from the world's big
Researchers successfully sent a simulated elementary particle back in time
Don't start investing in flux capacitors just yet, though.
- The second law of thermodynamics states that order always moves to disorder, which we experience as an arrow of time.
- Scientists used a quantum computer to show that time travel is theoretically possible by reverting a simulated particle from an entropic to a more orderly state.
- While Einstein's general theory of relativity permits time travel, the means to achieve it remain improbable in nature.
In 1895 H.G. Wells published The Time Machine, a story about an inventor who builds a device that travels through a fourth, temporal dimension. Before Wells's novella, time travel existed in the realm of fantasy. It required a god, an enchanted sleep, or a bonk on the head to pull off. After Wells, time travel became popularized as a potentially scientific phenomenon.
Then Einstein's equations brought us into the quantum realm and there a more nuanced view of time. No less than mathematical logician Kurt Gödel worked out that Einstein's equations allowed for time travel into the past. The problem? None of the proposed methods of time travel were ever practical "on physical grounds."
So, "Why stick to physical grounds?" asked scientists from the Argonne National Laboratory, the Moscow Institute of Physics and Technology, and ETH Zurich before they successfully sent a simulated elementary particle back in time.
Fair warning: their results are tantalizing but will ultimately dishearten any time lords in training.
The great quantum escape
A quantum computer mixing chamber (Photo: IBM Research/Flickr)
Many of the laws of physics view the future and the past as a difference without a distinction. Not so with the second law of thermodynamics, which states that a closed system always moves from order to disorder (or entropy). Scramble an egg to make your omelet, for example, and you've added a whole lot of disorder into the closed system that was the initial egg.
This leads to an important consequence of the second law: the arrow of time. A process that generates entropy — such as your egg whisking — will be irreversible unless you input more energy. It's why an omelet won't reform back into an egg or why billiard balls don't spontaneously reform a triangle after the break. Like an arrow released, the entropy moves in a single direction, and we witness the effect as time.
We are trapped by the second law of thermodynamics, but the international team of scientists wanted to see if the second law could be violated in the quantum realm. Since such a test is impossible in nature, they used the next best thing: an IBM quantum computer.
Traditional computers, like the one you are reading this on, use a basic unit of information called a bit. Any bit can be represented as either a 1 or a 0. A quantum computer, however, uses a basic unit of information called a qubit. A qubit exists as both a 1 and a 0 simultaneously, allowing the system to compute and process information much faster.
In their experiment, the researchers substituted these qubits for subatomic particles and put them through a four-step process. First, they arranged the qubits in a known and ordered state and entangled them — meaning anything that happened to one affected the others. Then they launched an evolution program on the quantum computer, which used microwave radio pulses to break down that initial order into a more complex state.
Third step: a special algorithm modifies the quantum computer allow disorder to more to order. The qubits are again hit with a microwave pulse, but this time they rewind to their past, orderly selves. In other words, they are de-aged by about one millionth of a second.
According to study author Valerii M. Vinokur, of the Argonne National Laboratory, this is the equivalent of pushing against the ripples of a pond to return them to their source.
Since quantum mechanics is about probability (not certainty), success was no guarantee. However, in a two-qubit quantum computer, the algorithm managed a time jump an impressive 85 percent of the time. When it was upped to three qubits, the success rate dropped to about 50 percent, which the authors attributed to imperfections in current quantum computers.
The researchers published their results recently in Scientific Reports.
Bringing order from chaos
The results are fascinating and spur the imagination, but don't start investing in flux capacitors yet. This experiment also shows us that sending even a simulated particle back in time requires serious outside manipulation. To create such an external force to manipulate even one physical particle's quantum waves is well beyond our abilities.
"We demonstrate that time-reversing even ONE quantum particle is an unsurmountable task for nature alone," study author Vinokur wrote to the New York Times in an email [emphasis original]. "The system comprising two particles is even more irreversible, let alone the eggs — comprising billions of particles — we break to prepare an omelet."
A press release from the Department of Energy notes that for the "timeline required for [an external force] to spontaneously appear and properly manipulate the quantum waves" to appear in nature and unscramble an egg "would extend longer than that of the universe itself." In other words, this technology remains bound to quantum computation. Subatomic spas that literally turn back the clock aren't happening.
But the research isn't solely a high-tech thought experiment. While it will not help us develop real-world time machines, the algorithm does have the potential to improve cutting-edge quantum computation.
"Our algorithm could be updated and used to test programs written for quantum computers and eliminate noise and errors," study author Andrey Lebedev said in a release.
Is non-simulated time travel possible?
As Kurt Gödel proved, Einstein's equations don't forbid the concept of time travel, but they do set an improbably high hurdle to clear.
Writing for Big Think, Michio Kaku points out that these equations allow for all sorts of time travel shenanigans. Gödel found that if the universe rotated and someone traveled fast enough around it, they could arrive to a point before they left. Time travel could also be possible if you traveled around two colliding cosmic strings, traveled through a spinning black hole, or stretched space via negative matter.
While all of these are mathematically sound, Kaku points out that they can't be realized using known physical mechanisms. Similarly, the ability to nudge physical particles back in time remains beyond our reach. Time travel remains science fiction for all intents and purposes.
But time travel may one day become an everyday occurrence in our computers, making us all time lords (in a narrow sense).
- Time Travel is Possible. Einstein Taught Us That. - Big Think ›
- Neil deGrasse Tyson Explains the Strange Paradoxes of Time Travel ›
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From "if-by-whiskey" to the McNamara fallacy, being able to spot logical missteps is an invaluable skill.
- A fallacy is the use of invalid or faulty reasoning in an argument.
- There are two broad types of logical fallacies: formal and informal.
- A formal fallacy describes a flaw in the construction of a deductive argument, while an informal fallacy describes an error in reasoning.
Appeal to privacy<p>When someone behaves in a way that negatively affects (or could affect) others, but then gets upset when others criticize their behavior, they're likely engaging in the appeal to privacy — or "mind your own business" — fallacy. Examples:<br></p><ul><li>Someone who speeds excessively on the highway, considering his driving to be his own business.</li><li>Someone who doesn't see a reason to bathe or wear deodorant, but then boards a packed 10-hour flight.</li></ul><p>Language to watch out for: "You're not the boss of me." "Worry about yourself."</p>
Sunk cost fallacy<p>When someone argues for continuing a course of action despite evidence showing it's a mistake, it's often a sunk cost fallacy. The flawed logic here is something like: "We've already invested so much in this plan, we can't give up now." Examples:<br></p><ul><li>Someone who intentionally overeats at an all-you-can-eat buffet just to get their "money's worth"</li><li>A scientist who won't admit his theory is incorrect because it would be too painful or costly</li></ul><p>Language to watch out for: "We must stay the course." "I've already invested so much...." "We've always done it this way, so we'll keep doing it this way."</p>
If-by-whiskey<p>This fallacy is named after a speech given in 1952 by <a href="https://en.wikipedia.org/wiki/Noah_S._Sweat" target="_blank">Noah S. "Soggy" Sweat, Jr.</a>, a state representative for <a href="https://en.wikipedia.org/wiki/Mississippi" target="_blank">Mississippi</a>, on the subject of whether the state should legalize alcohol. Sweat's argument on prohibition was (to paraphrase):<br></p><p><em>If, by whiskey, you mean the devil's brew that causes so many problems in society, then I'm against it. But if whiskey means the oil of conversation, the philosopher's wine, "</em><em>the stimulating drink that puts the spring in the old gentleman's step on a frosty, crispy morning;" then I am certainly for it.</em></p>
Slippery slope<p>This fallacy involves arguing against a position because you think choosing it would start a chain reaction of bad things, even though there's little evidence to support your claim. Example:<br></p><ul><li>"We can't allow abortion because then society will lose its general respect for life, and it'll become harder to punish people for committing violent acts like murder."</li><li>"We can't legalize gay marriage. If we do, what's next? Allowing people to marry cats and dogs?" (Some people actually made this <a href="https://www.daytondailynews.com/news/national/cats-marrying-dogs-and-five-other-things-same-sex-marriage-won-mean/dLV9jKqkJOWUFZrSBETWkK/" target="_blank">argument</a> before same-sex marriage was legalized in the U.S.)</li></ul><p>Of course, sometimes decisions <em>do </em>start a chain reaction, which could be bad. The slippery slope device only becomes a fallacy when there's no evidence to suggest that chain reaction would actually occur.</p><p>Language to watch out for: "If we do that, then what's next?"</p>
"There is no alternative"<p><span style="background-color: initial;">A modification of the </span><a href="https://en.wikipedia.org/wiki/False_dilemma" target="_blank" style="background-color: initial;">false dilemma</a><span style="background-color: initial;">, this fallacy (often abbreviated to TINA) argues for a specific position because there are no realistic alternatives. Former British Prime Minister Margaret Thatcher used this exact line as a slogan to defend capitalism, and it's still used today to that same end: Sure, capitalism has its problems, but we've seen the horrors that occur when we try anything else, so there is no alternative.</span><br></p><p>Language to watch out for: "If I had a magic wand…" "What <em>else</em> are we going to do?!"</p>
Ad hoc arguments<p>An ad hoc argument isn't really a logical fallacy, but it is a fallacious rhetorical strategy that's common and often hard to spot. It occurs when someone's claim is threatened with counterevidence, so they come up with a rationale to dismiss the counterevidence, hoping to protect their original claim. Ad hoc claims aren't designed to be generalizable. Instead, they're typically invented in the moment. <a href="https://rationalwiki.org/wiki/Ad_hoc" target="_blank">RationalWiki</a> provides an example:<br></p><p style="margin-left: 20px;">Alice: "It is clearly said in the Bible that the Ark was 450 feet long, 75 feet wide and 45 feet high."</p><p style="margin-left: 20px;">Bob: "A purely wooden vessel of that size could not be constructed; the largest real wooden vessels were Chinese treasure ships which required iron hoops to build their keels. Even the <em>Wyoming</em> which was built in 1909 and had iron braces had problems with her hull flexing and opening up and needed constant mechanical pumping to stop her hold flooding."</p><p style="margin-left: 20px;">Alice: "It's possible that God intervened and allowed the Ark to float, and since we don't know what gopher wood is, it is possible that it is a much stronger form of wood than any that comes from a modern tree."</p>
Snow job<p><span style="background-color: initial;">This fallacy occurs when someone doesn't really have a strong argument, so they just throw a bunch of irrelevant facts, numbers, anecdotes and other information at the audience to confuse the issue, making it harder to refute the original claim. Example:</span><br></p><ul><li>A tobacco company spokesperson who is confronted about the health risks of smoking, but then proceeds to show graph after graph depicting many of the other ways people develop cancer, and how cancer metastasizes in the body, etc.</li></ul><p>Watch out for long-winded, data-heavy arguments that seem confusing by design.</p>
McNamara fallacy<p>Named after <a href="https://en.wikipedia.org/wiki/Robert_McNamara" target="_blank">Robert McNamara</a>, the <a href="https://en.wikipedia.org/wiki/United_States_Secretary_of_Defense" target="_blank">U.S. secretary of defense</a> from 1961 to 1968, this fallacy occurs when decisions are made based solely on <em>quantitative metrics or observations,</em> ignoring other factors. It stems from the Vietnam War, in which McNamara sought to develop a formula to measure progress in the war. He decided on bodycount. But this "objective" formula didn't account for other important factors, such as the possibility that the Vietnamese people would never surrender.<br></p><p>You could also imagine this fallacy playing out in a medical situation. Imagine a terminal cancer patient has a tumor, and a certain procedure helps to reduce the size of the tumor, but also causes a lot of pain. Ignoring quality of life would be an example of the McNamara fallacy.</p><p>Language to watch out for: "You can't measure that, so it's not important."</p>
A new study looks at what would happen to human language on a long journey to other star systems.
- A new study proposes that language could change dramatically on long space voyages.
- Spacefaring people might lose the ability to understand the people of Earth.
- This scenario is of particular concern for potential "generation ships".
Generation Ships<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="a1e6445c7168d293a6da3f9600f534a2"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/H2f0Wd3zNj0?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Many of the most popular apps are about self-improvement.
Emotions are the newest hot commodity, and we can't get enough.