I started by researching futhark, Germanic/Teutonic, Anglo-saxon runes. I don't interpret the characters too tightly as "modern" letters. (Note: These are stylised characters, bull past the flair to "see" them.)
The crosses ARE Greek as suggested by a few commentators in the article linked to in OP. I don't see how the crossbars at the tips ...
The secret of the universe is
Because the famous leader who found the tabelet is
He invented a code named
The message on the piece of paper has been decoded using
so if we use the cipher above to encode it back we get
When we undo what the MAGE has done to it
which again decoded by the cipher of the great leader gives us
My solution probably isn't going to earn any points, because I solved it within a couple of minutes by
without even thinking of
and the Mage was nowhere to be seen either.
At first I immediately noticed that
but that was a false clue.
Seems like I did stumble on a backdoor to the universe, though...
As noted in @Peszo's answer,
They have been jointly solved by @Peszo, @Gamow, and @MariaDeleva in that answer.
It remains to predict the fate of future earth.
The fate of future earth is
The clues were
Therefore the future earth is going to be
The answer is:
I will never be written, that surely would be impossible.
For thousands of years I was unused for practical purposes.
Reputedly the Irish invented me?
Nowadays I am often literally omitted – which can lead to embarrassment.
You may see me as part of a crossword answer – then again you wouldn’t.
The English use me after; the ...
The year is:
Mechanical calculations are sickened by the brain.
A boom in four's power brings the tsardom lasting pain.
Icarus's opponent is failed by an 'O'.
A confused maple fool falls after a show.
An unlawful caress of the globe is divine.
Switzerland flames bring blood to the Rhine.
A topsy-turvy lake strangles the land.
The whole new ...
As suggested by the language tag, I think a Veteran Word™ may be
All the words in the left-hand column, according to
satisfy this criterion. VETERAN is "only just" a Veteran Word™ because
The words in the right-hand column which are "half a Veteran Word™" are so because
They're called Veteran Words™ because
I think the fourth door might possibly be
and the plant on the door
(This has been confirmed by the questioner in comments. Thanks, Maria!)
Now, the time on door 2 looks to me like
(... and now I look at other answers I see that Yandrakus got there first and his answer has been confirmed correct.)
So, so far it seems that:
Some ideas ...
Answer: Thanks to everyone as listed
First (Courtesy of @Beastly Gerbil) is:
Second row is
Line four (Courtesy of @Acerfire37):
Line five (Courtesy of @Juan Tomas):
The relationship is
The message is written in this jagged spiral:
In memoriam: Henrietta, 1st wife of S. Bean, M.D., who died 27th Sep. 1865 aged 23 years 2 months & 17 days, & Susanna, his 2nd wife, who died 27th April 1867 aged 26 years 10 months & 15 days. 2 better wives 1 man never had. They were gifts from God but are now in heaven. May God help me, S. B., ...
The rest are here just because I was instructed to add them so the puzzle would be complete.
All credits go to Kruga. I would not be able to find them otherwise.
From the remaining letters you can form:
This might not be the right approach, but here's a possible interpretation of the first two:
Haven't found something similar for the third stamp yet. But these seem more rebus-y to me...
Anyway, as others have found this makes the kingdom the
Here's a guess for the third stamp (not super happy with it):
Here's a second guess for the third stamp that I ...
So, going in the thread of @AndrewSmith's answer, I'm going to fully answer the question here:
You worked at:
The first who came and worked with me was fresh from Ivy League,
But at twenty-two her labours brought her burn-out and fatigue.
The second one could rival her, just as strong and smart,
But one day pushed herself too hard and sadly fell apart.