It was happening to me from my childhood, I have always had such dreams in my mind that are we alone in the universe. I know it can't be true. If we compare the whole universe to ocean then if we suppose that we take only a spoon water from ocean and the water is our solar system if we search only the spoon water there will be no one instead of our solar system rather there are so many living beings in whole ocean. Oh my god, that is mind-blowing.
In today's world, we all are receiving strange massages from space in different countries.
I wish we could have met aliens in the future.
At a particular instant roughly 15 billion years ago, all the matter and energy we can observe, concentrated in a region smaller than a dime, began to expand and cool at an incredibly rapid rate. By the time the temperature had dropped to 100 million times that of the sun’s core, the forces of nature assumed their present properties, and the elementary particles known as quarks roamed freely in a sea of energy. When the universe had expanded an additional 1,000 times, all the matter we can measure filled a region the size of the solar system. When the free quarks became confined in neutrons and protons. After the universe had grown by another factor of 1,000, protons and neutrons combined to form atomic nuclei, including most of the helium and deuterium present today. All of this occurred within the first minute of the expansion. Conditions were still too hot, however, for atomic nuclei to capture electrons. Neutral atoms appeared in abundance only after the expansion had continued for 300,000 years and the universe was 1,000 times smaller than it is now. The neutral atoms then began to coalesce into gas clouds, which later evolved into stars. By the time the universe had expanded to one fifth its present size, the stars had formed groups recognizable as young galaxies.
When the universe was half its present size, nuclear reactions in stars had produced most of the heavy elements from which terrestrial planets were made. Our solar system is relatively young: it formed five billion years ago, when the universe was two thirds its present size. Over time, the formation of stars has consumed the supply of gas in galaxies, and hence the population of stars is waning. Fifteen billion years from now, stars like our sun will be relatively rare, making the universe a far less hospitable place for observers like us.
One can estimate this quantity from knowledge of the universe’s average density. One expects that because gravity exerts a force that opposes expansion, galaxies would tend to move apart more slowly now than they did in the past. The rate of change in expansion is therefore related to the gravitational pull of the universe, set by its average density. If the density is that of just the visible material in and around galaxies, the age of the universe probably lies between 12 and 20 billion years. The range allows for the uncertainty in the rate of expansion.
Yet many researchers believe the density is greater than this minimum value. So-called dark matter would make up the difference. A strongly defended argument holds that the universe is just dense enough that in the remote future the expansion will slow almost to zero. Under this assumption, the age of the universe decreases to the range of seven to 13 billion years.
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