The best-fit model to observational data is a spatially flat and spatially infinite universe. The mystery of its flatness, both in the present and the past, is a fascinating aspect of our cosmic understanding.
Dark energy In physical cosmology and astronomy, dark energy is a proposed form of energy that affects the universe on the largest scales. Its primary effect is to drive the expansion of the universe.
The ‘initial singularity’ is a concept that challenges our understanding of time and existence. It’s not a part of the universe, but a moment, a point in time that does not exist; only subsequent points in time do..
Dark energy is a hypothetical form of energy that is proposed by physicists to explain why the universe is not just expanding, but is doing so FASTER.
Think of dark energy as the “evil counterpart” to gravity–an “anti-gravity” force providing a negative pressure that fills the universe and stretches the very fabric of spacetime. As it does, dark energy drives cosmic objects apart at an increasingly rapid rate rather than drawing them together as gravity does.
Time is arbitrarily close to the singularity. The closer a point in time is to the singularity, the denser and hotter the universe is. But still infinite.Yes, things that are very far apart today would have been very close in the early universe. However, that does not mean that they originate from a single point. They were very close, and no matter how great a distance you name or how early in the universe you go, you will always find things farther apart than that distance.Things would be different if we lived in a positive curvature, a spatially closed universe. Such a universe would have a finite volume; earlier in its history, it would have had a smaller volume. Extremely close to the singularity, its volume would have been minimal. But even in this case, the singularity is not part of the universe. This is hypothetical; there are no indications that we live in a spatially closed universe, and there are plenty of indications that we do not.Scientists do not know why.
A day on Venus is longer than a year on Venus, meaning that Venus rotates on its axis much more slowly than it orbits the sun.
The sheer number of stars in the universe is a humbling thought. There are more stars out there than grains of sand on all the beaches on Earth.The largest known structure in the universe is a cluster of galaxies called the Hercules-Corona Borealis Great Wall. This massive structure, which is 10 billion light-years away and over 10 billion light-years long, is a testament to the vastness and complexity of our universe. The universe is estimated to be around 13.8 billion years old. However, because of the effects of time dilation, some regions of the universe may be older or younger than others.
If you were to fall into a black hole, the process of ‘spaghettification’ would stretch you out into a long, thin strand of matter. This bizarre phenomenon, caused by the extreme gravitational forces of a black hole, is a fascinating yet terrifying aspect of our universe. The universe is mainly made up of dark matter and energy, which cannot be seen directly.
Rona Borealis Great Wall, a staggering 10 billion light-years away and stretching over 10 billion light-years, showcases the unfathomable vastness of our universe. While we estimate the universe to be around 13.8 billion years old, the effects of time dilation introduce a fascinating mystery- some regions of the universe may be older or younger than others, sparking curiosity and intrigue. Imagine the bizarre process, where falling into a black hole would stretch you out into a long, thin strand of matter, a concept that is both fascinating and mind-boggling. The universe is mainly made up of dark matter and energy, which cannot be seen directly.
Observed or detected, but can be inferred from gravitational effects.
here are more atoms in a single grain of sand than there are grains of sand on earth.
Cording to theories such as string theory and the many-worlds interpretation of quantum mechanics, there may be parallel universes or multiple dimensions of reality that we cannot directly observe or interact with; according to the original answer, Before the Big Bang, there was nothing. What is still needed to learn what, if anything, existed before the Big Bang. Of course, this does not stop people from speculating and sounding like they know.There is good evidence for the Big Bang as what is left lying around in the universe and what that stuff is doing. We can be confident that the universe was once highly compressed and extremely energetic and that after the Big Bang, the universe developed in a way consistent with known physics. This should not be surprising because “known physics” is modeled on the observed universe.to get to the instant of the Big Bang, which could be more apparent. When physicists find they are in this kind of chaos, the usual strategy is to gather data and then find equations and models that match the data. Unfortunately, all the data available comes from this universe.
and in the time after the Big Bang. We are stuck! It is like trying to build a car using a cake recipe or something. If we had just one reliable observation from before the Big Bang (if there was anything) or another universe (if there is any), that would be incredibly illuminating and provide enormous guidance to physics. Still, there appears to be nothing available, and there is probably no hope of ever getting any of the data we require.In In this situation, physicists have to make stuff up. They don’t make up random stories (like the universe was vomited up by a giant tortoise) but try to form models that are consistent with what they think are the deeper underlying principles of physics. Unfortunately, no one actually knows what these deep underlying physics principles are either. We have to make a guess about that, too.The universe from nothing is one such idea. Or, more correctly, one ‘group’ of ideas: most of these speculations come in multiple versions and may overlap with other speculative models. The general idea is there is a background vacuum realm that is even more empty than space. It doesn’t even have spatial dimensions, and maybe not even time. This is impossible to visualize; you h believe it, kind of or not. What this proto-space does – or is assumed to have – is quantum fluctuations, a phenomenon in which energy is created in a vacuum because of the inherent uncertainty in quantum mechanics. These fluctuations, a little like the quantum fluctuations in the ’empty’ space in our universe that can produce random particles, can create a bit of natural space. If this bit of space is too tiny, it may disappear, but if it has a critical size, it grows in a kind of wild runaway process into a universe, aka a Big Bang. The gravitational potential energy of the new space itself provides the power of the Big Bang.
