Editing Cold fusion (section)

==History==
[[Nuclear fusion]] is normally understood to occur at temperatures in the tens of millions of degrees. This is called "[[thermonuclear fusion]]". Since the 1920s, there has been speculation that nuclear fusion might be possible at much lower temperatures by [[Catalysis|catalytically]] fusing hydrogen absorbed in a metal catalyst. In 1989, a claim by Stanley Pons and Martin Fleischmann (then one of the world's leading [[Electrochemistry|electrochemists]]) that such cold fusion had been observed caused a brief [[media sensation]] before the majority of scientists criticized their claim as incorrect after many found they could not replicate the excess heat. Since the initial announcement, cold fusion research has continued by a small community of researchers who believe that such reactions happen and hope to gain wider recognition for their experimental evidence.

===Early research===
The ability of [[palladium hydride|palladium to absorb hydrogen]] was recognized as early as the nineteenth century by [[Thomas Graham (chemist)|Thomas Graham]].{{sfn|ps=|US DOE|1989|p=7}}<ref>{{Cite journal|title = On the Absorption and Dialytic Separation of Gases by Colloid Septa|journal = Philosophical Transactions of the Royal Society of London|date = 1 January 1866|issn = 0261-0523|pages = 399–439|volume = 156|doi = 10.1098/rstl.1866.0018|first = Thomas|last = Graham|doi-access = free}}</ref> In the late 1920s, two Austrian-born scientists, [[Friedrich Paneth]] and [[Kurt Peters (chemist)|Kurt Peters]], originally reported the transformation of hydrogen into helium by nuclear catalysis when hydrogen was absorbed by finely divided palladium at room temperature. However, the authors later retracted that report, saying that the helium they measured was due to background from the air.{{sfn|ps=|US DOE|1989|p=7}}{{sfn|ps=|Paneth|Peters|1926}}

In 1927, Swedish scientist John Tandberg reported that he had fused hydrogen into helium in an [[electrolytic cell]] with palladium electrodes.{{sfn|ps=|US DOE|1989|p=7}} On the basis of his work, he applied for a Swedish patent for "a method to produce helium and useful reaction energy".{{sfn|ps=|US DOE|1989|p=7}} Due to Paneth and Peters's retraction and his inability to explain the physical process, his patent application was denied.{{sfn|ps=|US DOE|1989|p=7}}<ref>[http://www.nyteknik.se/popular_teknik/smatt_gott/article3092779.ece Kall fusion redan på 1920-talet] {{webarchive|url=https://web.archive.org/web/20160303210020/http://www.nyteknik.se/popular_teknik/smatt_gott/article3092779.ece |date=3 March 2016 }}, Ny Teknik, Kaianders Sempler, 9 February 2011</ref> After [[deuterium]] was discovered in 1932, Tandberg continued his experiments with [[heavy water]].{{sfn|ps=|US DOE|1989|p=7}} The final experiments made by Tandberg with heavy water were similar to the original experiment by Fleischmann and Pons.<ref name="similar_to_tandberg">{{harvnb|Pool|1989}}, {{harvnb|Wilner|1989}}, {{harvnb|Close|1992|pp=19–21}} {{harvnb|Huizenga|1993|pp=13–14, 271}}, {{harvnb|Taubes|1993|p=214}}</ref> Fleischmann and Pons were not aware of Tandberg's work.<ref>{{harvnb|Huizenga|1993|pp=13–14}}</ref><ref group="text" name="tandberg_not_known_by_FP" /><ref group="text" name="tandberg_not_known_by_FP2" />

The term "cold fusion" was used as early as 1956 in an article in ''The New York Times'' about [[Luis Walter Alvarez|Luis Alvarez]]'s work on [[muon-catalyzed fusion]].{{sfn|ps=|Laurence|1956}} [[Paul Palmer (physicist)|Paul Palmer]] and then [[Steven E. Jones|Steven Jones]] of [[Brigham Young University]] used the term "cold fusion" in 1986 in an investigation of "geo-fusion", the possible existence of fusion involving hydrogen isotopes in a [[planetary core]].{{sfn|ps=|Kowalski|2004|loc=II.A2}} In his original paper on this subject with Clinton Van Siclen, submitted in 1985, Jones had coined the term "piezonuclear fusion".{{sfn|ps=|Kowalski|2004|loc=II.A2}}<ref>C. DeW. Van Siclen and S. E. Jones, "Piezonuclear fusion in isotopic hydrogen molecules," J. Phys. G: Nucl. Phys. 12: 213–221 (March 1986).</ref>

===Fleischmann–Pons experiment===
The most famous cold fusion claims were made by Stanley Pons and Martin Fleischmann in 1989. After a brief period of interest by the wider scientific community, their reports were called into question by nuclear physicists. Pons and Fleischmann never retracted their claims, but moved their research program from the US to France after the controversy erupted.

====Events preceding announcement====
[[File:Cold fusion electrolysis.svg|thumb|Electrolysis cell schematic]]
[[Martin Fleischmann]] of the [[University of Southampton]] and [[Stanley Pons]] of the [[University of Utah]] hypothesized that the high compression ratio and mobility of [[deuterium]] that could be achieved within palladium metal using electrolysis might result in nuclear fusion.{{sfn|ps=|Fleischmann|Pons|1989|p=301}} To investigate, they conducted electrolysis experiments using a palladium cathode and heavy water within a [[calorimeter]], an insulated vessel designed to measure process heat. Current was applied continuously for many weeks, with the [[heavy water]] being renewed at intervals.{{sfn |ps= |Fleischmann |Pons |1989 |p=301}} Some deuterium was thought to be accumulating within the cathode, but most was allowed to bubble out of the cell, joining oxygen produced at the anode.{{sfn |ps= |Fleischmann |Pons |Anderson |Li |1990}} For most of the time, the power input to the cell was equal to the calculated power leaving the cell within measurement accuracy, and the cell temperature was stable at around 30&nbsp;°C. But then, at some point (in some of the experiments), the temperature rose suddenly to about 50&nbsp;°C without changes in the input power. These high temperature phases would last for two days or more and would repeat several times in any given experiment once they had occurred. The calculated power leaving the cell was significantly higher than the input power during these high temperature phases. Eventually the high temperature phases would no longer occur within a particular cell.{{sfn|ps=|Fleischmann|Pons|Anderson|Li|1990}}

In 1988, Fleischmann and Pons applied to the [[United States Department of Energy]] for funding towards a larger series of experiments. Up to this point they had been funding their experiments using a small device built with $100,000 [[Out-of-pocket expenses|out-of-pocket]].{{sfn|ps=|Crease|Samios|1989|p=V1}} The grant proposal was turned over for [[peer review]], and one of the reviewers was [[Steven E. Jones|Steven Jones]] of [[Brigham Young University]].{{sfn|ps=|Crease|Samios|1989|p=V1}} Jones had worked for some time on [[muon-catalyzed fusion]], a known method of inducing nuclear fusion without high temperatures, and had written an article on the topic entitled "Cold nuclear fusion" that had been published in ''[[Scientific American]]'' in July 1987. Fleischmann and Pons and co-workers met with Jones and co-workers on occasion in [[Utah]] to share research and techniques. During this time, Fleischmann and Pons described their experiments as generating considerable "excess energy", in the sense that it could not be explained by [[chemical reaction]]s alone.{{sfn|ps=|Fleischmann|Pons|Anderson|Li|1990}} They felt that such a discovery could bear significant commercial value and would be entitled to [[patent]] protection. Jones, however, was measuring neutron flux, which was not of commercial interest.{{sfn|ps=|Crease|Samios|1989|p=V1}}{{clarify|date=November 2015}} To avoid future problems, the teams appeared to agree to publish their results simultaneously, though their accounts of their 6 March meeting differ.{{sfn|ps=|Lewenstein|1994|pp=8–9}}

====Announcement====
In mid-March 1989, both research teams were ready to publish their findings, and Fleischmann and Jones had agreed to meet at an airport on 24 March to send their papers to ''[[Nature (journal)|Nature]]'' via [[FedEx]].{{sfn|ps=|Lewenstein|1994|pp=8–9}} Fleischmann and Pons, however, pressured by the University of Utah, which wanted to establish priority on the discovery,<ref name="utah patent"/> broke their apparent agreement, disclosing their work at a press conference on 23 March<ref name="nature-lessons">{{Cite journal |last=Ball |first=Philip |date=2019-05-27 |title=Lessons from cold fusion, 30 years on |journal=Nature |language=EN |volume=569 |issue=7758 |pages=601 |doi=10.1038/d41586-019-01673-x|pmid=31133704 |bibcode=2019Natur.569..601B |doi-access=free }}</ref> (they claimed in the press release that  it would be published in ''Nature''<ref name="nature-lessons" /> but instead submitted their paper to the ''Journal of Electroanalytical Chemistry'').{{sfn|ps=|Crease|Samios|1989|p=V1}} Jones, upset, faxed in his paper to ''[[Nature (journal)|Nature]]'' after the press conference.{{sfn|ps=|Lewenstein|1994|pp=8–9}}

Fleischmann and Pons' announcement drew wide media attention,{{refn|group="notes"|name=Brooks|For example, in 1989, the ''Economist'' editorialized that the cold fusion "affair" was "exactly what science should be about."<ref>{{Cite book|mode=cs2|first=J. K.|last=Footlick|title=Truth and Consequences: how colleges and universities meet public crises|isbn=978-0-89774-970-1|page=[https://archive.org/details/truthconsequence0000foot/page/51 51] |location=Phoenix|publisher=Oryx Press |year=1997 |url=https://archive.org/details/truthconsequence0000foot/page/51}} as cited in {{Cite book|mode=cs2 |first=M|last=Brooks|title=13 Things That Don't Make Sense|isbn=978-1-60751-666-8 |page=67|location=New York|publisher=[[Doubleday (publisher)|Doubleday]]|year=2008|title-link=13 Things That Don't Make Sense}}</ref>}} as well as attention from the scientific community. The 1986 discovery of [[high-temperature superconductivity]] had made scientists more open to revelations of unexpected but potentially momentous scientific results that could be replicated reliably even if they could not be explained by established theories.<ref>{{harvnb|Simon|2002|pp=57–60}}, {{harvnb|Goodstein|1994}}</ref> Many scientists were also reminded of the [[Mössbauer effect]], a process involving [[Isomeric transition|nuclear transitions]] in a solid. Its discovery 30 years earlier had also been unexpected, though it was quickly replicated and explained within the existing physics framework.{{sfn|ps=|Goodstein|1994}}

The announcement of a new purported clean source of energy came at a crucial time: adults still remembered the [[1973 oil crisis]] and the problems caused by oil dependence, anthropogenic [[global warming]] was starting to become notorious, the [[anti-nuclear movement]] was labeling nuclear power plants as dangerous and getting them closed, people had in mind the consequences of [[strip mining]], [[acid rain]], the [[greenhouse effect]] and the [[Exxon Valdez oil spill]], which happened the day after the announcement.<ref>{{harvnb|Petit|2009}}, {{harvnb|Park|2000|p=16}}</ref> In the press conference, [[Chase N. Peterson]], Fleischmann and Pons, backed by the solidity of their scientific credentials, repeatedly assured the journalists that cold fusion would solve environmental problems, and would provide a limitless inexhaustible source of clean energy, using only seawater as fuel.<ref>{{harvnb|Taubes|1993|pp=xviii–xx}}, {{harvnb|Park|2000|p=16}}</ref> They said the results had been confirmed dozens of times and they had no doubts about them.{{sfn|ps=|Taubes|1993|pp=xx–xxi}} In the accompanying press release Fleischmann was quoted saying: "What we have done is to open the door of a new research area, our indications are that the discovery will be relatively easy to make into a usable technology for generating heat and power, but continued work is needed, first, to further understand the science and secondly, to determine its value to energy economics."{{sfn|ps=|Scanlon|Hill|1999|p=212}}

====Response and fallout====
Although the experimental protocol had not been published, physicists in several countries attempted, and failed, to replicate the excess heat phenomenon. The first paper submitted to ''Nature'' reproducing excess heat, although it passed peer review, was rejected because most similar experiments were negative and there were no theories that could explain a positive result;<ref group="notes" name="Beaudette rejection"/>{{sfn|ps=|Beaudette|2002|pp=183, 313}} this paper was later accepted for publication by the journal ''Fusion Technology''.

[[Nathan Lewis (chemist)|Nathan Lewis]], professor of chemistry at the [[California Institute of Technology]], led one of the most ambitious validation efforts, trying many variations on the experiment without success,<ref name="CAB">{{cite web |last=Aspaturian |first=Heidi |date=14 December 2012<!-- pdf metadata, archive record page updated 2012-12-26 --> |title=Interview with Charles A. Barnes on 13 and 26 June 1989 |publisher=The Caltech Institute Archives |url=http://resolver.caltech.edu/CaltechOH:OH_Barnes_C_coldfusion |access-date=22 August 2014}}</ref> while [[CERN]] physicist Douglas R. O. Morrison said that "essentially all" attempts in Western Europe had failed.{{sfn|ps=|Browne|1989}} Even those reporting success had difficulty reproducing Fleischmann and Pons' results.{{sfn|ps=|Schaffer|1999|p=2}} On 10 April 1989, a group at [[Texas A&M University]] published results of excess heat and later that day a group at the [[Georgia Institute of Technology]] announced neutron production—the strongest replication announced up to that point due to the detection of neutrons and the reputation of the lab.<ref name=Broad1989a/> On 12 April Pons was acclaimed at an ACS meeting.<ref name=Broad1989a/> But Georgia Tech retracted their announcement on 13 April, explaining that their neutron detectors gave false positives when exposed to heat.<ref name=Broad1989a/>{{sfn|ps=|Wilford|1989}}

Another attempt at independent replication, headed by [[Robert Huggins]] at [[Stanford University]], which also reported early success with a light water control,<ref>Broad, William J. 19 April 1989. [https://www.nytimes.com/1989/04/19/us/stanford-reports-success.html Stanford Reports Success], ''[[The New York Times]]''.</ref> became the only scientific support for cold fusion in 26 April US Congress hearings.<ref group="text" name="only-support"/> But when he finally presented his results he reported an excess heat of only one degree [[Celsius]], a result that could be explained by chemical differences between heavy and light water in the presence of lithium.<ref group="notes" name="differences"/> He had not tried to measure any radiation<ref>{{harvnb|Close|1992|pp=184}}, {{harvnb|Huizenga|1993|p=56}}</ref> and his research was derided by scientists who saw it later.<ref>{{harvnb|Browne|1989}}, {{harvnb|Taubes|1993|pp=253–255, 339–340, 250}}</ref> For the next six weeks, competing claims, counterclaims, and suggested explanations kept what was referred to as "cold fusion" or "fusion confusion" in the news.{{sfn|ps=|Lewenstein|1994|pp=8–9}}<ref>{{harvnb|Bowen|1989}}, {{harvnb|Crease|Samios|1989}}</ref>

In April 1989, Fleischmann and Pons published a "preliminary note" in the ''[[Journal of Electroanalytical Chemistry]]''.{{sfn|ps=|Fleischmann|Pons|1989|p=301}} This paper notably showed a gamma peak without its corresponding [[Compton edge]], which indicated they had made a mistake in claiming evidence of fusion byproducts.<ref>{{harvnb|Tate|1989|p=1}}, {{harvnb|Platt|1998}}, {{harvnb|Close|1992|pp=277–288, 362–363}}, {{harvnb|Taubes|1993|pp=141, 147, 167–171, 243–248, 271–272, 288}}, {{harvnb|Huizenga|1993|pp=63, 138–139}}</ref> Fleischmann and Pons replied to this critique,<ref>{{cite journal|mode=cs2 |title=Measurement of gamma-rays from cold fusion (letter by Fleischmann et al. and reply by Petrasso et al.) |journal=Nature |volume=339 |issue=6227 |date=29 June 1989 |doi=10.1038/339667a0 |bibcode=1989Natur.339..667F |page=667 |last1=Fleischmann |first1=Martin |last2=Pons |first2=Stanley |last3=Hawkins |first3=Marvin |last4=Hoffman |first4=R. J |s2cid=4274005 |doi-access=free }}</ref> but the only thing left clear was that no gamma ray had been registered and that Fleischmann refused to recognize any mistakes in the data.<ref>{{harvnb|Taubes|1993|pp=310–314}}, {{harvnb|Close|1992|pp=286–287}}, {{harvnb|Huizenga|1993|pp=63, 138–139}}</ref> A much longer paper published a year later went into details of calorimetry but did not include any nuclear measurements.{{sfn|ps=|Fleischmann|Pons|Anderson|Li|1990}}

Nevertheless, Fleischmann and Pons and a number of other researchers who found positive results remained convinced of their findings.{{sfn|ps=|Browne|1989}} The University of Utah asked Congress to provide $25&nbsp;million to pursue the research, and Pons was scheduled to meet with representatives of President Bush in early May.{{sfn|ps=|Browne|1989}}

On 30 April 1989, cold fusion was declared dead by ''The New York Times''. The ''Times'' called it a circus the same day, and the ''Boston Herald'' attacked cold fusion the following day.<ref>{{harvnb|Taubes|1993|p=242}} (Boston Herald's is {{harvnb|Tate|1989}}).</ref>

On 1 May 1989, the [[American Physical Society]] held a session on cold fusion in Baltimore, including many reports of experiments that failed to produce evidence of cold fusion. At the end of the session, eight of the nine leading speakers stated that they considered the initial Fleischmann and Pons claim dead, with the ninth, [[Johann Rafelski]], abstaining.{{sfn|ps=|Browne|1989}} [[Steven E. Koonin]] of [[Caltech]] called the Utah report a result of "''the incompetence and delusion of Pons and Fleischmann,''" which was met with a standing ovation.{{sfn|ps=|Taubes|1993|p=266}} [[Douglas R. O. Morrison]], a physicist representing [[CERN]], was the first to call the episode an example of [[pathological science]].{{sfn|ps=|Browne|1989}}<ref>{{cite web|url=http://www.ibiblio.org/pub/academic/physics/Cold-fusion/vince-cate/aps.ascii|title=APS Special Session on Cold Fusion, May 1–2, 1989|website=ibiblio.org|url-status=live|archive-url=https://web.archive.org/web/20080726071304/http://www.ibiblio.org/pub/academic/physics/Cold-fusion/vince-cate/aps.ascii|archive-date=26 July 2008}}</ref> On 4 May, due to all this new criticism, the meetings with various representatives from Washington were cancelled.{{sfn|ps=|Taubes|1993|pp=267–268}}

From 8 May, only the A&M tritium results kept cold fusion afloat.{{sfn|ps=|Taubes|1993|pp=275, 326}}

In July and November 1989, ''Nature'' published papers critical of cold fusion claims.{{sfn|ps=|Gai|Rugari|France|Lund|1989|pp=29–34}}{{sfn|ps=|Williams|Findlay|Craston|Sené|1989|pp=375–384}} Negative results were also published in several other [[scientific journal]]s including ''[[Science (journal)|Science]]'', ''[[Physical Review Letters]]'', and ''[[Physical Review|Physical Review C]]'' (nuclear physics).<ref group="notes" name="nature critical papers"/> In August 1989, in spite of this trend, the state of [[Utah]] invested $4.5&nbsp;million to create the National Cold Fusion Institute.{{sfn|ps=|Joyce|1990}}

The [[United States Department of Energy]] organized a special panel to review cold fusion theory and research.{{sfn|ps=|US DOE|1989|p=39}} The panel issued its report in November 1989, concluding that results as of that date did not present convincing evidence that useful sources of energy would result from the phenomena attributed to cold fusion.{{sfn|ps=|US DOE|1989|p=36}} The panel noted the large number of failures to replicate excess heat and the greater inconsistency of reports of nuclear reaction byproducts expected by established [[conjecture]]. Nuclear fusion of the type postulated would be inconsistent with current understanding and, if verified, would require established conjecture, perhaps even theory itself, to be extended in an unexpected way. The panel was against special funding for cold fusion research, but supported modest funding of "focused experiments within the general funding system".{{sfn|ps=|US DOE|1989|p=37}}

Cold fusion supporters continued to argue that the evidence for excess heat was strong, and in September 1990 the National Cold Fusion Institute listed 92 groups of researchers from 10 countries that had reported corroborating evidence of excess heat, but they refused to provide any evidence of their own arguing that it could endanger their patents.<ref>{{harvnb|Huizenga|1993|p=165}}</ref> However, no further DOE nor NSF funding resulted from the panel's recommendation.{{sfn|ps=|Mallove|1991|pp=246–248}} By this point, however, academic consensus had moved decidedly toward labeling cold fusion as a kind of "pathological science".<ref name="nytdoe"/>{{sfn|Rousseau|1992}}

In March 1990, Michael H. Salamon, a physicist from the [[University of Utah]], and nine co-authors reported negative results.<ref>{{cite journal|last1=Salamon|first1=M. H.|last2=Wrenn|first2=M. E.|last3=Bergeson|first3=H. E.|last4=Crawford|first4=H. C.|last5=Delaney|first5=W. H.|last6=Henderson|first6=C. L.|last7=Li|first7=Y. Q.|last8=Rusho|first8=J. A.|last9=Sandquist|first9=G. M.|last10=Seltzer|first10=S. M. |s2cid=4369849|display-authors= 4|title=Limits on the emission of neutrons, γ-rays, electrons and protons from Pons/Fleischmann electrolytic cells|journal=Nature|date=29 March 1990|volume=344|issue=6265|pages=401–405|doi=10.1038/344401a0|bibcode=1990Natur.344..401S}}</ref> University faculty were then "stunned" when a lawyer representing Pons and Fleischmann demanded the Salamon paper be retracted under threat of a lawsuit. The lawyer later apologized; Fleischmann defended the threat as a legitimate reaction to alleged bias displayed by cold-fusion critics.<ref name="nytimes escapes">{{cite news|last=Broad|first=William J.|title=Cold Fusion Still Escapes Usual Checks Of Science|url=https://www.nytimes.com/1990/10/30/science/cold-fusion-still-escapes-usual-checks-of-science.html?pagewanted=all&src=pm|access-date=27 November 2013|newspaper=The New York Times|date=30 October 1990|url-status=live|archive-url=https://web.archive.org/web/20131219181647/http://www.nytimes.com/1990/10/30/science/cold-fusion-still-escapes-usual-checks-of-science.html?pagewanted=all&src=pm|archive-date=19 December 2013}}</ref>

In early May 1990, one of the two A&M researchers, [[Kevin Wolf]], acknowledged the possibility of spiking, but said that the most likely explanation was tritium contamination in the palladium electrodes or simply contamination due to sloppy work.<ref>{{harvnb|Taubes|1993|pp=410–411}}, {{harvnb|Close|1992|pp=270, 322}}, {{harvnb|Huizenga|1993|pp=118–119, 121–122}}</ref> In June 1990 an article in ''Science'' by science writer [[Gary Taubes]] destroyed the public credibility of the A&M tritium results when it accused its group leader [[John Bockris]] and one of his graduate students of spiking the cells with tritium.<ref>{{harvnb|Taubes|1993|pp=410–411, 412, 420}}, the Science article was {{harvnb|Taubes|1990}}, {{harvnb|Huizenga|1993|pp=122, 127–128}}.</ref> In October 1990 Wolf finally said that the results were explained by tritium contamination in the rods.{{sfn|ps=|Huizenga|1993|pp=122–123}} An A&M cold fusion review panel found that the tritium evidence was not convincing and that, while they couldn't rule out spiking, contamination and measurements problems were more likely explanations,<ref group="text" name="spiking"/> and Bockris never got support from his faculty to resume his research.

On 30 June 1991, the National Cold Fusion Institute closed after it ran out of funds;<ref>{{cite web|mode=cs2 |title=National Cold Fusion Institute Records, 1988–1991 |url=http://content.lib.utah.edu/cdm4/item_viewer.php?CISOROOT=/UU_EAD&CISOPTR=160 |url-status=live |archive-url=https://archive.today/20120717185323/http://content.lib.utah.edu/cdm4/item_viewer.php?CISOROOT=/UU_EAD&CISOPTR=160 |archive-date=17 July 2012  }}</ref> it found no excess heat, and its reports of tritium production were met with indifference.{{sfn|ps=|Taubes|1993|p=424}}

On 1 January 1991, Pons left the University of Utah and went to Europe.{{sfn|ps=|Taubes|1993|p=424}}{{sfn|ps=|Huizenga|1993|p=184}} In 1992, Pons and Fleischmann resumed research with [[Toyota Motor Corporation]]'s IMRA lab in France.{{sfn|ps=|Taubes|1993|p=424}} Fleischmann left for England in 1995, and the contract with Pons was not renewed in 1998 after spending $40&nbsp;million with no tangible results.{{sfn|ps=|Taubes|1993|pp=136–138}} The IMRA laboratory stopped cold fusion research in 1998 after spending £12&nbsp;million.{{sfn|ps=|Voss|1999a}} Pons has made no public declarations since, and only Fleischmann continued giving talks and publishing papers.{{sfn|ps=|Taubes|1993|pp=136–138}}

Mostly in the 1990s, several books were published that were critical of cold fusion research methods and the conduct of cold fusion researchers.<ref>{{harvnb|Close|1992}}, {{harvnb|Taubes|1993}}, {{harvnb|Huizenga|1993}}, and {{harvnb|Park|2000}}</ref> Over the years, several books have appeared that defended them.<ref>{{harvnb|Mallove|1991}}, {{harvnb|Beaudette|2002}}, {{harvnb|Simon|2002}}, {{harvnb|Kozima|2006}}</ref> Around 1998, the University of Utah had already dropped its research after spending over $1&nbsp;million, and in the summer of 1997, Japan cut off research and closed its own lab after spending $20&nbsp;million.<ref name="wired steam"/>