Search
Write a publication
Pull to refresh
862.87

Popular science

Popular science as is

Show first
Rating limit
Level of difficulty

Flightradar24 — how does it work? Part 2, ADS-B protocol

Reading time9 min
Views8.1K
I’m going to have a guess and say that everyone whose friends or family have ever flown on a plane, have used Flightradar24 — a free and convenient service for tracking flights in real time.

image

In the first part the basic ideas of operation were described. Now let's go further and figure out, what data is exactly transmitting and receiving between the aircraft and a ground station. We'll also decode this data using Python.
Read more →

Most common misconceptions in popular physics

Reading time5 min
Views3.4K
Somewhere in an alternative Universe, based on MWI, I became a genius in physics. But in our Universe, I just read professional publications in physics, trying to keep myself up to date, meanwhile working as pizza delivery guy as DBA. Because of a slightly deeper knowledge of the subject it is almost impossible for me to watch the Discovery channel and other popular TV shows and the YouTube videos. I see nothing but oversimplifications, lies, and half-truths and can’t enjoy the shows.

I decided to compile a list of the most popular misconceptions. And the winner is...., or course, this one:

The Big Bang


Usually it is pictured like this:

image
Read more →

Stonehenge. The secrets of megaliths

Reading time2 min
Views1.2K
A version how people transported megaliths in Stonehenge.

image

They started their work in summer.

They prepared road for transportation. They needed a clean and glade road without stones and other irregularities. (No.4 on picture)
Perhaps they cut the topsoil and covered the road with clay. (No.3 on the picture)
On each side they made curbs ( 5-10 cm). (No.2 on the picture)
They used clay because they wanted to hold water inside the road.
In autumn rains filled road with water. It looked like a big puddle. (No.5 on the picture)

In winter road froze. Then they got a smooth ice skating rink slightly wider than a megalith.

Megaliths (No.11) were transported in winter.

Mechanism and vehicles for transportation were prepared in summer.

Mechanism consisted of three parts.

image
Read more →

How does a barcode work?

Reading time6 min
Views13K
Hi all!

Every person is using barcodes nowadays, mostly without noticing this. When we are buying the groceries in the store, their identifiers are getting from barcodes. Its also the same with goods in the warehouses, postal parcels and so on. But not so many people actually know, how it works.

What is 'inside' the barcode, and what is encoded on this image?



Lets figure it out, and also lets write our own bar decoder.
Read more →

Researchers from MIT designed «rectenna» which converts Wi-Fi signals into electricity

Reading time2 min
Views3K

Source: eeNews Europe

I'm glad that Habr got brand new English version. And my first post in English is about new MIT project. Researchers designed an ultra-low capacitance and ultra-low resistance Schottky diode capable of switching at GHz frequencies. This diode is able rectify and convert random WiFi signals into DC electricity.

MoS2 «rectenna» (this is how scientists called their invention) could become the main element of roll-to-roll process to cover a huge areas. To be fair antennas capable transform radio signals in to electricity is not a new thing. The main achievement of MIT engineers is creation of soft rectenna made from special alloy.
Read more →

Authors' contribution