Frank J. Tipler

Frank Jennings Tipler III was born on February 1, 1947 in Andalusia, Alabama. He received his BS from MIT and doctorate from the University of Maryland. Tipler is currently a professor of mathematics and physics at Tulane University, where he has worked since 1981.

I looked at two short articles that Tipler wrote concerning the SETI program.  The first is an article from Physics Today in 1981, and is in our reading packet. He starts off the article by agreeing with those of his contemporaries that say taht we are probably the only intelligent life in the universe.  He believes that if intelligence beings existed and "had the means for interstellar communication they would also have technology for interstellar travel" and be here, but they aren't.  He then goes on to discuss the logistics necessary for interstellar travel. Space exploration can only be possible with a von Neumann machine, an engine to get the machine to the stellar system, and an engine to move the machine around the stellar system. With these you can colonize the galaxy in less than 300 million years, by Tipler's calculations.

A von Neumann machine is a universal replication device that would use the materials on the planet it is on to make copies of itself to send out to other stellar systems. After it has made enough copies it begins to explore the area and transmit the data back to the source (Earth). It could even make space stations in systems that have no inhabitable planets. At this point, it is not our rocket technology that is holding us back, but our computer technology. Tipler believes that sending out probes is a much better way to search than radio searches. These are ineffective, which he talks about more in the next article.

Next comes a large section about the unlikelyhood of intelligence. Tipler references the Drake Equation, saying that it is almost impossible to find what the real number would be, especially since we only have a sample size of 1 (Earth). To increase our sample size we need to start developing these von Neumann machines. Tipler says that some recent (in 1981) proposals by Carl Sagan for Mars probes are the closest we have come to von Neumann machines as of yet.

The second article is a letter written to the magazine Science in 1983 in response to a letter written by another reader. The letter was talking about the use of radio searches for the SETI program. There are two assertions that the other author made that Tipler wants to address. The first assertion is that "the radio search...assumes nothing about other civilizations that has not transpired in ours". To this Tipler says that Earth has not intentionally broadcasted radio messages in the past, therefore we cannot assume that other civilations have done so. We would then have to look for leakage and not intentional messages. The problem with this is that the level that the radio search is being conducted at is above the highest frequency level of leakage that Earth has.  With the level of leakage that Earth puts out, we would only be able to detect the same from a few nearby stars.  Tipler says that the radio search can only be effective if an intelligent civilization was close or the frequency search was changed. Tipler says this assertion is false because we are actually assuming that the civilizations we are searching for are more advanced than us. But once again, if they were and they existed they would already be here.

The second assertion is that "the results [of the proposed search]--whether positive or negative--would have profound implications for our view of our universe and others". Tipler says that this experiment could never decisively rule out ET intelligence because SETI supporters could never be convinced; there would always be provisions. For example, the intelligent beings have no radios anymore, they have advanced past that. Because this cannot be proven, negative results would not be profound. Tipler ends the letter by saying that radio searches do not even count as a scientific experiment because they are not falsifiable. 

Here are the pictures that were missing from my power point:

Frank Tipler: http://www.tulane.edu/newwave/images/070207_tipler1.jpg

von Neumann machine (artist's representation): http://www.daviddarling.info/images/von_Neumann_probe.gif

Tune in to the Universe!  http://www.setileague.org/photos/mdse/tunein.jpg