In the Middle Ages, the Catholic church was against science, now they accept it. Why?

The Church was never against Science. Tom Short does a good job explaining it. https://www.youtube.com/watch?v=1l81xQyhwW0

The Opus Maius (1267) of the Franciscan Roger Bacon (d 1292), written at the request of Pope Clement IV, largely initiated the tradition of optics in the Latin world. The first spectacles were invented in Italy around 1300, an application of lenses that developed later into telescopes and microscopes.

While many people think of Galileo (d 1642) being persecuted, they tend to forget the peculiar circumstances of these events, or the fact that he died in his bed and his daughter became a nun.

The Gregorian Calendar (1582), now used worldwide, is a fruit of work by Catholic astronomers, as is the development of astrophysics by the spectroscopy of Fr Angelo Secchi (d 1878).

Most remarkably, the most important theory of modern cosmology, the Big Bang, was invented by a Catholic priest, Fr Georges Lemaître (d 1966), a historical fact that is almost never mentioned by the BBC or in popular science books.

Catholic civilisation has made a remarkable contribution to the scientific investigation and mapping of the earth, producing great explorers such as Marco Polo (d 1324), Prince Henry the Navigator (d 1460), Bartolomeu Dias (d 1500), Christopher Columbus (d 1506) and Ferdinand Magellan

(d 1521). Far from believing that the world was flat (a black legend invented in the 19th century), the Catholic world produced the first modern scientific map: Diogo Ribeiro's Padrón Real (1527). Fr Nicolas Steno (d 1686) was the founder of stratigraphy, the interpretation of rock strata which is one of the principles of geology.

Jean-Baptiste Lamarck (d 1829), a French Catholic, developed the first theory of evolution, including the notion of the transmutation of species and a genealogical tree. The Augustinian monk Gregor Mendel (d 1884) founded the science of genetics based on the meticulous study of the inherited characteristics of some 29,000 pea plants. &c., &c., &c... http://catholiceducation.org/articles/apologetics/...

Oremus pro invicem

You seem to be overstating the case. Yes, there are some Christians against the study of science. There are some who have no problem with science--as defined as honest, unbiased research into a particular situation, not the politically correct stuff being passed off as "science". Please remember that the Bible is not a book of science, per se, but it's absolutely true that every scientific fact or statement has been proved correct. Can you find one Bible statement about science that's been proven wrong? Science and the Bible are complementary, not contradictory, realms of God's creation. The Bible speaks of science in general terms, always with the design to point people to the Creator. Science, as properly explored and reported, shows the logical patterns and designs by which the universe operates. Why not post this question or other concerns to groups like the Institute for Creation Research, or Answers in Genesis, or other groups of Christians devoted to science and research? I'm sure they would be glad to answer any questions you might have.

Roger Bacon and Robert Grosseteste - who between them reintroduced the notion of empirical science to the western world - were both Roman Catholic clergy. The Catholic church opposed science only when it was in conflict with the revealed truth of Scripture.

Even the famous prosecution of Galileo Galilei is misunderstood by almost everyone these days. Galileo was not condemned for asserting that the earth orbited the sun, he was condemned for suggesting that when the evidence contradicts the Bible - you should follow the evidence.

There is a fairly thorough examination of the Galileo case in Arthur Koestler's The Sleepwalkers.

But the Catholic church has never opposed science the way that the Discovery Institute does today. Darwin's ideas have never been censured by the church in any way.

Catholicism realizes that times are changing. They know they need to change to maintain the Catholic Church. They don't realize that the only change they need is less ritualism. Many Catholics are modern day Pharisees (pharisees were the ultrareligious jews who hated Jesus)

Christianity is supposed to be a relationship with the Savior. If Catholicism focused more on that fact, they wouldn't have to try and lure in people with their "progressive" ideas on evolution, etc.

I believe evolution vs creationism is up to you to believe. There can't be ONE man to speak on behalf of God. The Bible clearly says the only mediator needed between man and God is Jesus Christ.

Because people have become more enlightened than they were in those times. It is unlikely the church would have changed their position if it wasn't for the fact that a massive part of their followers would have dropped off due to having common sense.

Wrong, Aquinas, 13th cen, accepted reason as a gift from God that must be used to understand God, he employed science in his theology, Augustine claimed all truth is in God, which included science. Were there elements that were opposed to it yes, but it is wrong to claim that is the whole story

In th emiddle ages science was in it's infancy and many facts were considered to be wrong because they did not apparently fit in with religeous thought at the time.

No one in the middle ages "accpeted science". The Scientific Method had not been developed yet.

they only accept some science now

not all science

they are just behind the tmes about 300 years or so

People, societies, organizations, civilization...it can "evolve" if we let it. The Catholic Church did.