This does indeed have something to do with quantum electrodynamical Feynman diagrams, where electrons are represented by lines with an arrow pointing one way, and positrons with the arrow pointing the other way:
But I am not sure what it buys you to imagine the positrons (or the electrons) as going “backwards in time”.
The wooden box at the end of the journey awaits you patiently. I’m not convinced speeding this process up is really what you want. But you do you; far be it from me to intervene.
Dr. Don Lincoln, Fermilab, Youtube science explainer for Fermilab explained it that way, that’s what helps me make sense of it.
You’re moving through time at light speed unless you are also moving along the spatial axiseseseses (axes?). Then your speed of causality is divided amongst the 4 axes of travel (3 spatial one time)
My take away from it all is that time coordinates are plottable similar to spatial coordinate, but to move about the time axis like you would spatial axes require a massive investment of energy to affect your inertia. Like you’re actually trying to affect the inertia of the entire universe sooooo, good luck, maybe it will eventually end up just being a technical problem, but I ain’t gonna see the day.
My take away is not clear on being able to actually leave your original light cone or if it shifts around with you as you traverse the time axis in a non-linear way or not.
I don’t think this is accurate in any way, just my crude understanding.
Exactly. Presumably all the information about the state of the universe ten minutes ago exists in some form (like a photograph or viewing an object ten light-minutes away). But short of rearranging the entire universe with your Omega 13 device, it’s not really clear to me how one could “travel” to ten minutes ago.
Reminds me of a bit by comedian Ron White during the Blue Collar Comedy Tour days.
He’s describing sex with his wife in terms of a rodeo. He then comments something like “There’s some doubt about me staying on for the FULL eight seconds…”
I’m now in day 9 of 10 of COVID isolation. Having lived alone in one guest bedroom, one bathroom, and one patio with only you folks for company for 9 days I can say time has sure dragged. Despite how much fun I could have had with the same 9 consecutive days off around town with my wife.
Brian Greene was the first person I know of to use this analogy, though it wouldn’t surprise me if someone else used it before. If you poke in to the detail though, at best it is a trivial and slightly misleading statement, but at the same time it is a good analogy
The analogy comes the 4-velocity of a particle, observer, etcwhich is always c, when defined. 4-velocity is analogous to 3-velocity as it is the differential of 4-position wrt to proper time. However the 4-velocity turns out just to be the unit vector (using normalized units such as c=1) tangent to the object’s wordline. So you can reduce the analogy to the statement that a unit vector always has a lenght of ‘1’, which is trivial as it is just the defintion of a unit vector. The 4-velocity is also undefined for a lightspeed particle like a photon.
The reason it is a good analogy though is it makes you think about how unit timelike vectors project on to each other, without even explaining what a timelike vector is. Since Minkowski, realivity has mostly been thougt of geometrically and the geometrical thinking motivated general relativity and this analogy introcues geometrical thinking by stealth.
Same question. What does it even mean “traveling backwards through time”? Like the antimatter jumps back into the particle accelerator before I turn it on, like those inverted bullets in Tenet?
This reminds me of a story arc in a recent season of Legends of Tomorrow (Spoliered below: note it isn’t actually about Hitler)
They want to stop WW1 by preventing arch duke Ferdinand from being assassinated. When they get there they find that there is a bar filled with time travelers many of whom are waiting their turn to try. But it turns out that the death of Ferdiand is an unalterable fixed point in time and anyone who tries to stop it fails and usually ends up dead. The rest of the patrons are there for the entertainment of watching the first group fail.
The analogy implies that you can only slow down the passage of time by moving thru space. Does the math say otherwise? (for the purpose of moving backward/fwd in time).
Physicists don’t look at things traveling through time. They have equations. Equations can have pluses or minuses.
Feynman saw that the equations put a minus sign in whenever antimatter was considered. Otherwise they were equivalent to matter’s equations. So what did that mean? Feynman noted that it was equivalent to saying that matter travels forward in time and antimatter travels backwards in time. In fact, a position might be an electron that had traveled into the future and returned as a positron. (Sorry for an oversimplified take.)
What is time? Relativity and quantum theory each treat time differently so they’re no help. Right now it’s all let’s you and them argue.
Thank you. It’s been the most logistical hassle for the least symptoms and apparent health impact of my entire life. Considering how many people my age have died of COVID, to be bitching about how mild it’s been seems … ungrateful.
As General Kuhster said of all matters military in that epic work of cinematic literature, The Great Race