Wrong again, sorry my friend. Scientific models do change: But they change along with the evidence that becomes available, something which you constantly lack in trying to squeeze in your god of the gaps. 3 and 4 are predictions of GR but still speculative as yet, and 2 [a BH Singularity while certainly existing mathematically [GR being a classical theory and non applicable at the quantum/Planck level] is not believed to exist physically by most reputable physicists, your god of the gaps not withstanding. That does not though invalidate a BH per se.
GR does not apply at the quantum/Planck level. Well, wrong again. Actually expansion of spacetime, and yes exactly what the evidence shows. Mathematically a fact: GR is not applicable at the quantum/Planck level and most reputable physicists are sure no physical singularity exists. That in no way though, invalidates the concept of a BH. Your friend expletive deleted argued long and hard on that and lost. Worm Holes are a prediction of GR but as yet still speculative with no observational evidence. Time travel is another prediction of GR but again, remains rather speculative, although to a small extent could be said to occur now. Please Register or Log in to view the hidden image!
Time travel will always be speculative, because we will never have the means to make it happen. Even if it could theoretically happen. Building the space craft to conduct such an experiment would be enough of a problem, but to fuel it? lol That would take an unbelievable amount of energy.
I think that if it could theoretically happen then it could have in actuality however I don't think that it is theoretically possible. I'm speaking of travelling back in time rather than forward in time.
Returning to the track of interest, this from #25 deserved more: The course involved was introductory calculus, as taken by a wide range of students almost none of whom will ever "use" any of the techniques employed in the class, or even remember them a year later. Even if they were ever again to face a situation in which they had to employ some such technique - separation of variables, say, or even something apparently applicable like calculating the value at a point of the derivative of a simple exponential function - they would be fools to trust their answer after a few weeks away from the class itself. The only "technique" of any use to them is the ability to enter such problems into a calculator and hit "solve". If the purpose of the class is to train them in techniques, it's as big a waste of time and intense, struggling effort as one can imagine. At least the techniques of underwater basket weaving are likely to be remembered, years later. So much as I mistrust the word "hermeneutics" - to the point of rejecting it - the issue it points at is real.
As I said, the laws of physics and GR do not forbid time travel: And as I also hinted at, in a small way, some of us are time travelling. eg: The Astronauts in the ISS experience a passing of time that is slower than we do on Earth. When they return to Earth, they have actually aged slower and consequently travelled forward in time as compared to all us poor souls that were left back on Earth: Of course the effect that I just exampled is infinitesimal. The thing is if we could ever reach a technically advanced stage where we could obtain speeds that approach light speed, the effect would certainly be real. Backward time travel is another matter. The following explains it far better than I. https://plus.maths.org/content/time-travel-allowed
Then they will take the calculations to others. Of course. As they should anyway - you do not want the accuracy of your drug dosages dependent on your doctor's ability to do calculus problems with the proper techniques.
1. What do you mean and does it have any value when you say that...law of physics and GR do not forbid time travel. Law of nature forbids it. 2. And time dilation is not time travel. Its falsely popoed and you got hooked. Time travel in stricter sense is reaching in past or future with variable flow of time in same frame. The astronaut has aged less, does not mean that has time traveled, it would have been a time travel if he could reach circa 2025 while others are still in 2016 or if he could go back to 1905 while others are in 2016.
You have been making this statement very often...GR does not apply at Quantum / Planck level. Why? As far as I know like any equation GR has a problem when it encounters division by zero, otherwise its ok. GR applies everywhere, its a metric theory. There is nothing special about quantum level for GR.
Please Register or Log in to view the hidden image! You know what I mean...the laws of nature are the laws of physics of which GR is a part. Well I'll take that denial along with the first, and your many other denials that have ended up in the fringes, as the best example of your thinking.
Yep, many many times and with many reputable links supporting such common knowledge. Of course all you need to do is supply some citation supporting your own nonsense and you may then have a leg to stand on. Again, GR does not apply at the quantum/Planck level, and of course your division by zero and Singularity is a mathematical concept. Physically, most believe the Singularity does not exist. But perhaps your confusion ties into your preconceived notion as to the quantum/Planck level and your expectations of the singularity being of infinite quantity: Wrong....It "may" lead to infinite quantities, but it also may not.
Just a matter of technology my friend.... If for example I invented a ship that travelled at 99.999% c and I travelled for 6 months, turned around and returned to Earth, another 6 months later, obviously I have aged 12 months, both biologically, and my clocks have shown a similar passage of time. I hop out of my ship and I would find an Earth 230 years older, with you long dead and buried! No god of the gaps needed to explain that.
There is no need for citations. GR is a mathematical set of equations. it does not fail at Quantum Level. Some popo got pumped into you.
I have right notion. Singularity is not some physical thingie as you are making out. In maths division by zero.
I'll just leave this here. Please Register or Log in to view the hidden image! https://en.wikipedia.org/wiki/Sokal_affair