As I said I like Tipler very much but he is controversial as I am sure you know. Just washing your hands can increase lifespan, technology does not always do so. In fact it can increase the rate of death. We kill much more and easier. Population expansion is putting humanity under great pressure. and what will be the motive to stop death? Super Centenarians die off regularly. Though our population has increased dramatically There have been less than 80 for a long time. Everything only physical dies and so far you have shown no reason this is not so except some vague hope in technology. We may solve many diseases in the coming years and also create few but there is nothing I see that overcomes this basic fact. 
Biological immortality exists in nature, some say maybe even within the human body at the cellular level(neurons, iirc), if I didn't mishear, we're at the stage of vast technological change, one area is in biological technologies.
From advanced tissue engineering, to advanced genetic engineering, to advanced cell therapies, to brand new young organs generated through chimera research. We're at an age, when any organ will be soon replaced by brand new organs, and the technological fields interact, such that such new organs will receive genetic tweaking and be generation 2.0, then 3.0, etc. Theoretically, a cell therapy could be used to replace the stem cells of the body and over time the descendant cells would slowly be of a version 2.0, 3.0, etc upgrade.
You'd have to be blind to deny the reality of technological potential. Already some level of hearing, movement, and sight has been given to those that lacked such. Even the ability to remotely control devices and communicate thanks to advanced computer interfaces allow those not even able to move except for small facial or eye movements to speak and communicate.
You call it vague technology, but it is my knowledge of the fields and their progress. Biologists have constantly had to reassess their views on the limits of life, with extremophiles, with the synthesis of compounds like rocket fuel components which were believed impossible within a cell, etc The power of biological machinery has even been underestimated by many transhumanists. The world will likely not go post biological, at least that's my opinion for now, but post evolved biology, such that synthetic biology brings the unevolvable into being.
As I said a mouse neuron can live twice as long as a mouse, a human neuron can last at the least 50% longer than the average human lifespan, and I'd say it's likely it will last over twice as long as a human. At the level of single cells, even one's with extraordinary metabolic activity(which generates the byproducts that damage the cell and cause deterioration), even non-dividing cells which can't dilute garbage, we see over 120 years per cell lifespan. The genetic instructions to repair and maintain at that level is present in every cell of the body. Yet the body dies, in mice at half the potential lifespan of some of its very cells.
As I said, many biologists said that one or a few mutations would never be able to significantly lengthen lifespan, yet it was so in simpler organisms a few mutations led to drastic life extension. The same was said about simple compounds, iirc, yet resveratrol nearly doubled the lifespan of some single celled organisms and even increased lifespan by over 50% in some short lived vertebrates, iirc. Right now I believe, as I stated non-vaguely, that the longer lived an animal the closer it is to a state of negligible senescence, some believe radical change is needed to eek out every extra year or decade, I find this unlikely. The neuron of the mouse did not need any genetic modification to last twice as long as the mouse does, and it could likely have lived longer in a longer lived host. I also stated non-vaguely that it may be the case that a suitable drug cocktail might be able to alter gene expression and make the final leap into the ageless state known as negligible senescence, depends how close we are to that state, evolution takes you part of the way as it increases lifespan again and again.
The CR experiments in monkeys, i think, were non-conclusive and gave opposite results, iirc. So the primate data, is not clear enough. But even in long lived dogs, iirc, we've got about 16% increase for 25% calorie reduction, haven't looked at the data closely but given that in longer lived animals it seems protein intake needs to be regulated for some of the CR parameter changes ,and given we don't know if the degree of CR was calculated appropriately, we still see a large lifespan increase, a proportional lifespan increase even in these long lived animals. If I'm not mistaken some would have expected single digit increases even from max 65% CR in such animals.
And again, some of the things I've heard about CR, calorie restriction, do not jive with it being solely a famine survival mechanic, at least from what I heard it seems. I've heard it needs to be brought in gradually in adult organisms or there is no life extension, iirc, yet I don't think famines, at least not all famines would be gradual affairs. Also it scales up to 65% but needs all micronutrients to work, as I've heard insufficient micronutrient quality will abolish the effect, so it seems rare to believe an animal could scavenge an extraordinarily high nutrient quality meal of 35%and function in real world famine. One would imagine food scarce, and needing vast scavenging, thus energy expenditure, and food quality should likely suffer as something's affecting food production. So the idea of an animal accomplishing such in nature at least to the extremes permissible seem questionable.
Death is rest, but given that one is composed of immortal indestructible information, it seems unlikely to be a permanent state. The core, the essence of the mind is but a pattern in the physical world. Patterns never cease to exist, they transcend the physical, they can move from substrate to substrate as happens even in the real world as the matter composing the connections in the brain is replaced over time with new matter, new physical stuff. When you see a particular pattern, it may dissipate, but nothing stops its reformation. Unless it were impossible, so long as there's a small possibility, given enough time the pattern will come back into being. As a potential configuration it exists eternally, atemporally.