Ask any question you want about Physics

originally posted by: coomba98
a reply to: dfnj2015

dfnj2015.

"2. Is time real? In other words, does the Universe execute the laws of physics in discrete steps or is all the energy in the Universe part of one single continuous wave of energy?"

I found this you tube clip to be fascinating. Only 10mins and explains in layman's terms what Einstein was thinking about time being an illusion.

youtu.be...

Coomba98

I think videos like that are more likely to lead to misunderstanding rather than understanding. If you take the comments in that video at face value you can come to all kind of kooky and wrong conclusions which is probably what the producers want since they are selling entertainment more than science.

Einstein did make the illusion comment but that was in the context of condolences. In a scientific context, what he really meant is that the understanding of time that preceded him (Einstein) was an illusion, but I don't interpret his work to mean time itself is an illusion which is the feeling one might get from watching that video. What Einstein said in his scientific work is that two different observers can perceive time differently and one must process a mathematical transformation to translate what one observer will see to what the observer will see (with respect to past, present, and future events).

That mathematical transformation is illustrated here:

Lorentz Transformation

The spacetime coordinates of an event, as measured by each observer in their inertial reference frame (in standard configuration) are shown in the speech bubbles.

I wouldn't say this shows time is an illusion, rather it shows that time is observer-dependent, and what math must be applied to understand why two different observers may observe events in space-time differently and in his scientific work I believe this is what Einstein actually explained.

Also keep in mind that some of the experiments testing this assertion help to illustrate how insignificant these effects are on everyday human scales. The Hafele–Keating experiment put atomic clocks in planes to test Einstein's idea which confirmed he was right, but the differences were so small they were measured in nanoseconds.

originally posted by: coomba98
a reply to: dfnj2015

dfnj2015.

"2. Is time real? In other words, does the Universe execute the laws of physics in discrete steps or is all the energy in the Universe part of one single continuous wave of energy?"

I found this you tube clip to be fascinating. Only 10mins and explains in layman's terms what Einstein was thinking about time being an illusion.

youtu.be...

Coomba98

Time is the sequence of events in the material Universe.

a reply to: Arbitrageur
a reply to: KrzYma

Arbitrageur/KrazYma,

Interesting, so the way the vid i posted about time is wrong? Damn you tube lol.

I understand time is not an illusion, thought the vid was interesting with that explaination.

Bout to go to work now so ill watch KrazYma vid when i get home.

... really my vid was wrong?

Coomba98

originally posted by: coomba98
... really my vid was wrong?

Did I say it was wrong? No.

Did I say the context of Einstein's statement about the "illusion" of time was not explained in the video? Yes. It's also lacking context for some of the other statements it makes which can be interpreted to mean totally different things in different contexts.

Einstein explained the mathematical relationship of events in space-time as observed by different observers and I would not describe this as an illusory concept. Again my interpretation of the context of his "illusion" statement was that he was referring to the Newton-Galileo concept of time which is the logical intuition that most of us wrongly have about time, and not his relativistic concepts which are not intuitive and which most of us don't understand.

For example, there is no evidence that the speaker in KrzYma's video understands relativity and he says that relativity is thoroughly confused, but as I said the Hafele–Keating and other experiments are consistent with relativity and not consistent with what KrzYma or his video says.

originally posted by: KrzYma
Time is the sequence of events in the material Universe.

Before Einstein that was a logical and intuitive view, but for you and your video to suggest that Einstein's relativity is wrong when it's consistent with so many experiments is ludicrous, especially when there are no experiments provided to show how it's wrong or to contradict it.

So maybe Newton and Galileo would have accepted that statement about the sequence of events, but what Einstein explained is that doesn't really work when considering relativistic effects as in this example:

Relativity of Simultaneity

Events A, B, and C occur in different order depending on the motion of the observer. The white line represents a plane of simultaneity being moved from the past to the future.

So if "Time is the sequence of events in the material Universe.", then what is the sequence of events shown in this animation? Is it A, B, C, or C, B, A, or are all three events simultaneous? Einstein's theory shows that those three observers will see three different sequences of events and they are all equally valid, and further that they all correspond to events in space time which can be mathematically translated from one observer's perspective to the perspective of another observer. In other words, the sequence of events depends on the motion of the observer.

Anytime you want to watch a video that starts out with the "electric Universe" logo, better put on the hip waders because it
typically means the BS is going to get real deep and this video is no exception. It doesn't talk about experiments at all which are the basis for testing relativity, it talks about philosophical BS instead. Philosophy might be OK if you want questions, but if you want answers, you're going to have better luck getting those from experiments, which along with quantitative models and predictions is something that real scientists use and electric universe hoaxers avoid even mentioning.

That drivel is made for weak minded fools who probably don't even understand what scientists are talking about, and then get their egos stroked when they are told that all those scientists you don't understand are wrong anyway and you're really smarter than they are because you're watching this mindless video saying they are all wrong.

Maybe science has got some things wrong; it probably does if history is any guide, but those mistakes were never corrected by dumb people watching dumb youtube videos, they were corrected with new quantitative models and new experiments confirming them, which again are things that electric universe avoids mentioning because they show EU to be wrong.

a reply to: Arbitrageur

Ouch! Damn that was an interesting post Arbitrageur. Where you in a bad mood when you wrote that? All good.

Yeah i dont buy into the electric universe theory.

What are some good you tube vids youd recommend for non-physicists?

Coomba98

originally posted by: dfnj2015
3. Is our Big Bang the result of a star collapsing to a black hole in another space-time dimension?

The answer to this is currently not known as Arbitrageur already said, BUT... from what we have observed and evidence pointing to a hot big bang origin, the process was an expansion OF space... not an expansion IN space.

This then precludes it being a comparable object as you describe. Same goes for extra dimensions. Unknown if there are any extra unobservable dimensions having influence on our own universe. So far there has been no extremely powerful evidence, and the theories that could be made to work better with extra dimensions, are typically easier to get working with other theories and models that open less cans of worms and actually have things we can observe.


Little side note regarding electric universe theories, some of our replies might appear a bit negative when responding, but it is due to a propensity of electric universe proponents to make wild claims that are absolutely incorrect, or are out right dishonest in their presentation. They also do a lot of comparative logic in which they cherry pic something that has some nice geometric shape, and then compare it to some pictures of plasma held in controlled fields in a lab setting and then say "LOOK, they are the same!" and that is about as far as they bother to provide evidence for...

They also make absolutely ludicrous statements in regard to what 'they' think the mainstream sciences view is on a subject... because they want to claim the mainstream is ignorant, when reality is usually 100% the opposite way around. Best one is the whole "Science ignores that space is full of plasma, and that stars contain plasma" its like... no... mainstream science has never EVER ignored those things after it was established to be the case.

It is good to keep all options open and on the table, but in my own view, the issue with some of the Electric universe stuff is that they make it sound scientific enough to fool the layman, who gets hooked on the notion that "OMG SCIENCE IS ALL WRONG!" kind of conspiracy or coverup. It breeds an almost cult like behaviour where most people who then go onto defend EU theories actually cannot... because they don't understand the fundamentals of the mathematics involved and why the theory is a pretty bad one.

originally posted by: ErosA433

Little side note regarding electric universe theories, some of our replies might appear a bit negative when responding, but it is due to a propensity of electric universe proponents to make wild claims that are absolutely incorrect,

ErosA433

Yeah i knew the harshness wasnt towards me, id forgotten who the EU people are.

Still it was an informative and amusing post.

Ohh thanks for your input.

Do you know any good you tube vids for a layman?

Coomba98

If I'm traveling at the speed of light, and I turn on a flashlight, won't the light from the flashlight going out ahead of me be moving faster than the speed of light?

If I'm traveling at the speed of light, and you're traveling toward me at the speed of light, won't our relative speeds be faster than the speed of light?

originally posted by: coomba98
a reply to: Arbitrageur

Ouch! Damn that was an interesting post Arbitrageur. Where you in a bad mood when you wrote that? All good.

I was in a good mood, at least before I watched the EU video, but I get a little annoyed when I lose 16 minutes of my life watching a totally ludicrous video that I can never get back.

Yeah i dont buy into the electric universe theory.

The problem is, it's not even a theory. Theories have quantitative models and EU doesn't have those. I've got nothing against scientists who offer alternative views to mainstream science, as long as they use a scientific approach in doing so. For example, I made a thread about a non-mainstream idea of how the moon might have formed, which is probably wrong, but I find it interesting because the scientist uses a quantitative model to make predictions, and then suggests an experiment to look for what his model predicts. If the experiment finds what he predicts, it will suggest his model may be right, and if it doesn't then as we already suspect his model is wrong. This is how science is done and this is how theories are developed and either confirmed or rejected, and this is what the EU folks don't do.

The other funny thing is the universe actually is electric according to mainstream science, but the EU folks seem to not get that and that the true electric nature is not what they claim it is.

originally posted by: ErosA433
They also make absolutely ludicrous statements in regard to what 'they' think the mainstream sciences view is on a subject... because they want to claim the mainstream is ignorant, when reality is usually 100% the opposite way around. Best one is the whole "Science ignores that space is full of plasma, and that stars contain plasma" its like... no... mainstream science has never EVER ignored those things after it was established to be the case.

yes, exactly!

originally posted by: coomba98
What are some good you tube vids youd recommend for non-physicists?

I would recommend these three youtube channels for some good physics videos for non-scientists:

MinutePhysics
This channel is done by Henry Reich who has a Masters degree in physics and works at the perimeter institute with some of the world's top physicists, and has a knack for explaining concepts simply in short videos. Sometimes maybe a little too short but if he's talking too fast you can always replay the video.

Sixty Symbols
Brady Haran made this channel. He's a video journalist who doesn't know much physics but the format of his channel is asking physics professors at the University of Nottingham for answers to physics questions. Earlier this year, he and two of the professors were awarded the 2016 Kelvin Medal and prize of the Institute of Physics " for innovative and effective promotion of the public understanding of physics through the Sixty Symbols video project."

Veritasium
Derek Muller does this channel and he has a PhD in physics education. Because his videos are longer than minutephysics he can go into more detail but then they take longer to watch. Unlike Brady Haran, Derek knows a lot of physics but on occasion you can still see him collaborating with other physicists, and even Henry Reich of minutephysics consults with his colleagues down the hall but you won't see that in his videos because they are too short and are focused on his illustrations rather than people like the other two channels.

originally posted by: LanceCorvette
If I'm traveling at the speed of light, and I turn on a flashlight, won't the light from the flashlight going out ahead of me be moving faster than the speed of light?

I agree it sounds logical the light coming from your flashlight would have a speed added to your speed, but experiments show this is not what happens, so even though it seems logical, it's wrong. You can't travel at the speed of light. but let's say you were going 50 miles per hour. The speed of light from your headlights doesn't travel at the speed of light plus 50 miles per hour.

If I'm traveling at the speed of light, and you're traveling toward me at the speed of light, won't our relative speeds be faster than the speed of light?

You can't travel at the speed of light because you have mass, so instead you can ask what if you go east at 60% the speed of light and Mary goes west at 60% the speed of light, won't you and Mary have a closing speed of 120% the speed of light? The answer is no, because velocities don't add like this in relativity. Delbert Larson posted the actual math some pages back, and it ends up always being less than the speed of light locally.

For non-local galaxies that are over 40 billion light years away, the metric expansion of space has them receding from us at about three times the speed of light, which doesn't violate relativity because it's not local.

a reply to: Arbitrageur

Arbitrageur

Cheers for the vid recommendation.

On hols after Thursday and will watch then.

Cheers

Coomba98

a reply to: Arbitrageur

Good stuff man.

Basically the answer is "Because I said so" - The Universe

a reply to: Arbitrageur

So if "Time is the sequence of events in the material Universe.", then what is the sequence of events shown in this animation? Is it A, B, C, or C, B, A, or are all three events simultaneous?

What this animation is, this is a very good question.
I see few lines and points...
There is also a grid
You tell me...

I see time on the horizontal axis and one spacial dimension on the vertical.
There is also a grid so it looks like an system of coordinates
then the picture gets distorted and I see point A moved on the coordinates in time, and so does point C

This isn't anything like time.
Time is constructed on counting, faster counting = more exact measurements.

It doesn't matter where you are or how fast you change your position relative to other objects, this "time ticking" is nothing you can do to it or manipulate it in any manner. The whole Universe, every atom, every moving charge is giving the background for counting. And if you move, you can not count any different number than anybody else of this background, YOUR local atoms ( in this complicated meter counting the "ticks" ) maybe vibrate in different "ticks" than the rest because of your movement and that's why your moving clock is going slower.
BUT time isn't any special number of "ticks" .
1 Year is a time,
1 Second is a time,
time is just a word it does not nothing at all !!

NOW here what happens if someone decides to limit the possibility of counting the information faster then they can arrive which is speed of light.

Einstein's theory shows that those three observers will see three different sequences of events and they are all equally valid, and further that they all correspond to events in space time which can be mathematically translated from one observer's perspective to the perspective of another observer. In other words, the sequence of events depends on the motion of the observer.

This animation above shows the propagation of information is space and time, and sure a traveling man will observe events differently, like the animations shows, but it has nothing to do with what time is.

Because time is just a concept and nothing you can stretch or slow down.

originally posted by: Arbitrageur

Events A, B, and C occur in different order depending on the motion of the observer... So if "Time is the sequence of events in the material Universe.", then what is the sequence of events shown in this animation? Is it A, B, C, or C, B, A, or are all three events simultaneous? Einstein's theory shows that those three observers will see three different sequences of events and they are all equally valid, and further that they all correspond to events in space time which can be mathematically translated from one observer's perspective to the perspective of another observer. In other words, the sequence of events depends on the motion of the observer.

On the equations relating (x, y, z and t) to (x', y', z' and t'), please note that the length contraction has been first credited to Fitzgerald and Lorentz, and that time dilation has been first credited to Larmor and Lorentz. Lorentz then put both concepts together into a single theory that was published in 1904. In the 1904 theory, if A occured before B, and B occured before C, this objective fact was not considered altered just because an observer was in motion. Instead, the theory was that there was some frame of reference, a particular (x, y, z and t), that existed in the rest frame of the Aether. The point was that if your moving meter sticks shrink and your moving clocks run slow you will now measure (x', y', z' and t') with those faulty instruments. With your faulty instruments, you will also set up simultaneity incorrectly in your flawed system. Only observers at rest in the Aether will have properly running clocks and fully correct meter sticks, and they can enlighten you on the folly of your ways. In that way of looking at the experimental reality, the "common sense" view of what space and time are stay the same as they were with Newton, Galileo, or your young self. Space is that three dimensional thing you walk around in. Time orders events in that space. Classical space and time remain.

The problems with that Lorentzian view are two-fold. First, there is no way to tell where that Aether frame is. Micheleson and Morley tried to find it, but when they tried the result was that it was moving along with them. This obsurd result was what led to the length contraction hypothesis, and later experiments required the time dilation hypothesis. And it was this experimental origin for the theory that led scientists of the day to look for something more fundamental. That was the second problem with the Lorentz approach - scientists feel that we should not generate ad hoc proposals for something as fundamental as space and time just because some experiments are explained that way. The idea being that we should not need ad hoc proposals every time we get a strange experimental result.

It was know in Einstein's time that you could derive the result that the speed of light is the same in every Lorentzian frame, due to the corruption of the measuring instruments. The Lorentz theory stipulated that the speed of light wasn't really the same with respect to all observers, but with their incorrect clocks and meter sticks they measured it to be the same. Einstein essentially started from that known fact (that the speed of light was the same in all Lorentzian frames) and raised it to the status of a postulate, and then ran the derivation backwards to arrive at the same equations as that of Lorentz.

However, Einstein proposed something radically new. He proposed that rather than the moving clocks and meter sticks being incorrect, they actually were correctly measuring time and space in their own frame. What he proposed was that time and space themselves transformed as a result of relative motion between observers. And with time and space so transformed, the events A, B and C can no longer be uniquely ordered.

It is often claimed that there is no experiment that can differentiate between the Lorentzian and Einsteinian points of view, but if you look above on this thread I have made the case that certain quantum mechanical results are rather confirmatory of Lorentz. If you search the web for "larson absolute electrodynamics theory" you can find more details, as well as a theory I have published that shows that the transformation equations may result from time dilation alone.

a reply to: Arbitrageur

The problem is, it's not even a theory. Theories have quantitative models and EU doesn't have those.

here it comes...

You don't even know what EU theory says, being convinced by the MS theory to be right you don't listen and think.

I don't want you to walk without light in a dark room so I will tell you some of the EU theory.


The Electric Atom:
. The electrically neutral atom is made of charged particles, positive and negative, in equal numbers.
. All particles are real with real location in space.
. There is a polarizable eather which transmits force & carries electromagnetic waves (light)
. DEFINE-- Energy is matter in motion relative to the matter in the rest of the universe
. DEFINE-- Mass is a measure of the distortion instead of acceleration of a subatomic particle in response to the electric forces from all other matter.
. Neutrons may not exist in the nucleus--if so, only 2 particles are needed to build ALL the elements


BUT, don't watch this video and don't waste one and a half hour of your time

I don't understand the 3-body problem. I've read about it in physics, never paid much attention to it, but came across a couple of discussions about it recently and realized that I have no understanding of what the "problem" really is.
I researched the topic, went through the Wiki about it but I don't understand the fundamental question - why are 3 bodies more complex than 2 bodies? Isn't it a function of adding up the forces on the 3 bodies and then doing some magic calculus to figure it out?
This article says that it can be solved mathematically but not analytically. I'm equally puzzled by that.
Any insight or links would be appreciated. Thank you as usual.


www.wired.com...

Numerical Solution for the Three-Body Problem Although there isn’t an analytical solution to the three-body problem, we can solve it numerically. I won’t go over all the details behind a numerical calculation (see this for a better start), but let me just cover the basics.

originally posted by: Phantom423
I don't understand the 3-body problem. I've read about it in physics, never paid much attention to it, but came across a couple of discussions about it recently and realized that I have no understanding of what the "problem" really is.
I researched the topic, went through the Wiki about it but I don't understand the fundamental question - why are 3 bodies more complex than 2 bodies? Isn't it a function of adding up the forces on the 3 bodies and then doing some magic calculus to figure it out?
This article says that it can be solved mathematically but not analytically. I'm equally puzzled by that.
Any insight or links would be appreciated. Thank you as usual.


www.wired.com...

Numerical Solution for the Three-Body Problem Although there isn’t an analytical solution to the three-body problem, we can solve it numerically. I won’t go over all the details behind a numerical calculation (see this for a better start), but let me just cover the basics.

How much do you know about differential equations?

With the three-body problem you have three coupled differential equations for which no general solution exists. Means you can not write up a function hat will satisfy those differential equations for any possible initial conditions.

This is not untypical for differential equations btw.

a reply to: moebius

Thanks for the reply. Yes, I am familiar with differential equations, although it's not something that I do every day.
The solution to a differential equation is a function, not a number. But as noted in the image below, it can't be written for the 3 body problem.


www.askamathematician.com...

In the article that I originally posted, the quote says that the problem can be solved mathematically but not analytically. I don't understand that. What's the difference? Am I reading that wrong? Apparently you can solve the 3 body problem using the 2 body technique, but you can't solve for the last 1% (according to the askthemathematician website) - that it goes to Chaos theory and other complex theories.

If the universe stood still at absolute zero and I was an observer outside this universe, wouldn't the relationship between all bodies and particles be the gravitational pull between all of them? So a 2 body solution or a 20 body solution or the solution to all matter in the universe would be a set of functions that describe these relationships - which of course would be in the quadzillions, but isn't that concept correct? Is time a factor if the universe stood still at absolute zero?

Since its christmas i have a question.

Angels and their wingspan.

The average eagle is abput 10lbs and needs a wingspan of about 6 feet to supply lift and fly around.

The average looking angel, if a man, is about 175 lbs with a 15-20 foot wingspan.

Wouldnt that be far too small to ever supply lift for the angel in the same manner bird wings would.

Granted its wings arent hummingbirds or Bumblebees. What in your guesstimation would be the realistic wingspan for a man trying to fly with wings. Not glide but fly like a bird.

40 foot? 75 feet?

a reply to: BASSPLYR

The wings are there for cooling area. The actual flight is done by psychic power, like flying reindeer.

originally posted by: Phantom423
I don't understand the 3-body problem. I've read about it in physics, never paid much attention to it, but came across a couple of discussions about it recently and realized that I have no understanding of what the "problem" really is.
I researched the topic, went through the Wiki about it but I don't understand the fundamental question - why are 3 bodies more complex than 2 bodies? Isn't it a function of adding up the forces on the 3 bodies and then doing some magic calculus to figure it out?
This article says that it can be solved mathematically but not analytically. I'm equally puzzled by that.
Any insight or links would be appreciated. Thank you as usual.

It means you can't solve, by equations and human thought, the differential equations of motion and write down general solutions in the form of:

vector[x](t) = F(t)

For two, and no more, gravitationally attracting objects (of small radius), you can do that. It's an ellipse, and Isaac Newton figured this out and gave an explanation from basic mechanism of the observations of Kepler in orbital mechanics.

The numerical solutions mean to write a computer program which approximates the infinitesimal integration of the differential equations through time, and draws out a specific trajectory given a specific input, but not a general formula.