**From:** Danila Medvedev (*danila.medvedev@mail.ru*)

**Date:** Fri Jan 05 2007 - 03:17:47 MST

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As an economist with a PhD about discounting and project valuation, I find

it highly disturbing that you are using such antiquated instruments as

"interest rates" and "discounting".

The whole discussion is completely wrong for the following reasons.

It is not justified to speak about required rate of return for an entity

which lives inside a computer. When most of the projects are carried out

inside a virtual space (i.e. subjective time is not equal to astronomical

time), when growth rates are high (and not limited by the same things as

they are today), when the entities themselves live in a virtual space,

when there might not be competition based on growth rates, etc. it is just

stupid to discount future resource flows in the same way as we do today.

From an economist viewpoint, there likely will not be any discounting

whatsoever, since what matters is total subjective time (i.e. amount of

calculations), which is unrelated to astronomical time and is related to

resources only. If a posthuman civilization is no longer worried about

"real-time threats" (space aliens, asteroid danger, supernovas, etc.) that

have to be countered quickly, it will probably concentrate on using

efficiently all avialable resources for its purposes (no longer directly

tied to the real physical world). I ignore all possibilities of final

resolutions such as creating new universes for computation or dyson/tipler

infinity scenarios.

Hope this helps.

Danila Medvedev

I find

*> Okay, I did some math, and it turns out to be highly UNLIKELY that ET
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*> would find it worthwhile to travel to the stars!
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*>
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*> Considering just the energy payoff, in order for it to be worthwhile
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*> to gather the energy of a sun, it would have to be the case that the
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*> energy investment, with interest, would be less than the energy
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*> payoff.
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*>
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*> Let
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*>
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*> T = time taken to harvest sun's energy
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*> S = energy of sun
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*> L = energy invested at launch time
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*> I = 1 + "interest rate", in same units as T
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*>
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*> We must have
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*>
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*> L(I^T) < S
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*>
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*> in order for the sun-harvesting to be worthwhile.
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*>
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*> Suppose that the star is 6 light-years away. This is a reasonable
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*> supposition, because, although you can find stars closer than that,
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*> they aren't distributed evenly throughout space, and rather soon
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*> you're going to find yourself at the edge of your local cluster,
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*> looking more than 6 light-years to the next star.
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*>
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*> I find, from the Wikipedia entry on "Orders of magnitude (energy)",
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*> that the theoretical total mass-energy of the sun is 1.8E47 J.
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*>
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*> We will suppose that our high-tech ET can accelerate to the speed of
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*> light instantaneously, and make the round-trip to the star and back in
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*> 12 years = 4380 days. We then have
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*>
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*> L(I^4380) < 1.8E47 Joules
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*>
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*> ln(L) + 4380ln(I) < ln(1.8) + 47ln(10)
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*>
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*> We will suppose that ET is very energy-efficient, and can create and
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*> launch a spaceship using 1 Joule of energy, so ln(L) = 0. We thus
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*> have
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*>
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*> ln(I) < [ln(1.8) + 47ln(10)] / 4380 = 0.0248423
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*> I < 1.02515
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*>
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*> Thus, even if ET is able to build an impossibly-perfect spaceship and
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*> launch it with 1 J of energy, it is not worthwhile for ET to do so, to
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*> gather the energy from a sun and bring it back, unless the "interest
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*> rate" (on investments; in our society we would think of it as an
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*> interest rate on money, but in ET's more advanced society they think
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*> of it as an interest rate on energy) is less than 2.5% per day.
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*>
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*> It seems to me more likely than not that the interest rate in a
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*> post-human society would be more than 2.5% per day. This is simply
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*> because moving from thinking based on the stochastic movements of
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*> proteins in fluid and currents traveling at 3m/s, to thinking based on
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*> the computer architectures we have today, would at first glance
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*> suggest a subjective speedup factor of about a million, making an
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*> interest rate of 10%/year in human society translate to an interest
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*> rate of about 27,400%/day.
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*>
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*> The only vulnerable point that I see to this argument is the
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*> supposition that ET needs to bring the energy back to his starting
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*> point. I'm assuming that ET at home does not feel especially
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*> benevolent, and wants the benefit of that sun's energy for himself.
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*> I'm also assuming that ET is part of a relatively large computational
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*> entity, and that sending out an ET would amount to making a copy of ET
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*> and putting it on a spaceship.
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*>
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*> You might argue that ET would be altruistic enough to let the copy of
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*> ET stay out by the sun and use its energy there. You might further
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*> argue that we should then consider the travelling ET's subjective
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*> time, which will be very small, since it will travel near the speed of
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*> light.
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*>
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*> I don't think that a stay-at-home ET would evaluate its return on
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*> investment from the point of view of the travelling ET. I might
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*> consider than an ET that planned to pull up stakes and travel itself,
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*> might consider the time to be that experienced on the voyage.
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*>
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*> - Phil
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*>
*

-- С уважением, Данила Медведев mailto:danila.medvedev@mail.ru Трансгуманизм - какое НА САМОМ ДЕЛЕ нас ждёт будущее http://www.transhumanism-russia.ru/

**Next message:**Philip Goetz: "Re: the end of fermi's paradox?"**Previous message:**Sampo Syreeni: "Re: the end of fermi's paradox?"**In reply to:**Philip Goetz: "Re: the end of fermi's paradox?"**Next in thread:**Gary F. York: "Re: the end of fermi's paradox?"**Reply:**Gary F. York: "Re: the end of fermi's paradox?"**Reply:**Piotr Szaniawski: "Re: the end of fermi's paradox?"**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ] [ attachment ]

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