View source for Olinto De Pretto

{{short description|Italian industrialist and geologist (1857–1921)}}
{{Multiple issues|{{POV|date=January 2022}}{{more citations needed|date=February 2022}}}}
{{Infobox scientist
|name  = Olinto De Pretto
|image = OlintoDePretto.JPG
|caption    = Olinto De Pretto
|birth_date = {{Birth date|df=yes|1857|4|26}}
|birth_place = [[Schio]], [[Austrian Empire]]
|death_date  = {{Death date and age|1921|03|16|1857|4|26|df=y}}
|death_place = Schio, Province of Vicenza, Italy
|nationality = [[Italian people|Italian]]
|citizenship =
|fields = {{Unbulleted list|[[Theoretical physics]]|[[Geology]]}}
|workplaces = {{Unbulleted list|Superior School of Agriculture, [[Milan]]|mechanical foundry mill|Alpinistic Circle}}
|alma_mater = Superior School of Agriculture, Milan
|academic_advisors = [[Gaetano Cantoni]]
|known_for = {{Unbulleted list|Claimed [[nonrelativistic]] derivation of the [[mass–energy equivalence]] relation (E{{=}}mc<sup>2</sup>)|Work on the [[radioactive decay]] of uranium and thorium|Effects of [[glaciers]] on the formation of [[mountains]]|Work on [[agronomics]]}}
|footnotes =
}}
'''Olinto De Pretto''' (26 April 1857 – 16 March 1921) was an Italian [[industrialist]] and [[geologist]] from [[Schio]], [[Vicenza]]. It is claimed by an{{Additional citation needed|date=January 2022}} Italian mathematician, [[Umberto Bartocci]],<ref>Umberto Bartocci, ''Albert Einstein e Olinto De Pretto—La vera storia della formula più famosa del mondo'', editore Andromeda, Bologna, 1999.</ref><ref name="guardianEinstein">{{Cite news | url=https://www.theguardian.com/world/1999/nov/11/rorycarroll | title=Einstein's E=mc2 'was Italian's idea'| newspaper=The Guardian| date=1999-11-11| last1=Carroll| first1=Rory}}</ref> that De Pretto may have been the first person to derive the energy–mass-equivalence <math>E=mc^2</math>, generally attributed to [[Albert Einstein]]. But this is refuted by [[Ignazio Marchioro]] in ''[[Quaderni di Schio]]'', where it shows that the similarity was a coincidence, and that the energy proposed by De Pretto doubles the one of Einstein's formula.<ref>{{Citation
| last        = Valente | first       = Luca
| title       = De Pretto come Albert Einstein?
| publisher   = Università degli Studi di Bari "Aldo Moro" | url = http://www.swif.uniba.it/lei/rassegna/020804a.htm
| publication-place = Italy
| archive-url = https://web.archive.org/web/20060408033350/http://www.swif.uniba.it/lei/rassegna/020804a.htm
| archive-date= 2006-04-08
}}</ref>
Also, De Pretto suggested that [[radioactive decay]] of [[uranium]] and [[thorium]] was an example of mass transforming into energy.{{Citation needed|reason=Never referenced|date=January 2022}}

==Early life==
Olinto De Pretto was born on April 26, 1857, in Schio in what is now the [[Provinces of Italy|province]] of [[Vicenza]] in northern [[Italy]]. Olinto was the sixth of seven children (three boys, and four girls). His mother was Angelica Boschetti (1822–1905). His father, Pietro De Pretto (1810–1891), was an [[architect]] whose hobbies included [[astronomy]] and [[geology]], two studies Olinto would later take up.

He attended the Superior School of Agriculture in Milan where he studied [[agriculture]] and [[geology]] with a major in [[agronomics]]. He graduated in 1879 with a degree in agronomics. Immediately upon graduation, he became a university assistant to professor [[:it:Gaetano Cantoni (agronomo)|Gaetano Cantoni]], a [[Dean (education)|Dean]] of the agricultural school. Together they developed methods that helped modernize Italian agriculture by improving methods of [[crop rotation]] and analyzing [[soil chemistry]].{{Citation needed|reason=Previous reference was not related|date=January 2022}}

When Cantoni died in 1887, Olinto left the university and became a director at a mechanical [[foundry mill]] owned by his older brother Silvio, where he worked for the rest of his life.

==Early scientific research and papers==
In 1888, as a result of his research with his brother Augusto, he published his first paper, "The Influence of the Raising and the Degradation of Mountains on the Development of Glaciers". In 1892, along with his brothers Augusto and Silvio, they founded the Alpinistic Circle with Silvio as the first president. In 1896 the Bulletin of the Italian Society of Geology republished his article as "The Degradation of Mountains and Its Influence on Glaciers".{{Citation needed|reason=cartesio-episteme.net is not a reliable source, see: https://en.wikipedia.org/w/index.php?title=Olinto_De_Pretto&type=revision&diff=587933317&oldid=587932272|date=January 2022}} In 1898, his paper titled "Glacial Epoch and [[Orology|Orografical]] Theory" was published in the Bulletin of the Italian Alpine Club.

In 1899, he published "Geological Signs in the Surroundings of Schio".

==Contributions to physics and energy–mass-equivalence==
From 1899 to 1903 De Pretto began to study the emerging field of [[nuclear physics]] and its relationship to [[astronomy]]. He focused on the theory of [[luminiferous aether|aether]], a hypothetical substance that at that time was believed to fill all space.

As a result of his research on November 29, 1903, De Pretto published a 62-page paper in the ''Atti del Reale Istituto Veneto di Scienze, Lettere ed Arti'', vol LXIII (''Proceedings of the Royal Veneto Institute of Science, Letters and Arts'') entitled "''Ipotesi dell'Etere nella Vita dell'Universo''" ("''Hypothesis of [[Aether theories|Aether]] in the Life of the Universe''"). The paper was endorsed by the famous astronomer [[Giovanni Schiaparelli]]. De Pretto's paper was later included in the proceedings of an Italian scientific institute The Royal Veneto Institute of Science.<ref>{{Cite journal|author=Olinto De Pretto|title=Ipotesi dell'etere nella vita dell'universo (Hypothesis of Aether in the Life of the Universe)|journal="Reale Istituto Veneto di Scienze, Lettere ed Arti" (The Royal Veneto Institute of Science, Letters and Arts)|year=1903|volume=LXIII|issue=II|pages=439–500|url=http://www.cartesio-episteme.net/st/mem-depr-vf.htm}} (Accepted November 23, 1903 and printed February 27, 1904.)</ref><!-- [[:it:Istituto veneto di scienze, lettere ed arti]] -->

This theory was similar to [[Samuel Tolver Preston]]'s 1875 hypothesis that matter and energy might be interchangeable. De Pretto's theory was based on his [[hypothesis]] that a mass traveling at velocity ''v'' has the [[potential energy]]<ref>{{cite book |title=Challenging Modern Physics: Questioning Einstein's Relativity Theories
|first1=Al |last1=Kelly|publisher=Universal-Publishers |year=2005 |isbn=1-58112-437-6 |page=18 |url=https://books.google.com/books?id=XVLmihZnsvUC}} [https://books.google.com/books?id=XVLmihZnsvUC&pg=PA18 Extract of page 18.]</ref> (''forza viva'') proportional to mv<sup>2</sup> (the exact formula is {{frac|1|2}}mv<sup>2</sup>). In the section of his paper headed ''Energy of the Ether and Potential Energy in Matter'', De Pretto wrote:

:''Matter uses and stores energy as inertia, just like a steam engine that uses the energy in steam and stores energy in inertia as potential energy[... ] All components of a body are animated by infinitesimal but rapid movements equal to perhaps the ''vibration of the ether''. It must be concluded that the matter in any body contains the sum of the energy represented by the entire mass of that body if it could move through space with the speed of a single particle.''<ref>{{cite book |first1=Al |last1=Kelly|title=Challenging Modern Physics}} [https://books.google.com/books?id=XVLmihZnsvUC&pg=PA17 Extract of page 17.]</ref>

By theorizing the "vibration of the ether", De Pretto asserted that mass is vibrating energy and that mass and energy are therefore interchangeable. He then speculated that ordinary matter may be considered to be vibrating at the [[speed of light]] ''c''.{{Citation needed|reason=Never referenced|date=January 2022}}

According to De Pretto,

:''The matter of any body contains within it a sum of energy represented by the entire mass of the body[... ] Nobody will easily admit that, stored in a latent state, in any kilogram of matter, completely hidden to all our investigations, hides such a sum of energy, equivalent to the amount that can be extracted from [burning] millions and millions of kilograms of coal."''

===½mv² versus mc²===
{{See|Mass–energy equivalence#History}}
De Pretto used the expression <math>mv^2</math> for the "[[vis viva]]" and the energy stored within matter, where he identified ''v'' with the [[speed of light]].{{Citation needed|reason=Never referenced|date=January 2022}} According to Italian mathematician [[Umberto Bartocci]], his formula precedes by two years, and is in agreement with [[Albert Einstein]]'s later formula <math>E=mc^2</math> for [[mass–energy equivalence]], which was derived by Einstein as a consequence of [[special relativity]]. According to Bartocci, Einstein may have learned of de Pretto's work through his Swiss-Italian friend [[Michele Besso]].<ref>{{cite news|title=E=mc2: "Tutto merito dell'italiano Olinto"|url=https://www.corriere.it/Primo_Piano/Scienze_e_Tecnologie/2007/04_Aprile/12/einstein_olinto_emc2.html|date=13 April 2007|first=Simona|last=Marchetti|newspaper=[[Corriere della Sera]]}}</ref>

===Radioactive decay===
De Pretto's paper discussed the [[radioactive decay]] of [[uranium]] and [[thorium]] and was the first to conclude that this decay was energy transformation from mass into energy. He also presented a hypothesis that the intense heat assumed to be in the centre of the [[Earth]] (theory of central fire) was caused by the tremendous mass of the earth creating a massive radioactive core giving off heat and energy.{{Citation needed|reason=Never referenced|date=January 2022}}

==Honours==
In 1906 De Pretto was accepted as a member of [[Accademia dei Lincei]], a [[Learned society|scientific organization]] whose members included [[Galileo Galilei]]. The director of the organization, [[Ernesto Mancini]], was also a member of [[The Royal Society of London]], an international scientific society. Mancini submitted De Pretto's paper to the Royal Society for international recognition. It was received favourably and was listed in the Society's ''[[International Catalogue of Scientific Literature]]''.<ref>{{Cite journal|author=Royal Society of London|title=International Catalogue of Scientific Literature|journal=International Catalogue of Scientific Literature|year=1906|issue=V|pages=83, 160}} (Printed November 1906.)</ref>

==References==
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{{DEFAULTSORT:De Pretto, Olinto}}
[[Category:1857 births]]
[[Category:1921 deaths]]
[[Category:19th-century Italian geologists]]
[[Category:People from Schio]]
[[Category:20th-century Italian physicists]]
[[Category:Italian industrialists]]
[[Category:Members of the Lincean Academy]]