Please, if the title is going to be that, at least remove the capitalization from that "m", so it represents an unity instead of "millions of something undisclosed".
I've always wondered this, as a non English native speaker. You could also say the "u" in unity is pronounced as "iu" which starts with a vowel and sounds the same as "you", so your reasoning sounds incorrect. Perhaps a better explanation is that the "iu" diphthong is already paired together, so attaching it to the "an" sound to form "aniu" doesn't roll off the tongue as well.
Correct, this particular diphthong and the substitution of "an" for "a" serve the same exact function, so having both would be redundant. If we were to look at a word that starts with u but doesn't have the diphthong, such as Ubuntu, then "an" is used.
English rules for using "a" or "an" depend on sounds used in the next word, not particular letters. "A unit" and "An hour" are easy examples that might trip people up when focused on the letters used in spelling, but if you sound it out, you can probably work out what sounds best.
Submitted title was "Researchers reached the bottom of ice sheet at -2670m after 7 years of drilling". I've reverted to the article title now, or rather a slightly rewritten version to omit the linkbait.
Thank you for pointing this out. I thought it was referring to the age of the samples taken before reading your comment. It made the abstract less disappointing.
It responds to the comment "I only clicked on the article because I thought it was the age of the samples too." Age is "The length of time that a person or thing has existed." AD and BC are both absolute values from a zero point, both positive ("1 BC is year 0, 45 BC is year −44" [0]). A relative chronological dating by some phenomenological method such as radiocarbon or thermolumenescence might establish a negative date relative to some other known benchmark [1].
How might something dated from the future be found? I'm not certain, but maybe it has to do with aliens that are all the rage nowadays.
If I were 12 years old, I would have been born 12 years ago.
2023
- 12
----
2011
If I were -12 years old, I would be born 12 years from now.