Posted on 11/14/2023 1:28:04 PM PST by Red Badger
Have you ever dreamed of traveling through time, like characters do in science fiction movies? For centuries, the concept of time travel has captivated people’s imaginations. Time travel is the concept of moving between different points in time, just like you move between different places. In movies, you might have seen characters using special machines, magical devices or even hopping into a futuristic car to travel backward or forward in time.
But is this just a fun idea for movies, or could it really happen?
The question of whether time is reversible remains one of the biggest unresolved questions in science. If the universe follows the laws of thermodynamics, it may not be possible. The second law of thermodynamics states that things in the universe can either remain the same or become more disordered over time.
It’s a bit like saying you can’t unscramble eggs once they’ve been cooked. According to this law, the universe can never go back exactly to how it was before. Time can only go forward, like a one-way street.
Time is relative
However, physicist Albert Einstein’s theory of special relativity suggests that time passes at different rates for different people. Someone speeding along on a spaceship moving close to the speed of light – 671 million miles per hour! – will experience time slower than a person on Earth.
People have yet to build spaceships that can move at speeds anywhere near as fast as light, but astronauts who visit the International Space Station orbit around the Earth at speeds close to 17,500 mph. Astronaut Scott Kelly has spent 520 days at the International Space Station, and as a result has aged a little more slowly than his twin brother – and fellow astronaut – Mark Kelly. Scott used to be 6 minutes younger than his twin brother. Now, because Scott was traveling so much faster than Mark and for so many days, he is 6 minutes and 5 milliseconds younger.
Time isn’t the same everywhere.
Some scientists are exploring other ideas that could theoretically allow time travel. One concept involves wormholes, or hypothetical tunnels in space that could create shortcuts for journeys across the universe. If someone could build a wormhole and then figure out a way to move one end at close to the speed of light – like the hypothetical spaceship mentioned above – the moving end would age more slowly than the stationary end. Someone who entered the moving end and exited the wormhole through the stationary end would come out in their past.
However, wormholes remain theoretical: Scientists have yet to spot one. It also looks like it would be incredibly challenging to send humans through a wormhole space tunnel.
Paradoxes and failed dinner parties
There are also paradoxes associated with time travel. The famous “grandfather paradox” is a hypothetical problem that could arise if someone traveled back in time and accidentally prevented their grandparents from meeting. This would create a paradox where you were never born, which raises the question: How could you have traveled back in time in the first place? It’s a mind-boggling puzzle that adds to the mystery of time travel.
Famously, physicist Stephen Hawking tested the possibility of time travel by throwing a dinner party where invitations noting the date, time and coordinates were not sent out until after it had happened. His hope was that his invitation would be read by someone living in the future, who had capabilities to travel back in time. But no one showed up.
As he pointed out: “The best evidence we have that time travel is not possible, and never will be, is that we have not been invaded by hordes of tourists from the future.”
Telescopes are time machines
Interestingly, astrophysicists armed with powerful telescopes possess a unique form of time travel. As they peer into the vast expanse of the cosmos, they gaze into the past universe. Light from all galaxies and stars takes time to travel, and these beams of light carry information from the distant past. When astrophysicists observe a star or a galaxy through a telescope, they are not seeing it as it is in the present, but as it existed when the light began its journey to Earth millions to billions of years ago.
Telescopes are a kind of time machine – they let you peer into the past.
NASA’s newest space telescope, the James Webb Space Telescope, is peering at galaxies that were formed at the very beginning of the Big Bang, about 13.7 billion years ago.
While we aren’t likely to have time machines like the ones in movies anytime soon, scientists are actively researching and exploring new ideas. But for now, we’ll have to enjoy the idea of time travel in our favorite books, movies and dreams.
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You are doing it right now.................
Oh dear. I travel through time and space everyday. Something odd must be going on because I somehow manage to be late for everything...
True that. Time seemed to stand still in 2004 when I'd hear a speech by John Kerry, who served in Vietnam.
I thought the “Big Bangers” threw in the towel at this point.
Only with a DeLorean, a flux capacitor, and some plutonium. 1.21 Gigawatts!
Ya gotta love people who self describe themselves as, "Experts" when they really have no clue whatsoever in regards to the fundamental basic questions involving cosmology/life.
I am actually teaching a course on time travel. If you’d like to attend, be here last Thursday at 8pm.
The past happened, the future hasn’t - we’re in the present.
Joshua asked God to stop the sun...
Does That Count?
Between Two Eternities.
Normal play is free, the rub is with reverse an fast-forward
Time is relative, dependent,
You can save it, you can spend it
Doing things you like to do
Or learning how
You can’t see it, you can’t taste it
But you certainly can waste it
Which is really what we’re doing here right now!
Yep.
If UFOs are not military hardware or natural phenomena, I think time traveling humans (our distant descendants) are far more likely than aliens.
“One of the major problems encountered in time travel is not that of becoming your own father or mother. There is no problem in becoming your own father or mother that a broad-minded and well-adjusted family can’t cope with. There is no problem with changing the course of history—the course of history does not change because it all fits together like a jigsaw. All the important changes have happened before the things they were supposed to change and it all sorts itself out in the end.
The major problem is simply one of grammar, and the main work to consult in this matter is Dr. Dan Streetmentioner’s Time Traveler’s Handbook of 1001 Tense Formations. It will tell you, for instance, how to describe something that was about to happen to you in the past before you avoided it by time-jumping forward two days in order to avoid it. The event will be described differently according to whether you are talking about it from the standpoint of your own natural time, from a time in the further future, or a time in the further past and is further complicated by the possibility of conducting conversations while you are actually traveling from one time to another with the intention of becoming your own mother or father.
Most readers get as far as the Future Semiconditionally Modified Subinverted Plagal Past Subjunctive Intentional before giving up; and in fact in later editions of the book all pages beyond this point have been left blank to save on printing costs.
The Hitchhiker’s Guide to the Galaxy skips lightly over this tangle of academic abstraction, pausing only to note that the term “Future Perfect” has been abandoned since it was discovered not to be.”
― Douglas Adams, The Restaurant at the End of the Universe
Everything in the universe is moving.
The moon circles the earth, the earth circles the sun, and the sun is moving within our galaxy and our galaxy is moving within the universe.
The reason time travel is impossible is that we are never in one spot with in the universe, we are in constant motion.
A plumber repairing somebody’s toilet is ten times more valuable to the society than experts discussing time travel and related “scientific” garbage.
To the future possibly, but not the past.
I was just discussing this with someone next month.
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