farmerman wrote:Set, I think that we all realize that "Contact" was a movie, but there are great distances involved even within our galaxy. !00000 light years wide is a lot of real estate.
I'm not sure what your point is in taking note of this, unless it is simply to re-enforce the point that we may be missing signals--which i consider a cogent objection to the "great silence."
Interstellar and intergalactic distances are just another reason why i remain unconvinced with the thesis advanced. I'll create another analogy which i hope will clarify what i mean. We are now involved in constructing a space station with the Russians (and do a lot of PR work bringing people from other nations there--but basically, is a Russo-American project). We have had the necessary technology to have begun the project for 40 years or more. Why did we not begin such a project until recently? I know that everyone in this discussion (except perhaps Spurious) is sufficiently perceptive to know, but i'll rehearse the reasons in aid of making my point.
In the 1960s when we were involved in the Mercury, Gemini and Apollo programs, we also were involved in the civil rights movement, the voting rights movement, the "War on Poverty," the Vietnam War, and had major military commitments in Europe and in Asia apart from Vietnam. The Russians had an even larger military commitment in Europe, and had large military commitments within the borders of their "empire," because so much of their territory was the homeland of people who were necessarily less than enthused with being a part of the Soviet system. They also made huge grants of resources in the form of military hardware and expertise to middle eastern nations. Both nations were deeply committed to huge military budgets which dwarfed their space exploration budgets, and the space programs of both were an outgrowth of the development of atomic weaponry delivery systems. We can only make the space station effort now because neither nation is any longer involved in the huge military outlays which characterized the period 1945-91. Even as it is, both nations are doing the current project on a shoe string, relying upon the huge Russian boosters to do the heavy lifting, and American prosperity to write the checks.
In other words, we did not then and do not now have a planet-wide unitary culture which would allow us to concentrate resources for the effort. The notion the even over billions of years, many, many civilizations would have arisen which would have committed significantly large portions of their resources to colonization, or even just to exploration, ignores the realities of culture as we know them based on the only technologically sophisticated civilization of which we have an example.
Fermi and company ignore the "human" factor in this question.