Air loop tunnels

Removing the air (vacuum) is a good solution for super sonic speeds. But what about moving sea level density air through the tunnel at sub sonic speeds such as 100s of meters per second? That way you can ride through the tunnel at say 200 meters/sec (~450 mph) with the top down without having your hat blow off thanks to a constant strong tailwind going roughly same speed as the vehicle. No need for pressurized cabins!

The moving air would also help propel the vehicle forward a bit. A light vehicle with a sail could possibly be propelled solely by the wind! The air could also whisk away heat generated by the magnetic propulsion system.

Maybe the air system could be in a loop, more efficient than sucking it in and blowing it out to the atmosphere. Maintaining airspeed shouldn't be a problem, not much air resistance to overcome.

https://en.wikipedia.org/wiki/Pneumatic_tube

Interesting facts about Seasons

Distance to the Sun
-Northern hemisphere Winter: Earth is closest to the Sun
-Northern hemisphere Summer: Earth is farthest from the Sun

Length of day
Days are longer during the Winter than in the Summer. I don't mean 'daylight hours', yes those are shorter during the Winter, I mean the time from Noon to Noon.

The Earth spins around it's own axis at the same rate all year around, however, the Earth orbits faster when it's nearer to the Sun, hence it takes longer for the Sun to return to the highest point in the sky. When viewed from above the Earth spins CCW and orbits CCW.

Because of this the Sun actually travels angularly faster across the sky in the Summer, but stays up longer because it travels along a longer arc than in the Winter.

Area facing the Sun is a major factor in Solar energy collection (and Seasons.)

I measured the power collected from a small solar panel.

When always facing the Sun:

-When the Sun is straight up 5 watts was collected.

-When the Sun is 60deg from zenith 4 watts was collected.

Not a huge difference from 0 to 60deg.

However if I tilt the small solar panel even when the Sun is straight up the power is greatly affected. Tilted so much that the area facing the Sun is halved, the power halved as well. (power breakdown: voltage remained around 24v, it's the current that changed.)

Same deal with the north and south hemispheres.

-In the Summer time more north hemisphere area faces the Sun.

-In the Winter time less north hemisphere area faces the Sun.

Not quite the extreme altitude of the Sun, but same principal in these examples:

Baja California takes up alot of screen space (so greater solid angle) during the Summer
https://earth.google.com/web/@22.01938439,-113.02998305,-2425.40930916a,12568971.6672492d,35y,0.17716338h,8.68143677t,-0r

Baja California takes up very little screen space (so less solid angle) during the Winter
https://earth.google.com/web/@-22.01938439,-113.02998305,-2425.40930916a,12568971.6672492d,35y,0.17716338h,8.68143677t,-0r

https://en.wikipedia.org/wiki/Solid_angle

A yelling language

Let's face it, you can't yell consonants. Hence words that are only differentiated by consonants will be easily confused with each other when you need to yell.

There are probably many better examples, but here are a few I can think of off the top of my head

code, mode

call, tall

lame, tame

A proper yelling language should consist of only vowels, or sounds that you can sustain. I think radio transmissions can be a good guide: variations of amplitude and frequency.  https://en.wikipedia.org/wiki/Yodeling probably utilizes these ideas, and could become a long distance language.