zergtoshi

Unexpected Keyboard
https://github.com/Julow/Unexpected-Keyboard
Available on F-Droid
You can pretty much configure the whole layout. Not sure about gif support though.

Solar panels can have more than 200 watts peak per square meter and provide around 200 kWh per year and square meter, although these values vary a lot depending on where the panels are installed.
Given these numbers, generating 200 TWh annually (which is more than the current electric energy consumption of Bitcoin mining devices) would require 10^9 square meters; that's slightly more than 31 square kilometers.
Don't misunderstand this as defending the electric energy consumption of Bitcoin mining! I'd rather see this electric energy being used elsewhere.
I merely wanted to show how much electric energy can be harvested using solar panels.

Yes, there's a queue called mempool.
Clogging up the network is possible, but costs money (BTC), because transaction fees need to be added to the transactions and those fees need to be higher than those of the highest not yet processed transactions if "regular" users' transactions shall be delayed.
Miners prefer transactions with higher fees (to be precise: higher fees per occupied block space), because they earn them when creating the block successfully - together with the BTC that get issued when a block gets created.

It's a bit more than just an estimate. If you want to know more, have a look here: https://bitslog.com/2013/04/17/the-well-deserved-fortune-of-satoshi-nakamoto/
The keys to the addresses exist. Whether someone is in control of them is unclear. It can't be proven that they've been lost.

Your understanding is correct.
Relativistic mass increases the faster the moving object gets. That in turn means more energy is required to accelerate an object the closer it gets to the speed of light.

Fun fact: the speed of light is not as absolute as it might seem when looking at relativistic effects. In media with a refraction index above 1 (only perfect vacuum has a refractiom index of 1), the speed of light equals 1/(refraction index).
For light moving in water that results in a speed of light of around 3/4 the speed of light in vacuum.

Just because it's useless to you doesn't mean it's useless in general.

You can look how much space a transaction requires, how much size is available per block and how many blocks per time are being created (at average).
The only way to exceed the figure is by creating transactions with 1 (or few) input(s) and a lot of outputs as they are more efficient in terms of space per tx. Individuals rarely have use for that, but exchanges tend to do that.
If you want to do your own research, start with the fundamentals and investigate the numbers (size per tx depending on type of tx, size per block, blocks per time).

Shall I add the mountain of electronic waste to the list?
I mean, Bitcoin mining devices can literally do nothing else but calculate SHA256.
Once they can no longer be operated economically, they're garbage.
At least Ethereum's PoW ran on GPUs, which can be used for, let's say: gaming!
And Ethereum showed that a transition from PoW to PoS is possible.
I think that Bitcoin sparked a great idea, but way better implementations of that idea are available. Bitcoin has a massive network effect and first mover advantage. technology wise it's no longer on top of the list.

Prime numbers are searched for doing the PoW. The blockchain essentially contains a data base with prime numbers. As far as I can tell Primecoin never was popular,.but I like the novel approach of doing things, when most cryptocurrencies of that time were lame copies.
Btw. the Primecoin creator made Peercoin, which was afaik the first (and apparently still running) network being secured by Proof-of-Stake.

It's a lot of energy for a global (!) maximum of around 7 transactions per second.
Unless you want to use the replica of traditional finance called Lightning Network. Then you have more transactions per second and a whole new set of drawbacks.

Not all crypto are the same.
Nano has been designed as digital money.
It has no mining, 0 fees (none for transactions, none for opening accounts), finalizes transactions sub-second (typically), has no built-in throughput limits and works across (political) borders.
I'd say these attributes offer some use and value.

Primecoin wants to have a word having done useful PoW for over a decade.