The ability to jump forward and backwards in time has long fascinated science fiction writers and physicists alike. So is it really possible to travel into the past and the future?
Scientists are trying to figure out if time travel is even theoretically possible. If it is, it looks like it would take a whole lot more knowledge and resources than humans have now to do it.
Sean Carroll is a theoretical physicist who serves as a Homewood Professor of Natural Philosophy at Johns Hopkins University. Carroll strives to convey complicated physics concepts in accessible terms on his Mindscape podcast and in his popular books, including last year’s The Biggest Ideas in the Universe: Space, Time, and Motion. He joins Preet to talk about the relationship between science and philosophy, how to comprehend quantum mechanics, and whether there are billions of similar universes operating alongside our own.
Plus, Special Counsel David Weiss’s testimony in front of the House Judiciary Committee about the Hunter Biden prosecution and Trump’s reported plan to use the Department of Justice for revenge if he retakes the presidency.
Don’t miss the Insider bonus, where Preet and Carroll talk more about depictions of time travel in Hollywood films. To listen, become a member of CAFE Insider for $1 for the first month. Head to cafe.com/insider.
Webb’s observations have offered key insights into the intricate process of rocky planet formation.
NASA, ESA, CSA, Joseph Olmsted (STScI)
This high-powered telescope focused its lens on the cosmic disks (protoplanetary disk), where planets came into being, and detected the presence of water vapor.
Continue reading “James Webb: NASA’s time-traveler telescope now traces roots of Earth” »
A simulation offers a means of probing time travel without worrying about whether it’s actually permitted by the rules of the universe.
“Whether closed timelike curves exist in reality, we don’t know. The laws of physics that we know of allow for the existence of CTCs, but those laws are incomplete; most glaringly, we don’t have a theory of quantum gravity,” said Yunger Halpern. “Regardless of whether true CTCs exist, though, one can use entanglement to simulate CTCs, as others showed before we wrote our paper.”
In America, roughly 40 million Americans have diabetes and about 95% of them have type 2 diabetes. Type 2 diabetes occurs when the body cannot correctly process sugar and fuel cells. More specifically, the body does not produce enough insulin to break down sugar into glucose for the cells to use. In this case, treatment includes insulin shots or a pump in addition to a strict diet excluding sweets or high fat meals. Treatment limitations disrupt patient quality of life. Some researchers have been working on better detection for diabetic retinopathy with artificial intelligence (AI), but research is limited on how to better detect diabetes itself. Thus, many researchers are working to detect diabetes early on and discover better treatments.
Klick labs, located in multiple cities across the world, is trying to detect type 2 diabetes by having a patient speak into a microphone for 10 seconds. Klick labs believes this technology can better detect diabetes and help patients get treatment earlier. The study was published in Mayo Clinic Proceedings: Digital Health, which details how patients spoke for 10 seconds and combined with health data, including age, sex, height, and weight, created an AI model that discerns whether a person has type 2 diabetes or not. After further tests, scientists determined it has 89% and 86% accuracy for women and men, respectively.
In the study, Klick Labs collected voice recordings of 267 people, either non-diabetic or diabetic. The participants were asked to record a phrase into their smartphones six times a day for a total of 2-weeks. Over 18,000 recordings were taken and analyzed to distinguish 14 acoustic features that helped distinguish non-diabetic to type 2 diabetic individuals. The research highlights specific vocal variations in pitch and intensity that could lead to how the medical community screens for early-onset diabetes. A major barrier to early detection includes time, travel, and cost, which many people do not have. Voice diagnosis can help eliminate those barriers and improve detection and treatment in diabetic patients.
This week, researchers proved empirically that life isn’t fair. Also, you’ll notice that, in a superhuman display of restraint, I managed to write a paragraph about the simulated universe hypothesis without once referencing “The Matrix.” (Except for this reference.)
Oh, so a European research team has proven that flipped coins aren’t actually fair? Buddy, life isn’t fair! Do you think the world owes you two equally probable outcomes as established by an axiomatic mathematical formalization? When I was a kid, we didn’t even have coins! We had to roll dice! It took 10 minutes to start a football game! Oh, so a coin is very slightly more likely to land on the same face as its initial position? Quit crying! It’s only a meaningful bias if you flip a coin multiple times!
Applying a recently discovered physical law, a physicist at the University of Portsmouth has contributed to the discussion about whether or not the universe is a simulation. The simulated universe hypothesis proposes that the universe is actually a simulation running on a vastly complex computing substrate and we’re therefore all just NPCs, walking through our animation loops and saying, “Hail, summoner! Conjure me up a warm bed!” and “Do you get to the Cloud District often?”
Hindsight, as they say, is 20/20, but sometimes it would be nice to have known the outcomes before making a choice. This is as true in day-to-day life as it is in quantum mechanics. But it seems that the quantum world has something we do not have: a way to alter yesterday’s choices today, before they become tomorrow’s mistakes.
None of this is real time-travel. Physicists remain skeptical about that possibility. However, it is possible to simulate a closed time-loop with quantum mechanics, thanks to the property of entanglement. When two particles are entangled, they are in a single state even if they are separated by huge distances. A change to one is a change to the other, and this happens instantaneously.
So a particle can be prepared for an experiment, entangled, and sent to the experiment. Then scientists can modify its entangled companion, changing the way the particle in the experiment behaves.
For most of us, the passage of time flies in just one inexorable direction.
But for theoretical quantum physicists, time’s direction isn’t quite so inflexible. It’s possible to theoretically model, simulate, and observe the backwards flow of time in ways that are impossible to achieve in the real world.
And now, scientists have shown that simulations of backwards time travel can help solve physics problems that cannot be resolved with normal physics.
