5 hours ago, martin-w said:

Time is a measurable, observable phenomenon though.

Ah, but how is it measured?  By referencing something moving from point A to point B, like how many periods some time reference it takes the Earth to rotate on its axis once.  There is actually no "time" involved, only the motion of a mass.  It is only our minds that perceive the passage of time.  Another example, objects don't "age" or decay due to the passage of time, but because particles move in chemical reactions that take place which change the object's composition.

Time is really just a reference to where an object is now and where it was before or after where it is now.  How "long" this takes is only our perception.  We can state that a second of time passes when an electron moves from one energy state to another in a particular element, but fundamentally it is still just the movement of a particle.

Just my 2c, no actual proof of course.

Dave

I'm not in any position to agree or disagree. All I can say is this...

"The currently accepted view of physics is that time is as real as space."

 

https://www.sciencefocus.com/science/is-time-an-illusion

Edited November 9, 20232 yr by martin-w

2 hours ago, martin-w said:

"The currently accepted view of physics is that time is as real as space."

https://www.scientificamerican.com/article/sometimes-science-is-wrong/

Dave

 

Yep, certainly true that science isn't infallible. Nobody and nothing is. But the scientific method is the best tool we have at our disposal and its proven its worth.

In terms of time being "real" most scientists believe so but im sure there are those that don't. What we can say is it's a measurable observable phenomonon. What that implies, I'll leave for you to continue to speculate on.

What I would say though is that science is more likely to be right than two non-scientists on Avsim.

Over to our resident scientist... what say you Mr Peter?

Edited November 10, 20232 yr by martin-w

Dave has a point, but that point also applies to space. Indeed, anything that we observe must be based on measurements, and time is no exception. Like Dave said, we measure time using clocks, which usually consist on some form of periodic motion. The Earth's rotation is a very old but inaccurate example, the current standard uses oscillations in Cesium atoms. And yes, in a universe that is completely static, time would lose its meaning since nothing could oscillate and allow us to measure time. You need something to change to perceive time.

The same argument refers to space. How do you measure a position? Typically by referring to a reference point, say the corner of a room. You then measure the change in position from that point using a ruler, for instance. In a completely empty universe, measuring position would be impossible. Both time and space are defined and observed through changes in something, either the advancement of a clock's hand, or the reading on a ruler.

The fun starts when you try to actually do that. To make something oscillate, you need a force, which changes the location. And progressing on a ruler also requires some form of motion, which involves a period of time. Hence, you can't measure time without perturbing location and vice versa. Nevertheless, we can get very accurate measurements of position and time, but not without limits. In relativistic quantum physics, the Compton wavelength of a particle sets a limit of how exactly we can localize it. If you tried, you would have to invest so much energy that you would start creating pairs of matter and anti-matter: instead of knowing the location of a single electron more precisely, you'd end up with two electrons and a positron.

Peter

What do you think of the Penrose Conformal Cyclic Cosmology idea?

 

Penrose examines implications of the Second Law of Thermodynamics and its inevitable march toward a maximum entropy state of the universe. Penrose illustrates entropy in terms of information state phase space (with 1 dimension for every degree of freedom) where particles end up moving through ever larger grains of this phase space from smaller grains over time due to random motion. He disagrees with Stephen Hawking's back-track^[1] over whether information is destroyed when matter enters black holes. Such information loss would non-trivially lower total entropy in the universe as the black holes wither away due to Hawking radiation, resulting in a loss in phase space degrees of freedom.

Penrose goes on further to state that over enormous scales of time (beyond 10¹⁰⁰ years), distance ceases to be meaningful as all mass breaks down into extremely red-shifted photon energy, whereupon time has no influence, and the universe continues to expand without event →∞. This period from Big Bang to infinite expansion Penrose defines as an aeon. The smooth "hairless" infinite oblivion of the previous aeon becomes the low-entropy Big Bang state of the next aeon cycle. Conformal geometry preserves the angles but not the distances of the previous aeon, allowing the new aeon universe to appear quite small at its inception as its phase space starts anew.

Penrose cites concentric rings found in the WMAP cosmic microwave background survey as preliminary evidence for his model, as he predicted black hole collisions from the previous aeon would leave such structures due to ripples of gravitational waves.

I have the greatest respect for Penrose's work, he was a giant in the field of General Relativity and his work from the 60s-80s truly deserves the Nobel Prize. But I haven't looked into the details of his conformal model since it contains several words that I am skeptic about.

1) Cosmology: a fascinating field with some great achievements, but there are no repeatable experiments, and it is a playground for all kind of fancy ideas that can't be tested. Just because a hypothesis is logically consistent doesn't mean it is right. And, frankly, 10^100 years is quite a big number, about 10^90 times the age of the universe. I don't care very much about predictions for time scales that will never be accessible to observations.

2) Conformal: Conformal symmetries are beautiful math, but they tend to create bad physics because they oversimplify things. Physicists do that quite a lot. You may have heard about the joke about spherical cows in a vacuum, but that's not really a joke: I once heard a serious research talk about a model with spherical crabs and the effect of sonar on those. At least they were in water and not in a vacuum. Plus, my first research field was superstring theory, which employs conformal field theory. I enjoyed the logic, but never looked back because the predictions weren't really relevant for any kind of experiment.

3) Thermodynamics: that may come as a surprise, but I never liked thermodynamics. Sure, it is an extremely useful theory and very successful in describing machines and many other things. However, it works differently than other physical theories; it is just not my taste. I prefer statistical mechanics (SM), from which thermodynamics can be derived. Thermodynamics mostly describes equilibrium situations (where everything has settled to some temperature), but SM can describe more general situations. Such as experimental violations of the second law of thermodynamics. 

 

Apparently it didn't launch on Transporter 8 and was rescheduled for Transporter 9.

However, T9 has now launched. No confirmation it was onboard yet. 

Yep, it launched! 👍

https://spacenews.com/startup-rogue-space-launches-its-first-demonstration-mission/

 

"It also will test customer payloads from the propulsion startup IVO. The company is developing so-called IVO Quantum Drive electric propulsion technology for low-Earth orbit spacecraft."

Edited November 12, 20232 yr by martin-w

On 11/10/2023 at 6:34 AM, qqwertz said:

The same argument refers to space. How do you measure a position? Typically by referring to a reference point, say the corner of a room. You then measure the change in position from that point using a ruler, for instance. In a completely empty universe, measuring position would be impossible. Both time and space are defined and observed through changes in something, either the advancement of a clock's hand, or the reading on a ruler.

The universe is not empty, though.  It is space with masses that fill it and displace/bend it.

I can measure distance between 2 objects in space, but the only way I can measure time is by using the periodic motion of some mass(es) as a reference.

I can actually observe how space affects things, but time is only my perception as a sentient being.  I don't see time as being an actual dimension like spacial dimensions.

Of course, I could be totally off base here.

Dave

11 hours ago, dave2013 said:

The universe is not empty, though.

Correct, that's why we can measure distance. However, the universe is also not static. As long as something moves, we can measure time. I doesn't have to be an oscillating motion, although they are extremely common and much more precise.

In fact, measuring time is now so precise that the most accurate way to measure distances is to measure the time light (or electromagnetic waves in general) travels between two points. That's how the unit of length, meter, is currently defined in the SI system of units. And that's how the GPS system works, it determines your position by measuring the time radio signals need to get from several satellites to your cell phone.