Latin as it is spoken today is not - to my knowledge - the same Latin that was spoken then. The spelling is different, we actually use punctuation and they would have difficulty reading our type-setting.
However, keep in mind that YMWV.
ymwv?
also they MIGHT be able to read it anyway!
Your Mileage Will Vary. It means: "If you want it in your game, go for it!" 
What future? The "future" doesn't exist!
then what are the astrologers for then?
They are not for "the" future - but to foresee auspicious moments. The future does not exist. We're waiting for the Kingdom Come and that's it...
Papal Bulls from the C21 would puzzle the C13 characters as the matters worrying the current Pope would seem stranage, dubious, and quite unlikely in most cases (Contraception? Wossat? Gay Marriage - What's "Gay"? ... Oh! Burn 'Em. Gay Priests - We Don't Have Them. No We Don't. Not Here. If they won't shut up, we'll Burn'Em);
if they got the Vatican Newspaper, it'd be equally strange and implausible (the Nuns' actions are quite implausible, as are the locations referred to - America, Asia?) - probably a deception of the Infernal or the Fae.
English wouldn't work at all - the language did not exist - Chaucer was born in 1343 in our history, and died 1400. And he is largely regarded as the first English writer... and most modern people think his language strange and difficult.
As for the subject matter of modern English-language newspapers.... Footballers, Posh'n'Becks, and Big Brother Reality Shows? Clearly Infernal!
To make it painfully clear: Ars Magica is set up in Mythic Europe, which is eerily similar to historical 13th century Europe, but is not our past. There were no such things as an Order of Hermes wielding great magics, there were no Covenants. There were no Auras, no Regios, no Divine, no Infernal, no Faerie, no Magic -- except possibly in the imaginations of the people of those times. Therefore it follows that their future is not our present. Even if you're playing White Wolf games, "modern times" are only similar to our world.
The Mythic Europ, the imaginary world of Ars Magica largely conforms to beliefs people of those times are known to have historically held. Way back then, they didn't know about dinosaurs: fossils were thought to be dragon bones. Therefore, in Ars Magica, fossils are dragon bones. Historically, diseases were thought to be the work of demons, humor imbalances or divine punishment. Therefore in Ars Magica, diseases are either of those things.
13th century people didn't imagine the modern world as we know it. As Furion points out, they were waiting for Kingdom Come. Therefore that is (or should be) the future of Ars Magica.
There are no modern times from which such books could come from, even if time travel is at all possible. And since time travel is itself a modern notion, time travel is impossible in Ars Magica. For that matter, only God knows the future.
As other people have pointed out in the thread, our world would seem so alien to 13th century people that, in Mythic Europe, it would definitely considered to be supernatural (horseless carts?). And given how our morals have evolved since that time, we would definitely be deemed Infernal. And burned. 
Since it is a game, you are free to run things however you want in your campaign, but once you start violating the setting the way you have, there is precious little we can help you with. Especially since you do not appear to understand the rules of the game, much less the setting itself.
If you would rather play Ars as a generic fantasy RPG, by all means, tell us so. Otherwise, make an effort and try to stick closer to the game's concepts.
ER, well I suppose
Large Cauldron +5 to brewing
Ladle (large spoon) +2 to brewing
Beer Barrel +3 to brewing
They are not very inspired as mguesses, but I'd allow any of those Abe.
cj x
I fear Abe has not conception of gaming outside Generic Fantasy, and much worse, in the year+ he has been here, he has shown not one single effort to understand and look beyond that, and attempt to understand the concept and style of Mythic Europe.
He just keeps throwing in random snippets from what appears to be readings from GF.
When he joined, it seemed worth working hard to try to help him - but he refuses to listen or learn.
They would cause immense chaos if anyone can read them. In canon, the way the game is written, there are no modern times, as others have pointed out. However, it soes lead to some interesting questions, such as what would the future of Mythic Europe look like anyway?
You can find a really long discussion of this here
forum.rpg.net/showthread.php?ref ... hic+Europe
Now just because the game is not written to work that way does not mean you can't do it. What if some magicians in terrible botch found themselves in 21st centurty New York? Or David Beckham found himself lost in a regio ina snowstorm while outy training, and showed up at Durenmar? What if a group of magi found themselves armed with a set of modern physics books??? I dunno, but it might make a fun story. There is really no right or wworong way to play any rpg abe - its not what the rules are written to support, but i think all those could be fun in the right place, they are just outside how we normally play Ars magica. So do as you choose mate, and have fun! It's very unlikely we can help you here though with ideas like that, but that does not mean it won't work for your players?
cj x
from the books of healing crystals(meadival uses only)what would be the forms & bonuses?
what sort of enchanted books have you fine people created?
While not exactly a book, the covenant I am working on has a small path winding around the valley walls, giving various views of the waterfall at the center of the covenant, and of the rainbows it produces. Contemplating on that path counts as studying an Imaginem summa. Unfortunately, the view is also popular among the covenant's visitors, of which there are plenty, and they often act as a distraction, reducing study totals.
Depends on the crystal.
I am not familiar with the various uses of crystals in meadevil times
new alchemetical item?-powdered water
a pinch of this substance & a drop of water & you have up to a gallon of water,probibly more useful in a wine skin first though huh?
might be the after efect of a spell,not sure thus the question mark.
what sort of spell effect the tempurature of metal(ie cause it to melt then reform into another form?)
what spells can create temporary vis?
Creo Ignem heats things while Rego Terram shapes metal.
So you could use CrIg to melt it and then ReTe to shape the slag. Or you could use ReTe by it self to reshape the item.
o.k then,but I was thinking of a spell that does both at once aka damages enemies as it reforms.