antihydrogen

American  

[an-tee-hahy-druh-juhn, an-tahy-] / ˌæn tiˈhaɪ drə dʒən, ˌæn taɪ- /

noun

Physics.

1. the antimatter counterpart to hydrogen.

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antihydrogen British  

/ ˈæntɪˌhaɪdrədʒən /

noun

1. hydrogen in which the nucleus is an antiproton with an orbiting positron

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antihydrogen Scientific  

/ ăn′tē-hī′drə-jən,ăn′tī- /

1. The antimatter that corresponds to hydrogen. Antihydrogen has been useful in studies of the relationship between matter and antimatter, because its matter equivalent (hydrogen) is one of the most studied and most well understood forms of matter.

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Example Sentences

Last year a separate team of researchers tested whether antihydrogen responded differently to gravity by seeing if it fell up or down when dropped.

From BBC

"Many indirect measurements indicate that gravity interacts with antimatter as expected" he added, "but until the result today, nobody had actually performed a direct observation that could rule out, for example, antihydrogen moving upwards as opposed to downwards in a gravitational field."

From Science Daily

As each antihydrogen atom escaped the magnetic trap, it touched the chamber walls either above or below the trap and annihilated, which the scientists could detect and count.

From Science Daily

They observed that when the weakened magnetic fields were precisely balanced at the top and bottom, about 80% of the antihydrogen atoms annihilated beneath the trap -- a result consistent with how a cloud of regular hydrogen would behave under the same conditions.

From Science Daily

Thus, gravity was causing the antihydrogen to fall down.

From Science Daily