This is no joke. What I am about to say is really a feasible method on how people could dramatically extend their lifespans, and have incredible lives for the duration.

Picture this: you are inside a machine, floating uninhibited in a bath of light liquid. Running the machine is an advanced supercomputer. This machine protects your floating body from all sources of badness -- Sun's rays, magnetic fields, germs, physical stress, enemies, etc. Outside the machine is a perfect replica of you, in android form. No one can distinguish the android from the your real body, save that the android has almost no intelligence to it. It is a stupid machine. Your brain is its mind. Essentially, there's a fake you walking around in the outside world, while you control it from inside a machine. This is not unachievable, given our pace of technological advances. Stay with me. Let me tell you how.

All pictures seen through the android's eyes would be played for the eyes of the human through fantastic eye wear, perhaps looking like Speedo swimming goggles, that shoot images directly onto your retinas. The android could have mechanical eyes far superior to human eyes, which would allow the human to see in the dark, underwater, to see telescopically, or anything that can be devised optically.

You could tell the computer (by speaking out loud, and the microphone that hears all would hear you) to project before your eyes information from a huge, global database that the computer is tied into. At all times you would have access to all information currently known, and the database would be continuously updated. Your monitoring computer could instantly translate all languages between you and anyone else, in essence making you multilingual in all languages without the pain or time expenditure of learning them.

Similarly, all sounds sensed by the android would be transmitted to and played for your ears in full stereo, again improved to include long-distance hearing, music on demand, full communications, or any other audio innovation conceivable.
A tube would go into the human's mouth and the computer would release certain substances which generate taste. In fact, the technicians could analyze the very best example of the food ever generated, and for example, every steak ever tasted by the android would taste like the greatest steak in the world. But eating wouldn't even be necessary, since your human body would be fed the precisely correct foods necessary for a perfectly tuned body either intravenously or through a stomach tube. Every Recommended Daily Allowance would be there. Thus, eating would be nothing but a luxury, of which you could do as much or as little of as you wished, with no consequences. Your android could simply go empty out his food receptacle when full and go eat more. Probably he would even simply simulate eating, while you enjoy the real thing from the computer. Thus you could eat whenever and wherever you are. The android's food could be electrical, or nuclear. Similarly, human waste would be removed through tubes.

The android's skin has a plethora of sensors covering all areas of its body, and every sensation the android feels would be transmitted to you. You would be wearing some kind of suit, perhaps looking like a diver's wet suit, which covers every single spot of your nude exterior body. Coating the inside of the suit would be electronic stimulators, which would impart to you exactly what the android felt, and which would make it feel exactly as if it were actually happening to you. Eventually, perhaps, you might even have the sensations transmitted directly to your brain, bypassing your body through a helmet of sensors and stimulators that communicate directly with your brain. You would find it difficult to believe the android's sensations weren't actually happening to you, since it would seem so real.

Your motions made in your vat of liquid would be transmitted to the android, who would replicate them perfectly. A person watching the android would think it was actually a person. Every word you say aloud would be transmitted instantly to the android, who would speak it. If you were walking, it would be walking, and the sensors inside your suit would even make you feel as if you were hitting the ground with your feet. You would "walk" inside your liquid vat (and actually go nowhere) while the android would really walk around in the outside world and would send his five senses back to you.

The android's sensations transmitted to you would either be neutral, or pleasurable. Thus, for example, a man and woman's sexual intimacy would be felt exactly as if the two people were actually touching each other, even though they weren't really. But it would feel like they were touching each other, and that would be enough. The only pain you could ever feel would be non-physical. If something horrible happened to the android, the computer running everything would only allow you to feel a safe amount of the sensation. Thus, if the android's head gets chopped off, you, the real human, would only feel pressure on your neck. The android would obviously be broken, but it could be fixed, and you could always have a backup android ready. You have not died, even though your android has. Even if the android were drowned in a lava pit, or de-materialized by a nuclear explosion, you could get a new android and be on your way. Since you are conscious in your machine, you would know something happened to your android and perhaps have a printout appear before your eyes explaining the problem with your android, so you would say, "Computer," to the microphone that hears every word you utter, "my android is broken. Have another made." You might even have an insurance policy on your android, to insure you always have access to the outside world.

Since your android is mechanical, a number of physical differences will be present. First, you would pick your favorite age when the android is first made, and it would never age. You could be as attractive as you wished and, unless you told someone they were looking at an android, they would never know. Second, the android could be as physically strong as you designed it to be. If you wanted, you could have multiple androids to use, one of which was Arnold Schwartzenegger size, another in Respectable Businessman-version, etc. I suppose you could change your sex, or species, even. You could have animal androids and really soar like eagles, or chase antelope in cat bodies, or charge bull fighters with the knowledge of a matador. No one could ever tell if they were looking at a live animal or an android replica.
Just think how it would be a vehicle to accomplish faster movement between places. You could easily have several androids around the world, and with a single word divert your transmissions to another body you own on another continent.

If you wanted a child, either you could have one artificially by removing some sperm from the man and an egg from the woman and creating the child in an artificial womb. Or you could both park your androids, leave your machines to get her pregnant, and she'd wait nine months in the outside world before returning to her machine and her android. If the child was put into a machine as an infant, and a baby size android began operating in place of the child, sending the enclosed child all sensory data it would normally receive in the outside world, would it know or even begin to suspect it wasn't actually outside, personally interacting with others? I submit that if the child's sensory machine and the android are good enough, the child would never know the truth until it was told. It would slowly grow up, in the tank, and gradually larger and larger androids would be substituted for the younger model ones while the child slept until the child grew to maturity, when it could be told. Only in maturity could a person deal with the gravity of that revelation.

All these assets are nothing, however, compared with three really big issues.

Lifespan Extension: First, consider this. Unless something bad happened to your real body, nothing could kill you, save general aging. And if you are removed from all the things that promote general or pre-mature aging, such as poor diet, the sun's harmful rays, general physical stress, germs and viruses, etc., would you age? Probably, although no one has checked, but you would surely do so at a considerably slower rate than people do today. Your wastes would be perfectly filtered out of your blood by machine (just like a kidney patient on dialysis now, but infinitely better). Your diet and metabolism would be totally perfect.
Your android would never get tired, and the effort you expend moving it would be minimal compared to the actual effort needed were you in the android's place. Your need for sleep would be greatly reduced, so the hours you would've spent sleeping you could consider as being newly alive. If you spend 8 hours a day sleeping before and 4 hours a day after this, imagine how much more you'd get done, or at least be able to do. And your sleep would be as enjoyable if not more so than it is now. You'd just need less of it.

If something did develop within your body, it would be noticed long before it became dangerous, since your body would be continuously monitored, and the correct drugs to treat the problem would be entered into your IV. If necessary, doctors could even pull you out of the machine to operate.

You’re a God in Virtual Reality:  Since the images and sensations from the android are digital, the computer could send you pretend (digitized) images not generated by an android, and in a sense, project you into a scene. You could travel anywhere, anytime, to your scene of choice, and you could interact with the inhabitants and be in a very real world, which didn't even exist. Anything you wish could be projected around you, complete with smells, tastes, sounds, sights, and sensations. Do you realize the magnitude of this? Your human body could literally become somewhat replaced by a computer image in a database on another continent, where perhaps you're enjoying a meeting of old friends who are all on different continents. But for that evening, your images all interact in a computer fantasy world, imparting total reality to you and your friends in your tanks. Don't be afraid. I can feel your fear arising a little. Don't reflect on your fearful ideas of how this show could go wrong. Think only of the positive. This is incredible! And the proper precautions would always be taken by you and yours before anyone stepped foot anywhere.

Now try this for me. Think of the number one thing in life that you want. What is it? What? Now snap your fingers. It would be that simple. When you were young, did you not dream of Genies granting you three wishes? What would they be now? What if your wishes were unlimited? Anything you could possibly want would be yours. Anything you or anybody can dream of. Do you want to fly to the moon? If we've mapped it and told the computer what it's like, we could walk naked in the lunar sun, basking and laughing, in a computer replica which we perceive as real. Pick your era of choice, and there will be a computer replica of it with humans controlling computer images of themselves there. It will all seem so real. It will be real. Inside a computer. You would feel just as you do right now. What do you feel like right now? Feel your reality right now. That is how it would feel. A computer reality would become as real as this reality.

Forward Time-Travel:  There is one other extremely important fact. I think it is possible to travel in time. Only forward, of course. What does that mean? It means to pop ahead in time one hundred or however many years into the future and live in that time rather than the one you left. Bang, it's fifty years later and you're still 35, not 85. And the amazing thing is that opps! Five years ago they cured the disease of aging. Hooray. You can get treated. NASA will need to develop suspended animation anyhow if we intend to travel very far into space. They're probably working on it right now. I'll tell you something else. Fifty years is a very very long time from now technologically speaking. Think of the last half century's discoveries. Incredible futures behold us.

How is it possible to travel in time? I take you back to the man in the vat. How can we put a man into suspended animation, where his body doesn't age as time passes, and he is totally turned off, so to speak, while that time occurs? In a coma of sorts, or a hibernation. Completely unconscious, but completely alive. Well I don't know how. I'm a visionary, not a medical researcher. But I suspect it will have to do with lowering body temperature. Perhaps the injection of certain substances similar to the hormones and proteins produced naturally by hibernating mammals like the bear and skunk (did you know that when they hibernate, they experience very little bone or muscle loss?). It would include assisted blood cleaning and feeding, waste removal, heart, organ and muscle stimulation, etc. All of which could be elegantly performed inside the vat of light oil you float in. Yes. You are back in your vat. And you decide, "Okay, time to travel forward in time oh, let's say thirty years just for kicks." Zap! Three decades later. Sort of. Actually it would probably be a very painful transition, what with needing to get chilled way down, and then having to be awoken. That would be one hell of a morning after. You'd weather it though, with pain killers. And you'd be thirty years into the future in the blink of an eye. Thirty years richer, having slept while your investments compounded. Thirty years closer to a cure for aging. Thirty years closer to eternal life. Hell you could pop thirty years into the future, hang out for five years, and repeat. Fifty years of your life later you'd be living in the late 23rd century.

What incredible things will have been developed for, by, and because of man? My god, I want to be there. It’s not a pathetic dream of a atheist. Why not do it? Why not stay alive? Why consign ourselves to death? Why decide to agree to die? Dammit, decide to live!!

You can think of countless problems with this proposal, I'm sure. There is always a majority of pessimists in the crowd. That's why you and I avoid the crowds. Yes? How would the information be transmitted between the person and the android fast enough (Perhaps satellites?). How would people afford it? (How much did a PC-quality computer cost forty years ago?) How would you protect the humans in their machines from saboteurs and murderers? What about space and deep sea travel? Isn't the technology needed to do all this decades away at best? Is it ethical? Does that matter?

I submit simply that the technology needed will arrive. No one in 1950 could have pictured the scope of today's technological advances. How long ago was that? We cannot predict our future any more accurately than they could. But many of the parts needed to make this work exist today, and you can expect the necessary advances to come.

Why not try to live forever? Why dismiss this plan as foolish science fiction? If we strode toward this idea as a joint goal, we would achieve it in time. And if we as a species aren't trying to better ourselves, then what are we doing? Just surviving? Why not survive in style? Forever!