What does "until now" mean in the context?

Question

I was doing a listening practice and came across the material:

Professor: Recently there was an archeological excavation in Egypt, on the Nile River around where enters the Mediterranean Sea where they discovered an ancient glass factory.

Robert: I thought our textbook said the Egyptians imported their glass from other countries.

Professor: Well, until now that’s what the evidence seemed to suggest. I mean, we have some evidence that suggested that the Egyptians were making glass objects, but not glass.

Robert: Ok. Am……Am I missing something? They are making glass but they are not making glass?

Professor: I said they were making glass objects, right? You see, it was previously thought that they weren’t actually making the raw glass itself that they were importing unfinished glass from Mesopotamia.

The professor says "until now that’s what the evidence seemed to suggest.". Does the evidence include the recently found one? In other words, did the Egyptians make raw glass at that time?

Answer 1

Explanation of "until now" in context

"Until now, what's what the evidence seemed to suggest" in this example suggests that up until that point, all of the previous evidence was believed. However, new evidence suggests that the previous evidence may be partially incorrect, but nothing has been proven yet. https://www.lib.uoguelph.ca/get-assistance/writing/writing-disciplines/using-evidence-effectively does a great job at explaining ways to present new evidence in writing. They say that when telling the reader evidence that has recently been discovered, make sure to use words like "suggest" to show that this evidence has not been compiled to prove something yet. This is exactly what the professor does in this dialogue.

Answering your questions

We can use this link to answer your question. To answer your first question, the evidence does not include the recently found evidence. To answer your second question, the Egyptians possibly made raw glass at that time, but nothing has been confirmed yet. There is still a chance that they imported their glass instead of making it themselves because not enough evidence has been gathered to prove that they did or did not. For more information about this, read below.

Additional information

Many sources such as http://www.historyofglass.com/glass-invention/egyptian-glass/ and http://link.springer.com/content/pdf/10.1007/978-94-007-3934-5_10089-2.pdf say that the Mesopatamians were the first to make glass, but the Egyptians further advanced the process of making glass.

Answer 2

'until now' carries a slightly negative meaning.

In the listening context, it means there is limited / little evidence to show that Egyptians were making glass.