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Eliminating contrails from flying could be cheap

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Re: Eliminating contrails from flying could be cheap

#111

Post by klodolph »

DoctorOetker wrote: post #101

N2O (laughing gas) is not combustible, but autodecomposes into a mixture composed of 1 part oxygen gas and 2 parts nitrogen gas, which happens to be the approximate composition of the atmosphere. In theory we could design and use N2O engines and airplanes etc, and their exhaust could be a gas that is nearly equivalent to atmospheric composition. One important issue is making sure all the N2O has decomposed because it…

Someone can break out their chemistry references, but I think N₂O is probably not workable as a fuel (or at best, not very good). It forms naturally in internal combustion engines, from air, at the temperature and pressures found in engines, given O₂ and N₂. If something has the habit of forming in an engine, I don’t think you could use it as fuel, but my thermodynamics is a bit too rusty to do any kind of ELI5 and I could just be wrong here. At the very least, it would be difficult to use or inefficient.

It decomposes into N₂ and O₂ at normal atmospheric temperatures and pressures, outside an engine.

Re: Eliminating contrails from flying could be cheap

#112

Post by wasabi991011 »

DominikPeters wrote: post #41

Given that the warming impacts of contrails are short-lived (roughly a day), I think it is a good idea to do research now on the weather forecasting needed to avoid producing contrails. But I don't really see a reason to actually start avoiding them now, with the associated costs in terms of fuel, CO2 emissions, and time. We can start avoiding them in a few decades when it might have become urgent to have cooling.

Given the feedback loops associated with climate change, I'd expect early interventions to have a larger impact on the climate than later ones.

Re: Eliminating contrails from flying could be cheap

#113

Post by exasperaited »

The claims they are making seem slightly at odds with the (I thought well-established) claims that jet emissions cause measurable global “dimming”: that is, that the pollutants reflect enough sunlight that it is accidentally retarding global warming, supporting the concern that necessarily cleaning up our air will briefly accelerate global warming itself. Are they? Or is it also a double whammy?

This was seen to be evident in global pan evaporation measurements after the essentially global flight travel bans in the few days after 9/11; I have often wondered whether the equivalent restrictions in the early days of the pandemic show it as clearly because the impacts on pollution were very striking.

Re: Eliminating contrails from flying could be cheap

#114

Post by wil421 »

Den_VR wrote: post #69
aerostable_slug wrote: post #47

Earlier quoted context omitted.

Fun fact: the B-2 bomber has a LIDAR-based contrail detection sensor, called the Pilot Alert System. https://tridsys.com/our-divisions/optical-precision-sensors/

There’s always been something disturbing about public internet advertisements of military equipment. I suppose it’s dual use, but it seems like baiting a malicious actor to play with it in detail.

A malicious actor is probably not going to meet them at their place of business and do FBI background checks, in person DOD interviews, even polygraphs, to be able to really talk to them.

Re: Eliminating contrails from flying could be cheap

#115

Post by [deleted] »

aeternum wrote: post #94
the__alchemist wrote: post #36

This is something the military, e.g. fighter jets worry about. The altitudes (in a given airspace) that form contrails are briefed as part of "tactical weather". You try to avoid them if able, because no matter how stealthy you are, you are lit up for all to see if you fly at those altitudes.

This seems pretty useless in an age with super cheap 8k cameras and novice ability to do a delta-recorded image.

[deleted]

Re: Eliminating contrails from flying could be cheap

#116

Post by dustfinger »

There are a lot of comments here mocking “chemtrail” believers, but I think the confusion is understandable. There seems to be a mix-up between three terms: contrails, chemtrails, and cloud seeding.

Contrails are just condensation trails caused by jet exhaust and air pressure differences at high altitude.

Cloud seeding, on the other hand, is a real weather-modification technique that uses aircraft to disperse substances like silver iodide to encourage rainfall [1]

I completely empathize with people confused by this. They aren't all just a bunch of conspiracy nuts, many just don’t know how to identify what they’re seeing or how these technologies actually work. I don’t mock them, I try to educate.

[1]: https://en.wikipedia.org/wiki/Cloud_seeding

Re: Eliminating contrails from flying could be cheap

#117

Post by solid_fuel »

tbrownaw wrote: post #95
ryandrake wrote: post #42

Earlier quoted context omitted.

Plus, the invisibility of a thing does not stop the conspiracy loons from building conspiracies around it. 5G RF is invisible, yet still being used by the government to control our brains. For chemtrails, the conspiracy is just going to turn into: "They're spraying invisible chemicals all over us to turn us into communists." There's no end to it.

> 5G RF is invisible, yet still being used by the government to control our brains. Well it's one of the main last-mile mediums people use to doomscroll their propaganda feeds, so... yes?

It's funny how often the conspiracy types are both right and wrong. We have precision targeted ~~propaganda~~ content streaming straight to the tracking device everyone willingly carries, but they land on 5G being some sci-fi form of mind control.

It's some form of motivated reasoning. The same people who will tell you a secret cabal of billionaires controls the government will roll their eyes if you bring up the heritage foundation.

Re: Eliminating contrails from flying could be cheap

#118

Post by [deleted] »

wil421 wrote: post #114
Den_VR wrote: post #69

Earlier quoted context omitted.

There’s always been something disturbing about public internet advertisements of military equipment. I suppose it’s dual use, but it seems like baiting a malicious actor to play with it in detail.

A malicious actor is probably not going to meet them at their place of business and do FBI background checks, in person DOD interviews, even polygraphs, to be able to really talk to them.

[deleted]

Re: Eliminating contrails from flying could be cheap

#119

Post by [deleted] »

aeternum wrote: post #94
the__alchemist wrote: post #36

This is something the military, e.g. fighter jets worry about. The altitudes (in a given airspace) that form contrails are briefed as part of "tactical weather". You try to avoid them if able, because no matter how stealthy you are, you are lit up for all to see if you fly at those altitudes.

This seems pretty useless in an age with super cheap 8k cameras and novice ability to do a delta-recorded image.

[deleted]

Re: Eliminating contrails from flying could be cheap

#120

Post by jfengel »

extraduder_ire wrote: post #90
Agree2468 wrote: post #72

Earlier quoted context omitted.

If you're ever in DC, you should check out the ads in the metro stops near the Pentagon. Seeing those kinds of ads in real life is even more shocking.

I saw some photos of those ads on twitter a few years back about a certain manufacturer's engine being the correct choice for a specific in-development military plane. It's weird seeing physical advertising be so targeted. Like, multiple physical ads to target less than a dozen people total.

It's a little broader than that, because these are general defense contractors who have their fingers in every pie. So it's seen by contracting officers, partners, potential employees, etc.

It's a bit like a Coke ad -- you do not need to be informed about Coke, but it creates an atmosphere of nebulous positive feelings. Still, kinda weird.

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