How do astronomers observing distant galaxies talk about looking backward in time?
The speed of light is not infinite. Light takes time to travel from distant galaxies to our eyes here on Earth. If a galaxy is 1 billion light years away, it has taken 1 billion years for the light emitted by said galaxy to reach us here, so (obviously) we are seeing the light emitted 1 billion years ago. In a sense, we are seeing 1 billion years into the past at the light emitted by that galaxy.
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In all probability, one that is beyond the observable Universe. The furthest known galaxy is IOK-1, which formed about 750 million years after the big bang. It is, now, approximately 12.9 billion light years from us. Abell 1835 IR1916 was believed to be around 13.2 billion light years fro…m us, but there is controversy about whether it was a galaxy or not. ( Full Answer )
because . they want to look at a star one moment then go back and see if it moved or if the star is in the same place . that's mainly what the are searching for. to learn more about our galaxy.
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They move out from the center of the universe (where the big bang happened). ______________ However, we don't know where the Big Bang happened, so all we can really see is that all\\\\ MOST of the other galaxies are moving "away from us". There are a few, like Andromeda, that are actually movi…ng closer to us, but not very fast. ( Full Answer )
Because they are so far away that the light is too dim and diffuse to make out individual stars or groups of stars. With a high-powered telescope, you can distinguish other galaxies from the closer objects in our own Milky Way galaxy, whose stars are all around us.
because they are trying to find possible life or inhabitable planets. There are also some that just love the sky
Objects studied by astronomers are so far away that it takes a significant time for their light to reach earth.. For example, even in the case of the sun, what you see in the sky is not what the sun looks like 'right now', but what the sun looked like about 8 minutes ago ... because that's how long… it took for its light to travel the 93 million miles from the sun to the earth.. After the sun, the next nearest star to us is so far away that its light takes four years to reach us.. So there's actually nothing visible to us in the sky that we see as it exists 'right now'. ( Full Answer )
Images of distant galaxies are taken from powerful telescope. Bystudying its redshift, its distance is measured and we came to knowabout it.
They look at far-away galaxies. When they watch the far-away galaxies, they see the Universe in its early stages.
Because the star's light takes time to reach Earth. So, if the star's light suddenly changed, we would not see it until the time taken for ligh to travel from the star to Earth. The light is showing what happened in the past, or back in time.
Because they want to know if there is another planet out there that we can live on. but God provided our planet and he loves us just as much!
When we view an object in space, we are notobserving it "as is" we are observing it "as it was". What we are seeing, is the light that was emitted at that time. For example: A galaxy is 1,000,000 light years away. When we view it, we are seeing it as it was 1,000,000 years ago, because that is how …long light has taken to get to us. The galaxy may well have been swallowed by a giant mutant turtle 999,998 years ago, but we will not know for another year. So we are seeing objects in space as that were, relative to their distances from us, not what they are. Eg looking back in time. ( Full Answer )
Most galaxies don't have names, they have catalogue numbers. Some do have names, such as the Andromeda galaxy, or the Greater and Lesser Magellanic Clouds.
The light of those distant stars and galaxies took an appreciable period of time in getting here to be detected in our telescopes. So when we look at distant galaxies, we're seeing the light that those galaxies emitted thousands, millions or BILLIONS of years ago. So it almost is like looking back i…n time. ( Full Answer )
Light has a finite and constant speed. It always takes time to travel from the object to our eyes. When we look out at the sun moon and stars we see into the past. We see the moon as it was 1.29 seconds ago. It takes light 1.29 seconds to travel the 384,000 km to the earth. It is 1.29 light secon…ds away. We see the sun as it was 8 minutes ago. If it were to explode suddenly then we would be unaware for 8 minutes. It is 8 light minutes away. We see Proxima Centuri our nearest stellar neighbour as it was 4.2 years ago. 4.2 ly We see the center of the Galaxy as it was 26,000 years ago. It is 26 Kly We see Andromeda Galaxy as it was 2.5 million years ago. 2.5 Mly and so on. The more distant the object the further into the past we see. The most distant galaxy group we have seen was the cluster JKCS041 which is 10.1Gly away only some 3.63 billion years after the Big bang. The most distant object we have seen was a gamma ray burst 13.1 Gly. This massive explosion took place only 630 million years after the big bang. ( Full Answer )
They study distant galaxies because they want to know whats out in other galaxies and how many planets it has
Because by the time the light from those galaxies gets here, much times passes, so we see what happened years, decades or even millenia ago. Because the light we see now , emanated from other galaxies many, many years ago.
Light years of dust lanes obscure the view of distant stars invisible light. However, radio telescopes can penetrate the dust andcan detect (in the x-ray and infrared spectra) the stars in thecore of our galaxy. . They don't understand how redshift affects stars. .
The most farthest galaxy,Which is also the oldest,is about 13 Billion light years away. It is called the A1689-zD1 Galaxy.
Millimeter wavelengths are short frequency radio waves astronomers use because they can see gases and other phenomena not visible in visible light. MM wavelengths are usually used where the air is dry so water vapor can't scatter the waves.
There are many stars in each stage of development, so the obvious assumption is that they represent similar stars, with similar stages, except that they began their existence at different times. Imagine you knew nothing of people. You were then given millions of pictures of people in varying stat…es of aging. Different people, each one in a different stage of development. Would you be able to figure out that the tiny ones were young ones and that the wrinkly ones were old ones? Maybe. It is in that way that studying the pictures of the distant galaxies, and for that matter, stars, that human beings can guess at how these inter-stellar bodies age. ( Full Answer )
Picture this: You and your best friend are in constant communication, and your friend constantly informs you of every little thing that happens in her life. But the method of communication is "snail mail", which usually takes two or three days in transit. So, every time you read a line that sa…ys "my brother just walked in the door, and he's taking a beer out of the fridge", you know that it's not really happening right now, but it actually happened 2 or 3 days ago. That's the situation when you look into the sky, because light takes time to travel from place to place. Look at the moon, and you see light that left the moon 1.3 seconds ago. Look at the sun, and you see light that left the sun 8.3 minutes ago. Look at the nearest star outside the solar system, and you see light that left the star 4.4 years ago. And so it goes. You never see anything in the sky that's happening right now. It's always something that happened some time ago. And of you're looking at stars, you're seeing things that happened years ago. ( Full Answer )
Explain why looking at distant galaxies gives scientists an idea about how galaxies change over time?
Light from distant galaxies took billions of years to reach us. Therefore, we are looking at the far past of the Universe.
Why are astronomers actually looking into the past when they observe objects that are very far away?
It takes a really long time for light to travel the distance of the object. Therefore, the image that you're currently seeing, isn't exactly how that object looks at that moment.
No. You can only see other stars in the Milky Way. _________________________________________ Actually, there are some galaxies that are visible to the naked eye. In the southern hemisphere, the Greater and Lesser Magellanic Clouds, satellite galaxies of our own Milky Way, are perhaps the best e…xamples. But other more distant galaxies are also visible, although only as dim smudges of light. The visible galaxies are close by as galaxies go, but still incomprehensibly distant on any human scale. Really DISTANT galaxies? No. Answer. From the southern hemisphere, the large and small Magellanic clouds are easily visible to the naked eye, and they are other galaxies. On very clear nights in isolated areas, the closest spiral galaxy to us, Andromeda, is visible to the naked eye and looks like a fuzzy star. If we could see Andromeda's entire width with the same brightness as we see its center, we would see a cloudy disk larger than the moon! Many other more distant galaxies are visible but only with a telescope. ( Full Answer )
How does the light that astronomers see from distant stars and galaxies tell htem that the same atoms with the same properties exist throughout the universe?
We determine the types of elements contained in the star or within the corona by analyzing the spectrum of the light we receive. Each element will radiate at a set of specific discreet frequencies, and the frequencies they radiate tell us what the element is, and how deeply ionized it is. The spectr…al analysis is exact; we can even determine the proportions of the elements that we see by the relative brilliance of their light. But there IS one thing that the spectrum cannot tell us; is this a normal matter star, or an anti-matter star? ( Full Answer )
What can astronomers conclude based on the observed red shifts in the spectral lines of distant galaxies?
The strongest consensus (near unanimous of the astronomical community is that the redshifts of distant galaxies indicate that all distant galaxies are receding from us. This recession is currently the only known mechanism for redshifting light. Take this inference, that all galaxies are receding … and you are led to the idea that the universe is expanding, a phenomena described by Hubble's Law. This is a central tenet to the Big Bang Theory.. I will include the counterpoint originally described below, but I will point out that the papers cited are very old, and a huge number of corroborating observations and predictions of the big bang have occurred since then. The conclusion that the Universe is expanding is a wrong conclusion. Alan Sandage talks about Hubble's position at the related link below. To the very end of his writings he maintained this position, favouring (or at the very least keeping open) the model where no true expansion exists, and therefore that the redshift "represents a hitherto unrecognized principle of nature". This viewpoint is emphasized (a) in The Realm of the Nebulae , (b) in his reply (Hubble 1937a) to the criticisms of the 1936 papers by Eddington and by McVittie, and (c) in his 1937 Rhodes Lectures published as The Observational Approach to Cosmology (Hubble 1937b). It also persists in his last published scientific paper which is an account of his Darwin Lecture (Hubble 1953). . ( Full Answer )
The observations made from distant galaxies suggest that Dark energy exists. This is because of the fact that the galaxies are moving away from each other. This is given by Hubbles law.Instead of being attracted by the force of gravitation,galaxies tends to move away suggesting the presence of a gr…avity opposing force called dark energy. ( Full Answer )
How does the observation that light from distant stars and galaxies is redshifted support the theory of the big bang?
When we look at the light from other stars and examine the spectrum of their light, we can see dark "absorption lines" in the star's light. This helps us to determine what elements are in the star. Those lines are at VERY precise frequencies. When astronomers began measuring the spectrum of distant …galaxies, they were unable to figure out what elements they were, because the patterns of lines in the spectrum didn't match up with any known elements. Edwin Hubble realized in the 1920's that the spectrum lines matched known elements, but only if he assumed that those distant galaxies were moving away from us, that the lines were Doppler-shifted to the red end of the spectrum. (Hence, "red-shift") By measuring the amount of the shift, he was able to calculate precisely how fast the galaxies were moving away. ( Full Answer )
When astronomers observe a supernova explosion in a distant galaxy they see a sudden simultaneous rise in visible light and other forms of electromagnetic radiation?
Actually before the rise of visible light there is a surge in neutrinos that can give a warning of a super-nova by as much as five days. Then comes the light flash in all forms of electromagnetic radiation (including visible light).
They only see a small part of the Universe/Galaxy as their Telescope is focused to view specific object/s.
Astronomers can watch galaxies that are far away. Since the lighttakes billions of years to reach us from the farthest knowngalaxies, they would be watching galaxies in the early Universe. Itturns out, from such observations, that the Universe is changing.
Because in the spring, the night sky is pointed out of the Milky Way and therefore it is easier to see distant galaxies.
The discovery and mapping of the Cosmic Microwave Background Radiation (CMBR) via WMAP mission has been interpreted as being left over from the Big Bang. It provides support for the hypothesis of a hot dense state at the beginning and also provided measurements to explain that galactic clusters are …still moving away from each other at an ever increasing acceleration. WMAP's measurements played the key role in establishing the current Standard Model of Cosmology: the Lambda-CDM model. In the Lambda-CDM model of the observable universe, the age of the observable universe is 13.772 Â± 0.059 billion years. ( Full Answer )
Why is it that when scientists look at very distant galaxies through powerful telescopes they see the galaxies as they were millions or billions of year ago?
Because that's how long it has taken the light from those galaxies to reach us. You don't 'see' something until the light from it reaches you. If the thing is on the moon, it takes about 1.27 seconds. It it's on the sun, it takes about 8 1 / 3 minutes. If it's on the nearest star outside our… solar system, it takes about 4.2 years. If it's in the nearest galaxy outside of ours, it takes about 2.5 million years. And if it's in the farthest galaxy that our present technology is able to detect, it takes about 14 billion years. To get here at the speed of light. Here's another way to start understanding it. You get a letter in the mail from an old friend. In the letter, he writes "Today we had a terrible storm here. The wind was howling, the thunder and lightning went on for hours, trees were blowing by in the sky, and by the time it was over, we had almost 30 inches of rain." When did the storm happen ? When you opened the envelope, took out the paper, and read the letter, it said "Today". But you know very well that the storm didn't happen "today" because it took some time for the letter to reach you. And that's the whole idea. Light takes time to move from place to place. It's awesomely fast ... like 7 or 8 times around the Earth in one second ... but it does take time to cover a distance. You can never see anything at exactly the same time as it happens. You have to wait until the light from it reaches you. ( Full Answer )
When you observe a distant galaxy whose photons have traveled for 10 billion years before reaching Earth you are seeing that galaxy as it was when the universe was?
Yes. If the photons have travelled 10 billion years, that means youare seeing the galaxy as it was 10 billion years ago.
When astronomers study distant galaxies they notice changes to the waves they observe describe the change to the waves they observe?
Because the universe as a whole is expanding, distant galaxies are moving away from us. As a result, electromagnetic waves emitted by those galaxies experience what is known as a red shift. Their wavelengths get longer.
How did 1920's astronomer Edwin Hubble explain his observations that all light from distant galaxies exhibits the red-shift Doppler effect?
He concluded that all of space was expanding. Answer2: Hubble did not conclude that all space was expanding! Hubble concluded that he did not know what the redshift was. 1. "Red shifts represent Doppler effects, physical recession of the nebulae, or the action of some hitherto unrecognized… principle in nature." 2. If the nebulae are stationary, the law of red shifts is sensibly linear ; red shifts are a constant multiple of distances. In other words, each unit of light path contributes the same amount of red shift. 3. On the other hand, if the nebulae are receding, and the dimming factors are applied, the scale of distances is altered, and the law of red shifts is no longer linear. The rate of expansion increases more and more rapidly with distance. The significance of this result becomes clear when the picture is reversed. Light that reaches us today left the distant nebulae far back in the dim past - hundreds of millions of years ago. When we say that the rate of expansion increases with distance, we are saying that long ago, the universe was expanding much faster than it is today ; that, for the last several million years at least, the rate of expansion has been slowing down. Therefore, the so-called "age of the universe," the time interval since the expansion began, is much shorter than the 1800 million years suggested by a linear law of red shifts. If the measures are reliable, the interval would be less than 1000 million years - a fraction of the age of the earth and comparable with the history of life on the earth. The nature of the expansion is permissible and, in fact, specifies certain types of possible worlds. But the time scale is probably not acceptable. Either the measures are unreliable or red shifts do not represent expansion of the universe. Hubble admits to not knowing what the red shift is, he considers it a. Doppler effects, b. physical recession of the nebulae, or c. the action of some hitherto unrecognized principle in nature. The answer is c. the hitherto unrecognized principle in nature. The short answer is the red shift is the inverse of the refreaction coefficient, v/c= 1/n. The red shift is derived from the so-called "dark Energy", cP = cmV. Current Theories do not account for this because they do not recognize vector energy cP and Quaternion energy, W = -vh/l + cP = -vp + cP The red shift comes from the Continuity Condition where the centripetal force vp/r is balanced by the centrifugal force cDEL.P= -cp/r cos(P) thud vp/r=cp/r cos(P) gives v/c=cos(P) = 1/n This is the hitherto unrecognized prijnciple of nature, the Divergence of the vector energy produces the anti-gravity force (centrifugal ) that prevents the gravitational collapse, the earth from falling into the sun and the electrons from falling into the nucleus. Newton and Einstein did not consider the energy, cP, associated with momentum P, that is the "Dark Energy". This energy cP is the particel energy with different velocities v=(GM/r)^.5 for mass; v=Alpha Z c for electrons; and v=c for photons. Mass n= c/v; electrons n= alpha Z; and photons n=1. ( Full Answer )
Astronomers have difficulty looking at distant stars because whilewe have highly specialized telescopes, they are in constantcontention with various other celestial bodies. In addition tothis, the light of distant stars takes hundreds of thousands ofyears to reach us, making it impossible to get a c…urrent look at adistant star. ( Full Answer )
Astronomers have difficulty looking at distant stars because theyare just so far away. They use special telescopes but they can'tsee everything.
There are distant galaxies all around us - in all directions, and at varying distances.
How can astronomers survey at least 100 billion galaxies to make a 3D map of the observable universe?
No, because it will be impossible for astronomers to survey atleast 100 billion galaxies (each with 100 billion stars) to make a3D map of the observable universe.
No. Because it will be impossible for astronomers to make an atlasof at least 100 billion galaxies in the observable universe.
Can astronomers make an astronomical catalog that lists B1950 and J2000 equatorial coordinates and cross-identifications for all 100 billion galaxies in the observable universe?
No, because it will be impossible for astronomers to make anastronomical catalog that lists B1950 and J2000 equatorialcoordinates and cross-identifications for all 100 billion galaxiesin the observable universe.
It is possible that someday astronomers have all J2000 coordinatesof 100 billion galaxies in the observable universe.
Someday astronomers may have measured all the distances of 100billion galaxies in the observable universe.
Someday astronomers may have classified all the shapes of 100billion galaxies in the observable universe.
It is possible that astronomers will measure all the sizes of 100billion galaxies in the observable universe.
When scientists look at very distant galaxies through powerful telescopes they see the galaxies as they were millions or billions of year ago. Why is this?
The vast distances involved means that the light we see left thosegalaxies a long time ago.
Why When scientists look at the very distant galaxies through powerful telescopes they see the galaxies as they were millions or billions of years ago?
Because light takes time to travel. Light travels at approximately300,000km/second. The Sun is about 150 million km away from Earth. Light takes 8minutes to reach us from the Sun.. But for a galaxy 1 million lightyears away, the light takes 1 million years to reach us. So when itfinally gets here, i…t shows that galaxy as it was 1 million yearsago. It could explode tonight but we wouldn't know until the lightreached us in 1 million years. ( Full Answer )