Poland is not, and never was, a scientific powerhouse. However, she managed to invent a few things: oil wells, Esperanto, radiotherapy, bulletproof vest, mine detector (well, re-invented), movie projector (pleograf invented allegedly a year before Lumiere's invention), walkie-talkie, holography (additionally the same guy made a prototype of a TV set called electroscope), Melex, delta type wing, paraffin lamp (and first refinery and petroleum mine), hydrogen bomb (google Stanisław Ulam) and blue laser technology. Poland has an element named after her in the periodic table (polon).
Polish pioneers in physical chemistry Zygmunt Wróblewski and Karol Olszewski liquefied, for the first time in the world, components of air thereby opening to science and industry new fields of research and application.
Jacek Karpiński was a Polish pioneer in computer engineering and computer science. He became a developer of one of the first machine learning algorithms, techniques for character and image recognition.
In 1971 he designed of one of the first minicomputers, the K-202. Because of the policy on computer development in the People's Republic of Poland, belonging to the Comecon that time, K-202 was never mass produced. Karpiński later became a pig farmer, and in 1981, after receiving a passport, emigrated to Switzerland.
Polish mathematicians broke German Enigma code machine before WW2. Recently there is a pulsar clock (an atomic clock based on pulsar timing. The most accurate ever).
Useful link http://pl.wikipedia.org/wiki/Kategoria:Polscy_wynalazcy