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I guess that is why the governments of the world and heads of businesses have commonsense advisors instead of economic advisors.

Where there's a will, there's a way. And even where there isn't exactly a will, there may still be a way.

Hello everyone, Why -2 .(-3) = 6 Why is it positive? Why we accept that (minus sign) times (minus sign) is positive ? What is its origin? Thanks in advance

But we're talking about PR here, not NTSB investigations. No, it is not a false perception. It is the perception from my perspective, that of a user. From your perspective it is also harder to order socks from Amazon than climb the tree in my yard because of all the difficult technology involved, but from my perspective I can order the socks in about 30 seconds without getting off the couch. Much easier than getting to the top of that oak tree. You mean like how they teach all the passengers how to pilot a 747 before they are allowed to board the aircraft and begin their tour of Europe?

Awesome, I actually did not know this but now I do! Makes me wonder why we didn't just pay ULA to do it any differently? I mean decades ago...now that boat has kind of sailed. If SpaceX can bring the cost down to like ... $40,000 per seat for a meaningful visit (few days, a week?) I'd probably be more supportive of the tourism program myself. Currently I'm probably just miffed that I'm getting older, a lot older, and all the cool stuff to do is being done by rich people who never worked a day in their life. Even the engineers building SpaceX rockets aren't the ones getting space-rides. And they are the reason that space-rides will even exist. Get my drift? I'm very bitter at the idea of corporate effort // private gain. If it takes 400,000 people to send one person into space, then the one person going into space better be the best person, not the richest person.

It is much easier to get into space. I cannot physically climb to 29,000 feet altitude, but I can sit in a comfy chair as I rocket to 254 miles in altitude. I guess it will be pretty much the same as handling the PR of death in Mt. Everest tourism.

There. FTFY

This. Some pertinent considerations: Our lungs are not simply compressors. They are also highly efficient heat exchangers and humidifiers. In short, the process is near isothermal, and exhaled breath emerges from our lips (pursed or otherwise), at core body temperature and saturated with water vapour. Skin thermoreceptors sense rate of temperature change rather than absolute temperature. Simultaneous mass and heat transfer can become quite an intense study subject. However, when evaporation or condensation are involved, these processes tend to dominate overall heat transfer rates (compared to 'dry' conductive/convective processes).

It's a continual process, and some of the effects have many layers of Feynman diagrams, with multiple loop structures even at the first layers (they tend to get much more complex as you go to more loops), so I don't think you can narrow it down to just the recombination. The whole process is responsible for the contribution, AFAIK. The application of conservation laws at the nodes is bookkeeping. Plus, I don't know that there would be any way to test this hypothesis

It seems to me @Bufofrog has got it pretty well spot-on. Air entrainment will account for the faster stream of air being a bit cooler. There is negligible pressure drop across pursed lips, so adiabatic cooling won't be relevant. Cooling by evaporation - accelerated by rapid removal of evaporated vapour - will be very important in the soup/tea case. A cup of tea drunk outside cools a lot faster than indoors at the same temperature, if there is a bit of a breeze.

Yep. It is called gravitational redshift.