The Universe is thought to consist of three types of substance: normal matter, 'dark matter' and 'dark energy'. Normal matter consists of the atoms that make up stars, planets, human beings and every other visible object in the Universe.
✏️Some scientists interpret this to mean that the ‘dark energy’ which most astronomers now believe dominates the Universe simply does not exist.
Clusters of galaxies emit lots of X-rays because they contain a large quantity of high-temperature gas. By measuring the quantity of X-rays from a cluster, astronomers can work out both the temperature of the cluster gas and also the mass of the cluster.
✏️Normal matter consists of the atoms that make up stars, planets, human beings and every other visible object in the Universe.
As humbling as it sounds, normal matter almost certainly accounts for the smallest proportion of the Universe, somewhere between 1% and 10%.
✏️But more than 13 billion years ago, following the big bang, the early universe was hot, and all that existed were a few types of atoms, mostly helium and hydrogen.
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Answer:
The Universe is thought to consist of three types of substance: normal matter, 'dark matter' and 'dark energy'. Normal matter consists of the atoms that make up stars, planets, human beings and every other visible object in the Universe.
Explanation:
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✏️Some scientists interpret this to mean that the ‘dark energy’ which most astronomers now believe dominates the Universe simply does not exist.
Clusters of galaxies emit lots of X-rays because they contain a large quantity of high-temperature gas. By measuring the quantity of X-rays from a cluster, astronomers can work out both the temperature of the cluster gas and also the mass of the cluster.
✏️Normal matter consists of the atoms that make up stars, planets, human beings and every other visible object in the Universe.
As humbling as it sounds, normal matter almost certainly accounts for the smallest proportion of the Universe, somewhere between 1% and 10%.
✏️But more than 13 billion years ago, following the big bang, the early universe was hot, and all that existed were a few types of atoms, mostly helium and hydrogen.
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