There are more stars in the universe than grains of sand on Earth

The best-fit model for observational data is a spatially flat and spatially infinite universe. It is spatially endless today and was always spatially infinite in the past.

The “initial” al singularity” is “not part of the Universe. It is a moment, a point in time that does not exist; only subsequent points do. There are points in time 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 far apart today would have been very close in the early Universe. But 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 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.

There are more stars in the Universe 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, which is 10 billion light-years away and 10 billion light-years long.

The Universe is estimated to be around 13.8 billion years old. Still, because of the effects of time dilation, some regions may be older or younger than others.

If you were to fall into a black hole, space and time would stretch you out into a long, thin matter strand.

The Universe is mainly made up of dark matter and energy, which cannot be directly
observed or detected but can be inferred from gravitational effects.

There are more atoms in a single grain of sand than there are grains of sand on Earth.

According 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.

There is good evidence for the Big Bang as it is left lying around in the Universe and what that thing is doing. We can be confident that the Universe was once extraordinarily compressed and energetic and that after the Big Bang, the Universe developed in a way consistent with known physics. This should not be surprising because “know” physics” is “modeled on the observed Universe.
The problem is that physics gets confusing when you try to work back and forth in time to get to the instant of the Big Bang. When physicists find they are in this kind of muddle, 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 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 from another universe (if there is any), that would be incredibly illuminating and provide enormous guidance to physics, but there appears to be nothing available. There is probably no hope of ever getting the data we require. In this situation, physicists have to make things up. They do not make up random stories (like a giant tortoise or something vomited up the Universe) but try to form models consistent with what they think are the more profound underlying principles of physics. Unfortunately, no one knows what these underlying physics principles are the same. We have to guess that, too.

The Universe from nothing is one such idea. Or, more correctly, one “group” of “dead: 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 empty. It does not even have unique dimensions and maybe not even time. This is impossible to visualize; you have to believe it or not. This proto-space does have – or is assumed to have – quantum fluctuations, a little like the quantum fluctuations in the “empty” space in our Universe that can produce random particles. Here and there, now and then – whatever that means with no space and maybe no time – quantum fluctuations create a tiny miniature of real space. If this bit of space is too tiny, it might just 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 energy of the Big Bang is provided by the gravitational potential energy of the new space itself (I believe).
Is there any evidence for this? Nothing, or almost nothing. There is just one key bit of evidence: Our Universe has not been around forever, or at least the current form of it did start somehow, about 14 billion years ago.
This is just one model out of many. It has a bit of inner logic, but it has no objective evidence and is not even fully worked out. No one has seen the proto-vacuum; it is highly speculative. We know that the Universe exists, and we guess there is some cause, even if it is just a random fluctuation. Hopefully, someday, someone will propose a model that fits all known observations and is internally self-consistent. Plus, it is simple enough and does not have too many arbitrary elements, but we are not there yet. We have a bunch of partially worked-through speculations and physicists chatting about them.

I’ve requested and, so I’ll join you; at the risk of sounding flip or insulting, let me start by indicating that for most readers… “You Antonn don’t do anything, I have? Just brushed the surface of the subject.

But ‘nothing’ is a subtle idea, and the naïve (new, inexperienced) views of it may have also been naïve in the sense of over-simplistic or just plain wrong. But we can still say quite a bit about nothing, and in particular, that some people think might have been the start of things.

Before the Big Bang, nothing was syntactically correct but meaningless, just like the sentence, “North of the North Pole, there is nothing. “The latter sentence implies that there is a location north of the North Pole that contains emptiness, when, in fact, “not” of the North Pole” is not a valid concept. The same goes for the Big Bang.

Well, at least in the standard Big Bang cosmology. There are alternatives (e.g., bouncing cosmologies, eternal inflation) in which the Big Bang is not a singularity, just a moment in time when the univeUniversevery hot and very dense, and it was preceded by something like a pre-inflationary state eternal inflation) or a contracting phase. But in these cases, “before” e the Big Bang,” there were lots of things, an entire universe quite different from our own but complete,

The NASA/ESA/CSA James Webb Space Telescope’s mid-infrared view of the Pillars of Creation strikes a chilling tone. Thousands of stars in this region disappear from view — and seemingly endless layers of gas and dust become the centerpiece. Dust detection by Webb’s Mid-Infrared Instrument (MIRI) is crucial — dust is a major ingredient for star formation.Numerous stars Numerous stars are actively forming in these dense blue-grey pillars. When knots of gas and dust with sufficient mass form in these regions, they begin to collapse under their own gravitational attraction, slowly heat up, and eventually form new stars. Although the stars appear to be missing, they are not. Stars typically do not emit much mid-infrared light. Instead, they are easiest to detect in ultraviolet, visible, and near-infrared light. In this MIRI view, two types of stars can be identified. The stars at the end of the thick, dusty pillars have recently eroded most of the more distant material surrounding them, but they can be seen in mid-infrared light because cloaks of dust still surround them. In contrast, blue tones indicate older stars that have shed most of their gas and dust. Mid-infrared light also details dense regions of gas and dust. The red region toward the top, which forms a delicate V shape, is where the dust is diffuse and cooler. And although it may seem like the scene clears toward the bottom left of this view, the darkest grey areas are where the densest and coolest dust regions lie. Notice that many fewer stars and no background galaxies are popping into view. Webb’s mid-infrared data will help researchers determine exactly how much dust is in this region — and what it has made of it has made of it. These details will make models of the Pillars of Creation far more precise. Over time, we will begin to understand more clearly how stars form and burst out of these dusty clouds over millions of years. Contrast this view with Webb’s near-infrared

2Most of the answers are wrong about one thing. The most recent theories about the UUniverseincorporating dark energy and the acceleration of the UUniverseindicate that there was something before the classical t=0, about 13.7 billion years ago. Classical models of the Big Bang assume that the initial was governed by mass density, or equivalently, observable energy density”, and” those angels show spacetime converging to a single point at t=0.

However, those models also predict that the inner Universe’s statehood slows down as the overall mass density of the Universe increases as our observations show that this expansion is increasing. The models also predict a more homogeneous universe than we have been able to observe. Last, observations of galaxies lead to conclusions that the gravitation observed is more significant than can be accounted for by observable matter. And we’re discussing orders of magnitude difference, not statistical error.
This leads to the conclusion that there is to what we thought was the “obese” viable” uni” verse than we can observe and that something other than the four classical fundamental forces governs the expansion universe. That supposed something is referred to as dark energy, which we have found evidence to support in the cosmological background radiation of the Engrossing dark energy as the driver of universal expansion. They predict a rapid expansion overcoming gravity beginning somewhere around what we classically know as t=0 and faithfully follow the current acceleration of the expansion. They do not but edict a convergence of all matter to a zero-volume space at that point. Instead, they show that at what we might call t=0 (the point just before expansion ballooned), the univeUniverseady had a nonzero volume and asymptotically approaches a zero volume as t continues arbitrarily far before t=0, which effectively means there may never have been “both” ng.”
On “op of topic, because we cannot determine a definite point of zero volume, it is not correct to say that the univeUniverseever small; it was, at one point, merely very dense, so much so that before the Planck Epoch, all models of what the univeUniverselike fail, because the inventress hot that nothing but energy itself could exist, and at least so dense that multiple instances of whatever makes up the univeUniversehe very lowest level would be crammed into a space smaller than we would ever be able to
measure. The univeUniversed still has been effectively infinite in volume; there’s more in a unit volume of the univeUniversehis state than we can measure. So, before this time, any expansion would appear to result.
In something from nothing. It does not; it results in more energy than we can measure being emitted from a smaller volume than we can measure.

In addition, our inability to observe anything for which light has not yet reached us means we cannot see all the universes, and universes never, part of the part, expanding away from us faster than light can travel. So, we do not know how big the university is, so we cannot do more than take an extraordinarily wild guess.

How much matter exists in the entire university rate? It is impossible for us to more than theorize about what the university has looked like at or near t=0. Before the end of the Grand Unification Epoch at 1E-36 seconds, the properties that define matter and even energy as we know it are meaningless, so no tool we could ever conceive of could exist within the univeUniversebserve it before this time.
It is also believed impossible to simulate the creation of the univeUniverseny on a smaller scale within our inventress the univeUniversepacetime, so anything we can observe happens inside our already-existing spacetime) or leave our university and observe it from outside. So, it is possible, and maybe likely, that we will never know what the very early university was and, thus, its origins.\

Originally Answered: Before the Big Bang, there was nothing. What is nothing?

We do not know \ about what, if anything, was before the Big Bang. Of course, this does not stop people from speculating and sounding like they know.

There is good evidence of the Big Bang in the univeUniversewhat it is doing. We can be confident that thatunwaserseiwass is highly compressed and extremely energetic and that, after the Big Bang, it developed in a way consistent with known physics. This should not be surprising because “known” physics is modeled on the observed inventories problem is that physics gets confusing when you try to work back and forth in time to the instant of the Big Bang. When physicists find they are in this kind of muddle, 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 univeUniversein 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 from another universe (if there is any), that would be incredibly illuminating and provide enormous guidance to physics, but there appears to be nothing available. There is probably no hope of ever getting the data we require.
In this situation, physicists have to make things up. They do not make up random stories (like the UUniversevomited by a giant tortoise or something) but try to form models consistent with what they think are deeper, more profound physics principles. Unfortunately, no one knows these more profound underlying physics principles either. We have to guess that, too.
The inventors, nothing is one such idea. Or, more correctly, one “group” of “deas: most of these speculations come in multiple versions and may overlap with other speculative models. The general idea is that a background vacuum realm is even more empty than space. It does not even have special dimensions and maybe not even time. This is impossible to visualize; you have to believe it or not. This proto-space has – or is assumed to have – quantum fluctuations, like the quantum fluctuations in the “empty” space in our universe w, which can produce random particles. Here and there, now and then – whatever that means in a realm with no space and maybe no time – quantum fluctuations create a tiny miniature of real space. If this bit of space is too tiny, it might just 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 energy of the Big Bang is provided by the gravitational potential energy of the new space itself (I believe).

Is there any evidence for this? Nothing, or almost nothing. There is just one key bit of evidence: our university has been around forever, or at least the current form of it did start somehow, about 14 billion years ago.

Possible model out of many. It has some inner logic but no objective evidence and has not been thoroughly worked out. No one has seen the proto-vacuum; it is highly speculative. We know the university and guess there is some cause, even if it is just a random fluctuation. Hopefully, someday, some will propose a model that fits all known observations and is internally self-consistent. Plus, it is simple enough and does not have too many arbitrary elements, but we are not there yet. We have a bunch of partially worked-through speculations and physicists chatting about them in their tea rooms.

This simple trick can save tons of money on Amazon, but most Prime members have been asked to answer, so I’ll go into the fray here! And, at the risk of sounding flip or insulting, let me start by indicating that for most readers… “You “on don’tnothing.” Nei” he r do I; I’ve brushed the surface of the subject.

But ‘nothing’ is a subtle idea, and our naïve (new, inexperienced) views of it are also naïve in the sense of over-simplistic or just plain wrong. But we can still say quite a bit about nothing, particularly noting that some people think might have been the start.
The Big Bang there was nothing “is “a syntactically correct but meaningless sentence, just like the sentence, “or” of the North Pole, there is nothing.” The” letter she implies that there is a location north of the North Pole that contains emptiness, when in fact,”””””””” of the No rah Po”””” ” ” “not a concept. The same goes for” “before” and” The Big Ban.””

“e, “at least in the standard Big Bang cosmology. There are alternatives (e.g., bouncing cosmologies, eternal inflation) in which the Big Bang is not a singularity, just a moment in]] time when the inventors.
Hot to dense, and it was preceded by something like a pre-inflationary state (with eternal inflation) or a contracting phase (with “n “on” .our these case,” “bef” re” before Ba”g,” “he” were lots of things, an entire universe in fact, quite different from our own but full “f.”

“t. of the answers are wrong about one thing. The most recent theories about the univeuniuniverseorating dark energy and the acceleration of the university are something before the classical t=0, about 13.7 billion years ago. Classical models of the Big Bang assume that the initial expansion was governed by mass density, or equivalent”, “b”se” vibes,e energy dense”y,” “and “tho e models do show spacetime converging to a single point at t=0.

However, those models also predict that the universe would slow down as its overall mass density increases when, in fact, our observations show that this expansion is accelerating. Their models indicate a more homogeneous universe than we have observed. Lastly, observations of galaxies lead to conclusions that the gravitation observed is more significant than can be accounted for by observable matter. We are discussing orders of magnitude differences, not statistical errors.

This leads to the conclusion that there is to what we thought was “he “b” st,” via be”t, ” ni,” ve,r, and set, as we can observe and that something other than the four classical fundamental forces governs the expansion universe. That supposed something is referred to as dark energy, which we have found evidence to support in the cosmological background radiation of the u.Universe

Models using dark energy as the driver of universal expansion, while they predict a rapid expansion overcoming gravity beginning somewhere around what we classically know as t=0 and also faithfully follow the currently observed acceleration of the expansion, do not predict a convergence of all matter to a zero-volume space at that point. Instead, they show that at what we might call t=0 (the point just before expansion ballooned), the unUniverselready had a nonzero volume and asymptotically approaches a zero volume as t continues arbitrarily far before t=0, which effectively means there may never have b” n “””t h” ng” On” top of that because we cannot determine a definite point of zero voluiit’sincorrectrect to say tUniverse’sse’sse’s ever slight; it was, at one point, merely very dense, so much so that before the Planck Epoch, all models of what the universes like fail, because the universes are so hot that nothing but energy itself could exist, and at least so dense that multiple instances of whatever makesUniverseuniverse the very lowest level Universe crammed into a space smaller than we would ever be able to r measuUniverseuniverse would still have been Universeely infinite in volume; there is a unit volumeUniverseuniverse in this state than we can meaUniversefore this time, any expansion would appear to result in the creation of something from nothing. It does not; it results in more energy than we can measure being emitted from a smaller volume than we can measure.
In addition, our inability to observe anything for which light has not yet reached us means we cannot see all of the universes, and we may never, if partsUniverseuniverse, be expanding away from us faster than light can travel. So, we dance; we don’t know what the university can do more than take an extraordinarily wild guess of how mto at how much nitrate is; we cannot do more than theorize about what the unenforced have looked like or very near t=0. Before the end of the Grand Unification Epoch at 1E-36 seconds, the properties that define matter and even energy as we know it are meaningless, so no tool we could ever conceive of could. It existedUniverseuniverse. Observe it before this time.

It is also believed impossible to simulate the creation of a universe on any smaller scale with the universe because of the university spacetime, so anything we can observe happens inside our already-existing spacetime), leaving our university observing it from outside. So, it is possible, and maybe likely, that we will never know what the very early universes were like and, thus, their origins.

Originally Answered: Is Andrei LindeLinLiLlinde’sationmultiverseerse possible if the Universes is flat and Infinite?

Is AndLinde’s theory compatible with our obsUniverseuniverse, which appears flat and posUniversefinite?
Chaotic inflation is usually assumed to imply eternal inflation. The Penrose diagram for an eternally expanding (inflating) uniUniverseike the old Steady-State model, in some ways) looks like the lower half of a diamond, where the flat top represents the infinite future and the lower vertex represents the infinite.
Spacetime. (In reality, this space should be Hubble expanding, but let the expansion halt immediately so we can model it easily.)quickly universes, embedded within the eternal inflation Penrose diagram, form finite-sized diamonds (squares tipped over at 45 degrees). They get smaller as you move up the diagram because of the scaling, and there would be an infinite number of them. But here is the surprise universe model: a static, infinitely large, flat universe with an infinite past and an infinite future.

Quantum physics begins when we take some equations from classical physics, play with them a little, and propose equations that have the classical solutions, also solutions that make no freaking sense in a classical context. And then we say that these solutions nonetheless describe reality.
Remember that famous line from the movie”e: “her” iThere s”oon” It” is like that. There is no (classical) electron path. There is no electron position. Or momentum

If protons have no charge in an atom, how do they stay in the nucleus “d “tactic stick the protons?

Its ITT neutrons do not participate in interactions based on electromagnetic force since they have no charge. However, the strong nuclear force affects them (or the quarks that comprise them). That has the force that holds protons and neutrons together in nuclei, and in non-radioactive (stable) atoms, it is decidedly more potent than the EM repulsion the protons produce on one another. Even when the EM for”e “lu” ais artfuRalph’sh’s more potent for”e “lu” a,tf uo, ates “he “str, of the race, still wins. In heavier, radioactive atoms, those fluctuations can cause the EM to force protons to fly apart – that is why radioactive atoms decay from time to time.

So, you rarely get taught about separate forces in high school. Gravity and electromagnetism are “e “common common” y” in our day-to-day lives, but strong and weak nuclear forces are also important. They operate on very short distances.

EEinstEinstein’swidelyacceptedpted photon theory, a precursor to his general relativity theory, states that light is packaged” to “an “hat” has had article-like properties (later experiments would sho” a “ave” particle dua”city” proper per,tain other small massive particles). With the elisions with matter, light tends to behave more particle-like. We know that the atoms that makeup matter have a lot of space because electromagnetic forces separate atomic nuclei from each other. When light encounters a solid material, a nonzero amount of it will pass right through (though that amount may not be detectable by the human eye). The amount that passes through depends on the density of the material; the more tightly the atoms of the material are packed, the less likely a photon will get through without collisions.

A half-silvered mirror places a thin layer of atypical reflective material like metal or a usually transparent material like glass. While glass is relatively high-density, the properties of the material allow for the transmission of light by capturing and releasing photons along the same vector (or very near so), so it slows but does not stop or scatter visible light (glass blocks UVblocksthat has another question). The silver, however, will reflect light, capturing and releasing it at a very ” h” re” action auction. So, whether the photon is reflected by the silver or refracted through the mirror’s glass depends on what that photon hits first: silver or silica. The principles behind quantum theory state that it is impossible to predict precisely what material each photon will hit first, and thus, it is a random event; we can use probability and the Law of Large Numbers to predict percentages of light reflection and transmission, but tracing any single photo ortho phphoton’son’s spacetime is impossible.

It might not be the most satisfying explanation, but it is the honest answer. According to the most up-to-date and most t

The vital lesson to remember is that the initial singularity is a moment in time that is the universeverse; only subsequent moments are like the set of all real numbers greater than 0. This set includes.

Thursday, Thursday, and Thursday, since the Big Bang is what is lefUniverseathe universeUniversee and what that is doing. We can Universedent that theUniversee was once extraordinarily compressed and highly energetic and that afUniverseBig Bang, theUniversee developed in a way consistent with known physics. This should not be surprising because “use ” now,” “now” is” mod. The observed universe-blem is that physics gets confusing when you try to work back and forth in time to get to the instant of the Big Bang. When physicists find they are in this kind of muddle, the usual strategy is to gather data and then find equations and models that match the data. Unfortunately, the universe, the universe, and the period after the BiUniversere is incomplete. WUniverseuck! 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 this situation, physicists have to make things up. They doUniversee the Universe (like a giant tortoise or something that the universe universes) but try to form models consistent with what they thinUniversee more profound underlying principles of physics. Unfortunately, no one knows what these more profound underlying principles are. We have to Universehat, too.
The universeversee from nothing is one such idea. Or, more correctly, “one, “group,” or group: most of these speculations come in multiple versions and may overlap with other speculative models. The idea is t that there is a background vacuum realm that is even more empty than eSpace. It does not even have SPECIAL dimensions and maybe not even time. You cannot believe, kind of or not, what this proto-space does. Or is it assumed to have – is it a little like the quantum fluctuations in the un”versUniverse in our universe that can produce random particles? Here and there, now and then, is the universe, which means that quantum fluctuations create a tiny miniature of absolute space in a realm with no space and maybe no time. If this bit of space is too tiny, it might just 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 energy of the Big Bang is provided by the gravitational potential energy of the new space itself (I believe).
Is there any evidence for this? Nothing, or almost nothing. There is just one piece of your universeUniversee has not been around forever, or at least the current form of it did start somehow, about 14 billion years ago.

This is just one model out of many. It has a bit of inner logic, but it has no objective evidence, and it hasn’t fully worked out. No one has seen the proto-vacuum; it is highly Universeed. The universe exists, and there is some cause, even if it is just a random flUniversen. Hopefully, someday, someone will propose a model that fits all known observations and is internally self-consistent. Plus, it is simple enough and does not have too many arbitrary elements, bI don’tdon’t have a bunch of partially worked-through speculations and physicists chatting a

There are more stars in the universe than grains of sand on Earth

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