¶1concurring specially.
¶2In this case we are dealing with admissibility of speculative scientific expert opinion evidence as to economic value.
¶3This writer, while attending the September 23, 24, 1977, Conference of Judges, Scientists and Lawyers on "The Use of Scientific and Technical Evidence in Formal Judicial Proceedings” held at the National Science Building in Washington, D. C., submitted the following proposal, which I believe is applicable and relevant in this case.
¶4There are four classifications of scientific, technical *497or other specialized knowledge, expert evidence:
¶5Nonspeculative, Class A. Exact or true science is anything that technically or scientifically can be observed and demonstrated, tested and falsified by experiment and repeated over and over under similar conditions. This is provable science and evidence which is uncontradicted among the scientific community. That evidence which has been proven and is not speculative may be judicially noticed by the courts as no further proof in court is needed. Rome R. &c. Co. v. Keel, 3 Ga. App. 769 (60 SE 468) (1907). Compare Cornett v. Agee, 143 Ga. App. 55 (237 SE2d 522) (1977), wherein the second law of thermodynamics is noticed as the most well recognized law in science. As a further example, Louis Pasteur has long ago demonstrated that life only comes from life, and no one now questions this fact.
¶6Speculative Class B, C, and D. All expert evidence that is not exact science or that is subject to being disproved may not be judicially noticed. "Courts should never take judicial cognizance of anything that is subject to be disproved.” Irwin v. Torbert, 204 Ga. 111, 125 (49 SE2d 70) (1948). Class D evidence is that type of speculative evidence which neither the General Assembly nor courts recognize. One example is results of a polygraph or lie detector test. This evidence moves up into Class C category only with the stipulation and agreement by both parties to utilize same in a court of law. Class B evidence is also speculative but is that which has been approved by the General Assembly and the courts. An example is blood, ballistics, breathalizer and fingerprints evidence which are all admissible with an expert’s opinion relating to his findings and opinions as to this evidence. Class C evidence is more speculative, less trustworthy and that which has not been approved by the General Assembly but is still admissible by the courts. An example would be results of the polygraph test only when stipulated and agreed to by both parties..
¶7In summary, Class A, nonspeculative expert evidence, is most trustworthy, as it is exact and proven science. Judicial notice of it may be taken because no further proof is required. Classes B, C and D are all speculative expert evidence and become progressively *498less trustworthy as we move away from Class A. In fact, the jury is generally charged that they may reject all testimony of the experts (B, C & D) and use their own common sense based on cause and effect. "An expert need not give reasons for an opinion . . . but, if the expert does give reasons, and it appears that the opinion is not based on sheer speculation, then this court cannot second guess the methodology utilized to reach the opinion.” Peachtree Mtg. Corp. v. First Nat. Bank, 143 Ga. App. 17, 19 (237 SE2d 416) (1977).
¶8The expert in the case sub judice knows the general historical facts of the present and past inflation. To extrapolate into the future that which has already occurred is not unreasonable, although highly speculative, but it is not sheer speculation. On the other hand, for example, spontaneous generation does not now occur, and for an expert to extrapolate into the past something that we know does not occur would not only be inadmissible speculation but sheer speculation, both impossible and incredible! Sheer speculative methodology is all, as in Class D expert evidence, that is proscribed as suspect and nontrustworthy. All Class A, B and C evidence of opinions of experts should be admissible. If in doubt, as bordering on the penumbras of C or D, then it should be admitted. I would affirm the case as the jury may have even rejected the expert opinions and used their own common sense based on cause and effect as provided by the Georgia law on evidence.