There are some similarities between science and Buddhism. Both rely on intuition, rationality and wisdom in search of truths or universal laws about life, human beings, and all events and phenomena in the universe(s). Like Buddhists, most scientists, especially modern physicists, believe in such laws as cause and effect, impermanence, emptiness, and cyclic interdependence. Science uses qualitative and quantitative experiments, relies on observation, mathematical formula, and exact measurements to test hypotheses, models and theories. Buddhism also relies on observation, analysis, direct experiences, and profound contemplation to find out the ultimate reality. Both Buddhism and science demand long and rigorous training, much efforts and strong determination on the part of the follower.
However, science and Buddhism have some huge differences.
First, while science searches for conventional truths (usually agreed upon and easily accepted by conventional thinking), Buddhism goes against all conventional (which is “illusory” in the Buddhist view), and dualistic ways of thinking. Science aims at conquering or mastering Nature, making it serve humanity; Buddhism has only one purpose: to find the ultimate truth, that is, to free all beings from suffering and help them attain Nirvana/Enlightenment (liberation from the cycle of suffering, of birth, old age, illness, and death).
Another difference is related to ethical issues. As a spiritual path leading to liberation of all beings from suffering, Buddhism respects life and emphasizes equality among all beings, and harmony between beings and environment (Nature). Buddhism and Buddhist followers treat and serve every being equally out of the strong belief that each has Buddha Nature (the natural awareness that every being /the Part has and shares with others in the immense open space/the Whole). As part of human knowledge and discoveries, science may serve some groups of humans, but harm others, as well as animals and environment.
Finally, Buddhist teachings aim at transforming human three poisons (greed, anger, and ignorance) into three noble virtues (donation/giving, loving-kindness/compassion, and wisdom). It focuses on this mind training through such methods as meditation, or contemplation on, and developing insights about, a subject or a topic (for example, breath, images of Buddhas, chanting names of Buddhas, chanting mantras, Death, the impurities of the body, carcasses...). In science so far there is no such training that aims at liberation from the cycle of life and death (Nirvana). Nor is there any scientific law regarding life after death (Karma), and reincarnation.
(See also A Convergence of Modern Science and Buddhism, a blog entry in November, 2011)