4 ms·
Using https://www.everythingrf.com/rf-calculators/line-of-sight-calculator https://www.everythingrf.com/rf-calculators/line-of-sight-ca... because it's the firs
by agf 5y ago
Using https://www.everythingrf.com/rf-calculators/line-of-sight-calculator 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?
- soneil 5y agoIt'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-michigan-mirage https://www.abc57.com/news/skyline-skepticism-the-lake-michi...
- agf 5y agoThe 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.
- someguydave 5y agoyou 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
- mdturnerphys 5y agoI wonder if the right weather conditions could result in enough atmospheric refraction to make the mountain visible.
- ink_13 5y agoYes, this is called "looming": https://en.wikipedia.org/wiki/Looming_and_similar_refraction_phenomena https://en.wikipedia.org/wiki/Looming_and_similar_refraction...
- midasuni 5y agoIt would need a hell of a lot of atmospheric bending, but I don’t think it’s unprecedented.
- tdeck 5y agoOddly 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/calculator/radio-line-of-sight/?mobile=1 https://www.translatorscafe.com/unit-converter/el-GR/calcula...
- agf 5y agoSame result, just true "line of sight" vs. including light bending. The calculator I used gives both values.