360 cameras missing a critical spec

All cameras have 360 degree azimuth. However what is not listed is the pitch.

-A 45deg pitch means 90deg FOV
-A 90deg pitch means is shows an entire hemisphere
-A 180deg pitch means is shows an entire sphere

Too many ads out there claiming 360 deg, which really doesn't tell you anything. Please show the pitch as well!

Seasonal Date Pairs

Seasonal Date pairs are days that exhibit the same Sun path in the sky (same number of days from nearest Solstice.) For example, Apr10 and Sep01 are date pairs (both 72 days from Summer Solstice.) For both of these days at 33deg north latitude, when the Sun is at 270deg azimuth it's also at 15deg elevation.

DOY (day of year)

Equinox (Spring)
081 (W +91, S -91) Mar22 (33deg north Sun: 260.6deg azim 15deg elev)

Closer to Solstice (Summer)
082 (S -90) Mar23 (day after Equinox)
...
100 (S -72) Apr10 (33deg north Sun: 270deg azim 15deg elev)
...
125 (S -47) May05 (33deg north Sun: 280deg azim 15deg elev)
...
172 (S +00) Jun21 (33deg north Sun: 288.6deg azim 15deg elev)
...
219 (S +47) Aug07 (33deg north Sun: 280deg azim 15deg elev)
...
244 (S +72) Sep01 (33deg north Sun: 270deg azim 15deg elev)
...
263 (S +91) Sep20 (day before Equinox)

Equinox (Autumn)
264 (S +92 W -91) Sep21 (33deg north Sun: 260.6deg azim 15deg elev)

Closer to Solstice (Winter)
265 (W -90) Sep22 (day after Equinox)
...
286 (W -69) Oct13 (33deg north Sun: 250deg azim 15 deg elev)
...
308 (W -47) Nov04 (33deg north Sun: 240deg azim 15 deg elev)
...
355 (W +00) Dec21 (33deg north Sun: 228.5deg azim 15 deg elev)
365 (W +10) Dec31 (last day of year)
001 (W +11) (first day of year)
...
037 (W +47) Feb06 (33deg north Sun: 240deg azim 15 deg elev)
...
058 (W +68) Feb27 (33deg north Sun: 250deg azim 15 deg elev)
...
080 (W +90) Mar21 (day before Equinox)

Notes
(yes Solstice doesn't always fall on the 21st, but it makes a good average)
(yes Leap Year offsets most of this by 1 day, leap day should really be at the end of the year)

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.

Cameras or mirrors in the front of vehicles

Notice that when exiting this parking lot just to see cars coming down the road half of your vehicle has to stick halfway out into the lane due to not being able to see through the parked cars! (posted speed limit is 30mph, but vehicles typically travel faster than that.)

https://www.google.com/maps/@32.8698966,-117.233749,3a,89.9y,137.32h,54.45t/data=!3m6!1e1!3m4!1syTOgwwzuE8VnmnDWT9kZXQ!2e0!7i13312!8i6656

This is because people's eyes are in the middle of the vehicle. One solution would be to have mirrors or cameras on the front of the vehicle. Or having a mirror in the middle road island. Or being to access nearby cameras mounted on say light posts.

Designing containers for smooth pouring

I'm sure many have noticed that when pouring liquid bottles it comes out in big clumpy waves. One wouldn't need a funnel if they'd design these things with proper airflow in mind to fill up space vacated by the liquid. Either use larger diameter spouts, or have another spout for air intake while liquid pours (as seen in a few liquid detergent bottles.)

Layers of tunnels to add traffic lanes

After the https://en.wikipedia.org/wiki/Interstate_Highway_System little has been done to significantly improve traffic flow. The populations have ballooned while road lanes have not.

Many places were designed street widths for a certain amount of traffic. The streets are now adjacent building locked so they can no longer widen them to accommodate the massive amount of traffic during the rush hour.

Since lateral road expansion isn't possible without razing buildings, we are left with vertical expansion. Going up with say double decker roads would be unsightly, no one would go for that. This leaves underground tunnels as the only real solution for adding more lanes. Only so many opt for mass transit such as buses and trolleys, many want the freedom and flexibility that automobiles afford

So much talk about housing crisis with little mention of the associated traffic crisis. People also need more lanes not just more houses. Less time on roads means more time to be productive. I suppose self driving cars will make waiting in traffic more bearable in the mean time as you'll then be able to do many of the things you'd do when you got home, such as check email.

Slightly north is the quickest way south

Ever wonder why the Sun sometimes appears to the north of your location even though the sub solar point https://en.wikipedia.org/wiki/Subsolar_point is at a lower latitude from your location? One must remember that the initial direction is just that; initial. A straight line on the globe follows a great circle https://en.wikipedia.org/wiki/Great_circle . Unless that great circle follows a line of longitude or the Equator, the path direction along each point of that great circle changes. Great circles are basically the same as https://en.wikipedia.org/wiki/Orbital_inclination where if you keep going it bounces between a northern and southern latitude line.

4.9 mega meter distance example
Cabo San Lucas: +22.9 lat -109.9 lon
Honolulu: +21.3lat -157.8lon

A straight line path from Cabo has an initial heading of 277.6 deg (7.6 deg north of west) even though Honolulu is at a lower latitude (1.6 deg lower.) The great circle path will actually reach up to +24.0 deg latitude along the way.

13.0 mega meter distance example
Cabo San Lucas: +22.9 lat -109.9 lon
Manila: +14.6 lat +121.0 long

A straight line path from Cabo has an initial heading of 302.0 deg (32 deg north of west) even though Manila is at a lower latitude (8.3 deg lower.) The great circle path will actually reach up to +38.6 deg latitude along the way.

20 mega meters is halfway around the Earth.

The entire Earth should go Metric

The United States of America is one of 3 countries not using the metric system.

Who enjoys converting miles to feet? Gallons to cups to tablespoons to teaspoons? Tons to pounds to ounces? Speaking of ounces, are you referring to volume or weight? When you say weight, do you really mean mass or weight? In the metric system grams is mass, newtons is force (weight being force due to gravity.)

The word cup can be confusing. Do you mean just a drinking container of an unspecified size, or do you mean 8 ounces?

At least the meter is based on the measurement of the Earth and not some random person's foot! Halfway around the Earth is 20 mega-meters. Even the British abandoned the British system for the French! Feet, miles are in-congruent. Who wants to memorize 5280 in a statute mile? Then you got your 6075 feet per nautical mile to pile onto that. There are 1000 millimeters in 1 meter, there are 1000 meters in 1 kilometer, very simple.

Sure app and search engines will convert, but when you got oil on your hands when cooking do you really want to play with an app on the phone to know how to convert tablespoons to teaspoons? (maybe ask a voice assistant, but if it's loud it probably won't understand you) With metric it's easy to deal with with conversions in your head. 1000ml in a liter, 1000g in a kg, for example. I don't want to remember how many cups in a gallon!

Also the entire Earth should go full metric, km/h isn't much better than mph. You still gotta deal with that unwieldy 3600 second value. Meters per second would be ideal. Say you're travelling at 10 meters/sec (22.3mph) and you have to travel 10 kilometers. Simply divide 10,000 by 10 = 1000 seconds (16.7 minutes). Say you were going 36km/h, how long will it take to travel 10 kilometers? Not readily apparent, gotta do something like 10/36 to get hours, then times that by 60 to get minutes. We should just get rid of hours and minutes and stick with seconds and kilo-seconds to make it even simpler, 86.4 kilo seconds per day.

Related links
http://kilosecond.info/

A better explanation of lift of an airfoil

-Air never leaves the flat bottom, hence it always gets pushed upward, known as lift.
-Drag is air pushing upon the leading edge, bending around it.
-The key is the lack of air on top to apply down pressure.

The reason is that the airfoil traveling above a certain speed causes the following:
-After being displaced by the leading edge air doesn't travel back down to the top surface faster than the top surface tapers downward. Therefore it is unable to apply pressure. It's that simple.

I've heard explanations saying low pressure on top due to higher velocity that is due to farther distance to travel. While those conditions might be true, that does not properly explain the phenomenon.

Airfoils depend on air pressure, going through unpressurized air wouldn't yield any lift (if you could somehow get unpressurized air to stay put that is.)

Precision and accuracy

So many people don't understand that these are fundamentally different aspects.

-Precision is basically how many significant digits, or how many digits right of the radix point.
-Accuracy is how close the measurement is to a target value.

For example:

Dale's discus throw was measured PRECISELY at 36.821 meters.
Bob's discus throw was measured at around 50 meters, plus or minus 2 meters.

Since the target was 50 meters Bob's throw was more ACCURATE than Dales.

Maybe time should just be sub solar longitude

It's very easy to convert UTC time to sub solar longitude (longitude where the Sun is directly over)

0000hrs UTC the Sun is directly over the ante meridian (180deg lon)
1200hrs UTC the Sun is directly over the prime meridian (0deg lon)

Every 30 deg longitude is 2 hrs (hence every 90deg is 6 hrs)

Why not just denote time as sub solar longitude? One can easily compare local longitude with sub solar longitude to figure where the Sun will be located.

Universal time of day: should be the longitude of the sub solar point.
Time of year should be latitude of sub solar point.

Links
https://en.wikipedia.org/wiki/180th_meridian
https://en.wikipedia.org/wiki/Prime_meridian
https://en.wikipedia.org/wiki/Coordinated_Universal_Time

Fish eye lens would offer no distortion on spherical displays

Fish eye lens would offer no distortion on spherical displays, the problem is the lack of spherical displays! We're stuck with flat rectangular displays.

https://www.youtube.com/watch?v=7dtH6uKj-QI
https://www.youtube.com/watch?v=a2e9noEg1zg

Seasons shouldn't be 3 months

The Sun spends more time near tropics than it does near the equator. Maybe Winter/Summer should be 4 months, and Spring/Autumn 2 months.

https://rl.se/zenith-calendar

-Winter: From Oct24 to Feb17 (roughly 4 months) the Sun travels from -12deg to -23deg back to -12deg latitude
-Spring: From Feb17 to Apr20 (roughly 2 months) the Sun travels from -12deg to +12 latitude
-Summer: From Apr20 to Aug21 (roughly 4 months) the Sun travels from +12deg to +23deg back to +12deg latitude
-Autumn: From Aug21 to Oct24 (roughly 2 months) the Sun travels from +12deg to -12 latitude

Not only is Summer 4 months, but the Sun stays in the sky higher and for well over half the day.
Furthermore for most of the time the Sun is closer to 23deg than at 12 deg:
-1 month after the Sun passes the equator the sun is 1/2 way to the tropic line
-10 days after that the Sun is 2/3 the way to the tropic line
-10 days after that the Sun is 4/5 the way to the tropic line

Then for about the next 80 days the Sun stays 4/5 of the way to the tropic line! It does this 80 day stint 2 times a year, so for almost half a year!