Scientific Laws and Theories
1 )Heisenberg's Uncertainty Principle
Einstein's broader theory of relativity
told us more about how the universe works and helped to lay the
foundation for quantum physics, but it also introduced more confusion
into theoretical science. In 1927, this sense that the universe's laws
were, in some contexts, flexible, led to a groundbreaking discovery by
the German scientist Werner Heisenberg.
In postulating his Uncertainty Principle, Heisenberg realized that it was impossible to simultaneously know, with a high level of precision, two properties of a particle. In other words, you can know the position of an electron with a high degree of certainty, but not its momentum and vice versa.
Niels Bohr later made a discovery that helps to explain Heisenberg's principle. Bohr found that an electron has the qualities of both a particle and a wave, a concept known as wave-particle duality, which has become a cornerstone of quantum physics. So when we measure an electron's position, we are treating it as a particle at a specific point in space, with an uncertain wavelength. When we measure its momentum, we are treating it as a wave, meaning we can know the amplitude of its wavelength but not its location.
Keep reading for more science stuff you might like.
In postulating his Uncertainty Principle, Heisenberg realized that it was impossible to simultaneously know, with a high level of precision, two properties of a particle. In other words, you can know the position of an electron with a high degree of certainty, but not its momentum and vice versa.
Niels Bohr later made a discovery that helps to explain Heisenberg's principle. Bohr found that an electron has the qualities of both a particle and a wave, a concept known as wave-particle duality, which has become a cornerstone of quantum physics. So when we measure an electron's position, we are treating it as a particle at a specific point in space, with an uncertain wavelength. When we measure its momentum, we are treating it as a wave, meaning we can know the amplitude of its wavelength but not its location.
Keep reading for more science stuff you might like.
2)Theory of General Relativity
Albert Einstein's theory of general relativity
remains an important and essential discovery because it permanently
altered how we look at the universe. Einstein's major breakthrough was
to say that space and time are not absolutes and that gravity is not
simply a force applied to an object or mass. Rather, the gravity associated with any mass curves the very space and time (often called space-time) around it.
To conceptualize this, imagine you're traveling across the Earth in a straight line, heading east, starting somewhere in the Northern Hemisphere. After a while, if someone were to pinpoint your position on a map, you'd actually be both east and far south of your original position. That's because the Earth is curved. To travel directly east, you'd have to take into account the shape of the Earth and angle yourself slightly north. (Think about the difference between a flat paper map and a spherical globe.)
Space is pretty much the same. For example, to the occupants of the shuttle orbiting the Earth, it can look like they're traveling on a straight line through space. In reality, the space-time around them is being curved by the Earth's gravity (as it would be with any large object with immense gravity such as a planet or a black hole), causing them to both move forward and to appear to orbit the Earth.
Einstein's theory had tremendous implications for the future of astrophysics and cosmology. It explained a minor, unexpected anomaly in Mercury's orbit, showed how starlight bends and laid the theoretical foundations for black holes.
To conceptualize this, imagine you're traveling across the Earth in a straight line, heading east, starting somewhere in the Northern Hemisphere. After a while, if someone were to pinpoint your position on a map, you'd actually be both east and far south of your original position. That's because the Earth is curved. To travel directly east, you'd have to take into account the shape of the Earth and angle yourself slightly north. (Think about the difference between a flat paper map and a spherical globe.)
Space is pretty much the same. For example, to the occupants of the shuttle orbiting the Earth, it can look like they're traveling on a straight line through space. In reality, the space-time around them is being curved by the Earth's gravity (as it would be with any large object with immense gravity such as a planet or a black hole), causing them to both move forward and to appear to orbit the Earth.
Einstein's theory had tremendous implications for the future of astrophysics and cosmology. It explained a minor, unexpected anomaly in Mercury's orbit, showed how starlight bends and laid the theoretical foundations for black holes.
3)Evolution and Natural Selection
Now that we've established some of the fundamental concepts of how
our universe began and how physics play out in our daily lives, let's
turn our attention to the human form and how we got to be the way we
are. According to most scientists, all life on Earth
has a common ancestor. But in order to produce the immense amount of
difference among all living organisms, certain ones had to evolve into distinct species.
In a basic sense, this differentiation occurred through evolution, through descent with modification [source: UCMP]. Populations of organisms developed different traits, through mechanisms such as mutation. Those with traits that were more beneficial to survival such as, a frog whose brown coloring allows it to be camouflaged in a swamp, were naturally selected for survival; hence the term natural selection.
It's possible to expand upon both of these theories at greater length, but this is the basic, and groundbreaking, discovery that Darwin made in the 19th century: that evolution through natural selection accounts for the tremendous diversity of life on Earth.
In a basic sense, this differentiation occurred through evolution, through descent with modification [source: UCMP]. Populations of organisms developed different traits, through mechanisms such as mutation. Those with traits that were more beneficial to survival such as, a frog whose brown coloring allows it to be camouflaged in a swamp, were naturally selected for survival; hence the term natural selection.
It's possible to expand upon both of these theories at greater length, but this is the basic, and groundbreaking, discovery that Darwin made in the 19th century: that evolution through natural selection accounts for the tremendous diversity of life on Earth.
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