Search results

Three points: 1. The radiosonde data shows humidity levels with respect to water. The factor that is relevant for persistent contrail formation is supersaturation with respect to ice - this can occur at water humidity levels below 70 %. 2. Humidity data from radiosondes at low temperatures...

That "Contrail Evolution" image from cieliazzurri is extremely useful! It also shows how the gap between plane and trail varies with the conditions of the surrounding air.

Weather modification in the 21st century - a "hail buster" in a German documentary (excerpt): https://www.metabunk.org/files/Deutschland von oben 3 - Cloud Seeding clip.mov It shows nicely what cloud seeding looks like ... small plane in a cloud with no visible trails. It also illustrates the...

Well then, state your claim and provide your evidence, but do so in a new thread.

I was not referring to the individual researcher. I mean the process of peer review and the condition of repeatability by fellow (or rather competing) specialists. Humans will stay fallible and more or less biased, but the knowledge created - and probably built upon many times - is not bound to...

That may well be true, however the scientific process itself dictates that if opinion (or expectation, or hypothesis) does not hold in the light of evidence, it must be changed. The research mechanism in natural sciences is designed to overcome bias and subjectivity. Of course, debunkers are in...

Chris Shelton has spent a good part of his life working for Scientology before he left the organization in 2013. Since then he has provided many clear and analytical insights into the inner workings of what he calls a "cult" now. The article at hand advocates scientific thinking on a very...

I just retried and it is working again, so I guess someone must have been tampering with SSL. However, I confess that I still use Opera 12.17 due to the unmatched configurability ...

I have a problem that started a day ago (or so). I'm also using Opera, and upon trying to connect to Metabunk, I now receive an error from the browser: "The secure transaction could not be completed". A more detailed text below states: "The identity of the web site could not be confirmed (OCSP...

I don't think this should be seen as an attack on someone specific. The point is that human memory is generally unreliable, in varying degrees. As stated before, I don't trust my own memory very much, and every proper skeptic should do so in my opinion. Vindog has demanded references - which is...

If you refer to the variability in humidity, and the existence of clouds (and gaps between them) does not convince you, then look at diagrams of sounding measurements taken by weather balloons. This is the current one from Albany, NY...

Two things worth noting: 1. Once you determine a trail to be persistent, it must obviously have been hanging around quite a while. Consequentially, the plane that had created it may have been gone already. 2. The main source of data for the visualizations of FR24 is the ADS-B signal...

More efficient burning of fuel and cooler exhaust. But more importantly most efficiency achieved at higher altitude levels = flying in colder environment.

Even without any concrete reference, it may still be possible that Vindog's memory is correct after all. If I'm not mistaken, Mick is just now checking for air traffic history.

Yes, with more and higher flights and newer airplane technology. Global increase, with local variations. I don't think anyone here disagrees.

If Vindog agrees to move on, why shouldn't we? I consider the question of the traffic increase much less interesting than why he thinks the trails today are not normal contrails.

I never thought about persistent contrails prior to my pilot's exam (around the year 2000). I must have seen them but I did not notice them. They were referred to in the meteorological class as an indicator of an approaching warm front. From then on, I started looking out for them - and saw lots.

Hmm, as far as I read it, nobody here claimed that there was always the same amount of persistent contrails in the sky then and now. Quite the contrary. Personal memory is unreliable. That's what science is there for. It starts with taking notes.

Well, the "quality" of your memory is obviously central to your claim, so its correctness is certainly an issue. Again, your memory may be excellent regarding things that really counted in your life, or things that you learned actively. But how involved were you with watching the sky, the...

Allow me to return that suggestion regarding your original claim "no persistent contrails in the nineties". If you expect references, you should be able to to provide some yourself. I think everyone around here is aware of the shortcomings of personal memory. I wouldn't trust myself with such...