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agf·

Using https://www.everythingrf.com/rf-calculators/line-of-sight-ca... because it's the first result that came up.

298m height where he's viewing from = 61.6km line of sight

610m height of Knockbrack = 88.2km LOS

Total of 149.8km theoretical visible distance.

And in the article he mentions a real distance of 154 miles -- not kilometers. So doesn't sound like there is any chance it was actually Ireland?

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It's not an unreasonable distance for a refraction mirage, however. My math reached the same number as yours, but it does assume the light goes in a straight line.

Reminders me of this article; https://www.abc57.com/news/skyline-skepticism-the-lake-michi...

The 170km number given in another comment (and by the calculators) is meant to take into account "normal" light-bending; the distance here is 250km. While I'm not an expert, that seems like a lot of extra distance / angle to make up.

you can use shortwave radios to communicate 10,000 miles using ionospheric refraction.

It is reasonable to think there are similar refraction phenomena in the troposphere, probably associated with thermal inversions

Oddly this calculator gives a different result of 172km for those heights, I assume from a different value of R: https://www.translatorscafe.com/unit-converter/el-GR/calcula...

Same result, just true "line of sight" vs. including light bending. The calculator I used gives both values.

I wonder if the right weather conditions could result in enough atmospheric refraction to make the mountain visible.

Yes, this is called "looming": https://en.wikipedia.org/wiki/Looming_and_similar_refraction...

It would need a hell of a lot of atmospheric bending, but I don’t think it’s unprecedented.

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