Lemuria and Mu are not the same continent.
Mu was first theorized by Augustus Le Plongeon, who claimed it to be in the Atlantic Ocean, and was later popularized by James Churchward who asserted it to be in the Pacific.
Lemuria is said to have been located between the Indian and Pacific Oceans.
The similar citation of the Pacific Ocean is about all the two have in common, besides the letters "m" and "u."
No known geological formation exists under the Indian or Pacific Oceans that can correspond in size to either of them; and no, the Yonaguni structure doesn't count even remotely in the favor of either continent, because a single series of ruins and structures cannot denote something so large as a continent.
Mu has been discredited many times over. The idea that some hyper-advanced civilization kickstarted everything has no known evidence, as the Americas and Old World developed independently because of oceanic separation. Urban societies have more evidence pointing to have started near the Levant region thousands of years ago and expanding slowly from there. Even Neolithic cities like Çatalhoyuk are easily attributed and more defended as having been the result of gradual evolution of human settlements and societies.
Lemuria was basically discredited in full when plate tectonics became understood. India was once connected with Madagascar in a single supercontinent called Gondwana, and it bore many geographical similarities to how Lemuria has been thought of. Gondwana did not sink, however, but split apart into the continents we see in the Southern Hemisphere. Lemuria also has some very loose ties to the concept of Kumari Kandam, which is another beast of inaccuracies and inconsistent theories entirely.
Bottom line is, most theories regarding the lost continents were thought up during periods of history in which the world wasn't quite all known yet, and theories would emerge trying to explain the unknown. There are even continents that were completely made-up out of an old belief that the world had to have an "equal balance" of continents (one such instance being a large expansion on the Antarctic continental shelf). One must consider the time periods in which these theories were penned, as our understanding of the world was not what it is now. One must also consider the knowledge that things so large as continents do not sink overnight--there is no known instance of this ever happening. Continents take very long times to sink, which automatically makes such things as sunken-land stories somewhat sketchy in nature.
This is not to say that I fully discredit the ideas; our knowledge of history is only what we can see, and we know that it isn't as verbatim fact as we'd like it to be. Maybe there was an Atlantis or Mu, or at the very least islands or smaller landmasses to inspire their stories, and maybe they did indeed sink overnight. But right now, with what research has been done using the knowledge and tools we have available to use in this day and age, there has so far been no conclusive evidence made known about any such continents having existed as they are written in history and legend. We have things like sonar scanners and the ability to photograph the oceans from orbit and see underwater formations and landmasses, things that people back then didn't have (again, to the best of our current knowledge).
I don't close myself off to the possibility; possibility always exists. But I cannot discredit or ignore the decades of research and exploration and theorizing done by more educated and intelligent individuals than myself, which so far leaves no credible room for any of the lost continents to have been real. Perhaps in the future we'll find out they did exist and our methodology of the present simply wasn't good enough, and perhaps we'll have conclusive proof they never existed at all. I cannot know these things for certain.
All I can do is go with the information and scientific evidence that has been presented so far, and that evidence pretty much disproves the lost continents' existence as they are written (I keep saying "as they're written," because there are smaller formations off of Greece that are being looked into). We thought Troy was a myth for the longest time, until it was found; and its ruins don't quite stack up to how it was described in the Iliad and the Odyssey, not even taking into consideration the thousands of years it's been falling apart. Mythology and legend often stretch the truth of the real sources of their inspiration, after all.
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Maybe my first reply was harsh and a bit of overkill; I apologize for that. But consider where I'm coming from. I'd spent a few hours straight busting my ass trying to find the translations of the symbols, poring over the littlest of details in each real-world letter and character, comparing to very small pixelated versions and hoping they lined up right, and trying my best to ensure as accurate an attempt as I could manage; and then you come in out of absolutely nowhere bringing up completely unrelated topics to the thread's context. With the amount of work I'd exerted trying to contribute to this thread, that felt more than a little rude and I most definitely took some offense to it and lashed out. That post I apologize for.
This one, not so much. You made assumptions as to my knowledge on the subjects and made declarations and accusations based on those assumptions, and I am letting you have it in (Kumari) tandem. Mythologies and legends and ancient stories and all the things that go along with them are a particular area of history that I have been fascinated by and have read and researched thoroughly since I was a child. For you to assume that I was dismissing you based on close-mindedness is an insult, as well as being a very presumptuous error on your part.
No, I dismissed you one, because a distant connection between Sanskrit and Lemuria and the lost continents themselves have absolutely nothing to do with the actual topic of this thread (deciphering Dogether's symbols), and two because you presented your information in a manner that very heavily lends credence to the idea that you don't know the history of the subject as well as you act like you do. This could be an error in judgment on my part, but so far you've not given me any reason to think otherwise.
If you're going to call me close-minded, educate yourself on the history of what you're citing first, and don't assume that my skepticism is outright dismissal and patronize me based on that assumption.