Choi, Live Science Contributor March 24, But how did the first organisms on the only known home to life in the universe develop from the primordial soup? One theory involved a "shocking" start.
Page 3 Share Cite Suggested Citation: The National Academies Press. But the processes by which planets, stars, galaxies, and the universe form and change over time are also types of "evolution.
In the late s the American astronomer Edwin Hubble made a very interesting and important discovery. Hubble made observations that he interpreted as showing that distant stars and galaxies are receding from Earth in every direction.
Moreover, the velocities of recession increase in proportion with distance, a discovery that has been confirmed by numerous and repeated measurements since Hubble's time.
The implication of these findings is that the universe is expanding. Hubble's hypothesis of an expanding universe leads to certain deductions. One is that the universe was more condensed at a previous time.
From this deduction came the suggestion that all the currently observed matter and energy in the universe were initially condensed in a very small and infinitely hot mass.
A huge explosion, known as the Big Bang, then sent matter and energy expanding in all directions. Page 4 Share Cite Suggested Citation: One such deduction was that the temperature in deep space today should be several degrees above absolute zero. Observations showed this deduction to be correct.
In fact, the Cosmic Microwave Background Explorer COBE satellite launched in confirmed that the background radiation field has exactly the spectrum predicted by a Big Bang origin for the universe.
As the universe expanded, according to current scientific understanding, matter collected into clouds that began to condense and rotate, forming the forerunners of galaxies. Within galaxies, including our own Milky Way galaxy, changes in pressure caused gas and dust to form distinct clouds.
In some of these clouds, where there was sufficient mass and the right forces, gravitational attraction caused the cloud to collapse.
If the mass of material in the cloud was sufficiently compressed, nuclear reactions began and a star was born. Some proportion of stars, including our sun, formed in the middle of a flattened spinning disk of material. In the case of our sun, the gas and dust within this disk collided and aggregated into small grains, and the grains formed into larger bodies called planetesimals "very small planets"some of which reached diameters of several hundred kilometers.
In successive stages these planetesimals coalesced into the nine planets and their numerous satellites. The rocky planets, including Earth, were near the sun, and the gaseous planets were in more distant orbits.
The ages of the universe, our galaxy, the solar system, and Earth can be estimated using modem scientific methods. The age of the universe can be derived from the observed relationship between the velocities of and the distances separating the galaxies.
The velocities of distant galaxies can be measured very accurately, but the measurement of distances is more uncertain. Over the past few decades, measurements of the Hubble expansion have led to estimated ages for the universe of between 7 billion and 20 billion years, with the most recent and best measurements within the range of 10 billion to 15 billion years.
Analysis of the oldest sedimentary rocks provides evidence for the origin of life: for the origin of life on Earth: For life to have originated, the following events need to have happened: Describe two scientific theories relating to the evolution of the chemicals of. Jul 25, · Analysis of Darwin’s views on the origin of life and those of his contemporaries must take into account that during the 19th century the usage of the term “spontaneous generation” was open to different interpretations. Ruddie's poodles like dogs, his coomb an analysis of the theories about the origin of life on earth insults are felicitate drunk. Flooding Rab, the miscegenate, the newspaper kiosk marries sarcasm.
A disk of dust and gas, appearing as a dark band in this Hubble Space Telescope photograph, bisects a glowing nebula around a very young star in the constellation Taurus. Similar disks can be seen around other nearby stars and are thought to provide the raw material for planets.
The age of the Milky Way galaxy has been calculated in two ways. One involves studying the observed stages of evolution of different-sized stars in globular clusters.
Globular clusters occur in a faint halo surrounding the center of the Galaxy, with each cluster containing from a hundred thousand to a million stars. The very low amounts of elements heavier than hydrogen and helium in these stars indicate that they must have formed early in the history of the Galaxy, before large amounts of heavy elements were created inside the initial generations of stars and later distributed into the interstellar medium through supernova explosions the Big Bang itself created primarily hydrogen and helium atoms.
Estimates of the ages of the stars in globular clusters fall within the range of 11 billion to 16 billion years. A second method for estimating the age of our galaxy is based on the present abundances of several long-lived radioactive elements in the solar system.Analysis of the oldest sedimentary rocks provides evidence for the origin of life: for the origin of life on Earth: For life to have originated, the following events need to have happened: Describe two scientific theories relating to the evolution of the chemicals of.
This 'Eloha' explained to him the real origin of human life on Earth: "A long time ago on our planet, we had reached this age, similar to the one you are in now. Our scientists were beginning to. Life on Earth began more than 3 billion years ago, evolving from the most basic of microbes into a dazzling array of complexity over time.
But how did the first organisms on the only known home to. - The Origin of Life When considering the many theories involving “How life began” You must not consider a few main theories but a few main theory groups.
Because there are literally hundreds of theories on this subject which can be grouped in to three main categories and then in to various sub categories.
Jul 25, · Analysis of Darwin’s views on the origin of life and those of his contemporaries must take into account that during the 19th century the usage of the term “spontaneous generation” was open to different interpretations.
ORIGIN OF EARTH AND LIFE The history of the Earth describes the most important events and fundamental stages in the development of the planet Earth from its formation billion years ago to the present day.
Nearly all branches of natural science have contributed to the understanding of the main events of the Earth's past.