Un tro, roedd Daf wedi penderfynu rhoi darlith i’r madarch. Roedd gyda fe ddiddordeb mawr mewn gwyddoniaeth, fel mater o ffaith. Bocs mawr â chaead yn gynnwys powlen o fwyd cathod yr oedd o’i flaen. Tawel oedd ei gynulleidfa o fadarch, yn edrych ar Daf yn ddisgwylgar.
– Reit, ‘te, meddai Daf, – dw i’n mynd i esbonio arosodiad cwantwm gan ailadrodd fersiwn o arbrawf Schroedinger, sef Gath Schroedinger. Dyma’n nghynorthwyydd hyfryd, Jeff, meddai, gan ddangos ei ffrind calico.
Roedd golwg ofnus ar y madarch.
– Wyt ti’n mynd i’w haneru â llif? gofynnodd un ohonynt.
– Nadw, sdim Sellotape ‘da fi, ymatebodd Daf.
Parhaodd y gath wyddonol.
– Gall pethau’n bodoli mewn cyflyrau amrywiol ar yr un pryd. Ni’n newid pethau gan ‘u sylwi nhw. Os fydda i’n cau’r caead, bydd y bwyd cathod yn bresennol ac yn absennol. Nid cyn i ni ail-agor y caead bydden ni’n gwbod pa un.
Caeodd y caead, ac aros am funud.
Pan ei ail-agorodd e Daf, roedd pawb yn gallu gweld powlen wag, a chath lawn yn y bocs. Roedd Jeff wedi bwyta popeth.
– Shwt wnest ti hwnna? meddai madarch.
– Hyblygrwydd. Galla i fodoli mewn cyflyrau amrywiol ar yr un pryd, meddai Jeff, gyda winc.
– QED, meddai Daf.
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Saesneg / English
Quantum Cats
One day, Dave had decided to give a lecture to the mushrooms. He had a great interest in science, as a matter of fact. A big box with a lid containing a bowl of cat food was in front of him. The audience of mushrooms were quiet, and looking at Dave expectantly.
– Right, then, said Dave, – I’m going to explain quantum superposition by repeating a version of Schroedinger’s thought experiment, namely Schroedinger’s Cat. Here is my lovely assistant, Jeff, he said, indicating his calico friend.
The mushrooms looked scared.
– Are you going to saw her in half? asked one of them.
– No, I haven’t got any Sellotape, responded Dave.
The scientific cat continued.
– Things can exist in various states at the same time. We change things by observing them. If I close the lid, the cat food will be both present and absent. Not until we re-open the lid will we know which one.
He closed the lid, and waited for a minute.
When Dave reopened it, everyone could see an empty bowl and a full cat in the box. Jeff had eaten everything.
– How did you do that? said a mushroom.
– Flexibility. I can exist in multiple states at the same time, said Jeff, with a wink.
– QED, said Dave.
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