From Ham Radio Workbench episode #250, around 2:23:00 mark.

They are talking about VHF, UHF, and microwave frequencies going beyond line-of-sight.
These are line-of-sight frequencies which do NOT bounce off the "ionosphere" according to their model.
These frequencies should TOTALLY, ABSOLUTELY go off into space rather than bounce around, according to their model.

But experienced hams point out that "not rarely" you get comms from Hawaii to California. Or other 600-700 km comms. That is WAY BEYOND LINE-OF-SIGHT.

They don't ever put 2 + 2 together, and start to question the Globe model they have been given since childhood.

It's not just "weird" or "one of those things" -- it DISPROVES THE MODEL. It FALSIFIES the model. Given the model we have been taught, the experimental results they speak about are LITERALLY NOT POSSIBLE.

You need to go back and question the model when you encounter evidence like this. AS A SCIENTIST.

You see, I was faced with this and similar evidence. But rather than suffer cognitive dissonance in silence, or willfully dismiss the truth because I didn't like it (or it made me uncomfortable), I looked into flat earth with an open mind. And guess what? Now I'm a "flat earther". I know, that's one of the only unforgivable beliefs these days, similar to r4cist or n4z|, but c'est la vie.

What about tropospheric ducting and sporadic E-skip?

https://3fs.net.au/tropospheric-ducting/

https://northpine.com/2020/06/18/tropo-or-e-skip-nows-the-time-to-listen-for-distant-fm-signals/

Neither of these propagation methods rely upon line of sight.

Many times during the year, I receive TV stations 300-400 miles away through tropospheric ducting.  (I have a high-performance antenna, the Televes DATBOSS that is designed both for low- and high-VHF as well as UHF.)  Sadly, though, with the sharp reduction in the number of TV stations broadcasting on low-VHF, viz. channels 2 through 6, E-skip is a fairly rare phenomenon these days.  Back in the analog days, I received stations from all across North America, and the beauty of it was, no specialized equipment was really needed.  I've picked up stations on E-skip with just a set of rabbit ears.

Also, in analog days, the picture was very often smeared or distorted, whereas with the advent of digital TV, you either have the signal or you don't, and a distant signal is just as clear as a local one.

There is also the phenomenon of knife-edge propagation, where you don't strictly have a line of sight, but the signal reflects off various terrestrial barriers such as ridges and mountains, and ricochets on past them.  I regularly get stations from 80 to 100 miles away using knife-edge propagation, and a handful of them are reliable enough for almost-daily reception.  With tropo and E-skip, it's just a chance phenomenon.  (Tropo can also combine with knife-edge for some very good results.)

Here's one example of an discussion about Marconi's experiment ...

Scientific discovery: At the time of Marconi's experiment, the existence of the ionosphere was not yet fully understood. The transmission was an empirical proof that radio waves could travel beyond the horizon, and scientists later worked to understand the principles of ionospheric reflection. The electrically conducting layer was first named the "E-Layer" by Sir Edward Appleton in 1927, derived from the name "electrical-layer".

You'll notice the embedded assumption, that the radio waves could travel beyond the "horizon" ... which assumes a ball earth horizon, 100% begging the question.  So then they had to figure out a way to explain this away but without touching the sacrosanct embedded assumption.

My forte is TV DX, not ham radio (though I do hold a Technician license) or other types of audio reception.  I can tell you that the site rabbitears.info allows you to do a signal search based upon your location, and provides Longley-Rice "heat maps" as well, which take into account terrain, and are of course based upon a GE model.  Those maps tend to hold up when compared with actual reception of various stations at any given location.  The stations it predicts I will get are indeed receivable (I have a copse of pine trees to the north of my property, which makes reception in that direction more difficult, and which the heat maps don't take into account, but in all other directions it's smooth sailing), and the further out you get from the transmitter, terrain and elevation have their way with the signal.  If you can get out over a completely unobstructed area (such as a body of water), the heat maps predict a gradual diminution of signal as you get further away from the TX, then a sharp drop-off after about 100 miles tops.  It would be interesting to have some kind of boat, go out to the limit that the heat maps predict, and see if the signal does, indeed, completely vanish.  Now, as to whether this would prove FE or GE could depend on various factors, such as the downtilt of the signal (ordinary TV signals are not like microwaves, they fan out from the top of the TX and, so I have been told, are flattened out above the TX, as there is no point sending a signal straight up in the air).

Here is a sample map showing a station directly on the Florida coast (WJXT Jacksonville FL, RF channel 18, tower height 997 feet at 670 KW).  The "sharp drop-off" is at the outer edge of the salmon-colored band.  The PSIP information (i.e., the channel number you see on your TV set) is channel 4 (4-1, 4-2, and so on for the various subchannels), but that is not the actual RF channel, when the FCC forced all stations to switch over to digital, using different channel allocations in the vast majority of cases, they allowed the broadcasters to retain the same channel numbers on PSIP, for continuity of marketing.  WJXT has been channel 4 in Jacksonville forever, so even now that it is broadcast on RF channel 18, the viewer still sees channel 4 on the screen.  It's complicated.

I would add to the list that one should be open to the possibility of a dome, allowing for signals to possibly reflect off of that depending on the scenario, and of course, more than just open to the possibility, since Sacred Scripture quite clearly describes a physical dome, so we as Catholics must believe it.

Even Dr. Sungenis departed from his original "firmament is space" hypothesis, realizing that it was inadequate, and moved first toward the Planck fabric explanation, which I think again he found inadequate (speaking to some intellectual honesty there on his part), since the Planck fabric could not have the properties attributed to the firmament (preventing water from inundating the earth during the Flood), and moved toward the Ice Firmament theory as described in his latest video series from Kolbe that appears to have had the plug pulled on it.  He was working on a series on "How God Created the World in Six Days", but it appears to have been cancelled after Day 2.  I do suspect that both Kolbe and he got so much heat about the giant space ice ball theory (from the same types that deride FE, ironically, and with whom he had joined forces against FE) that they pulled the plug.  I wrote to Kolbe asking them what happened, since I had purchased Day 1 and Day 2, with the hope that I could get the entire series.  I may request a refund to see if that will inspire them to tell me why they aborted the series.

FWIW, I seem to recall that when Pius XI made his speech announcing the debut of Vatican Radio in 1931, he referred to the "ether".  I have to think that he was just using the common terminology of the time, and wasn't attempting to give a detailed explanation of how radio waves are propagated.  I haven't been able to find the text of the message, which was in Latin to begin with.