In logic, the second problem on David Hilbert's list of open problems presented in 1900 was to prove that the axioms of arithmetic are consistent.

Following the decisive Ethiopian victory at Adwa, Menelik II rapidly negotiated a series of treaties fixing Ethiopia's boundaries — with French Somaliland in March 1897, British Somaliland a few months later in June 1897, with Italian Eritrea in 1900, Anglo-Egyptian Sudan in 1902, British East Africa in 1907, and Italian Somaliland in 1908 — which simplified this problem on one level.

This was followed by the 1859 statement of the black body radiation problem by Gustav Kirchhoff, the 1877 suggestion by Ludwig Boltzmann that the energy states of a physical system can be discrete, and the 1900 quantum hypothesis of Max Planck.

The history of quantum chemistry essentially began with the 1838 discovery of cathode rays by Michael Faraday, the 1859 statement of the black body radiation problem by Gustav Kirchhoff, the 1877 suggestion by Ludwig Boltzmann that the energy states of a physical system could be discrete, and the 1900 quantum hypothesis by Max Planck that any energy radiating atomic system can theoretically be divided into a number of discrete energy elements ε such that each of these energy elements is proportional to the frequency ν with which they each individually radiate energy and a numerical value called Planck ’ s Constant.

In 1900, David Hilbert posed an influential question about transcendental numbers, Hilbert's seventh problem: If a is an algebraic number, that is not zero or one, and b is an irrational algebraic number, is a < sup > b </ sup > necessarily transcendental?

In this way, the year 1900 is to the Year 2000 problem as is the year 1901 to the Year 2038 problem.

Possibly the most famous bug is the Year 2000 problem, also known as the Y2K bug, in which it was feared that worldwide economic collapse would happen at the start of the year 2000 as a result of computers thinking it was 1900.

Hilbert's tenth problem is the tenth on the list of Hilbert's problems of 1900.

In mathematics, Hilbert's second problem was posed by David Hilbert in 1900 as one of his 23 problems.

Hilbert's fifth problem is the fifth mathematical problem from the problem list publicized in 1900 by mathematician David Hilbert, and concerns the characterization of Lie groups.

Since 1900, other mathematicians and mathematical organizations have announced problem lists, but, with few exceptions, these collections have not had nearly as much influence nor generated as much work as Hilbert's problems.

In 1905, Albert Einstein demonstrated the physical reality of the photons, hypothesized by Max Planck in 1900, in order to solve the problem of black body radiation in thermodynamics.

The term " ultraviolet catastrophe " was first used in 1911 by Paul Ehrenfest, although the concept goes back to 1900 with the first derivation of the dependence of the Rayleigh – Jeans law ; the word " ultraviolet " refers to the fact that the problem appears in the short wavelength region of the electromagnetic spectrum.

The analogous statement about polyhedra in three dimensions, known as Hilbert's third problem, is false, as proven by Max Dehn in 1900.

In 1900 David Hilbert included it in his list of twenty three unsolved problems of mathematics — it forms part of Hilbert's eighteenth problem.

Hilbert's 16th problem was posed by David Hilbert at the Paris conference of the International Congress of Mathematicians in 1900, together with the other 22 problems.

Hilbert's seventh problem is one of David Hilbert's list of open mathematical problems posed in 1900.

When Ernest died in 1900, money became a problem for the rest of the family.

In order to solve the problem, the railway company changed the name of the station in 1900 to " Estação de Villa Americana " ( American Town Station ).

Upon opening, the Red Building had been starkly underfurnished, a problem which was not fully remedied until after the Hurricane of 1900, when the state rallied around the ravaged city.

Hilbert's eighth problem is one of David Hilbert's list of open mathematical problems posed in 1900.

By 1900 the city was operating its own sewage system.

Around 1900, Seattle began discharging sewage into Lake Washington.

Most cities in the United States underwent their sanitary revolutions between 1900 and 1935, by adding more expensive sewer systems and other technology to rid themselves of bad bacteria by chlorinating water and filtering water and sewage.

Before completion of the canal in 1900, the sewage in the Chicago River flowed into Lake Michigan, the city's drinking water supply.

When the City permanently reversed the flow of the Chicago River in 1900, the intent was to prevent the Stock Yards ' waste products along with other sewage from flowing into Lake Michigan and contaminating the City's drinking water.

A mixture of a general decline in the popularity of spa bathing and, reportable, contamination of the waters from mining activities led to the eventual closure of the baths just before 1900.

The northern part of the site had been within the Los Angeles City Oil Field, an industrial area which contained over 1, 000 active oil wells around 1900, and a concern of soil contamination – specifically, methane and hydrogen sulfide – was confirmed during development in 1999.

In 1900 the South was only 15% urban ; ;

It is difficult to say what Thompson expected would come of their relationship, which had begun so soon after his emotions had been stirred by Maggie Brien, but when Katie wrote on April 11, 1900, to tell him that she was to be married to the Rev. Godfrey Burr, the vicar of Rushall in Staffordshire, the news evidently helped to deepen his discouragement over the failure of his hopes for a new volume of verse.

If, as Reid says, `` nearly all his poetry was produced when he was not taking opium '', there may be some reason to doubt that he was under its influence in the period from 1896 to 1900 when he was writing the poems to Katie King and making plans for another book of verse.

These must have been for local calls strictly, as in May 1900 the `` only long distance telephone '' in town was transferred from C. B. Carleton's to Young's shoe store.

On June 14, 1900 the Manchester Journal reported that an electrical engineer was installing an electric light plant for Edward S. Isham at `` Ormsby Hill ''.

In November 1900 surveying was done under John Marsden on the east mountains to ascertain if it would be possible to get sufficient water and fall to operate an electric power plant.

Poems Of The Past And The Present and Time's Laughing Stocks, both published while Hardy was at work on The Dynasts, draw heavily on poems written before 1900.

For those affiliated with it, the A.L.A.M. pool was a haven from the infringement actions involving detail patents that beset the industry with mounting intensity after 1900.

In 1900, with the completion of his licentiate in theology, he was ordained as curate, and that year he witnessed the Oberammergau Passion Play.

Electric street lighting was introduced in 1900 and electric trams were transporting passengers in 1909.

It was designed by the Catalan architect Antoni Gaudí and built in the years 1900 to 1914.

In 1900 Spalding was appointed by President McKinley as the USA's Commissioner at that year's Summer Olympic Games.

In 1900 he moved to San Diego and became a prominent member and supporter of the Theosophical community Lomaland, which was being developed on Point Loma by Katherine Tingley.

By 1900, he was a world-renowned artist.

Ajax was founded in Amsterdam on March 18, 1900.

In 1900, when the club was founded, the emblem of Ajax was just a picture of an Ajax player.

However in the United Kingdom, pioneering research into painting materials and conservation, ceramics, and stone conservation was conducted by Arthur Pillans Laurie, academic chemist and Principal of Heriot-Watt University from 1900.

* AT & T Mobility-In areas where AT & T Mobility previously had D-AMPS operating on 1900 MHz frequencies, no analog AMPS network existed, and the D-AMPS network on the 1900 MHz frequency was shut down in mid-2007.

By 1900 the advertising agency had become the focal point of creative planning, and advertising was firmly established as a profession.

Its population in 1900 was 1, 675.