著者
谷川 卓
出版者
The Philosophy of Science Society, Japan
雑誌
科学哲学 (ISSN:02893428)
巻号頁・発行日
vol.54, no.2, pp.51-70, 2022-03-31 (Released:2022-03-31)
参考文献数
16

In this paper, I show what philosophical topics we should examine in order to answer the question “Do holes exist?” First, I point out that the meaning of “concreate” is to be clarified in order to explicate the ontological status of holes. Then, I argue ontological problems of holes in relation to property theory and space-time theory. In my opinion, the ontology of holes should be approached in relation to space-time theory. But in that case, some distinctive features of holes we ordinarily acknowledge might be lost.
著者
谷川 卓
出版者
科学基礎論学会
雑誌
科学基礎論研究 (ISSN:00227668)
巻号頁・発行日
vol.47, no.1, pp.1-13, 2019 (Released:2019-11-07)
参考文献数
24

In this paper, I defend the contingency view on the laws of nature: laws of nature hold in metaphysically contingent way. First, I present an argument to demonstrate that categorical properties exist, and point out that the contingency view follows if we accept the existence of categorical properties. Second, through the critical examination of the view that laws of nature hold in metaphysically necessary way, I point out that we should take the conceivability into consideration in deciding the range of possibility and hence we should accept the contingency view. Third, I argue that this paper's approach to appeal to the conceivability mitigate the severity of a problem with categorical properties, that is, a problem of quiddity. Finally, I argue the philosophical implication of the contingency view in relation to contemporary Humeanism. In my view, though it may sound strange, those who support contemporary Humean metaphysics should take a rationalistic stance.
著者
谷川 卓
出版者
The Philosophy of Science Society, Japan
雑誌
科学哲学 (ISSN:02893428)
巻号頁・発行日
vol.47, no.1, pp.37-51, 2014-07-30 (Released:2015-07-24)
参考文献数
23

David Lewis argues that the thesis of Humility follows from two metaphysical principles; combinatorial principle and quidditism. The thesis has received attention of philosophers because of its skeptical implication, but only by focusing on that point one may underestimate the significance of Humility. Another implication drawn from the thesis pertains to the methodological issue, that is, justification of metaphysical principles. A key for the justification of two metaphysical principles in question is correspondence between our thought and the world, and it is required to develop modal epistemology in the way to oppose to Saul Kripke's view.
著者
長谷川 卓
出版者
日本古生物学会
雑誌
化石 (ISSN:00229202)
巻号頁・発行日
vol.101, pp.75-80, 2017-03-31 (Released:2019-04-03)

We often consider whether the sedimentary features observed in strata of remote areas with similar ages represent identical event or not. One of them may precede the other with a mutual or causal relationship. International correlation is prerequisite for such basic discussions. We are still waiting for definitions of GSSPs (GSSP: Global Boundary Stratotype Section and Point) for five Lower Cretaceous stages. It is partly due to the endemism of index fossil groups including ammonoids from middle-late Jurassic. There have been some important progresses; a working group of International Subcommission on Cretaceous Stratigraphy under International Commission on Stratigraphy voted and selected basal horizon of a zone of calpioneriids as a candidate of primary marker for the basal Cretaceous boundary. GSSP for the Aptian/Albian stage boundary was decided and ratified in March of 2016; planktonic foraminiferal Microhedbergella renilaevis was selected as a primary marker and a negative excursion of carbon isotope value as a crucial secondary marker. Cyclostratigraphy and astronomical tuning across Cretaceous GSSPs and chemostratigraphy of rare elements appear to be more significant for finer international correlation.
著者
谷川 卓
出版者
科学基礎論学会
雑誌
科学基礎論研究 (ISSN:00227668)
巻号頁・発行日
vol.37, no.2, pp.77-85, 2010
参考文献数
27

In this paper, I argue that non-occurrences of events are not qualified as causal relatas from an ontological point of view. It is a matter of fact that we usually use sentences which appear to report non-occurrences of events as causes or effects. But such sentences do not represent the states of the world straightforwardly and hence requires an interpretation. According to the interpretation I endorse, sentences mentioning non-occurrences of events should be interpreted in terms of counterfactuals. This interpretation shows that non-occurrences of events are mentioned on the basis of the concept of possibility. This view is supported by clarifying the ontology of events, confirming the truth condition for counterfactuals, and analyzing cases of double prevention.
著者
長谷川 卓
出版者
日本有機地球化学会
雑誌
Researches in Organic Geochemistry (ISSN:13449915)
巻号頁・発行日
vol.23.24, pp.43-52, 2008-12-30 (Released:2017-04-10)
参考文献数
41

The Paleocene-Eocene thermal maximum (PETM) is marked by a large negative carbon isotope excursion (CIE) and massive seafloor carbonate dissolution. Both phenomena are thought to have been caused by a sudden release of a large mass of carbon. The step-like nature of the CIE onset combined with the CIE magnitude has been explained by multiple dissociation of methane clathrate as the primary source of carbon. The natures of onset and the magnitude of CIE, however, are different between marine and terrestrial records implying potential artifacts in either or both records. Recently, the carbon isotope stratigraphy based on various techniques including compound-specific isotope analysis on terrestrial and marine biomarkers, single specimen analysis on surface-dwelling planktonic foraminifera revealed that 'actual' CIE is as large as 4‰ or larger, and the onset of the CIE was geologically instantaneous. These results demonstrated that the CIE magnitude (2-3‰) previously applied to estimate the mass of carbon released during the PETM was considerably underestimated and that abrupt input of 13C-depleted carbon to the ocean-atmosphere system. Forthcoming high-resolution studies on the PETM with precise inter-regional correlation would provide a unique opportunity for comparative research of global warming between PETM period and the present.
著者
長谷川 卓 中村 英人 黒田 潤一郎 守屋 和佳
出版者
金沢大学
雑誌
基盤研究(B)
巻号頁・発行日
2019-04-01

C4植物は700万年前頃に顕在化した被子植物で,通常の光合成回路の前段にCO2濃縮回路を持ち効率的な炭素固定を行う.この形質の成立過程は謎に包まれているが,「白亜紀中期の約1億年以上も前のオーストラリア南西~南極大陸にかけてがC4植物誕生の場である」という仮説を立て,これを検証する.炭素循環の大きな攪乱期の前後の試料から有機分析を進め,分子レベルの炭素同位体比分析など先進的手法も取り入れる.どの時代でどの環境激変と連動してC4植物が誕生・進化したかを明らかにし,その時代の環境背景を更に詳しく理解していく.C4植物のみに由来する有機分子の発見を期待している.
著者
谷川 卓
出版者
科学基礎論学会
雑誌
科学基礎論研究 (ISSN:00227668)
巻号頁・発行日
vol.37, no.2, pp.77-85, 2010-03-25 (Released:2017-08-01)
参考文献数
27

In this paper, I argue that non-occurrences of events are not qualified as causal relatas from an ontological point of view. It is a matter of fact that we usually use sentences which appear to report non-occurrences of events as causes or effects. But such sentences do not represent the states of the world straightforwardly and hence requires an interpretation. According to the interpretation I endorse, sentences mentioning non-occurrences of events should be interpreted in terms of counterfactuals. This interpretation shows that non-occurrences of events are mentioned on the basis of the concept of possibility. This view is supported by clarifying the ontology of events, confirming the truth condition for counterfactuals, and analyzing cases of double prevention.
著者
谷川 卓
出版者
日本科学哲学会
雑誌
科学哲学 (ISSN:02893428)
巻号頁・発行日
vol.38, no.2, pp.93-107, 2005-12-25 (Released:2009-05-29)
参考文献数
23
被引用文献数
1 1

In this paper, I show that David Lewis' theoretical framework is basically sufficient to solve the problem of causal preemption. Causal preemption cases have been regarded as a counterexample to the counterfactual analysis of causation. This view is, however, incorrect. Even under the counterfactual analysis, the problem can be solved by adopting the event theory which defines events as properties of spatio-temporal regions. The source of the problem lies in the assumption that two distinct intuitions should be preserved in causal preemption cases. The appropriate event theory is required in order to sort out the intuitions.
著者
谷川 卓
出版者
The Philosophy of Science Society, Japan
雑誌
科学哲学 (ISSN:02893428)
巻号頁・発行日
vol.47, no.1, pp.37-51, 2014

David Lewis argues that the thesis of Humility follows from two metaphysical principles; combinatorial principle and quidditism. The thesis has received attention of philosophers because of its skeptical implication, but only by focusing on that point one may underestimate the significance of Humility. Another implication drawn from the thesis pertains to the methodological issue, that is, justification of metaphysical principles. A key for the justification of two metaphysical principles in question is correspondence between our thought and the world, and it is required to develop modal epistemology in the way to oppose to Saul Kripkes view.
著者
安藤 寿男 長谷川 卓 太田 亨 山本 正伸 長谷部 徳子 高橋 正道 長谷川 精
出版者
茨城大学
雑誌
基盤研究(B)
巻号頁・発行日
2009

モンゴル南東部の白亜紀中期(シネフダグ層)とジュラ紀中期(エーデムト層)の湖成層を対象に,(1)炭素同位体比,カイエビ化石,凝灰岩のF-T年代などに基づく年代層序の構築と,(2)岩相変化(頁岩・ドロマイト互層)から復元した湖水位変動の周期解析,鉱物・主要元素組成による化学風化度変動,有機化学指標(TEX_<86>)による湖水温復元などに基づく古環境変動復元を行い,モンゴル湖成層には,白亜紀中期温室期に頻発した海洋無酸素事変期(OAE1a~1b)の,地球軌道要素を反映した降水量および古気温変動が記録されている.
著者
高橋 正道 山田 敏弘 長谷川 卓 安藤 寿男
出版者
新潟大学
雑誌
基盤研究(B)
巻号頁・発行日
2009

これまでに、2009~2011年の間、5回にわたるモンゴルの白亜紀についての野外調査を行った。主な調査地は、バガヌール、フレンドホ、テブシンゴビ、ツグルグ、シーブオーボ、シネフダク、バヤン、エルヘートなどのウランバートルの東南のゴビ地域である。この調査に参加した人数は、モンゴル古生物学研究所、エール大学、シカゴ植物園、金沢大学、新潟大学のメンバーである。これらの調査によってモンゴルの白亜紀の地層から初めて、3次元的構造を残している小型炭化化石を発見し、被子植物の初期進化と地球環境の変遷解明に有効な手掛かりを得ることができた。分担者の長谷川は,フレンドホ地域のフフテグ層において地質柱状図を作成し,植物化石試料採集露頭周辺についての地質学的な記載を行った。また、シネフダク地域のシネフダク層に関して柱状図を作成の上、採集した試料について有機炭素の同位体比を測定した.その結果,7‰程度の変動があることが明らかになった.この結果は,湖堆積物への植物プランクトン類と高等植物の相対的な含有率の変動を示していると考えられ,湖の成層状態や河川による高等植物遺体の流入量など,気候に関連する要因の変動読み取れることが判ってきた。また、マレー大学のLee教授と筑波大学の久田教授の協力を得て、モンゴルと対比可能なマレーシアで、熱帯地域での白亜紀の地層からの小型炭化化石の探索の可能性を探った。
著者
長谷川 卓
出版者
日本有機地球化学会
雑誌
Researches in organic geochemistry (ISSN:13449915)
巻号頁・発行日
vol.23, pp.43-52, 2008-12-30

The Paleocene-Eocene thermal maximum (PETM) is marked by a large negative carbon isotope excursion (CIE) and massive seafloor carbonate dissolution. Both phenomena are thought to have been caused by a sudden release of a large mass of carbon. The step-like nature of the CIE onset combined with the CIE magnitude has been explained by multiple dissociation of methane clathrate as the primary source of carbon. The natures of onset and the magnitude of CIE, however, are different between marine and terrestrial records implying potential artifacts in either or both records. Recently, the carbon isotope stratigraphy based on various techniques including compound-specific isotope analysis on terrestrial and marine biomarkers, single specimen analysis on surface-dwelling planktonic foraminifera revealed that 'actual' CIE is as large as 4‰ or larger, and the onset of the CIE was geologically instantaneous. These results demonstrated that the CIE magnitude (2-3‰) previously applied to estimate the mass of carbon released during the PETM was considerably underestimated and that abrupt input of ^<13>C-depleted carbon to the ocean-atmosphere system. Forthcoming high-resolution studies on the PETM with precise inter-regional correlation would provide a unique opportunity for comparative research of global warming between PETM period and the present.