Sorcerer

I was just wondering what would change in the results of the schwarzschild metric if the time coordinate was instead measured at a finite distance from the massive body, rather than the infinite distance it is currently placed at. How would the results vary as the finite distance increased or decreased?

When photons cross a black holes event horizon we say it means they can never been seen again by anyone outside it. Does a photon then: A) Travel forever towards the center of the black hole, never quite reaching it. B) Travel in a finite ammount of time towards the center and stays there for an infinite ammount of time. C) Travel to the center and continue outwards for an infinite ammount of time never crossing the event horizon again. Does it make a difference to an outside observer?

Mutations don't have to be useful to survive, they only need not be harmful. If the mutant is equally as reproductively fit as the non mutant, those new genes have a chance to stay in the population. Various mechanisms like genetic drift can cause those new genes to be more abundant even though there wasn't any real advantage to them. It is then possible for another mutation to cause, by changing the gene again, or adding another gene to it, the previous neutral mutation to become advantageous, this could be in a short time or in a long time, as long as the gene is in the population to be added to or modified. This by the way can (but is less likely each time) carry on many times, adding neutral mutations cumulatively untill eventually they add up with the ultimate mutation to form something advantageous. The problem with neutral mutations is that genetic drift can also go the other way, and the genes can simply disappear from the population. But it must be remembered when talking of chance and life, that there have been billions of years and many times that generations of life since its origin, which means there have been that many chances, even unlikely things occur sometimes if there are enough events. But, since it is the chance of another mutation, (in the same or another gene), and the chance of the original required, they are far less likely to lead to advantageous adaptions than the other possibility, which is: Each mutation confers a small advantage, and each sucessive mutation builds on that adding a little more of an advantage. These types of mutations spread through the gene pool faster because they are actively selected for, the more reproductively sucessful in each sucessive generation outcompete the less sucessful untill more of their DNA is in the gene pool. It is also possible to have a combination of these 2 processes working on the same adaption. So neutral mutations which effect advantageous mutations can stay around in the genepool, another mutation can occur which otherwise wouldn't be advantageous unless in the presence of the extra neutral one, the neutral one spreads because of the new mutations mutual advantage. And there could be any kind of combination of these mutation timelines. So in the case of the wing, it would have had a function prior to that which was useful, the ancestors of birds are dinosaurs, they had arms for doing various things with which gave them an advantage, arms became wings. Genes for arms arms added with a mutation that gave them feathers could provide insulation from cold, or they could help attract mates, or if they didn't do much at all, but didn't hurt much at all, could also spread. So in essence macroevolution can happen in any time frame, but it is chance, selection, genetic drift and cumulative adaptive or neutral mutations which creates new forms.

Foods like beans contain protease inhibitors which could enable more enzymes to survive. http://onlinelibrary.wiley.com/doi/10.1111/j.1432-1033.1968.tb00365.x/pdf

I said: Earlier you said photons have no (valid) frame of reference, why would any other thing travelling at the speed of light have one? I guess it doesn't matter since no observer to have that frame of reference could be stationary in the metric anyway (dont use impossible spaceship stories). Exactly and when you use arbitary values for infinites to model objects which actually include infinities, you can get finite answers to infinite realities. Oh it's not meaningless, especially when dealing with objects whos parameters are otherwise finite, it's a great way to model things, it's a excellent approximation, in regards to modelling finite things. Just not Black Holes, it becomes a rather poor approximation then. Exactly.

lol never mind on that last one about t, it's self defeating. If it needs to be a finite distance to show it's an infinite distance, then it's not a finite distance. wow, my bad Photons have relativistic mass / inertial mass. https://en.wikipedia.org/wiki/Mass#Special_relativity https://van.physics.illinois.edu/qa/listing.php?id=1424 And in their frame of reference you are? It doesn't seem correct to me, objects travelling at the speed of light shouldn't experience this relativistic effect, only objects travellng below. I'm probably wrong though, can you back this up? Exactly, too much math and not enough reality, there is a huge problem with that assumption modeling the reality. The universe is a finite age, this will never happen, the universe may come to an end at some point in time, if it doesn't there will always be another unit of time to follow, so it will never be infinitely old. Also, something infinitely far away began outside hubble volume of the BH, the universe is expanding it will never reach the BH ever. This model makes no physical sense. Remove the infinities, see what happens. I got an A+ in the last year of highschool for Calculus, never really touched it much since. I understand limits as they approach 0. The key word is APPROACH. They never actually ever reach that limit. EVER. Well you contradict yourself there, if you want to "minimise the effect on the gravitational field you are calculating" you would choose a photon. The relative mass would have an effect and would need to be taken into consideration, because by definition, you then wouldn't be using proper time. From wiki: I guess it is a more simplistic way of thinking of a black hole and infinity, unfortunately not a logically correct one, when you use it to state factual information about real black holes.

Photons have mass right? You mean a particle with rest mass? Yes but you're travelling at the speed of light too. How can it "START" at rest an infinite distance away, that would mean it was never at rest. To travel an infinite distance would take an infinite amount of time, there would always be a preceeding point on the timeline when it was in motion. What's more important, that the particle was originally at rest or that it was orginally an infinite distance away? You could also look at that, if the observer DID start at rest an infinite distance away, it would not have yet reached a place to be able to observe, because the age of the universe is finite. The metric only deals with test particles. If this metric requires "t is the time coordinate [to be] (measured by a stationary clock located infinitely far from the massive body)", (which is impossible unless there is an infinite distance to the singularity) if instead the solution included those two values as being from a finite distance, which is a far more reasonable assumption, how would it change the results? Would finite values for time to reach a singularity become infinite?

So can the test particle be a photon? It seems to fit the criteria. While a sentient observer doesn't. -From Wiki Ahead of you? What if they crossed the event horizon at the same time as you. I can't find an exlanation for what this means after alot of searching, the term comes up alot but the definition is scarce. It also sounds like a fictional observer (or one at the singularity). Which would be outside the observable universe, beyond another event horizon. I guess there's nothing wrong with that, but it just seems like an odd concept. I guess it's to control for the relativistic effects of gravity. Maybe like the concept of there being a clock measuring the time outside the event horizon of the Black Hole, to the singularity, which is infinitely far away? (actually thinking about that is its inverse, the first clock is outside the observable universe, the second is inside.)

And don't forget we were talking about photons, because we were talking about how the gravitational field of a black hole doesn't let photons escape the event horizon. This http://casa.colorado.edu/~ajsh/singularity.html is (a story, because it's impossible, it makes no mistake saying so) about a sentient observer. I'm guessing here but I don't think the Schwarzschild equations deal with infinity, or if it existed in them it was re-normalised. I will look into that later.

Observers see an object ahead of them towards the singularity frozen in time and they never see it reach it. So it takes an infinite amount of time or has an infinite path inwards. Similarly, at the singularity (or just outside of it if you want), any photon would have an infinite path to travel to exit the blackhole.

http://casa.colorado.edu/~ajsh/singularity.html

What observer can observe this reaching of the singluarity, the photon will never return to be observed.

You could've said my original statement here had no valid frame of reference...... I mean how do you observe a photon falling away from you towards a singularity, it will never be observable to you once it has passed you. I thought it would be obvious therefore I was talking about it from a photons point of view. That's what I was doing and I found statements that directly contradict him.

http://casa.colorado.edu/~ajsh/singularity.html lol sorry I have to look up what that last part actually means now Sheesh u must be butthurt to -1. What did I do?

Perhaps but it also makes little sense to speak of events within an event horizon. Yet you're giving the times in seconds, from what observer?

We spoke earlier of asymtotes. An asymptote starting from any 4d coordinate approaching the origin/ intersection of x,y,z,t with the origin, that is the point where space time is singular, will only ever be at the origin after an infinite amount if spacetime

If you think I'm just "making that up" without considering it, you're wrong. I'll read that link eventually. Frame of reference is important. What one observer may experience quickly can be a limitless experience from another observers frame of reference. Photons are an observers measure of their frame of reference. A photon travels with the frame of reference, so to it events aren't seperate, because at C time stops for an observer. A photon travelling to a place where there is no frame of reference because there is no time and no space to make that possible will never be the observer of that event. If something never happens but is still in a positive 4d direction. Then it is an infinite 4d distance away.

Well if there is inefficiency in the recoil that could be used to generate current. Waste energy as noise is one of those inefficiencis, shock absorbed to the operators arms, not directed back to impact for breaking is another. I know there is no such thing as perpetual motion machines, but there are maximum efficiency machines. So why not transfer that ease energy to a more useful form and at the same time reduce noise and impact on the operator?

What observers frame of reference is that timing from? It must be from something inside the event horizon any other observer couldn't know. Sorry haven't read the link yet will do later. A photon travels at the speed of light, from its frame of reference all time is concurrent. All events happen simultaneously to a photon travelling at c, except the event when time and space cease to exist because this event is dependent on time and spaces existence, so is the frame of reference. It can be in 4d approaching that place but never exists in the place where 4d isn't. If it never is there but it must travel to there then it must travel for an infinite amount of time.

Why? If you're sretching 4d into 0d. Where is the time/space at that point? How long would it take for something to travel to a place where time doesn't exist?

Under general relativity wouldn't it be better to think of it like this: a BH contains a singularity so the space time from the event horizon to that singularity is infinitely stretched towards it, therefore a photon crossing the event horizon would never reach the singularity, however would still always be contained within the BH. This would then also true of the opposite; any photon emitted by a recently formed singularity would need an infinite amount of time to reach the event horizon. There perhaps however is a point very close to the infinite end of the assymptote where the size of the photon and the spatial distance between the singularity overlap.

That makes more sense, but it could be said that there is no center because there is no outward direction just an infinite path inwards. And since you mention curvature I guess this is a spiral? Sorry rethinking that curvature would mean more simply asymptotic. Since photons paths are linear, I was visualising a circle or sphere. Or would a photon actually eventually stop moving and come to rest in the center? Sorry how would something that crossed an event horizon have the means to make a decision? I'm sorry again I don't understand the event horizon was also in the future of the object that was previously outside of it... this has some meaning? We only measure future events in hindsight.

Not really I'm not good with analogies. If space is curved so there is no path then there is no path.... Surely there must be a path it's just impossible for a photon to reach the end of it from one direction. Ie a path that's stretched to infinity.

I understand what you are saying here but I also immediately thought the question "how can there be a path in if there is no path out due to curvature?" I haven't yet thought of a sensible answer.... any ideas?

I was thinking not of any mechanism in the road that moves or adds extra friction, but simply something that absorbs that road noise/vibrations which are normally there.... the house can shake when a big truck 2 blocks away goes by fast.... why can't that energy be useful? Also there are some places where it could be used and slow down traffic, for instance speed bumps, I know I feel them when I hit them, surely the speed bump feels it too why couldn't that energy be used?