Breaking the Speed of Light and Contemplating the Demise of Relativity
Einstein released many theories during his scientific career, but it was the publishing of his two theories of relativity that literally shook the foundations of physics. The theories proposed by Einstein still stand today even though there are many individuals who have tried to challenge them. In 1905, Einstein published his special theory of relativity and he later followed that with the general theory of relativity in 1915. Each of these theories are comprised of their own sets of equations, laws and principles that explain why things act the way they do, from the largest of galaxies to the smallest of particles.
Einstein was in his mid-20's when he published his special theory of relativity, which became an absolutely essential tool for scientists, physicists, theorists and experimentalists around the world today. Some of the concepts that were introduced were time dilation, length contraction, and his famed theory of mass-energy equivalence with the introduction of E = mc2. One of Einstein's other concepts, and the subject of this blog entry, was Einstein's introduction of the cosmic speed limit which states that no physical object or information can travel faster than the speed of light in a vacuum.
Shortly after the publishing of his special theory of relativity, Einstein immediately began working out equations that encompassed geometric views of gravitation and introduced new and exciting concepts that replaced Newtonian mechanics, which had lasted 250 years. Scientists had been able to calculate low energy effects of gravity for centuries with Newton's theory, but until Einstein, what actually caused gravity had remained a mystery. Einstein's general theory showed the world that gravity was caused by the bending of space and time. So in short, it's not a gravitational force that is holding us all firmly down to the ground but it's space that is actually pushing you down. The theory explained such phenomenon as the bending of light by gravity and opened up the entirely new field of cosmology. The theory also made entirely new predictions, such as the Big Bang theory and also black holes, which continue to be a rich area of research for scientists.
Needless to say, Einstein's theory has withstood the test of time for almost a century and if there's one data-point out of place, we would have to throw the entire theory out. So everywhere we look into the heavens, Einstein's theory of general relativity comes right on the spot.
Last week, an international team of researchers and scientists reported that they have recorded sub-atomic particles appearing to travel faster than the speed of light. Over a period of three years, neutrinos were shot from the particle accelerator at CERN in Switzerland to a detector in Italy (the OPERA - Oscillation Project with Emulsion Tracking Apparatus) about 500 miles away. What the team found interesting was that the neutrinos arrived around 60 nanoseconds quicker than the light would have traveled. This recent result from the accelerator at CERN, which seems to contradict Einstein's theory of relativity, has generated enormous interest, among scientists as well as the public. However, not much has been written about precisely what this means for relativity itself.
Special Relativity of 1905, as discussed above, is based on the idea that the speed of light is the same, no matter who measures it, as long as you move smoothly and do not accelerate. This violates Newton's common sense notion that there is nothing special about the speed of light. Hence, something has got to give. So, our common sense notion of the universe must change if light speed is the same no matter how we measure it, whether it is coming toward us, away from us, or sideways. What gives is space-time. Hence:
All of the effects above have been observed. For example, our GPS satellites slow down a bit as they whiz overhead, just as Einstein predicted. There is also cosmic waves and particle accelerators that are also used to verify this fact.
If you get heavier the faster you move, then the energy of motion has turned into mass. The precise amount of kinetic energy that turns into mass is easily calculated using relativity (the derivation is 1 line long) and that result is the most celebrated equation in science, E = mc2.
So why is light speed the maximum speed in the universe? As you approach the speed of light, bizarre things begin to happen such as:
If you exceed the speed of light, then you get nonsense such as:
For these reasons, Einstein stated that you cannot go faster than the speed of light. This also affects general relativity, which is the foundation of cosmology, since (for small distances) general relativity reduces down to special relativity. Hence, both are wrong if the recent CERN experiments are correct. Not only is cosmology, nuclear physics, atomic physics, laser physics, etc. all in doubt, but also the fundamental theories of particle physics are also thrown in doubt. The Standard Model of particle physics (containing quarks, electrons, neutrinos, etc). is also based on relativity and would also mean that string theory, my field, may also be wrong. String theory has relativity built-in from the start and the lowest octave of string contains the entire general theory of relativity.
So you can see why physicists are breaking out in a cold sweat contemplating the demise of relativity. Not only will all textbooks have to rewritten but we will also have to recalibrate all our physics calculations, not to mention all of our theories of both nuclear, atomic physics and cosmology. What a headache! So, I think most physicists are holding their breath, wishing that the recent CERN experiment is shown to be flawed and something of a false alarm. However, there is the slim chance that the result holds up. Then relativity may fall and we will have to await the coming of the next Einstein who can make sense out of it all -- In retrospect however, This is How Science is Done.
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The team caught a glimpse of a process that takes 18,000,000,000,000,000,000,000 years.
- In Italy, a team of scientists is using a highly sophisticated detector to hunt for dark matter.
Researchers hope the technology will further our understanding of the brain, but lawmakers may not be ready for the ethical challenges.
- Researchers at the Yale School of Medicine successfully restored some functions to pig brains that had been dead for hours.
- They hope the technology will advance our understanding of the brain, potentially developing new treatments for debilitating diseases and disorders.
- The research raises many ethical questions and puts to the test our current understanding of death.
The image of an undead brain coming back to live again is the stuff of science fiction. Not just any science fiction, specifically B-grade sci fi. What instantly springs to mind is the black-and-white horrors of films like Fiend Without a Face. Bad acting. Plastic monstrosities. Visible strings. And a spinal cord that, for some reason, is also a tentacle?
But like any good science fiction, it's only a matter of time before some manner of it seeps into our reality. This week's Nature published the findings of researchers who managed to restore function to pigs' brains that were clinically dead. At least, what we once thought of as dead.
What's dead may never die, it seems
The researchers did not hail from House Greyjoy — "What is dead may never die" — but came largely from the Yale School of Medicine. They connected 32 pig brains to a system called BrainEx. BrainEx is an artificial perfusion system — that is, a system that takes over the functions normally regulated by the organ. The pigs had been killed four hours earlier at a U.S. Department of Agriculture slaughterhouse; their brains completely removed from the skulls.
BrainEx pumped an experiment solution into the brain that essentially mimic blood flow. It brought oxygen and nutrients to the tissues, giving brain cells the resources to begin many normal functions. The cells began consuming and metabolizing sugars. The brains' immune systems kicked in. Neuron samples could carry an electrical signal. Some brain cells even responded to drugs.
The researchers have managed to keep some brains alive for up to 36 hours, and currently do not know if BrainEx can have sustained the brains longer. "It is conceivable we are just preventing the inevitable, and the brain won't be able to recover," said Nenad Sestan, Yale neuroscientist and the lead researcher.
As a control, other brains received either a fake solution or no solution at all. None revived brain activity and deteriorated as normal.
The researchers hope the technology can enhance our ability to study the brain and its cellular functions. One of the main avenues of such studies would be brain disorders and diseases. This could point the way to developing new of treatments for the likes of brain injuries, Alzheimer's, Huntington's, and neurodegenerative conditions.
"This is an extraordinary and very promising breakthrough for neuroscience. It immediately offers a much better model for studying the human brain, which is extraordinarily important, given the vast amount of human suffering from diseases of the mind [and] brain," Nita Farahany, the bioethicists at the Duke University School of Law who wrote the study's commentary, told National Geographic.
An ethical gray matter
Before anyone gets an Island of Dr. Moreau vibe, it's worth noting that the brains did not approach neural activity anywhere near consciousness.
The BrainEx solution contained chemicals that prevented neurons from firing. To be extra cautious, the researchers also monitored the brains for any such activity and were prepared to administer an anesthetic should they have seen signs of consciousness.
Even so, the research signals a massive debate to come regarding medical ethics and our definition of death.
Most countries define death, clinically speaking, as the irreversible loss of brain or circulatory function. This definition was already at odds with some folk- and value-centric understandings, but where do we go if it becomes possible to reverse clinical death with artificial perfusion?
"This is wild," Jonathan Moreno, a bioethicist at the University of Pennsylvania, told the New York Times. "If ever there was an issue that merited big public deliberation on the ethics of science and medicine, this is one."
One possible consequence involves organ donations. Some European countries require emergency responders to use a process that preserves organs when they cannot resuscitate a person. They continue to pump blood throughout the body, but use a "thoracic aortic occlusion balloon" to prevent that blood from reaching the brain.
The system is already controversial because it raises concerns about what caused the patient's death. But what happens when brain death becomes readily reversible? Stuart Younger, a bioethicist at Case Western Reserve University, told Nature that if BrainEx were to become widely available, it could shrink the pool of eligible donors.
"There's a potential conflict here between the interests of potential donors — who might not even be donors — and people who are waiting for organs," he said.
It will be a while before such experiments go anywhere near human subjects. A more immediate ethical question relates to how such experiments harm animal subjects.
Ethical review boards evaluate research protocols and can reject any that causes undue pain, suffering, or distress. Since dead animals feel no pain, suffer no trauma, they are typically approved as subjects. But how do such boards make a judgement regarding the suffering of a "cellularly active" brain? The distress of a partially alive brain?
The dilemma is unprecedented.
Setting new boundaries
Another science fiction story that comes to mind when discussing this story is, of course, Frankenstein. As Farahany told National Geographic: "It is definitely has [sic] a good science-fiction element to it, and it is restoring cellular function where we previously thought impossible. But to have Frankenstein, you need some degree of consciousness, some 'there' there. [The researchers] did not recover any form of consciousness in this study, and it is still unclear if we ever could. But we are one step closer to that possibility."
She's right. The researchers undertook their research for the betterment of humanity, and we may one day reap some unimaginable medical benefits from it. The ethical questions, however, remain as unsettling as the stories they remind us of.
Some back story
A Dunbar Correlation
Professor Dunbar's response:
Friendship, kinship and limitations
Gray matter matters
There is an eclectic list of reasons why compassion may collapse, irrespective of sheer numbers:
In the end
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