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Tag: What is the Big Bang theory of the universe

how does hubble’s law prove the big bang

how does hubble’s law prove the big bang插图

Hubble’s observations of an expanding universe lead to the Big Bang Theory. Hubble’s law shows themathematical relationship between the distance from the earth and rate of expansion observed. The further from the earth the faster the object is moving away from the earth.

What does Hubble’s law say about the universe?

Hubble’s law says that the universe is expanding outward. Actually Hubble’s law was discovered before the Big Bang theory was formulated. The Big Bang Theory is an attempt to explain the observations that led to Hubble’s Law. Before the 1900s the theory was that the universe was eternal and self existent.

How did Hubble’s observations lead to the Big Bang theory?

Hubble’s observations of an expanding universe lead to the Big Bang Theory. Hubble’s law shows the mathematical relationship between the distance from the earth and rate of expansion observed. The further from the earth the faster the object is moving away from the earth.

What is the Big Bang theory of the universe?

Edwin Hubble The Big Bang model was a natural outcome of Einstein’s General Relativity as applied to a homogeneous universe. However, in 1917, the idea that the universe was expanding was thought to be absurd. So Einstein invented the cosmological constant as a term in his General Relativity theory that allowed for a static universe.

How did Edwin Hubble discover that the universe is expanding?

In 1929, Edwin Hubble announced that his observations of galaxies outside our own Milky Way showed that they were systematically moving away from us with a speed that was proportional to their distance from us. The more distant the galaxy, the faster it was receding from us. The universe was expanding after all,…

What does the red shift mean in the universe?

Hubble observed that most of the universe has a red shift indicating that the universe is expanding and moving away from itself. The further out that the universe is observed the faster it is moving apart. These observations were inconsistent with a steady state universe. The Big Bang theory extrapolated backwards.

How did the Big Bang theory explain Hubble’s observations?

The Theory explained Hubble’s observations by the idea that at the beginning of time ( for our universe) all the matter and energy were together in one place.

Why did Albert Einstein change the equations in his theory of relativity?

Albert Einstein even changed the equations in his general theory of relativity to reflect the idea of a steady state. Later he called putting in a fudge factor to result in a steady state the worse mistake of his life.

What does Hubble’s law say about the universe?

Hubble’s law says that the universe is expanding outward.

Did the Big Bang happen in 1998?

The answer found in 1998 was no. The rate of the expansion of the universe is increasing not slowing down and the universe will not collapse back into the super dense ball of matter that it began as. The Big Bang Theory postulated based on the empirical evidence that our universe had a beginning and it will eventually cease to exist. …

Will the universe collapse back into the super dense ball of matter?

The answer found in 1998 was no. The rate of the expansion of the universe is increasing not slowing down and the universe will not collapse back into the super dense ball of matter that it began as.

What is the Big Bang Theory?

The Theory is that the universe had a beginning starting from a central point resulting in a rapid expansion of the universe.

What is the foundation of the Big Bang Theory?

Hubble’s law and observations are the foundation of the Big Bang Theory.

What is the relationship between the distance from the Earth and rate of expansion observed?

Hubble’s law shows the mathematical relationship between the distance from the earth and rate of expansion observed. The further from the earth the faster the object is moving away from the earth.

What did Hubble use to study galaxies?

Hubble’s Law. During his work studying galaxies, Hubble used Cepheid variable stars to measure the distances to a sample of galaxies. Even before the Shapley/Curtis debate and the discovery that spiral nebulae are external galaxies, observations had shown that the vast majority of galaxies had spectral lines redshifted from the laboratory values.

What does a redshift in a spectral line mean?

If you recall from our work on the Doppler effect, a redshift in a spectral line indicates that the object is moving away from us.

When did Hubble show that distance and velocity are directly correlated?

In a publication by Hubble in 1929 , he showed that if you plot the distance to a galaxy (measured from Cepheid variables) and the velocity of the galaxy (measured by the shift in the spectral lines), the two quantities are directly correlated! See the reproduction of his plot below.

Why are there discrepancies between distant galaxies?

The reason for the discrepancy for nearby galaxies is the "peculiar velocity" of the galaxy, that is, its real velocity through space that is unrelated to the expansion. For distant galaxies, their peculiar velocities are small enough that they still lie on or near the line for Hubble’s Law.

What does Hubble’s law say about the universe?

Hubble’s law, which says simply that a galaxy’s velocity (or as is sometimes plotted, its redshift) is directly proportional to its distance, also tells us something important about the state of the universe. If the universe is static and unchanging, there should be no correlation between distance and velocity.

Does Hubble’s law work for distant galaxies?

Hubble’s Law only works for distant galaxies. For nearby galaxies (in the Local Group), stars inside the Milky Way, and for objects in our Solar System, the relationship between distance and velocity does not hold. The reason for the discrepancy for nearby galaxies is the "peculiar velocity" of the galaxy, that is, …

Is there a correlation between distance and velocity?

The usual analogy used here is that of an explosion – the fragments of shrapnel produced are moving with a range of velocities, and the most distant objects from the source of the explosion have the largest velocities.

What is the Hubble Ultra Deep Field?

Called the Hubble Ultra Deep Field, the view represents the deepest portrait of the visible universe ever achieved by humankind. The snapshot reveals the first galaxies to emerge from the so-called "dark ages," the time shortly after the big bang when the first stars reheated the cold, dark universe. The new image should offer new insights into what types of objects reheated the universe long ago.

How many galaxies are in the Ultra Deep Field?

The Ultra Deep Field contains an estimated 10,000 galaxies. In ground-based photographs, the patch of sky in which the galaxies reside (just one-tenth the diameter of the full Moon) is largely empty. Located in the constellation Fornax, the region is so empty that only about seven stars within the Milky Way galaxy can be seen in the image. ( + View Graphic: Where Is Hubble Looking?)

How many galaxies are there in the Hubble telescope?

Hubble Digs Deeply, Toward Big Bang. An estimated 10,000 galaxies are revealed in humankind’s deepest portrait of the visible universe ever. View a full size version of this image, or a slightly farther look with Hubble’s infrared camera, in medium or large format.

What do oddball galaxies look like?

In vibrant contrast to the rich harvest of classic spiral and elliptical galaxies, there is a zoo of oddball galaxies littering the field. Some look like toothpicks; others like links on a bracelet. A few appear to be interacting. These oddball galaxies chronicle a period when the universe was younger and more chaotic.

How old was the universe when the universe was the smallest?

The smallest, reddest galaxies, about 100, may be among the most distant known, existing when the universe was just 800 million years old. The nearest galaxies — the larger, brighter, well-defined spirals and ellipticals — thrived 1 billion years ago, when the cosmos was 13 billion years old.

When did the Ultra Deep Field telescope start?

The Ultra Deep Field observations began Sept. 24, 2003 and continued through Jan. 16, 2004. The telescope’s ACS camera, the size of a phone booth, captured ancient photons of light that began traversing the universe even before Earth existed. Photons of light from the very faintest objects arrived at a trickle of one photon per minute, compared with millions of photons per minute from nearer galaxies.

Why did Hubble know that all the galaxies were moving away from Earth?

He knew this because the light coming from the galaxies exhibited redshift.

What was Hubble’s discovery?

After years of observation, Hubble made an extraordinary discovery. In 1923 he spotted a Cepheid variable star in what was known as the Andromeda Nebula. Using Leavitt’s techniques, he was able to show that Andromeda was nearly 1 million light years away and clearly a galaxy in its own right, not a gas cloud.

How did Edwin Hubble change the universe?

In the course of five years, Edwin Hubble twice changed our understanding of the Universe, helping to lay the foundations for the Big Bang theory. First he demonstrated that the Universe was much larger than previously thought, then he proved that the Universe is expanding.

What did Hubble do for the rest of his life?

Hubble achieved scientific superstardom for his discoveries and is still considered a brilliant observational astronomer. He ran the Mount Wilson Observatory for the rest of his life, popularized astronomy through books and lectures, and worked to have astronomy recognized by the Nobel Prize committee.

What did Hubble study?

At the University of Chicago, Hubble studied mathematics, astronomy, and philosophy — and played for the school’s basketball team. He graduated with a bachelor of science in 1910, and then spent 1911 to 1914 earning his master’s as one of Oxford University’s first Rhodes scholars. Though he studied law and Spanish there, his love of astronomy never diminished.

How big is the Milky Way?

Using the Cepheid variables, Shapley judged that the Milky Way was 300,000 light years across — 10 times bigger than previously thought.

How powerful is the Hale telescope?

At 5.08 meters, the Hale was four times as powerful as the Hooker Telescope and existed as the most advanced telescope on Earth for some time. After its completion in 1948, Edwin Hubble was given the honor of first use.

What happens if bread expands by the same amount?

If every portion of the bread expands by the same amount in a given interval of time, then the raisins would recede from each other with exactly a Hubble type expansion law. In a given time interval, a nearby raisin would move relatively little, but a distant raisin would move relatively farther – and the same behavior would be seen …

What was the Big Bang model?

The Big Bang model was a natural outcome of Einstein’s General Relativity as applied to a homogeneous universe. However, in 1917, the idea that the universe was expanding was thought to be absurd. So Einstein invented the cosmological constant as a term in his General Relativity theory that allowed for a static universe.

What is the specific form of Hubble’s expansion law?

The specific form of Hubble’s expansion law is important: the speed of recession is proportional to distance . Hubble expressed this idea in an equation – distance/time per megaparsec. A megaparsec is a really big distance (3.26 million light-years).

Did Hubble predict the universe was expanding?

The universe was expanding after all, just as General Relativity originally predicted! Hubble observed that the light from a given galaxy was shifted further toward the red end of the light spectrum the further that galaxy was from our galaxy.

Is Hubble law homogeneous?

In other words, the Hubble law is just what one would expect for a homogeneous expanding universe, as predicted by the Big Bang theory. Moreover no raisin, or galaxy, occupies a special place in this universe – unless you get too close to the edge of the loaf where the analogy breaks down.

How fast is a galaxy receding?

Hubble showed that, in our expanding universe, every galaxy is rushing away from us with a speed which is in direct proportion to its distance, known as Hubble’s Law, so that a galaxy that is twice as far away as another is receding twice as fast, one ten times as far away if receding ten times as fast , etc. The law is usually stated as v = H0D, where v is the velocity of recession, D is the distance of the galaxy from the observer and H0 is the Hubble constant which links them. The exact value of the Hubble constant itself has long been the subject of much controversy: Hubble ‘s initial estimates were of the order of approximately 500 kilometers per second per megaparsec (equivalent to about 160 km/sec/million light years ); the most recent best estimates, with the benefit of the Hubble Telescope and the WMAP probe, is around 72 kilometers per second per megaparsec. (It should perhaps be pointed out that the Hubble constant is technically a parameter, not a constant, because it will actually change over long periods of time.)

Why did Hubble notice the redshift?

With the benefit of improved telescopes, Hubble started to notice that the light coming from these galaxies was shifted a little towards the red end of the spectrum due to the Doppler effect (known as “ redshift ”), which indicated that the galaxies were moving away from us.

What is the broad brush effect?

This expansion, usually referred to as the "metric expansion" of space, is a “broad-brush effect” in that individual galaxies themselves are not expanding, but the clusters of galaxies into which the matter of the universe has become divided are becoming more widely separated and more thinly spread throughout space.

What did Einstein believe about gravity?

When Albert Einstein was formulating his ground-breaking theory of gravity in the early 20th Century, at a time when astronomers only really knew of the existence of our own galaxy, he necessarily used the simplifying assumption that the universe has the same gross properties in all parts, and that it looks roughly the same in every direction wherever in the universe an observer happens to be located. Like Sir Isaac Newton two hundred years before him, he assumed an infinite, static or “steady state” universe, with its stars suspended essentially motionless in a vast void.

What did Einstein think of space time?

However, when Einstein tried to apply his General Theory of Relativity to the universe as a whole, he realized that space-time as a whole must be warped and curved back on itself, which in itself would cause matter to move, shrinking uncontrollably under its own gravity.

Who discovered that there is more to the universe than the Milky Way?

Some years later, in 1925, the American astronomer Edwin Hubble stunned the scientific community by demonstrating that there was more to the universe than just our Milky Way galaxy and that there were, in fact, many separate islands of stars – thousands, perhaps millions of them, and many of them huge distances away from our own.

Was the Big Bang a static universe?

The old model of a static universe, which had served since Sir Isaac Newton, was thus proved to be incontrovertibly false, but Hubble’s discovery did more than just show that the universe was changing over time. If the galaxies were flying apart, then clearly, at some earlier time, the universe was smaller than at present. Following back logically, like a movie played in reverse, it must ultimately have had some beginning when it was very tiny indeed, an idea which gave rise to the theory of the Big Bang. Although now almost universally accepted, this theory of the beginnings of the universe was not immediately welcomed by everyone, and several strands of corroborating evidence were needed, as we will see in the following sections.