Christian walk out in front of the bus and see if God will save you." There are the usual consequences of such actions and you should not deliberately tempt fate and expect a miracle. The second quote needed a bit more digging for it was referring to another event even further back in time. In Exodus 17:6- 7 I suppose there is some reason for that saying but back in the day it didn't seem such a problem. I recall it had something to do with Moses doubt too. If you are really blessed never doubt that the Lord is amongst us.

New thread www.scienceforums.net/topic/93671-geodesics-free-fall-and-the-equivalence-principle-for-dummies/

Geodesics, free fall and the equivalence principle. How can I relate my Newtonian understanding of physics with the principles of general relativity? Is there no such thing as centripetal force, inertia and gravitational potential energy anymore? When I'm jumping in the air am I on a geodesic?

That was why I was trying to understand how the three interchange. The three being gravitational potential energy, deceleration via heat loss and kinetic energy gain and whether it was stepwise or instantaneous (in which case you wouldn't see some steps).

So at all times it stays on a geodesic, a different one accepted. Thanks

@Swansont - could you say this again in any other way that I can relate it to what happens when a rocket is accelerated in orbit please.

OK. Has the OP come back* to discuss what he thinks? Does he agree with that restriction? [* Not so far]

One day I might be so lucky as to look at an equation and see the physical image in my mind's eye. I can do this for the inverse square law and not much else.

How many Gods are there? All philosophies ought to be pointing to the one won't they? All will be trying to describe the same concept, which may or may not be "undefinable and untestable". We can't observe the spacetime curvature but we see the effects (gravitational lensing), so can we just test for effects of God and make predictions about God and see if they hold?

Sounds good. I hadn't heard from you yesterday so I wasn't sure whether we were still working on this together.

Understood the rubber sheet is an analogy and so I'll never mention it again, but going back to the physics of the situation I am trying to comprehend how mass "knows" how to make spacetime the right shape immediately after someone intentionally accelerates a rocket? That might be it, thanks Ajb. "It follows a geodesic when acted upon by gravity only" but when the acceleration occurs "the path taken is no longer a geodesic", so that is further out than the original geodesic for it will orbit at an increased radius, so how does matter rediscover where it is once the acceleration is stopped and it goes back to a circular orbit or more likely an elliptical orbit? MigL and ajb seem to be slightly at odds here for one says "all motion is constrained to the 'sheet'. How could it not be ?" and the other "It follows a geodesic when acted upon by gravity only". That is the heart of the topic: which solution is it? How does matter determine where it and the other is with or without forces acting on it?

So when you add that extra term would the orbiting mass still be on a geodesic? I imagine it as a surface that determines the path through space. Can you have an object above or below that surface as opposed to just somewhere else on that surface? I know if I was to look at the formulas I would also be none the wiser. It is hard to describe sorry.

T This question follows from a thought in the thread on RB law http://www.scienceforums.net/topic/93568-robittybobs-law-orbital-issue/#entry907577. If in a situation where thrust was applied to a rocket while it was orbiting would the effects of thrust, increase in velocity rising in the gravitation well and slowing down all be simultaneous. Or else the rocket may come away or go through the spacetime curvature. Wouldn't it be possible to always stick to the curvature during a manoeuvre? The more I think it through I must be wrong. It is possible to be in a position that isn't along a geodesic.

They were always putting God to the test in the Bible, so why not today?

Do the equations handle elliptical orbits ok? So the curvature of spacetime takes the orbiting body around on the ellipse, so it doesn't go through the sides gravitational well around the central mass which must always be concentric. How do you get the elliptical shape then? It would have to be climbing up out of the gravity well and later falling back in. Does that path describe an ellipse?

All I wanted was for Mordred to take me through the steps in the one and only science paper that actually gave formulas for the DDE but we didn't, instead we took another route.

No, it was something better than that. Yesterday wasn't it? http://www.scienceforums.net/topic/93429-what-dates-are-accepted-for-the-age-of-the-sun/page-8#entry907444

If you feel God should reveal himself why would he reveal himself to Homo sapiens in particular? What does "relative days" mean. Does God create the earthquakes, tsunamis, cyclones and hurricanes etc or just the sunny days? Did you look at this thread http://www.scienceforums.net/topic/66260-defining-god/ before posting your theory?

I only said that since Mordred said we had uncovered a positive effect. That is how I read his comment, I could be wrong for our communication is a little rough on the forum. But all in all even though you crucify me you mean well, for the advancement of science at least, and you definitely made me smile when I read "In this thread Robittybob1 has gone mad and decided that DDE has major effects on dust clearing". I nearly gave you a plus 1 just for that! I must be mad! What the Hell.

It is an unresolved mystery to me. Not to someone else, just to me, but even in this thread we have begun to show another major effect the DDE. What I believe is important otherwise I would not go to this bother of trying to show an alternative. I need a little break, I'm tired. Don't worry I'll be back. What one thing that would put doubts about the Nice II model in your mind? What is one crucial aspect in your opinion?

Is it possible to puncture the fabric of spacetime? In the demonstrations the ball rolls around the depressed well caused by the more massive weight, and you could imagine the rubber sheet tearing on occasions. Could such a thing happen in nature? What would be the consequence of a mass not following the geodesic? What made me ask this question was in elliptical orbits the object does not go around the circular sided well of the fabric of spacetime. Is it taking a sloped path then or does it puncture the fabric of spacetime?

How could we tell if it is not instantaneous? I used to think in those stages (slows > falls >speeds up) but now I'm tending to the thought (at least) it is instantaneous, but how that could be is baffling. Like when they refuel the ISS do they notice those stages? Forward thrust > increases speed > it increases in orbit due to the increased speed > as it goes up and gains GPE it slows. Do they see the sequence like this? Does anyone know? In elliptical orbits there definitely seems to be a sequence as there is this exchange of energy going on between velocity and gravitational effects. Is this represented by a tilted path on those rubber sheet models of spacetime? Nothing on YT to give me the picture of how it would work in elliptical orbits.

I can recommend this recent documentary "Birth of the Solar System [Full - HD 720p]" https://www.youtube.com/watch?v=kxTgyc8RbUI It is well researched and poses a real challenge to any alternative planet forming process that I might have advocated. It is the space missions and their results which sometimes yield the biggest challenges to the current theory. For that can be evidence we all can't explain. There is one thing about the current theory that seems unresolved to me and that is the clearing of the dust from the inner solar system. With the dust in place it could have been much colder closer in. The frost line closer in. The planets forming under much colder conditions. Secondly I can't accept that Jupiter as a formed planet would act as an effective vacuum cleaner of the dust and gas. Thirdly I don't accept the gas giant planets migrated (as much as they say). OK they need them to migrate in order to pick up the mass they could not have gained from their current positions. So it is not necessary to migrate them, why not just change the method of how they picked up their mass? We need another Kepler Mission or another Hubble to really see forming stars and their gas disks in more detail. But each one will just be a snapshot in one point in time. It will still help even though it will be hard to say what was the before and after of that snapshot. The project feels enormous ... I'm exhausted.

No that's fine the thread had nearly run its course.

How about tackling the causes of separation now rather than later? Magnetosphere induced separation I could accept but I was surprised by the term "heat convection", so how does that work? So how do you think it worked? it is the separation of the dust disk from the PMS sun so that the two spin independently, it allows the PMS Sun to increase it angular rotation rate but that only happens if the heat generated by the gravitational collapse is able to escape. Will IR radiation cause DDE like visible light can? Can the dust be driven back by heat radiation? Do you know the scientific term for the separation of the dust disk from the PMS sun? Imagine if the region of the Solar System where Mercury is the planetesimals started to form a planet (The unbalanced mass would cause an offset in the gravitational pull on the material within the protostar). This would cause the protostar to have a tidal bulge but the protosun matter forming the bulge is rotating faster than the matter forming into the planet Mercury. Proto-Mercury is gravitationally accelerated and drifts outward taking the dust from the region with it. Transfer of momentum to the first protoplanet means less momentum within the material in the protosun bulge, this allows it to fall gravitationally inward. The combined effect is a thinning of the inner region of the forming solar system, the thinning commences and finally a gap appears. The protosun has started the transition to a PMS Sun. Each protoplanet allows the DDE and tidal acceleration effects to be transferred to the next region further out. This way the planets form in a chain reaction one after the other in the face of an ever decreasing sized protosun while converting to the PMS Sun. So there are different influences as time progresses and not all the planets are made the same. Well there is an original idea of sound physics so I present this as a possibility.