The multiverse theory is famous for its striking imagery. Just imagine our own Universe, drifting among a veritable sea of spontaneously inflating “bubble universes”, each a self-contained and causally separate pocket of higher-dimensional spacetime. It’s quite an arresting picture. However, the theory is also famous for being one of the most criticized in all of cosmology. Why? For one, the idea is remarkably difficult, if not downright impossible, to test experimentally. But now, a team of British and Canadian scientists believe they may have found a way.
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Full story at Universe Today.
Showing posts with label multiverse. Show all posts
Showing posts with label multiverse. Show all posts
Friday, August 5, 2011
Friday, September 3, 2010
Hawking debunks "myth" of God.
Stephen Hawking is causing a stir. In a book excerpt published in tomorrow's Wall Street Journal, Hawking addresses the ever-controversial topic of science and religion. His take? The presence of a Creator is rendered completely unnecessary by modern science.
Hawking cites the so-called anthropic principle as the reason many people believe God must exist. The anthropic principle comes in two forms: the "weak" anthropic principle, which states that we developed on Earth because specific factors in our environment allowed us to do so, and the "strong" anthropic principle, which states that our existence as intelligent life-forms mandates the parameters inherent in the laws of nature themselves. For most, the weak anthropic principle is easily debunked. There are plenty of environments in the universe where intelligent life did not develop; we naturally find ourselves in one in which it did. This planet wasn't fine-tuned for the conditions of human life, human life was fine-tuned for this planet. Essentially, we are a statistic. Most people would agree with that in the context of the universe at large.
The controversial part of Hawking's statement, however, is his belief that the strong anthropic principle can be logically unravelled in the same way. The problem with the strong anthropic principle is that we have nothing to compare it to. As far as we are concerned, our universe is the only one. There are a variety of finely-tuned physical constraints inherent in the laws of physics, without which we would not exist. For instance, if gravity were any weaker, stars would never have formed in the early universe. Meanwhile, if gravity were stronger, our sun would have burned through all of its hydrogen already. Take your pick: the strength of the fundamental forces, the precise ratio of matter to antimatter, the stability of heavy elements like carbon, even the number of spatial dimensions in the universe; any of these is at the least, peculiar, and for some, explicit proof of God's existence.
But with the dawn of new cosmology - specifically evidence that points to the existence of multiple universes - Hawking believes that this principle too can be explained away. Just as there are many stars in our universe that are not orbited by planets, and many planets in our universe that are not hospitable to life, there are also many universes within our multiverse in which these physical parameters do have different values, and in which intelligent life was never able to form. Once again, we are a statistic. A Creator did not concoct a universe for our benefit; we evolved as a consequence of the specific universe we are in. Human life was inevitable, not essential. Or so Hawking believes.
First, let me say that I have no problem discussing science and religion in the same sentence. In fact, I think it can be extremely valuable. For my part, I know that science has profoundly affected and enriched my own spirituality. However, I don't think that Hawking's bold statement is going to do much to heal the schism between fundamentalist religion and modern science. There are altogether too many people who actually believe the Earth was created 6000 years ago, and who blatantly ignore scientific fact because they see it a contradiction of their own religious beliefs. Don't get me wrong - I'm a big believer in grey areas, but that is just absurd and ignorant. To be sure, a dialogue needs to be initiated, and a mutual one at that. Evolution absolutely needs to be taught in schools, but not at the expense of prayer or spiritual pride. Unfortunately, while I admire the conviction, I just don't think Hawkingism is going to win any new converts.
Hawking cites the so-called anthropic principle as the reason many people believe God must exist. The anthropic principle comes in two forms: the "weak" anthropic principle, which states that we developed on Earth because specific factors in our environment allowed us to do so, and the "strong" anthropic principle, which states that our existence as intelligent life-forms mandates the parameters inherent in the laws of nature themselves. For most, the weak anthropic principle is easily debunked. There are plenty of environments in the universe where intelligent life did not develop; we naturally find ourselves in one in which it did. This planet wasn't fine-tuned for the conditions of human life, human life was fine-tuned for this planet. Essentially, we are a statistic. Most people would agree with that in the context of the universe at large.
The controversial part of Hawking's statement, however, is his belief that the strong anthropic principle can be logically unravelled in the same way. The problem with the strong anthropic principle is that we have nothing to compare it to. As far as we are concerned, our universe is the only one. There are a variety of finely-tuned physical constraints inherent in the laws of physics, without which we would not exist. For instance, if gravity were any weaker, stars would never have formed in the early universe. Meanwhile, if gravity were stronger, our sun would have burned through all of its hydrogen already. Take your pick: the strength of the fundamental forces, the precise ratio of matter to antimatter, the stability of heavy elements like carbon, even the number of spatial dimensions in the universe; any of these is at the least, peculiar, and for some, explicit proof of God's existence.
But with the dawn of new cosmology - specifically evidence that points to the existence of multiple universes - Hawking believes that this principle too can be explained away. Just as there are many stars in our universe that are not orbited by planets, and many planets in our universe that are not hospitable to life, there are also many universes within our multiverse in which these physical parameters do have different values, and in which intelligent life was never able to form. Once again, we are a statistic. A Creator did not concoct a universe for our benefit; we evolved as a consequence of the specific universe we are in. Human life was inevitable, not essential. Or so Hawking believes.
First, let me say that I have no problem discussing science and religion in the same sentence. In fact, I think it can be extremely valuable. For my part, I know that science has profoundly affected and enriched my own spirituality. However, I don't think that Hawking's bold statement is going to do much to heal the schism between fundamentalist religion and modern science. There are altogether too many people who actually believe the Earth was created 6000 years ago, and who blatantly ignore scientific fact because they see it a contradiction of their own religious beliefs. Don't get me wrong - I'm a big believer in grey areas, but that is just absurd and ignorant. To be sure, a dialogue needs to be initiated, and a mutual one at that. Evolution absolutely needs to be taught in schools, but not at the expense of prayer or spiritual pride. Unfortunately, while I admire the conviction, I just don't think Hawkingism is going to win any new converts.
Wednesday, August 18, 2010
Quantum weirdness reaches new heights, now implies parallel universes.
Einstein's theory of general relativity states that nothing in the universe can travel faster than light. As usual, quantum mechanics disagrees. In special cases, a pair of particles can be connected in such a way that by measuring the state of one, the state of the other can be instantaneously known, even if the two particles are separated by a large distance. Einstein famously poked fun at the idea, sarcastically nicknaming it "spooky action at a distance." Many physicists today still have trouble accepting this so-called quantum entanglement, despite experimental evidence that implores them to think otherwise. In a recent paper, Dr. Frank J. Tipler, a mathematician and physicist at Tulane University, has developed a model that links alleged quantum nonlocality with the Many Worlds interpretation of quantum mechanics. He claims that his theory solves the paradox of faster-than-light travel, but only if we are prepared to accept the fact that we live in a multiverse, a wacky version of the cosmos in which parallel universes are born every time a decision is made.
Einstein's famous gibe, paired with the mathematical notation for "spin-up."
Image courtesy of Matt Mechtley.
The most oft-cited example of quantum entanglement is a system in which two electrons exist in a singlet state; that is, they must have opposite spins. Spin is a property that measures the angular momentum of a particle. When measured in the vertical direction, the spin of a particle can either be "up" or "down." In a singlet state, if one electron is spin up, the other must be spin down; this holds true even if the electrons are separated by hundreds of thousands of lightyears. The problem with such systems is that electrons should not be able to communicate with each other any faster than light can travel. For instance, if they are positioned 100,000 lightyears away from each other, it should take no less than 100,000 years for the news of one electron's chosen spin to reach the other so that it can choose the opposite spin; however, experiments indicate that such information seems to travel instantly.
How can this be? According to Tipler, we should embrace the Many Worlds interpretation of quantum mechanics in order to make sense of this seeming paradox. In the Many Worlds interpretation, every possible set of circumstances exists in a separate universe. Every time one choice is made over another, the universe splits. In my current universe, I am writing this article at a coffee shop in downtown Boulder. In a separate but equally real parallel universe, I am writing from home, successfully resisting the lure of overpriced tea. In yet another universe, I have horrible command of the English language and am instead spending my afternoon pondering the financial merits of becoming a stripper. Regardless of circumstance, each of these alternate universes is just as real as the one in which I sit, fully clothed, diligently pounding out a wordy and rambling piece of science writing.
Image courtesy of anomalous4.
Back to Tipler. In his model, there are four distinct universes that are born of such an experiment: one in which electron #1 is spin up, one in which electron #1 is spin down, one in which electron #2 is spin up, and one in which electron #2 is spin down. But because the two electrons exist in a singlet state, there are only two possible combinations of these worlds. Either electron #1 is spin up and electron #2 is spin down, or electron #1 is spin down and electron #2 is spin up. When an observer measures the state of electron #1 here on Earth, two universes result, each one containing an observer that detects an opposite spin. Thus, the resulting spin of electron #2 has nothing to do with any kind of faster-than-light communication by its counterpart. It is simply a consequence of the particular universe the observer happens to find himself in. Measurement of one electron does not determine the spin of the other; instead, it selects for one universe over another, one in which the two electron spins have been predetermined.
Confused yet? Don't worry, in another universe you know exactly what's going on. I promise.
Einstein's famous gibe, paired with the mathematical notation for "spin-up."
Image courtesy of Matt Mechtley.
The most oft-cited example of quantum entanglement is a system in which two electrons exist in a singlet state; that is, they must have opposite spins. Spin is a property that measures the angular momentum of a particle. When measured in the vertical direction, the spin of a particle can either be "up" or "down." In a singlet state, if one electron is spin up, the other must be spin down; this holds true even if the electrons are separated by hundreds of thousands of lightyears. The problem with such systems is that electrons should not be able to communicate with each other any faster than light can travel. For instance, if they are positioned 100,000 lightyears away from each other, it should take no less than 100,000 years for the news of one electron's chosen spin to reach the other so that it can choose the opposite spin; however, experiments indicate that such information seems to travel instantly.
How can this be? According to Tipler, we should embrace the Many Worlds interpretation of quantum mechanics in order to make sense of this seeming paradox. In the Many Worlds interpretation, every possible set of circumstances exists in a separate universe. Every time one choice is made over another, the universe splits. In my current universe, I am writing this article at a coffee shop in downtown Boulder. In a separate but equally real parallel universe, I am writing from home, successfully resisting the lure of overpriced tea. In yet another universe, I have horrible command of the English language and am instead spending my afternoon pondering the financial merits of becoming a stripper. Regardless of circumstance, each of these alternate universes is just as real as the one in which I sit, fully clothed, diligently pounding out a wordy and rambling piece of science writing.
Image courtesy of anomalous4.
Back to Tipler. In his model, there are four distinct universes that are born of such an experiment: one in which electron #1 is spin up, one in which electron #1 is spin down, one in which electron #2 is spin up, and one in which electron #2 is spin down. But because the two electrons exist in a singlet state, there are only two possible combinations of these worlds. Either electron #1 is spin up and electron #2 is spin down, or electron #1 is spin down and electron #2 is spin up. When an observer measures the state of electron #1 here on Earth, two universes result, each one containing an observer that detects an opposite spin. Thus, the resulting spin of electron #2 has nothing to do with any kind of faster-than-light communication by its counterpart. It is simply a consequence of the particular universe the observer happens to find himself in. Measurement of one electron does not determine the spin of the other; instead, it selects for one universe over another, one in which the two electron spins have been predetermined.
Confused yet? Don't worry, in another universe you know exactly what's going on. I promise.
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