Has the Hieroglyphics Ever Been Deciphered?

The question that I've been asked, over and over again, is this: "has the hieroglyphics ever been deciphered." This is a very sensitive question. Consequently, it's always been met with a polite parry, but I'll attempt to answer it as briefly as possible regardless of whose feelings may be hurt. 

The hieroglyphics is the pictographic ancient Egyptian writing system. It's supposedly ideographic, phonographic, determinative and complex. 

THE NOTABLE ACTORS IN THE HISTORY OF DECIPHERMENT

1. Ibn Wahshiyya the Nabataean (circa 8th-10th Century CE) was allegedly one of the first historians to be able to at least partly decipher what was written in the ancient Egyptian hieroglyphs.

2. Thomas Young (of the famed double-slit experiment in quantum physics, circa 1773-1829 CE) was an English polymath who made significant contributions in the decipherment of ancient Egyptian writing scripts including hieroglyphics.

3. Jean-Francois Champollion (circa 1790-1832 CE) was a French scholar who's credited for allegedly deciphering the hieroglyphics; although, there were accusations of plagiarism. Champollion' system of decipherment rested on Thomas Young's earlier works.

4. Joseph Fourier (of Fourier Series in Engineering and Applied Math, circa 1768-1830 CE) was a French mathematician, arguably one of the greatest mathematicians ever, who provided Champollion with some knowledge of calculus and statistics which allegedly helped in the decipherment of the hieroglyphics. Fourier was one of the scientists who accompanied Napoleon on the Egyptian expedition (circa 1799 CE). It's this expedition that led to the discovery of the Rosetta Stone - a trilingual stone; a key device in the decipherment. 

THE METHOD AND SYSTEM OF DECIPHERMENT

Both Young and Champollion reverse engineered the demotic Egyptian script on the Rosetta Stone to decipher the pictographic hieroglyphics. Young relied heavily on calculus and statistics in his system while Champollion relied heavily on Coptic, a language thought to be closely related to the ancient Egyptian language.

THE TWO KEY ASSUMPTIONS THAT WENT INTO THE DECIPHERMENT 

1. That all the three writing scripts and texts on the Rosetta Stone have the same meaning.

2. That the hieroglyphics is both ideographic and phonetic. 

Now, has the hieroglyphics been deciphered?

First off, even if I agree that the Rosetta Stone is authentic and not fictitious, the two assumptions above have to be correct for me to somewhat agree that the hieroglyphics has been deciphered. Secondly, if the hieroglyphics is indeed ideographic and phonetic. I agree, that one can map Latin alphabets (which English is based on) to the phonetic alphabets of the Egyptian script, but it's absolutely impossible for one to map same to ideographic alphabets. For example, under the Yoruba system, double stripes is a symbol of one of the two legs of Ifa. But here, in the West, double stripes is Adidas. In other words, you cannot arbitrarily map phonetic alphabets to symbols or ideograms like the pictographic hieroglyphics except if you're present in the culture from whence the symbols emanate. So, to the extent that I can't independently substantiate the two assumptions that were made above, I don't believe that the pictographic hieroglyphics texts of the ancient Egyptians has ever been deciphered.

I hope this answer your question. Ire o.