Non-rocket spacelaunch using solar powered ion engine. It might be possible for small payloads

Imagine a fixed-wing airplane with ion engine and solar panels. Currently it cannot take off from Earth surface due to very low thrust. It is caused mostly due to insufficient power of energy input.

But what if the size of the apparatus decreases. According to Square–cube law, decreasing dimensions n times will lead the surface area decreases n*n times while the volume and mass decreases n*n*n times. This means power-to-mass ratio increases n times. Small enough apparatus might have enough power to take off from the surface, fly in the atmosphere and become a satellite.

Travelling in lower and upper atmosphere seems to be possible. See Ion-propelled aircraft and Atmosphere-breathing electric propulsion.

Photovoltaic is good as an energy source:
1. Virtually unlimited amount of on-board energy.
2. High electric power density - thin-film solar cells might generate some 10 Watts per gram. For comparison Plutonium-238 generates 0.57 Watts of power per gram, that power yet needs to be converted to electricity.
3. Photovoltaic can produce high voltage output just by connecting solar cells in series. High voltage is necessary to power ion engines.
4. Lasers can provide additional power. The lasers can be designed to be safe for eyes.

So, there is a chance, Non-rocket spacelaunch will appear in the near future for small-sized payloads, e.g. several grams.

Page Merge Sort

Stable, O(nlog(n)) time, O(sqrt(n)) additional memory.

It is a sorting algorithm based on the approach of merging algorithm described here: https://max-arbuzov.blogspot.com/2021/10/merge-sort-with-osqrtn-auxiliary-memory_22.html

Merge sort with O(sqrt(n)) auxiliary memory complexity – example run

It is an example run for array merge algorithm described here: https://max-arbuzov.blogspot.com/2021/10/merge-sort-with-osqrtn-auxiliary-memory.html. Using that algorithm will allow to create Mergesort-based algorithm with O(sqrt(n)) additional memory usage. 

Merge sort with O(sqrt(n)) auxiliary memory complexity (and even less)

In this text an algorithm is described that merges two sorted arrays into one sorted array. Time complexity is O(n), auxiliary memory complexity is O(sqrt(n)), and stable. If this algorithm is used for merge sort, then resulting sorting algorithm will be stable, have O(nlog(n)) time complexity and have O(sqrt(n)) auxiliary memory (and even less for some cases).

Sunglasses to better view your smartphone or laptop screen

Sorry, no pictures yet.

The sunglasses are mostly as usual ones - they reduce ambient light and sunlight. But they do not reduce the light from smartphone/laptop screen. As the result the picture on smartphone/laptop screen is more contrast and visible when wearing such sunglasses.

Benefits:

1. Better image on smartphone/laptop screen.

2. Possible to reduce britness of the screen. It will increase battery life (due to lesser discharge) and lifetime (due to lesser charge-discharge cycles).

3. OLED displays can be more durable due to lower display brightness.

How to implement:

1. Filter light by wave length.Now it is possible to increase contrast 3 times.

2. Filter light by time. It will require impulses from the screen (e. g. 1000 Hz) and the sunglasses open and closes according to impulses from display.

3. Filter by polarization. I think it is possible to increase contrast 2 times or more.

Artificial Hadley cell

 

Artificial Hadley cell is a human-made construction that generates rain in order to produce fresh water.

It mimics natural Hadley cell.

It is ground surface area about 10 km in diameter and tens meters in height.

Artificial Hadley cell absorbs solar energy, heats air, creates upward air stream that in turn leads to precipitation and releasing fresh water.

How to convert sunlight into rain. Artificial Hadley microcell

Some areas on the Earth experience deficit of water while having abundant sunlight. What if convert some sun energy into water to solve water deficit? Artificial Hadley microcell could make such a conversion.
How it works is described here: Is it possible to create artificial rain by building small Hadley cells?