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Cosmology
Cosmology is the area of physics that studies the universe in and of itself. Through the use of incredible and ingenious methods of experimentation, cosmologists attempt to discover how the universe began, how it is developing, and how or if it will end. Questions regarding the Big Bang, dark matter, dark energy, the cosmic background radiation, and the initial formation of the fundamental particles can be placed into this category.
776 Questions
Do scientists still believe the universe will collapse in on itself eventually?
No. It's generally believed that the universe has insufficient mass density to slow or halt its expansion (and in fact, there's some evidence that the rate of expansion is actually increasing due to "dark energy", which is a slightly more academically acceptable way of saying "we don't know what").
Excellent answer!
The Universe (our universe) will probably end in a «Big RIP» or a «Big Freeze» scenario, after the «Dark Era and Photon Age», about 10100 years from now.
Please rememer that after the «Dark Era» age, what happens after this is speculative.
There could even occur a new «Big Bang», supereons after the «Dark Era».
Or else the «String Theory» is correct, and our universe is a «membane», or «Brane», and may collide with another «brane» sooner, creating a new universe, God nows what type of universe would be created...
What was a problem with the Big Bang theory?
Several problems that were found with the Big Bang theory were solved by cosmic inflation. I suggest you read about cosmic inflation. One of these problems was the fact that the Universe is fairly homogeneous. Without inflation, it wouldn't have had time to "spread out" any irregularities.
What is the ratio of dark matter to ordinary matter in a universe?
We're not certain that "dark matter" even exists, or what the proportions of "normal" to "dark" matter is. I have read some articles saying that the ratio might be as much as 20-1; 20 parts dark matter to one part normal matter, but these are predicated (I believe) solely on rough calculations based on the perceived mass of the galaxy and its apparent rotational speed.
There appears to be a great deal of speculation and estimation in these calculations.
One important trait of a scientist is to NOT GUESS about things that we don't know, and to admit the boundary between the known, the believed, and the unknown. Even if the current hypotheses about dark matter and dark energy turn out to have some basis in reality, we will certainly be surprised by the truth when we finally learn it.
Will dark energy end the universe?
The universe is incomprehensively vast. Nonetheless, some day it will cease to exist as we currently perceive it. The sun will use up all its fuel and die in about 5 billion years or so. At that time the solar system will no longer be habitable. Will humans be around at that time? No one knows.
The theory that currently has the most support in explaining what we think will end the universe is one called "The Big Freeze". The big freeze theory claims that the universe will continue to expand until it reaches nearly absolute zero and all things cease to move. This is supposed to happen in about 10100 years. For comparison the universe is currently 13.7 Billion years old (13,700,000,000) where as the big freeze would happen in approximately 10100 (100,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000, 000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000) years, and the entire history of the human race is a mere 200,000 years.
It is important to note that even if/when the big freeze occurred, the universe would still exist. it would merely be lifeless and void of all movement. Also, because matter and energy are nearly synonymous as far as physics is concerned (E=mc^2), there would still be movement on a super-subatomic level. The most recent theory regarding this being the string theory, but back to the main question.
It is possible to theorize that since the universe has a defined beginning, as calculated by Stephen Hawking, that it could have a legitimate end as well. speaking purely philosophically, it would seem that a finite universe, which has a beginning, may necessarily have an end that we do not know; the other theory would be that the universe could cease to exist upon the same grounds, which brought it into existence. I speak philosophically here because physics cannot be used to define knowledge of events that took place outside of our universe and thus outside of our laws and confines of natural science
Answer: No, the universe is Bounded, no beginning or end.
The Universe will change not cease to exist.
Answer: Although the Universe has a clear beginning (with the Big Bang), it seems it won't have a clearly-defined end - it will just continue expanding. However, a time will come when it won't be able to support any type of life, because of the Second Law of Thermodynamics. In other words, all useful energy will have been used up.
How did the vibration started in the universe?
Vibration was never started by anything. Vibration is just caused by shaking of objects, and it wasn't "started".
What is a way for scientists to find out about the internal parts of life science specimens?
they don't just find out they have 2 sturdy science that's why they know allot
What term is generally used to designate theories opposed to the Big Bang theory?
"Steady state".
The person who coined the term "big bang" meant it to be taken derisively; Sir Fred Hoyle was a proponent of the "steady state" theory of the cosmos, in which the universe had existed forever pretty much as it is now, and would continue forever.
But as evidence accumulated, the concept of a steady state universe began to be more and more untenable, and most astronomers and cosmologists now accept that the universe probably "began" at some point about 14 billion years ago. Some extremely exotic theories have bubbled up suggesting that the universe may be cyclical, that it may eventually collapse, or that it may continue to expand forever. These theories are still in flux, and are supported primarily by mathematical models rather than by observed facts.
But keep an open mind; we're only at the beginning of this story.
How long do black dwarf stars live for?
it depends on the conditions it could last as little as 100 years or up to 1 million years oh and are you sure you are talking about a brown dwarf because i do not think those exist but i don't know
What cosmological inference can you draw from the darkness of the night sky?
It is really the other way round - observing the Universe tells us that there must exist certain mysterious substances, currently known as dark matter and dark energy. We don't know the properties of dark matter by observing dark matter - it is not yet known what it is made of. Same for dark energy. We do know that for every kilogram of known mass in our Milky Way there must be 5-10 kg. of some unknown stuff. This stuff shows itself by its gravitation - our Milky Way rotates way too fast for the known matter. But we don't know what it is.
Answer1:
Dark matter and Dark Energy tells us that the current Theory of the Universe is wrong.
Dark energy is the result of neglecting the gravitational vector energy, mcV. Newton's Theory of Gravity involved only the scalar energy Es = -mu/r, Newton and Einstein neglected the vector Energy mcV. The complete Gravitational Energy is a Quaternion Energy E= -mu/r + mcV.
Dark Matter is the result of neglecting electricity in the Universe and the effect of magnetic fields on charged bodies like the Milky Way. The Cosmos is Electric the galaxies are like Homopolar motor/generators. Homopolar Motors are used to measure the electricity entering your homes. The more electricity you use the the faster the motor turns. The Universe is full of electric currents flowing to bodies and causing them to rotate like motors do.
See the Electric Cosmos:
http://www.electric-cosmos.org/summary.htm
What was dark matter named after?
"Dark matter" got its name for two reasons:
1) It doesn't interact with baryonic matter (ie, the stuff we understand) via the electromagnetic force, and thus doesn't give off light. In that sense, it's most likely all around us and yet we can never see it.
2) Our understanding of it is almost nil -- in other words, we're "in the dark" about its nature. In this sense, it got its name the same way "x-rays" did -- we don't understand dark matter anymore than William Roentgen understood the rays he found.
Is the universe really a computer program?
This is an idea supported by Stephen Wolfram and others.
It's not anywhere near being "proved".
Why was cosmic background radiation an important discovery?
It is important evidence of the Big Bang.
A lot of it is probably more or less spherical. You see, "dark Matter," as distinguished from "dark Energy," which is really mysterious, is mostly just ordinary matter, which we can't see because it isn't lighted, either by nearby stars or its own heat. There could be numberless dark worlds out there just cruising through space; alternatively, dark matter could be finer than dust. The only thing we can say for sure is that there's a lot of it.
The origin of the universe is still a question because we have yet to discover a complete and definitive explanation. Theories like the Big Bang provide a framework for understanding the early universe, but the ultimate cause or reason for the universe's existence is still a mystery that scientists continue to explore.
That's a very good question, and the truthful answer is "Nobody knows for sure".
Many have said, however, that the universe was very likely created as the energy and mass expanded. So the "dark, empty void" that is the fabric of space was actually created as the energy from the Big Bang moved outwards. Beyond the edges of the universe is... well, nothing. Perhaps another universe, although several have proposed the "no edges" idea. That is, much like a video game, if you pass through the "edge" of the universe on one side, you wind up on the other side. In other words, if you keep moving in a straight line across the universe, you will eventually get back to your own starting position, but you would never know that you had deviated from your path (because, in fact, you didn't). Think Pac-Man.
That's the best theory we can present at the current time.
One on the best books elaborating on the Big Bang Theory in an understandable format is Bill Bryson's "A Short History Of Nearly Everything". It explains that space was never there, but actually was created as the singularity that contained all the matter in the universe exploded and expanded. This singularity was so small that it had LITERALLY no dimensions, and took up absolutely no space, yet contained untold billions of tons of material all compacted together. As this singularity expanded, it expanded at just the right speed as to create all the forces in the universe, like gravity, inertia, and all those. If it expanded faster, the universe would have collapsed in on itself long ago, and the creation material would have been so far spread that nothing would have been made. Had it expanded slower, then everything would still be too compacted and close together, so that nothing would've been created. There is also a theory that, at some point, the universe will not be able to expand any further, and the theory also includes that the universe is still expanding. But at any rate, the theory goes that the universe will reach a point where it cannot expand any farther, and then it will slowly creep back into a singularity. And the process will start over again. This, however, cannot be proven, and is only one of several theories.
Scientists continue to investigate the conditions that created the early universe.
How is the universe changing by cosmic background radiation?
In a nutshell, the universe is expanding, and it will either expand forever, or there will be enough matter in the universe to slow down that crazy expansion and then pull everything back together. (There isn't much chance of a "steady state" option, but there are some things to review with that.) When we look around out there in space, we see lots of matter. But it's acting funny. It is acting as if there is more matter that is gravitationally influencing it that is visible. That's dark matter. It's the only way to explain things so far. Perhaps there is enough dark matter in the universe to slow the expansion up and keep everything from just flying apart to infinity. Is there? Use the link to the Wikipedia article on dark matter and get up to speed so you can make the call from an informed point of view.
Where did the big bang theory originate?
The theologian and physician Georges Lemaître is believed to be the founder of the big bang theory. He first described the conditions within the first seconds of our universe 1931,with the term "primordial atom".
The Big Bang theory explains only that such a rapid expansion caused the young universe to cool and resulted in its present continuously expanding state.
No common agreement exists as to the conditions leading up to the Big Bang, for it is believed that conditions were too different for our knowledge to be applicable.
It was the British mathematician Sir Fred Hoyle who coined the phrase "Big bang" in a radio broadcast in 1949. [He favoured an alternate hypothesis, subsequently abandoned.]
Where would you find visible energy and invisible matter in universe?
A good example of visible energy is found in the stars.
An example of invisible matter is the "dark matter" that scientists believe surrounds galaxies.
So, one answer to the question would be "in and around galaxies".
Why is nail mend paper torn instead of cut?
If "nail mend paper" is anything like sandpaper, cutting it (with scissors) would abrade the scissors. Cutting it with a knife from the back or nonabrasive side would be all right.
No, it is invisible, however it got gravity. No one actually come up with a theory that explain what dark matter really do, so there is still a Noble Price waiting for people to come up with a explanation of dark matter.
What is an antonym for big bang theory?
I would not use the word "antonym," as that word means "opposite of."
An ALTERNATIVE to the BB was the Steady State Hypothesis, which stated that the density of our Universe has been pretty much unchanged for all eternity, with matter continually coming into existence at all places within our Universe. Thus, as galaxies moved apart from each other, new matter formed new galaxies in what would have been empty space.
The Steady State Hypothesis has been abandoned by all but the fringes of science, as it fails to explain the Cosmic Microwave Background, the lack of quasars near our galaxy, the non-existence of white dwarfs older than about ten billion years, the ratio of long-lived isotopes and their decay products, and the ratio of hydrogen to helium -- all of which the BB explains perfectly.
No other hypothesis except the BB has any scientific evidence to support it.
What is the density of a stony iron meteorite?
Iron meteorites account for about 5% of all meteorites that fall to earth, they are likely to be either Kamacite or Taenite. The density of these minerals is 7.9 and 7.8-8.22 g/cm3 respectively.
Why do astronomers theorize that most of matter in galaxies and clusters is dark matter?
Dark matter may be invisible to light, but it can still be detected, through its gravitational interactions. Specifically, it can be detected:
* By the fact that galaxies rotate way too fast, for the amount of known matter.
* By gravitational lensing.
