Presumably because he is a Cornell alumnus from 1990. The article is at cornell.edu .

Listing alumni degree year is generally an "insider" thing (noone who isn't also a Cornell alum really cares which year, especially for a bachelor's degree; likewise Cornell doesn't mention the Harvard '95 PhD in Applied Physics, even if it's probably more relevant to the work...)

	▲	metalman 3 hours ago \| parent [-]
		"insider" thing, you can be certain that an exempliary mind such as his did not get fired up in a vacume, and that 90, was a year and place that likely produced an iteresting mixed bag of characters, or in other times would be refered to as "schools of thought", and then some went off to bell labs which still functions as an intelectual singuarity that leaks concepts through it's event horison ocasionaly, or in this case displays time dialation effects.

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userbinator 9 hours ago | parent | prev | next [-]

I first thought it was supposed to be a comma, and that he's 90 years old.

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kibibu 10 hours ago | parent | prev [-]

Ahh makes a lot of sense