Define "Upbeat"

A friend of mine recently announced that he was going to coordinate a mix-CD swap. If I wanted to participate, I'd have to pick a bunch of songs I liked that matched the theme, burn a couple CD's of them, and mail them to addresses I'd be provided. In return I'd get a couple CD's of songs picked by other quasi-random people. So I decided to participate.

Theme: upbeat.

Now... there are at least three definitions I can think of for "upbeat." Things that are up-tempo, things that inspire, or things that cheer one up. So... it wound up being a little bit of a mix. Up-tempo songs and instrumentals, songs with inspiring lyrics, and songs that were just plain funny or silly to make people laugh.

Here are the songs I chose. If you recognize every group named here, let me know immediately - that would indicate that you're me, and something is wrong with the fabric of reality.

1. Greetings by Star People.
2. Starman by Star People.
3. Princes Of The Universe by Queen.
4. Future Girls by Smile.dk.
5. Milligan's Fancy (instrumental) by Tempest.
6. Surf by Ka'au Crater Boys.
7. Bodhrans On The Brain by Black 47.
8. Stiletto In The Sand (instrumental) by Shadow Gallery.
9. My Heart Is A Flower by King Missile.
10. Beautiful by Marillion.
11. Breath Of Fresh Air by Echolyn.
12. Until You Fall by Steve Hogarth.
13. Cinema (instrumental) by Yes.
14. Rhythm Of Hope by Queensryche.
15. Finding The Strength by Finneus Gauge.
16. Mission Statement by Fish.
17. Everything In Life by Uriah Heep.
18. Someone Else? by Queensryche.
19. Plague Of Ghosts VI: Wake-Up Call (Make It Happen) by Fish.
20. Always Look On The Bright Side Of Life by Monty Python.

This doesn't really cover the full scope of my music collection, but it might give you some idea of some of the things I listen to. :)

Time of Useful Consciousness

Time of Useful Consciousness (TUC) is the sort of number none of us ever want to have to deal with in everyday life. Simply put, for any given altitude above sea level, TUC is how long you have before you black out - and probably never come to. Wonderful, eh?

For example, at 35,000 feet - a nice, normal cruising altitude for a jet airliner - the TUC is about 30 seconds. So when the nice cabin crew tell you "in the unlikely event of a sudden change in cabin pressure, a mask compartment above your seat will open automatically," they leave out the that by the way, you've got 30 seconds to get it on and get that oxygen flowing.

Anyway, as you go lower, the TUC gradually gets longer, and at 15,000 feet or less, it's presumed to be "indefinite." This doesn't necessarily mean that everyone can hang around at 15,000 feet for as long as they want without blacking out, but some people might manage it, so there's not a handy little number.

Of course, even below 15,000 feet, there are other issues to deal with, primarily hypoxia or "blood oxygen starvation." As altitude above sea level increases, availability of oxygen in the air decreases, as does the saturation of oxygen in your blood. Spending time at 10,000 feet, it's only about 90% of what it is at sea level. At 14,000 feet, it's about 84%. And so on. As your blood oxygen saturation drops, so does your ability to think clearly, react quickly, make good judgements, etc.

This, of course, is why airliner cabins are pressurized to the equivalent of 8,000 feet or less. And why Air Force crews are required to use supplemental oxygen at altitudes of 10,000 feet or more. And why there are FAA regulations about using oxygen at various altitudes. And why tourists who are going up for a 2-hour tour of the summit of Mauna Kea (nearly 14,000 feet) are required to acclimate at 9,000 feet for at least a half-hour, and preferably longer.

So now that you have a good understanding of the risks involved with spending lots of time above 10,000 feet... I'll confess to being an intermittent telescope operator on Mauna Kea. Every now and then, I find myself at almost 14,000 feet for a half-night (6-7 hours), or a full night (12-13 hours), or, in some cases, for four 12-13 hour nights in a row, sleeping days at 9,300 feet in between.

And no, they don't give us supplemental oxygen. :)