Technology

Telephones

The telephone is recorded as being invented by Alexander Graham Bell, in 1874. I'm not sure if they named the telephone bell after him or not. In fact, he actually invented TWO telephones (think about it).

Early Magneto Phone

Later Magneto Phone

Rotary-Dial Phone

Modern Mobile Phone

In my chidhood days (1940s), the 'phone was a box with a bell on top, a transmitter at the front to speak into and a hook at the side to hold the receiver. It also had a small handle on the other side connected to a small "magneto", or generator. When you turned the handle it generated a signal to tell the "operator" you wished to make a call. The operator asked who you wished to speak to, tested that line to make sure it was free, and connected your line to it by inserting plugs.
But technology was being developed to replace the cords with several rows of switches. Small steps?

Later, the automatic telephone exchange replaced most operators (some functions, such as "trunk" calls and calls to other areas were still carried out by them), and the rotary dial was introduced. This had the digits 1 to 0 on a disk on the front of the telephone. The disk was rotated until the required digit was at the stop-position and released, sending a series of pulses to the exchange. The exchange equipment counted these pulses and connected the line accordingly. The called phone was rung and ring tone was returned to the caller if the line was free, to indicate their call's progress. If it was busy, busy tone was returned to them. Magic!

Tone dialing later replaced this "pulse-dialing". Ten buttons replaced the rotary dial and each sent a unique pair of tones that the exchange interpreted as a digit and switched the call to the appropriate line. This meant there was no pulsing delay, so connection was much faster.
Nowadays, telephony is only one function of many telephones, especially portable ones. They have cameras, answering services, message-storing, GPS navigation and even internet access on an instrument small enough to fit in the pocket.

Sound

In early days, sound was produced from gramophone records - black discs, up to 12 inches (300mm) wide with a hole in the middle and a spiral groove that a needle ran along. The depth of the groove varied, causing the needle to vibrate.
Later, electronic circuits were made that gave better output and control of the sound. Then, an improved type of record was made that also moved the needle from side to side, allowing two sounds to be created at once.

Our choice of electronic sound-producing devices was limited to round speakers - the bigger it was, the better the sound, theoretically. Speaker quality improved, and small ones (around 3 inch) were used for higher sounds and large ones (up to about 12 inch) for lower sounds. They were referred to as "tweeters" and "woofers" respectively.

Volume and clarity were not the only things to be improved. Electronic filters were built that allowed selected frequency-ranges to be output from different speakers, at different positions, so for instance the low sound of a bassoon would be heard from one position, while the higher sounds of the violin would be heard from another. This was named "stereophonic" sound.

Computers

My first computer - a ZX81
A modern basic computer system Computers were virtually non-existent, at least, in the public domain, in my younger days: Colossus was the world's first electronic digital programmable computer, and was built in 1943, the year of my birth. I'd like to think my arrival prompted this! My first computer, which I bought in kit form for $199 in 1982 was a Sinclair ZX81. It had 1kb of memory but I bought the "luxury" version with 16kb (16384 bytes) of memory. It used casette tapes to load and save programmes and had a black and white display that was sent to a TV screen. Text mode was 22 lines of 32 characters, and graphics were restricted to solid blocks of 1/4 of a character size. It used a programming language called Sinclair Basic, which was considered quite good at the time.
Enhusiasts like myself mostly typed in programmes from magazines, sometimes with hundreds of lines of code, and because of all the syntax requirements (commas, semi-colons, quotes etc.) it often took more time to debug the programme than to actually type it in. Fortunately (or cleverly), on the ZX81 most of the keywords of the language were available on keys as one entry. Problem was, this meant every key had up to 5 functions on it, accessed by alt, shift, and combinations of these.
People who worked in the technical fields were able to type in programmes in "machine code", a very cryptic language indeed using only numbers, and this gave access to much finer graphics - 512x384 pixels, or dots.
Compare this with todays household computer with maybe 2 terabytes (two million million, or 2,000,000,000,000 bytes) of memory, graphics of 1920x1080 pixels, and several million colours, multi-channel sound, and files that are loaded and saved from DVDs or external drives that hold terabytes of data. Or, you can send it to "the cloud" for storage, freeing up your own computer's storage space.

Photography

Back in my younger days, the Box Brownie camera was probably the most popular camera around, and typical of most cameras available. It was called a Viewfinder camera, and had a viewer next to the main lens. This meant that what you saw through the viewer was not necessarily the picture you got, because of parallax error. This problem would have become even more severe when zoom lenses came into use, since a viewfinder would not adjust for zoom.
The arrival of the Single Lens Reflex camera, fixed this problem as the viewer actually looked out through the lens, and what you saw was what you got (sort of early days WYSIWYG?).

Film cost was a big consideration when deciding whether or not a "shot" was worth taking as film rolls only allowed 12, 24 or 36 pictures per roll. Once taken, that part of the film couldn't be used again - even if it was just a very close shot of your thumb! When the roll of film was finished you took it to the chemist's shop and they sent it away to be developed (unless you had your own darkroom and did it yourself).

Later, electronic cameras arrived which used solid-state devices instead of roll film, to create "digital" photos, which have the great advantage of never changing due to fading or mould etc. Electronic cameras allow several hundreds or thousands of photos to be taken on one "chip", printed or downloaded to your computer, then the chip re-used. So users could snap happily away, sometimes taking the same shot several times to ensure a good result, with no extra cost.
The reduction in size has allowed most mobile phones these days to have one or more quite sophisticated cameras built into them.

The arrival of digital cameras brought about the virtual demise, around 2013, of photographic film companies such as Kodak, Ilford and Agfa.
Some were able to change their production-model to produce things like synthetic paper for ID cards, radiology film, and inkjet and colour-printing items.
Interestingly, Kodak, one of the first of the photographic film companies, was also largely responsible for the creation of digital photography, which then caused their own closure.

Television

It's hard for young people to imagine life without television these days. But many of us grew up in a world where the idea was only science-fiction. Even the radio was in its infancy.
But eventually, we heard about people with this new invention in their homes, and the lucky ones were able to see it operating by visiting a rich neighbour. It left most of us gob-smacked that pictures were able to be produced on the front of a box, without a projector. Sure, they were only black and white, and they were very streaky, but they could move!
Then, someone had the brilliant idea of adding colour to the pictures. This was done by attaching a plastic sheet to the front of the screen, with a blue band at the top (for sky) and a green band at the bottom (for grass). Of course, this didn't work very well, due to the amount of film footage that had neither sky nor grass.
Later, colour transmission was achieved, and this was accepted more and more as prices fell. A development that accompanied this was 3-dimensional viewing. This was done by the viewer wearing a pair of "3D glasses" which had one green and one red lens. This gave the impression that the picture was being viewed from two different points, giving the 3D effect.

Clocks, Controllers and Timers

Once upon a time, clocks were mechanical devices with two, sometimes three hands to indicate the time, and the ability to "chime" every hour or half-hour. We could use this to control our day - to know when it was time to go to work, take the cake out of the oven etc. They required winding up every day or so to maintain the correct time. Pendulum clocks improved on this by only requiring winding weekly or even less frequently.
Then electricity came along, and we no longer had to wind them at all. Some retained their analogue face-and-hands display, while others adopted a new, digital display that gave the time in hours and minutes and if desired, seconds.
As they became more stable, with battery backup when power failed, they began to be used to control devices directly. They were built into ovens and similar appliances, allowing these to be started and stopped during our absence.
Watering of gardens became less of a hit-and-miss affair, with controllers being developed that not only started and stopped at a selected time, but, with the use of solenoids (electrically controlled taps) we could water several areas at different times, for different lengths of time, and on varied days. They could even skip days when rain had recently fallen.
Watches were used only to check the time in The Olden Days, but today they're able to monitor your heart-rate and other vital signs, tell you where you are and how far you've run, give you the weather forcast, send and receive messages and much more.
Nowadays, it's difficult to name an area of our lives that isn't controlled by a timer or automatic controller of some sort.
Of course, daylight saving is a whole 'nother story with several parts of a country using different times depending on their geographical position. I bet even the cows get confused about their milking time!