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ASTRONOMY CLUB TONIGHT: 2011 Nobel Prize in Physics, The Accelerating Universe October 12, 2011

Posted by jcconwell in Astronomy, Cosmology, General Relativity, supernova.
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Physics-Nobel-Prize Medal

Physics-Nobel-Prize Medal

Tonight at 8:00PM, October 12, 2011 in Room 2153 Physical Science Building

Dr James Conwell will be giving a talk on this years Nobel Prize in Physics: The Accelerating Universe and “Dark Energy”

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2011 NOBEL PRIZE IN PHYSICS October 4, 2011

Posted by jcconwell in Astronomers, Cosmology, supernova, white dwarf.
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The Royal Swedish Academy of Sciences said American Saul Perlmutter would share the 10 million kronor ($1.5 million) award with U.S.-Australian Brian Schmidt and U.S. scientist Adam Riess. Working in two separate research teams during the 1990s – Perlmutter in one and Schmidt and Riess in the other – the scientists raced to map the change in the  universe’s expansion over time. They were measuring the change in  Hubble’s Constant,  by analyzing a particular type of supernovas, Type Ia, or exploding stars.

SN 1994D in NGC 4526. in lower left

Type Ia supernovas are thought to be caused by a white dwarf star exceeding its maximum mass, the Chandrasekar limit, of about 1.4 Solar masses, collapsing and detonating into a supernova. Since this collapse occurs at the same mass limit , it’s though all Type Ia supernova are equally bright.

They found that the light emitted by more than 50 distant Ia supernovas was weaker than expected, a sign that the universe was expanding at an accelerating rate, the academy said.

“For almost a century the universe has been known to be expanding as a consequence of the Big Bang about 14 billion years ago,” the citation said. “However the discovery that this expansion is accelerating is astounding. If the expansion will continue to speed up the universe will end in ice.”

Perlmutter, 52, heads the Supernova Cosmology Project at the Lawrence Berkeley National Laboratory and University of California, Berkeley.

Schmidt, 44, is the head of the High-z Supernova Search Team at the Australian National University in Weston Creek, Australia.

Riess, 41, is an astronomy professor at Johns Hopkins University and Space Telescope Science Institute in Baltimore, Maryland.

Schmidt said he was just sitting down to have dinner with his family in Canberra, Australia, when the phone call came.

“I was somewhat suspicious when the Swedish voice came on,” Schmidt told The Associated Press. “My knees sort of went weak and I had to walk around and sort my senses out.”

The academy said the three researchers were stunned by their own discoveries – they had expected to find that the expansion of the universe was slowing down. But both teams reached the opposite conclusion: faraway galaxies were racing away from each other at an ever-increasing speed.

The discovery was “the biggest shakeup in physics, in my opinion, in the last 30 years,” said Phillip Schewe, a physicist and spokesman at the Joint Quantum Institute, which is operated by the University of Maryland and the federal government.

NEW PODCAST:Is There Cosmological Evidence for God? December 18, 2010

Posted by jcconwell in Astronomy, Cosmology, Podcast.
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Fine tuning is one of the central topics in modern cosmology. In order to see what we see in the present epoch of the universe, especially life, what were the conditions in the past?. How finely tuned did the fundamental constants have to be. This has lead to many ideas like inflation and the anthropic principle

http://365daysofastronomy.org/2010/12/18/december-18th-is-there-cosmological-evidence-for-god/

Description: Is the Universe finely tuned for human life? If so, is this cosmological evidence for God?

Bio: Dr Stuart Clark is an award-winning astronomy author and journalist. His books include The Sun Kings, and the highly illustrated Deep Space, and Galaxy. His next book is Big Questions: Universe, from which this podcast is adapted. Stuart is a Fellow of the Royal Astronomical Society, a Visiting Fellow of the University of Hertfordshire, UK, and senior editor for space science at the European Space Agency. He is also a frequent contributor to newspapers, magazines, radio and television programmes. His website is www.stuartclark.com and his Twitter account is @DrStuClark.

NEW PODCAST: Are There Alternate Universes? November 18, 2010

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http://365daysofastronomy.org/2010/11/18/november-18th-are-there-alternative-universes/

Are there alternate universes? If so, are they merely far away or in different dimensions altogether? Bio: Dr Stuart Clark is an award-winning astronomy author and journalist. His books include The Sun Kings, and the highly illustrated Deep Space, and Galaxy. His next book is Big Questions: Universe, from which this podcast is adapted. Stuart is a Fellow of the Royal Astronomical Society, a Visiting Fellow of the University of Hertfordshire, UK, and senior editor for space science at the European Space Agency. He is also a frequent contributor to newspapers, magazines, radio and television programmes. His website is http://www.stuartclark.com

Extreme Universe: The Most Distant Object Measured in the Universe October 21, 2010

Posted by jcconwell in Cosmology, Extreme Universe, Galaxy.
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Coming in as the most distant object with a confirmed redshift, UDFy-38135539 is the Hubble Ultra Deep Field (UDF) classification for a galaxy which, as of October 2010, is the most distant object from Earth known to exist in the universe. Its discovery is formally detailed in the 21 October 2010 article “Spectroscopic Confirmation of a Galaxy at Redshift z=8.6” in the journal Nature.

Hubble Ultra Deep Field

Other than putting a trophy on the wall for a new record distance, what makes this object so important? To understand this, it might be better to translate this from the most distant object  to the oldest measured object. With a measured cosmological redshift of z=8.6, the object emitted the light we are seeing  about 13.1 billion years ago, or more useful here, when the universe was only 600 million years old.

Cropped Image of UDFy-38135539

What was it like in the universe at that age? Conditions were quite different back then. This epoch of time  is when the Universe went from largely neutral gas to basically ionized plasma, called reionization.

The reionization period is about the farthest back in time that astronomers can observe. The Big Bang, 13.7 billion years ago, created a hot, plasma filled universe. Some 400,000 years after the Big Bang, temperatures cooled, from the expanding universe,  so  electrons and protons joined to form neutral hydrogen, and the murk cleared. By about 1 billion years after the Big Bang, this neutral hydrogen began to form stars in the first galaxies, which radiated energy and reionzied the hydrogen. Radiation from the hot new stars started to clear the opaque hydrogen plasma surrounding the newly formed galaxies that filled the cosmos at this early time.

Much of any ultraviolet light from these new stars was absorbed in the gas surrounding the stars, the remainder has been redshifted down to the infrared by the expansion of the universe over 13.1 billion years.

To obtain such dim spectra, scientists turned the the VLA (Very Large Telescope).

Very Large Telescope Array

Very Large Telescope Array

The Very Large Telescope (VLT) is made up of four separate optical telescopes (the Antu telescope, the Kueyen telescope, the Melipal telescope, and the Yepun telescope) organized in an array formation, built and operated by the European Southern Observatory (ESO) at the Paranal Observatory on Cerro Paranal, a 2,635 m high mountain in the Atacama Desert in northern Chile. Each telescope has an 8.2 m aperture. The array is complemented by four movable Auxiliary Telescopes (ATs) of 1.8 m aperture. Working together in interferometric mode, the telescopes can achieve an angular resolution of around 1 milliarcsecond, meaning it could distinguish the gap between the headlights of a car located on the Moon.

To get a spectra of such a dim object, about 4 billion times dimmer than the dimmest star you can see with the naked eye, the VLA took an exposure of about 16 hours.

COSMOLOGY Tonight! January 27, 2010

Posted by jcconwell in Cosmology.
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Astronomy Club meeting tonight! Room 2153, Physical Science Building.

Dr James Conwell will be giving a talk on Cosmology, the study of the Universe as a whole. How it all began with the Big Bang!

Top 10 Ways the Universe Could Kill Us! July 24, 2009

Posted by kfarley in Asteroid, Astronomy, Cosmology.
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Asteroid Impact

Asteroids and other near-Earth objects (NEOs) come near the Earth more frequently than one would guess. Question: Why don’t we ever hear of these objects hitting the Earth? Answer: Because they don’t. More often than not our atmosphere causes great friction on these solar bodies causing them to burn up. This happens before the asteroids can go through our atmosphere and hit the Earth. Our atmosphere can be a good friend to us – protecting us from solar debris that could potentially hit Earth and end civilization as we know it. If an asteroid were to make it through our atmosphere it becomes classified as a meteor. It is theorized that a large meteor hit the Earth about 65 million years ago wiping out the dinosaurs. According to NASA, a meteor about 1/5 that size will hit the Earth about once or twice every million years. If Earth did get hit by an asteroid of that caliber we would most likely not survive. I haven’t heard of an asteroid that size hitting the Earth in quite some time, maybe we’re overdue. With ≈6.7 billion people in the world your chance of seeing the Earth hit by that size meteor is…well, you do the math. To learn more information on NEOs check out NASA’s FAQs.

Illustration of an asteroid that could have wiped out the dinosaurs.

Illustration of an asteroid that could have wiped out the dinosaurs.

Solar Flare

A solar flare is a huge explosion of energy in the Sun’s atmosphere. Think of it like a giant spike of light and heat that suddenly rises off the surface of the Sun. The rays emitted (mainly X-rays and UV rays) from this explosion are strong enough to disrupt radio communication on Earth! The flares can influence the surface of Earth by having an effect on our weather. Just outside our atmosphere, the flares can present radiation hazards to spacecraft and astronauts. The solar flares can also produce streams of highly energetic particles in our atmosphere. These highly energetic particles help in the production of the beautiful aurora borealis! On the other hand, the radiation from solar flares also pose incredible complications that could arise during manned missions to Mars, the Moon, or other space travel. Satellites’ orbital paths can also be disrupted by the solar flares. Kind of a catch-22, amazing Northern lights produced but also possible space travel limit. Hmm…

Aurora borealis co-created by solar flares.

Aurora borealis co-created by solar flares.

Supernova

Ever had someone shine a flashlight in your eyes? Not very nice, huh? Think of shining a light in your eyes a billion times brighter! A supernova is just that – an exploding star billions of times brighter that our Sun. After the core of a star collapses it emits great energy as a flash of growing intensity before fading back out of sight. If a supernova was close enough and aimed toward our solar system, it could wipe out our atmosphere. Our planet would overheat from UV rays causing mass extinction. It’s messy too. The supernova will throw large clouds of dust and gas into space that could exceed 10 times the mass of our Sun. We should be thankful for supernovae in a way. It is hypothesized supernovae created the heavier elements such as gold, iron, and uranium found here on Earth.

Supernova.

Supernova.

Gamma Ray Burst

Gamma ray bursts (GRBs) are flashes of gamma rays that last from fractions of a second to almost an hour. They normally last a few seconds and usually come from outside our galaxy. They are the most luminous (electromagnetic) events that occur in the universe. GRBs often have an afterglow affect as longer wavelengths travel from the blast. The blast from a GRB in our galaxy would definitely cause mass extinction from the intense rays that would encompass our planet. It is hypothesized such an event caused the mass planetary extinction on Earth about 444 million years ago. A GRB depleted the ozone layer leaving our planet helpless to direct UV rays that heated and kill organisms until food chains were depleted.

P.S. Gamma rays gave the Hulk his powers (I think that is fictional though).

Illustration of a gamma ray burst hitting a planet like Earth.

Illustration of a gamma ray burst hitting a planet like Earth.

Black hole

Black holes are areas in space in which the gravitational field is so incredible that nothing can escape its pull. Not even light can be reflected from this object, hence its name. It is virtually impossible to escape a black hole once its immense gravitational pull has a hold of you. The point of no return at a black hole is called the horizon. It is an area just outside a black hole where the gravitational pull begins. Once you hit the horizon of a black hole your fate is sealed and escape from the black hole is futile. Knowing not even light can escape the pull of the black hole, you would have to travel faster than the speed of light to escape. If you were to see an object being pulled into a black hole (assuming the object can still reflect light), it would become extremely distorted. The gravitational pull is so intense, the part of the object entering the black hole first would stretch out of normal proportions. For example, if you were floating through space with your arms in front of you (Superman-style) and began to be sucked into a black hole, your arms would stretch out incredibly long before the rest of your body. Black holes are also very massive. They can range anywhere from 10 times to a million times the mass of our Sun. Currently, there are no known black holes in our galaxy. This known with the fact our space travel is limited to our Moon, you are probably safe from a black hole fate.

Illustration of what a black hole over the Milky Way might look like.

Illustration of what a black hole over the Milky Way might look like.

Death of Sun

The Sun goes through different stages during its life cycle. It’s about halfway through the “main sequence” before it goes into a different star phase. The Sun will most likely turn into a Red Giant star peaking at its highest luminosity. The Sun will then start to burn out as it turns into a small dwarf star. The Sun won’t turn into a Red Giant for another 5 billion years or so. A more immediate problem, as the Sun moves toward the next stage it becomes gradually warmer. It will get really hot. Life on Earth most likely won’t make it to the Red Giant stage. The Earth will warm up to the point where life will not be sustainable. The Sun has slowly been warming up ever since its birth. The Sun used to not be as hot, one of the reasons life didn’t always exist on the Earth. Just as the warmth of the Sun allowed life on Earth, it will also take it away.

The life cycle of our Sun.

The life cycle of our Sun.

Heat Death of Universe

The heat death of the universe occurs as all the stars and other universal matter continues to expand and uses up its energy or “burns out.” It’s like letting a candle burn and not blowing it out. Eventually it’s going to use up the wax and wick until it can’t burn anymore. The universe runs on “free” energy that is not endless. At some point the fuel for the universe will run out cutting of the energy for the cosmic bodies that give us life (namely our Sun). This probably won’t be happening anytime soon. It’s estimated the energy will run out after black holes vanish in about 10100 years (according to Hawking’s radiation). That’s one big candle!

The flame of life.

The flame of life.

The Big Rip

Just like how it sounds, all matter of the universe will be ripped apart.  We’ve all heard that the universe is expanding.  What would happen if the expansion increased at an accelerated rate?  If the universe expanded much faster than it is now, all the galaxies, stars, planets, dust, etc. would be ripped apart!  Think of it like a twizzlers.  If you pull slowly you can stretch out the twizzlers pretty far.  If you stretch too fast the twizzlers will just snap in half.  This is a possibility for our universe.  The hands pulling on our universe is something called dark energy.  Dark energy is a hypothetical energy that saturates all our universe.  It is theorized it helps our universe expand – at an accelerating pace.  This means the expansion is moving at a faster and faster rate as time goes by.  Eventually the universe will reach that point where it is pulling to fast, ripping apart everything.  What happens when everything is ripped apart and away from each other?  No one knows.

The Big Rip.

The Big Rip.

Cannibal Galaxies

Cannibal galaxies occur when a smaller galaxy is eaten by a larger galaxy! Natural selection at its best. Galaxies are gravitationally bound collections of stars, stellar bodies such as planets, space dust, and other objects. You are probably most familiar with the Milky Way galaxy (you should know this one, we live in it). Scientists can now detect our Milky Way galaxy is currently tearing apart and engulfing the Sagittarius galaxy as you read this! Closer to home than you might have expected. I guess we are saved this time but poor little Sagittarius galaxy…

Larger galaxy engulfing a smaller galaxy. (Swinburne)

Larger galaxy engulfing a smaller galaxy. (Swinburne)

Pulsar

When a star collapses on itself a neutron star is left behind. If we were to survive this giant explosion, we would have a new problem of pulsars to deal with. A pulsar is a neutron star that emits rays of electromagnetic radiation. Electromagnetic radiation is rays that vary depending on their frequency and wavelength. Some rays provide us with the visible light we use every day. Other rays below or above the spectra can be very harmful to us. For instance, radio waves (beyond red in the visible spectra) can vibrate the cells in your body heating them up to a deadly temperature while gamma rays (beyond blue in the visible spectra) can stop the function of the cells in your body. Oddly enough, both radio waves and gamma rays are used to treat different ailments.

The Vela Pulsar. NASA pic.

The Vela Pulsar. NASA pic.

New Podcast sponsered by EIU May 24, 2009

Posted by jcconwell in Astronomy, Cosmology, Podcast.
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http://365daysofastronomy.org/2009/05/24/may-24th-were-expanding-and-accelerating/

Description: There have been multiple theories of the ongoing evolution of the universe. Solid state, the big crunch – but hardly anyone expected the universe to not only expand, but to accelerate in it’s expansion. The Ordinary Guy talks to Dr Brian Schmidt, who explains the discovery, and what this means.

Bio: The Brains Matter podcast has been producing and communicating science stories and interviews since September 2006. The show is based out of Melbourne, Australia, and takes an everyday person’s perspective of science in easy-to-understand language.

New Podcast is up today at 365 Days of Astronomy May 12, 2009

Posted by jcconwell in Astronomy, Cosmology, IYA 2009, Podcast.
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Listen to the new podcast interview of Dr Michael Turner, who talks about the term he coined, DARK ENERGY.  It’s the May 12th episode of  365 days of astronomy sponsered by the EIU physics department. Permanent Link at:

http://365daysofastronomy.org/2009/05/12/may-12th-dark-energy/