Short answer: to have one (native) language shared by every human being in the universe would be almost impossible.

Long answer:

note: all numbers are very rough estimates.

It would be almost impossible to have one shared (by shared I mean that any one human can understand any other human wherever they are from) native language.
The reason is the following:
Every language has dialects. Lets estimate the difference between these dialects to be 100-200 words every two-three hours journey (the faster people can go (to talk to neighbours note: this assumes that ), the larger the areas of the dialects).
Let us assume that the language in question has roughly half a million words in total (probably more than the words in the English language, but time turns into technology, which needs more words, and there will probably be a lot more synonyms because people will forget what words to use and invent new ones(which will later become standardised)).
Currently, the technology is there to cross the pacific in less than a day (i.e. concord), but it is too expensive. Making super-sonic submarines is another matter entirely. Assuming you haven't got fusion power yet, you are still using fossil fuels, which will be about as rare as diamonds (random guess). This means that the average speed will be roughly 30 kilometres per hour.

The metre was originally defined in 1793 as one ten-millionth of the distance from the equator to the North Pole.
(wikipedia)

Assuming the earth is a sphere(to make the maths easier) this means that the difference between the dialects at opposite sides of the globe would be:
n=num*((circ/2)/spe)
where circ is the circumference of the earth(4*10 million m), spe is the average speed (30 km/h) and num is the number of words that change per hour of travel (100-200)

I got an answer of 66 666 666.66 to 133 333 333.333. Assuming the numbers that I used were accurate, you could only have a single language where you have a planet less than half the size of Earth.

Note: I have not included anything about telephones, internet, email, etc. because you don't send any messages to people you don't know. If you haven't been to a place, you don't have any friends from there.

However there are ways out:

• Invent fusion, so you can have people gong at much faster speeds
• Kill off a lot of your population
• Use something like the babel-fish from the Hitch Hikers Guide to the Galaxy
• think of something else

Short answer: to have one (native) language shared by every human being in the universe would be almost impossible.

Long answer:

note: all numbers are very rough estimates.

It would be almost impossible to have one shared (by shared I mean that any one human can understand any other human wherever they are from) native language.
The reason is the following:
Every language has dialects. Lets estimate the difference between these dialects to be 100-200 words every one hours journey (the faster people can go (to talk to neighbours note: this assumes that ), the larger the areas of the dialects).
Let us assume that the language in question has roughly half a million words in total (probably more than the words in the English language, but time turns into technology, which needs more words, and there will probably be a lot more synonyms because people will forget what words to use and invent new ones(which will later become standardised)).
Assuming that the population continues to grow, you will need cities on the ocean floor (as well as colonies on Mars, orbiting cities etc., but the question asks about language on earth).

[...]in 2500 the world population could even top 60 billion at the current growth rate with no intervention by any government, entity or group. (https://www.quora.com/What-will-the-human-population-of-the-world-be-in-the-year-2500)

Currently, the technology is there to cross the pacific in less than a day (i.e. concord), but it is too expensive. Making super-sonic submarines is another matter entirely. Assuming you haven't got fusion power yet, you are still using fossil fuels, which will be about as rare as diamonds (random guess). This means that the average speed will be roughly 30 kilometres per hour.

The metre was originally defined in 1793 as one ten-millionth of the distance from the equator to the North Pole.
(wikipedia)

Assuming the earth is a sphere(to make the maths easier) this means that the difference between the dialects at opposite sides of the globe would be:
n=num*((circ/2)/spe)
where circ is the circumference of the earth(4*10 million m), spe is the average speed (30 km/h) and num is the number of words that change per hour of travel (100-200)

I got an answer of 66 666 666.66 to 133 333 333.333. Assuming the numbers that I used were accurate, you could only have a single language where you have a planet less than half the size of Earth.

Note: I have not included anything about telephones, internet, email, etc. because you don't send any messages to people you don't know. If you haven't been to a place, you don't have any friends from there.

However there are ways out:

• Invent fusion, so you can have people gong at much faster speeds
• Kill off a lot of your population
• Use something like the babel-fish from the Hitch Hikers Guide to the Galaxy
• If you have one political leader giving speeches every day/week/etc., then the dialect "effect" will be diminished
• think of something else