How many women would it take to carry a human baby from conception to viable birth in 1 month?
How many gold coins would it take for the Roman Empire to land a man on the moon, within 20 years, with 99% confidence?
How much money would it take to engineer biological immortality for at least half of the world's population, within 20 years, with 99% confidence?
More than the entire world's GDP.
Really, though, 99 % confidence is too big of a number to be throwing around when we're talking about problems that are this hard to solve. Also, things like "how is the money being spent" matter a lot, too.
The biggest money should be spent not on research, but on lobbing, by the way.
One of the ways to do it is to change regulation which will allow to create "human brainless clones" and a technology to transfer a brain from old body to the new one. (Now both technologies are banned, and head transplants banned even on rats).
Head transplant technology is now in its infancy but large investment could make it cheap and safe.
But other large scale investments in antiaging, cryonics, artificial organs digital immortality would also help.
Creation of safe AI in the next 20 years will also solve the problem.
I guestimate 1 trillion dollars a year for all it or even less.
Even if the goal could be reached in 20 years, it would take much more than 20 years to empirically test that the goal had been accomplished. In the prosaic world I come from we say brain-dead stuff like "if it isn't tested it doesn't work" and feel like we understand something important when we do so.
My naive linear model is that ~$400 billion research funding currently spent per year buys about 1 year increased lifespan per decade, so it would take about $4 trillion per year spent on research to stop aging, or a one-time investment of $80 trillion. For 99% confidence I'll add a safety factor of 4, yielding a one-time payment of $320 trillion, or $16 trillion per year. In other words, this back-of-the-envelope guess suggests the entire economic output of the United States would be just sufficient to discover and maintain an aging cure.
A lot of biological research is inherently slow, because you have to wait to observe effects on slow processes in living things. Probably the only way to get rapid research progress on immortality is with vastly superior computer models running on vastly superior computers substituting for as much as possible of the slow observing what really goes on in humans research. Though there would probably still be a lot of slow observing what goes on in humans going on in the course of testing the computer models for accuracy. Anyway, making more powerful computer...
If you and I were the only people on the planet, how much money would it cost to engineer biological immortality for one of us?
Which is to say, money is the wrong currency.
Would someone be able to enlighten me on what the cons of a hypothetical situation in which everyone on the planet decides to temporarily get rid of the concept of money or currency, and pool our collective resources and ideas without worrying about who owes who? I mean on paper it sounds great, and obviously this is extremely hypothetical as it's virtually impossible to get all human life on Earth to actually do that, but are there hidden cons here that I'm not really seeing?
I've not really gone into too much thought on this, it was mostly a fleeting thought, and I was curious what others thought.
I'm deeply sure that this cost is far less than one trillion dollars if we put them in Cas9/CRISPR, tissue engineering, acerebral clone growing etc. I think this my website http://sciencevsdeath.com/index.html might be interesting for you.
Also, I'm glad to see people asking such great questions :)
Success of immorality is a function of a number of variables, money being just one of them. I don't think that money alone would get you what you want in 20 years' time.
The key variable other than money is probably reforming academia. Right now academia is horrifically wasteful.
So far not mentioned in replies to this is that there are many examples of productive organizations that do not organize around money. Two leap to mind:
Military. Rarely do the various units and platoons trade with the other components of the military for their supplies, nor do they bid on missions. To the extent trade occurs it is usually barter and usually outside official accepted ways of doing things.
Business units. Large businesses may use separate calculations of returns to determine some very macro choices between business units.
But there is essentially always some size of organization below which the subunits or individuals are not trading using money to get things done. Marketers don't bid to engineers to get the products they think they can sell. Engineers don't bid on the projects they want to work on within the organization.
Indeed the fact that firms form to avoid a whole bunch of bilateral trading is analyzed by one of the most respected economists ever Ronald Coase on the Nature of the Firm.
So another version of the answer to the OP would be that the reason EVERYONE on the planet doesn't do it is because the coordination problem without money and trade is too hard (meaning you will get a vastly suboptimal result) to do on a global scale, but it works on smaller scales. So whatever it is you want to achieve, form an organization to solve it, give them a pile of money to trade with the rest of the world, and do not require them to organize internally on a trade/money basis. If you make the organization too big, it will either organize internally using trade or it will be very ineffectual.
How much money would it take to engineer biological immortality for at least half of the world's population, within 20 years, with 99% confidence?