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Particle Physics and Pony Fiction Experimentalist

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Survival Probability · 12:06pm May 3rd

Any fans of Daring Do and the Inexplicable Artifact want to learn more about the mysterious ancient hieroglyphs that puzzled Daring Do and Twilight Sparkle in that story?

Do you, like Pinkie Pie, learn through musical intervention?

If so, take a look at this lecture:

To offer a bit more explanation, for those who are still confused, this is deriving the equation for the probability that a neutrino of energy E, created as an electron neutrino, is also an electron neutrino after travelling a distance L (the 'survival probability'), assuming neutrinos can oscillate between two flavours. If you have read the story you will know there actually three neutrino flavours, but that makes it bit difficult to fit all the maths in a short clip.

The underlying story is the Solar Neutrino Problem - why early neutrino experiments failed to detect the number of neutrinos that should be produced by the sun according to the Standard Solar Model (by John Bahcall). It was shown by later experiments (SNO and Super K) that they were changing to another flavour. As explained in this old post: Pony Adventures in Particle Physics: Twilight, Pinkie Pie and Rainbow Dash visit Sudbury, Ontario and shed light on neutrinos

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Comments ( 6 )

What’s even more impressive than reciting/lip-syncing the derivation to music is that he’s simultaneously writing it on glass — backwards.

Pineta #2 · May 3rd · · ·

This must be somehow connected to neutrino helicity and parity violation in the weak interaction.

Walabio #3 · May 5th · · ·


The rapping physicist writes forward while lipsynching. The audio is prerecorded and the video is flipped horizontally. This is videotrickery. "Because Science" is flipped horizontally too:

As an aside, in school, when the teachers got all excited that the brain could turn the visual field right-side-up, my response is that the image is the way it is to the brain with no flipping required. Visual processing is extremely complicated, but the teacher makes a mountain out of this molehill of a nonissue.


The rapping physicist writes forward while lipsynching. The audio is prerecorded and the video is flipped horizontally. This is videotrickery.

I stand corrected — turns out he has a “behind the scenes” video posted, as well, that clearly shows what you’ve described.

Still, it would have been at least 20% cooler if he’d written backwards. :twilightsheepish:


Given that scammers could try to take advantage of one, one should learn the tricks. Luckily, we have Captain Disillusion:

Those videos taught me quite a few tricks as well as somethings which I figured must be tricks, like landing pingpongballs in wineglasses across the room, which are real skills.

...that is both funny and an increfibly nerdy joke. Had to refresh my own learnin' to get it.

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