Sciencemadness Discussion Board - Myth of Streching Space

I was also going to suggest you swot up on physics and the scientific principal (the one that requires evidence and testable predictions). But that apparently has not always worked. Perhaps you need a better BS detector.

“No conspiracy” where did that come from ?. Did some one suggested there is a secret sect of Pi masons who spread unscientific phenomena in attempt to confuse undergraduates? (humour).

First of all, I'm glad to see that you're investigating this matter, rather than just writing off everyone that contradicts you as being idiots. Second, the trouble with astrophysics is that we can only observe the universe from a single point, and thus while we can observe many strange and interesting phenomena, it is often the case that it is barely within our power as a species to observe them, let alone reproduce them under experimental conditions. The best we can hope to do is to describe them using a model that people are able to wrap their heads around. The "inflation" model of the universe is a model and nothing more. It is a way of describing phenomena to other people. The paper you referenced describes shortcomings in a common use of this model, and ways in which the model is relied on too literally, but it is not saying the model is completely wrong.

edit: For some reason, I feel the need to make note of the text in my signature here.

[Edited on 10/28/17 by Melgar]

NEMO-Chemistry - 27-10-2017 at 20:17

Regarding if space stretches and where does it come from/go...

Why would it not be like elastic? You pull it and it stretches and let go and it shrinks back, nothing is added or taken away (except force). Personally i dont see why stretching space would need it to add or subtract anything.

Would answering the questions of the cosmos really give us peace of mind?

Like proving or disproving God, would it help or hinder?

[Edited on 28-10-2017 by NEMO-Chemistry]

Melgar - 28-10-2017 at 05:55

Regarding if space stretches and where does it come from/go...

Why would it not be like elastic? You pull it and it stretches and let go and it shrinks back, nothing is added or taken away (except force). Personally i dont see why stretching space would need it to add or subtract anything.

The usual description is that it's like the surface of a balloon that's being inflated, hence the inflationary model of the universe. However, I think that it's described as following similar rules as a quantity of gas released into a vacuum. Thus, it's expanding at a changing rate, based on some initial quantity that we call "dark energy" because we can't see it and don't know what else to call it. So it's not really "coming" from anywhere, it was here since the beginning, but can't be observed. I don't think we're very close at all to figuring out what "dark energy" is. Dark matter, we're perhaps a little closer to, though our hypotheses are still largely untestable.

Quote:

Would answering the questions of the cosmos really give us peace of mind?

It's human nature to wonder about things, regardless of their practicality. Like our primate ancestors, we're a curious species, by nature. It would be a sad universe indeed, if there was nothing we didn't know, and nothing new to learn.

NEMO-Chemistry - 28-10-2017 at 08:15

I often here we know more about space than we do about our own planet, particularly the Oceans. Space isnt my thing though, kind of got ruined with brightest object in the sky here, is the bloody space station!!

Space to me is just one them things likely to drive you insane thinking about it. Although I do belong to the group of 'there must be other life forms'. Seems to be too many Goldilock zones for life not to exist somewhere else, I doubt we will know though.

hissingnoise - 28-10-2017 at 09:22

What'd be nice is 3D astronomical viewing ─ two telescopes in space, a certain great distance apart, focused on the same area of space to produce pictures/video that may be viewed as in a 3D slide-viewer...? :cool:

And increasing/decreasing their degree of separation should make for 'interesting' effects, don'cha know?

Melgar - 28-10-2017 at 10:13

Quote: Originally posted by hissingnoise

And increasing/decreasing their degree of separation should make for 'interesting' effects, don'cha know?

For a parsecond there, I didn't know what on Earth you were talking about!

hissingnoise - 28-10-2017 at 10:30

Did you mean: what in Space you were talking about?

phlogiston - 28-10-2017 at 13:55

Real-life Elastic materials become thinner as they stretch. Think of the balloon analogy that Melgar mentiones. The material that provided the extra length did not come out of nowhere.
Ofcourse, it is only an analogy, and I am not sure if it is a useful line of thought to take it this far, but applied to the stretching of space, it would imply that space has another dimension ('thickness') that can become thinner to allow the 3 spatial dimensions of space that are visible to us to stretch.

If space is actually made of something, what does 'stretching' do to it?
Thinking of quanta of space being stretched a little further apart doesn't help. The very meaning of 'further apart' depends on the concept of space/dimensions.

Space that is 'stretched' accommodates more stuff. Therefore, if space is made of something, it seems to me that 'stretching' it implies creating more of whatever it is that space is (or thinning some unobserved 'thickness' dimension of it)

[Edited on 28-10-2017 by phlogiston]

Melgar - 28-10-2017 at 14:37

I often here we know more about space than we do about our own planet, particularly the Oceans. Space isnt my thing though, kind of got ruined with brightest object in the sky here, is the bloody space station!!

I'm not really sure where that saying comes from. Perhaps because we spend so much more resources studying space than our oceans? That makes complete sense though, because there's so much more to learn by studying space. Additionally, I think that quote was first used during the Cold War when we were trying to beat the Russians in the Space Race. (Not so we could launch nuclear warheads into an orbital that passed directly above Moscow, of course. That would be MAD.) The thing is, though, most of the oceans are pretty boring. Not much goes on in the abyssal plains, even though they make up most of the planet's surface. If it wasn't too dark to see there, which it is, it'd look like you were standing in a field of mud, with nothing but mud to be seen in every direction. All day, every day. With the temperature a constant 4 degrees celcius. (about 38 F)

Quote: Originally posted by hissingnoise

Did you mean: what in Space you were talking about?

Hmm... in case anyone missed the joke, parsecs are "parallax seconds" and describe arc-seconds, based on how much stars seem to move when the Earth is at opposite ends of its orbit. During the early 20th century, that was how astronomers determined how far away different stars are, although it only works well within our own galaxy. Now, we're sophisticated enough that we can use doppler shifting and other cool tricks to tell how far away things are, rather than wait six months to take another picture to compare with, and hope nothing moved in the mean time.

Quote:

If space is made of something, it seems to me that 'stretching' it implies creating more of whatever it is that space is.

There's no reason to expect space to follow the same rules as matter and energy. After all, space isn't made of either. Do we know what space is made of? Sort of. It's made of space-time. That's a bit of a cop-out answer, but if you have a better one, you're welcome to propose an experiment to test your hypothesis. Until then, we can only use models to describe our observations, and understand that whatever laws we believe the universe to operate by, if what we observe doesn't follow those laws, then our laws need revising, not the universe.

I think that this is the point aga was making, actually, with the whole broadway musical bit.

wg48 - 28-10-2017 at 15:31

In the first sentence of that post of mine was poorly written. I had meant it to mean that even some people whom presumable know a lot of physics like people who write the curricula of degree courses in physics or books on advanced physics who presumable have done a lot of swotting up believe the myth. So suggesting swotting up on physics is not necessarily going help dispel the myth.

I was not investigating expanding space. I was trying to understand how the observable universe is 100 billion compared to 13 billion light years. The calculation I gave previously is wrong I thought I had deleted that section perhaps I forgot to hit the edit button at the end of my edit. I have failed to understand size problem. The best I can do is: the surface of last scattering was moving away at about 0.9998c (redshift 1001) so its velocity can not have significantly increased so its present position is double that, double again for a diameter which makes the diameter of observable universe 52 billion light years (proper distance).

The relativistic redshift between distant objects in the universe is it caused by: either a) Relative motion between the objects or b) Space welling up between the objects while the objects are stationary” relative to each (the words of a physicist not mine). The more detailed explanation is that as the light travels between the objects the welling up space stretches the photons which causes the drop in frequency.

Its difficult for me to see how a) and b) as almost equivalents descriptions. This is supposed to be physics not fairy tales for children.

However the root of the welling up of space idea lies deeper in the incorrect belief that the universe expands faster than light. In an infinite and isotropic (all observers at rest in the locale frame see the universe identically with identical physical laws) universe is not observed to expand faster than light and hence does not violate SR. I have already explained this so I am repeating myself. It is not pseudosience just SR. Its the sort stuff I thought they teach on physics courses not fairy tales.

Melgar - 29-10-2017 at 11:08

What you call a "myth", others might call a "model", perhaps? Because regardless, the universe does behave in ways that can't be explained solely by general relativity. The most commonly used model is referred to as the "Lambda-CDM model", for the constant (lambda) and "CDM" for "cold dark matter". Here's the Wikipedia page, if you're interested in understanding this model:

https://en.wikipedia.org/wiki/Lambda-CDM_model

Melgar - 30-10-2017 at 04:42

The issue is that I'm pretty sure I understand the standard model of the universe, but I'm not sure I understand you. However, the sentence before your points a, b, and c was the one that I thought best explained it:

Quote:

Although this expansion increases the distance between objects that are not under shared gravitational influence, it does not increase the size of the objects (e.g. galaxies) in space.

That is, for objects that are not under shared gravitational influence, general relativity apparently doesn't describe the governing laws.

hissingnoise - 30-10-2017 at 08:24

Ahem! It's hard to offer anything but the most banal of generalities on a subject large as this, but let's see ─ the ever-accelerating expansion of the universe, as accepted, is mostly predicated on red-shifted light from distant objects.

The fact that the most distant observable objects display the greatest degree of red-shift is generally taken to mean that their rate of recession is also greatest.

But the most distant objects are also the most distant in time so that the oldest objects 'appear' to have the highest speeds of recession?

And as we know, when light travels in space, its wavelength increases over time so that there's a distance-dependence on the degree of red-shift observed and one must wonder how much red-shift is due to recession and how much is due to the distance travelled?

aga - 30-10-2017 at 14:39

Erm, i need to physically be in orbit around Proxima Centauri next weekend and would like to be back a couple of days later.

OK, so Science tells us that by accelerating an object to light speed is the max possible, and it'll take over 4 years each way.

That simply tells us that the trusted "Picking Things up and Throwing Them" method will not work, yet that is the current Best way (albeit with much stronger arms, i.e. rocketry).

Discovering of the limits of stone-throwing doesn't sound quite so impressive anymore, seeing as 102 years have passed already, and an awful lot of effort has been focused on verifying the stone-throwing theories instead of anything new.

So, how else can i physically get to our nearest star next weekend ?

Texium - 30-10-2017 at 15:28

Well... actually thanks to relativity and the elasticity of time, if you were hypothetically accelerated to near the speed of light and put on course to Proxima Centauri, you would feel as if you arrive in much less than 4 years (not sure exactly how long it would be, that would require some math that's beyond me, but probably much less than a year), and if you were then to come back to Earth immediately after at the same speed, you'd find that on Earth 8 years have passed even though to you it may have just been a number of days.

aga - 30-10-2017 at 15:42

That solution would not meet the requirement.

Picking me up and throwing me as hard as you can would simply not work, despite how attractive that may sound.

Science already tells us that it would not work, so another way is required.

Time to move on from apes throwing rocks around, although i'm not 100% sure it's time for that yet, insofar as the minds of us apes are concerned.

Edit:

This feels a bit like the Nitric Acid Challenge, where the ONLY methods were nitrate-and-sulphuric or birkland-eyde, as they were best documented, yet biology was already doing it in peat bogs and that process was already documented on SM.

[Edited on 30-10-2017 by aga]

Texium - 30-10-2017 at 18:45

I looked up the math for the time dilation effect and turns out it's actually really simple.

https://www.quora.com/Traveling-at-99-9-speed-of-light-insid...

With that, it would take just over two months to reach Proxima Centauri from the frame of reference of someone inside a rocket going 99.9% of the speed of light. That's about the best you could get, end of story. You won't be able to travel at light speed or faster to get there. Demanding that people offer you a sci-fi alternative is just trolling.

[Edited on 10-31-2017 by zts16]

wg48 - 31-10-2017 at 05:33

Sorry melgar and all I must have been half a sleep when I wrote my last post. I have deleted it while I still can. I will post an updated version when I have time.

If aga was traveling at c as his travel time in our frame suggests. He would arrive instantly. Stopping and starting would be painfull very painfull. This does assume SR is applicable.

Oops forgot to hit the post button on this post last night must have been in half sleep mode again.

wg48 - 31-10-2017 at 07:16

The issue is that I'm pretty sure I understand the standard model of the universe, but I'm not sure I understand you. However, the sentence before your points a, b, and c was the one that I thought best explained it:

Quote:

Although this expansion increases the distance between objects that are not under shared gravitational influence, it does not increase the size of the objects (e.g. galaxies) in space.

That is, for objects that are not under shared gravitational influence, general relativity apparently doesn't describe the governing laws.

Given you do not understand the difference between commoving parameters and proper parameters I would be surprised if you understand the geometry of the model but no more surprised than the fact that some physists don’t either.

If you willing deny two fundamental tenants of physics SR and GR and I do not, then we have no common frame of reference so will never come to a common understanding.

I have started so I will finish.

Locally the model obeys all laws of physics just like say the house I am in does.. Globally (large scale) if the modelled universe is not expanding or contracting its also correct. However If the modelled universe is expanding or contracting globally the model does not correctly represent the large distances in the actual universe They are larger relative to the real universe. The distances in model are called commoving distances to distinguish them from distances in the real universe which are called proper distances.

The confusion over expanding space and some values of the size of the universe arise from this simple confounding of comoving distances with proper distances and yes I find that hard to belive too.

This is not difficult its not rocket science but apparently its even harder LOL

PS I am not half a sleep so hopefully I have this about correct.

[Edited on 31-10-2017 by wg48]

aga - 31-10-2017 at 09:34

Quote: Originally posted by zts16

That's about the best you could get, end of story. You won't be able to travel at light speed or faster to get there. Demanding that people offer you a sci-fi alternative is just trolling.

I'm not Demanding anything of anyone.

It would be just great to hear about a new idea from anyone at some time, rather than the repeated refrain : "the science i learnt so far says it can't be done".

hissingnoise - 31-10-2017 at 10:00

Quote:

It would be just great to hear about a new idea from anyone at some time

Not to worry ─ if the good Lord wanted us to stay put he wouldn't have created dark energy...?

yobbo II - 31-10-2017 at 12:39

and then there was dark time

aga - 31-10-2017 at 13:22

In the end, Reality is RIGHT THERE, staring us in the face, every single day.

Strange nobody has thought sideways a bit and come up with another idea in 112 years.

SWIM - 31-10-2017 at 14:08

Sure they have, dozens and dozens of them.

Unfortunately most of them were total crap. ("gravity is just the kicked back nut of the screwing bolt of radiation")

The problem is that this isn't some Douglas Adams novel where you just make up a new cosmology and it's true because it's improbable, or because it was written down in a bistro. (Although here in America many people take supply-side economics seriously based on something a guy scribbled down on a napkin in a trendy restaurant)

Things have to actually fit with the reality which stares us in the face. And fit better than SR and GR do.

Coming up with something that does fit better, if that's possible at all, is unlikely to be possible if you structure your theories around the preconceived condition that it must make it possible for us all to play Captain Kirk, or Dr Who, in real life.

All this yearning for long distance travel is a waste anyway; because as Dr Banzai once said, "Wherever you go...there you are."

aga - 31-10-2017 at 14:24

Ah.

So Thinking and Imagining are useless in the face of Established Science.
Somebody should have told Copernicus that to save him the rather nasty bother.

OK.

So here, and only here, we remain, and die, same as most species ever seen on this planet, if we cannot be different.

Personally i see alternative options, however it does not fit with the Establishment.

Yes, new ideas MUST be evaluated to see if the magic potato is really just a potato.

Same as all science - idea, test it out, it ends up as real or bollocks.

Oh well, nothing really changes, ever, not even the fact that everything always changes.

Edit:

Clearly what has already been established though mountains of actual Work is the foundation to build on, and cannot be disregarded as it establishes Facts.

The only (not)New thing i'm pushing here is that people should Think for themselves and not be Bound by existing Science and thereby be limited in what they can imagine.

We cannot (currently) get to Mars and back in a useful time.

Someone make it so

[Edited on 31-10-2017 by aga]

SWIM - 31-10-2017 at 14:35

Quote: Originally posted by aga

Ah.

So Thinking and Imagining are useless in the face of Established Science.
Somebody should have told Copernicus that to save him the rather nasty bother.

If you don't like what someone says, just pretending they said something else is always a good way to convince yourself you're right and they're wrong.

Good luck with that.

aga - 31-10-2017 at 14:44

In my own experience i'm always wrong, no matter what subject, who i talk to, how much i know about a thing etc.

Basically i am always wrong.

Everyone knows better than me, always, making me the tenth man most times.

Chemetix - 31-10-2017 at 14:44

Some theories are complete Nuttery; I mean there are kooks that love to peddle electric aether theory of gravitation and others that deny SR based on specious understanding of the simplest mathematics that describe the theories, nuts flock to gravity and black hole theory like flies to shit. But then, the ideas like string theory are so complex that it takes decades to come to the conclusion it was nuts all along.

But amateur science shouldn't back away from tackling the big ideas any more than it should stick to the small ones.
It just means our peers need to be vigilant and be a bit more critical than when reviewing a more reputable source. I like kook, it's good to dabble in "free energy" stuff because it sort of sets a baseline of crazy and broken logic, reading orthodox work then becomes somehow clearer and the weaknesses in the science don't become lost by assumptions about it's validity.

I've got my own idea about what gravitiation is, the mathematics seems to work and the whole thing has an elegant simplicity about it...but I've never published it anywhere, I'm too afraid I'll get labelled a kook and the idea will never get developed. Can we float gedanken experiments on phys.org?

aga - 31-10-2017 at 14:50

If you have an idea about Gravity i would very much like to hear about it.

Edit:

"accepted" work with gravity are seriously lacking in actual Science.

[Edited on 31-10-2017 by aga]

Chemetix - 31-10-2017 at 15:00

Good to hear from you again Aga; I missed your irascible ways, and low tolerance of talking in preference to doing. I'll post something but have some work to do now, give me a few hours to put something together and I hope it can be shot down in flames by the SM team before I embarrass myself in front of academia.

aga - 31-10-2017 at 15:04

I look forward to your post.

Being 'shot down' is fine.

Every idea yields new ideas, especially if they are good ones.

Gravitation idea

Chemetix - 31-10-2017 at 22:45

Ok... let's just start off by saying that all mass interacts by it's matter wave, (https://en.wikipedia.org/wiki/Matter_wave) where it's wave function spreads inversely as a function of distance. The wave is really in information field that contains the quantum description of it's momentum. You can pin down either position or velocity but not both. This information of it's mass and velocity interacting as a wave gives rise to diffraction patterns with slits such as Youngs' double slit experiment (https://en.wikipedia.org/wiki/Double-slit_experiment) or phenomena like electron tunneling (https://en.wikipedia.org/wiki/Quantum_tunnelling).

Given that matter has a quantum level momentum interaction, matter also has a macroscale momentum interaction. Momentum in a multi mass system is conserved because momentum is a form of energy and energy just doesn't come from nowhere. m1v1 =m2v2 is a simple relationship that describes how a system will behave when two masses interact. I posit that two masses interacting via their matter waves, probability fields or wave function...whatever we want to call it, has consequences to the macroscale momentum.

Just think for a moment about two masses in space in some sort of proximity to each other, they have two wave matter fields that spread out and overlap at some point.
The field is a probability of finding the mass at any point in time, the mass is more or less a blur in spacetime, only after a large number of time periods does it seem like it is at a"position". What happens when the masses overlap their information about their position in space time is that there are consequences to the energy of the system.
As the two masses are 'statistically' brought closer, due to the randomness of their positions the two masses exchange information about momentum. If they decide that they are a system, they behave as though they have undergone an inelastic collision (or a part of one, statistically speaking). m1v1 =m2v2 becomes v2= m1v1/(m1+m2 ). Say both masses have a unit mass and a unit velocity in a perfect inelastic collision. As they collide the final velocity is halved. As the wave function 'collides' the mass increases but the velocity reduces.

The consequence of the wave field having a reduced 'velocity' is spacetime slowing. The energy consequence to the system can be described as a momentum increase with reducing distance. Mass one approaches mass two and the momentum changes with distance. The choice of which mass approaches which mass is relative to the frame of reference that is chosen, it's why relativity works. The main consequence of momentum changing is there must be a force involved. Momentum changing with distance is the same as saying force operating over distance. This is work.
Work is Force times distance. Two masses interacting set up a work potential between them, the potential is felt only at a quantum statistical level, but no less the effect is that if the masses are probabilistically closer they have lowered the work potential. In order to overcome the lowering of the work potential they will need external energy to change the system to have higher potential. In other words they fall towards each other. They need extra energy to overcome the loss of potential. This is the 'Force' of gravitation and why it's so weak compared to other fundamental forces. The pair of masses are statistically uphill and down hill of each other at any given moment but each quantum exchange means they inevitably get drawn closer and the work potential gets eventually turned into a macroscopic increase in velocity towards each other, the acceleration due to gravity, while at the quantum level they exchange information to become one mass with reduced velocity. You can also see that as you increase mass of the system, the velocity must slow down, the more mass the slower the velocity component to the wave function of the mass. Eventually with enough mass the velocity is slower than the speed of light, no quantum interactions, any particle exchange will take an infinite time to complete. No particle can escape the work potential created and voila, black hole.
The work function F.d can be expressed as F ~w/d (~ = proportional to) , the force that exists between two masses can be expressed as the sum of the two work functions. F~ (w1/d ) x (w2/d)
Work is proportional to the mass so the equation becomes
F~ m1.m2 / d^2
The force is equal to these variables only when the subtle quantum nature of the effect is taken into account, just how many particle exchanges translate to a "measurement" in the real world, per second is something someone with a particle accelerator can answer. In this case we'll say there's a variable k. So we have based on an interpretation of the work function derived from quantum momentum, we have an equation for the force due to gravity that looks like:
F= k m1m2 / d^2

Which I must say isn't very original.
But that's the point isn't it, it seems to be a step in the right direction and I'm kind of satisfied by the simple uncomplicated interpretation of the cause behind gravitation.

But I may very well have overlooked something blindingly simple and come to a conclusion from a disastrous flaw in logic. Which I humbly submit as a possibility.

zed - 1-11-2017 at 12:14

Well, there is the argument that as your ship goes faster, it becomes more massive, and thus much more difficult to accelerate.... But, we should keep in mind, that your fuel onboard shall have become more massive too, and thus should contain much more Umph.

[Edited on 1-11-2017 by zed]

Chemetix - 1-11-2017 at 12:55

Quote: Originally posted by zed

Well, there is the argument that as your ship goes faster, it becomes more massive, and thus much more difficult to accelerate.... But, we should keep in mind, that your fuel onboard shall have become more massive too, and thus should contain much more Umph.

[Edited on 1-11-2017 by zed]

Changing the rest mass by actual velocity I say comes from the Doppler shift of the matter wave. By compressing the matter wave you have shortened the wavelength, this is a change in energy. And so alters the work function of the matter wave to make it interchangeably more massive or higher velocity, as it's quantum momentum which has changed.

aga - 2-11-2017 at 14:13

@Chemetix thanks for sticking your neck out and posing an idea in public.

It will take some time (for me at least) to digest what you wrote before i could post any meaningful response/questions about it.

Edit:

What you mean by 'wave field' would be helpful.

[Edited on 2-11-2017 by aga]

Chemetix - 2-11-2017 at 14:47

I think the accepted term is wave function, written as the Greek letter Psi, the probability distribution of finding a particle in space. It's a complicated thing to describe, it's either the velocity or the position but not both. Rather than pin down one property it's easier to think of it as a momentum field but with wave like properties.

I read Tollmans' "principles of statistical mechanics" among countless general physics texts on introductory quantum principles, but as someone once said 'If you think you understand quantum mechanics, you obviously don't.'

aga - 2-11-2017 at 15:12

'Wave Function' i am familiar with, thanks to blogger's beating it into me with all that maths (i should sue for Maths Abuse as soon as he gets out).

'Wave Field' is still unclear.

Please describe it more.

Use loads of pitchforks and LaTex if needs be.

Chemetix - 2-11-2017 at 15:24

I think the way I used the term 'wave field' is my way of looking at the wave function acting as a field, because I introduce the concept of the wave function creating a field of potential energy.

Electric field or magnetic fields are gradients of potential energy and are able to do work. Field lines are points of equipotential, the resultant work function acts perpendicular to this field. Both in terms of Electromagnetism and gravitation.

zed - 3-11-2017 at 16:21

https://www.youtube.com/watch?v=LvN6-RK66Bo

Heh, heh. Lemme think on that.

Chemetix - 3-11-2017 at 17:03

Hah... ok stop me when I get to tiaba kolbaka lemongrass....

wg48 - 6-11-2017 at 05:46

The universe was very different 13 billion years ago, which means the simple calculation of its observable radius using its age and the velocity of light is incorrect. To correctly calculate the distance you need the mass energy density and velocity along its path. The simple calculation grossly underestimated that distance. It would be correct in a static universe.

Below is a pic of a plaque that appears at the Rose Centre for Earth and Space in New York. It does not even use the correct definition. You would think a centre for space would have got it better. Perhaps some would say myths and fairy tales are fine if they are directed at undergraduates and children (sarcasm) LOL

pic from wiki

aga - 6-11-2017 at 15:41

The Universe was a lot bigger when i was a lad.

It was all trees around here, now look at it.

NEMO-Chemistry - 6-11-2017 at 17:09

What if space was just 5 dimensions wrapped like some kinda twisted mobious band? If we can draw the shadow of a 4 dimension shape, why cant you have more than 4 dimensions? This makes the assumption, that having seen the drawing of the 4th dimension shadow, you then except it must exist.

If a 4th dimension didnt exist, how can you draw its shadow?

I wonder how much sense the above is going to make to me tomorrow??? having just distilled 300ml of Chloroform, it might not make much. But I can promise you that at the moment it makes perfect sense to me

.

[Edited on 7-11-2017 by NEMO-Chemistry]

NEMO-Chemistry - 7-11-2017 at 04:38

Nah dosnt make any sense today, maybe that proves chloroform makes you smarter then lol

Melgar - 7-11-2017 at 11:15

It can be useful to think of space-time as having 3.5 dimensions, or seven degrees of freedom. That is, in three of the dimensions, it's possible to move in both directions, but in one of the dimensions, movement is only possible in one direction.

String theory claims something like ten dimensions, but that's basically mathematical masturbation, and I wouldn't put much credibility in it these days.

aga - 7-11-2017 at 15:52

Attempting to understand how the Universe Actually Is can make you a bit crazy,

Trying to imagine it from the viewpoint of an entity moving along a linear Gravitational line (swapped for our linear Time axis) almost demolished my feeble brain.

Fortunately the cumulative effects of Beer not only hindered this occurrence, but allowed for the 'fuckit' contingency to release the brain from the difficult task of processing what is basically Madness for a human.

I may try again some day, and will definitely be prepared with large stocks of beer in case it goes wrong.

wg48 - 8-11-2017 at 02:25

While looking up some definitions of cosmological terminology I found the following text in a note titled: Expanding Confusion: common misconceptions of cosmological horizons and the superluminal expansion of the universe by Tamara M. Davis and Charles H. Lineweaver. It was written 14 years ago.

Murdoch's note on this subject is 40 years old. It’s amazing to me that this gobbledygook fairy tales stuff is still around. I guess its because its simpler to understand and teach in spite of the contradictions or maybe it really is the Pi masons LOL

“Popular science books written by astrophysicists, astrophysics textbooks and to some extent professional astronomical literature addressing the expansion of the Universe, contain misleading, or easily misinterpreted, statements concerning recession velocities, horizons and the “observable universe”. Probably the
most common misconceptions surround the expansion of the Universe at distances beyond which Hubble’s law
(vrec=HD : recession velocity = Hubble’s constant × distance) predicts recession velocities faster than the speed of light [Appendix B: 1–8], despite efforts to clarify the issue (Murdoch 1977, Harrison 1981, Silverman 1986, Stuckey 1992, Ellis & Rothman
1993, Harrison 1993, Kiang 1997, Davis & Lineweaver 2000, Kiang 2001, Gudmundssonand Bjornsson 2002). Misconceptions include misleading comments about the observability of objects receding faster than light [App. B: 9–13]. Related, but more subtle confusions can be found surrounding cosmological event horizons [App. B: 14–15]. The concept of the expansion of the universe is so fundamental to our understanding of cosmology and the misconceptions so abundant that it is important to clarify these issues and make the connection with observational tests as explicit as possible.”

The note can be found at https://arxiv.org/pdf/astro-ph/0310808.pdf

[Edited on 8-11-2017 by wg48]

Melgar - 8-11-2017 at 04:05

@NEMO If unicorns don't exist, then why can I draw one?

We can make computer models with as many spacial dimensions as we want to, extrapolating from 2D counterparts in 3D. Like, for a 2D square, all of its sides are at 90 degrees to each other. To get a cube, you add another square in the new dimension, the same distance away as one of its sides is long, and connect all of its corners to corresponding corners on the other square. This creates eight new edges, for a total of 12. To move to 4 dimensions and get a hypercube, you create another cube, one side-length away, in the new dimension, adding 12 new edges. Then connect all the 8 corners to corresponding corners on the other cube, adding 8 edges for a total of 32. Hypercube projections in three dimensions can be mind-warping, but this projection is probably the easiest to comprehend:

The fact is though, our universe doesn't show any signs of interacting with a fourth spacial dimension, and so arguing about whether one exists is a lot like arguing about the existence of God.

While looking up some definitions of cosmological terminology I found the following text in a note titled: Expanding Confusion: common misconceptions of cosmological horizons and the superluminal expansion of the universe by Tamara M. Davis and Charles H. Lineweaver. It was written 14 years ago. It’s amazing to me that this gobbledygook fairy tales stuff is still around. I guess its because its simpler to understand and teach in spite of the contradictions.

Oversimplifications aren't the same things as lies. If I explain how sunlight forms to a five-year-old, I have to choose between giving an answer that will hopelessly confuse him, or an answer that isn't 100% accurate but is as close to accurate as I think he can understand. The details can be elaborated on when he's old enough to understand them.

Physics professors are in the same predicament. With so many more students attending college than used to, you get a lot of dum-dums who you either hopelessly confuse, or make a judgment call regarding where to draw the line regarding simplification. The people who wrote this article seem to believe that some professors and authors have simplified too much. That's all.

I'm also glad to see that you're studying this stuff more. Knowledge is power, even if it's just the power to better articulate what, specifically is wrong with an oversimplified explanation of the standard model of the universe, without being wrong yourself.

aga - 8-11-2017 at 14:04

So if spacetime is deformed by the presence of a black hole for example (of which there are many) how can it be argued that over a distance of 13Billion light years the spacetime inbetween point A and B is uniform and contiguous ?

If Not, the calculation of the travel-time of light is a bit off, therefore so is the estimate of the Size of the everything.

If So, black holes and other bodies do Not affect spacetime significantly, which is at odds with established theory.

To be fair, i was struggling to move a boulder the other day and asked my wife to hand me the 5 foot iron bar.

She handed me a tiny teaspoon instead, with a knowing smirk

NEMO-Chemistry - 8-11-2017 at 14:52

@NEMO If unicorns don't exist, then why can I draw one?

We can make computer models with as many spacial dimensions as we want to, extrapolating from 2D counterparts in 3D. Like, for a 2D square, all of its sides are at 90 degrees to each other. To get a cube, you add another square in the new dimension, the same distance away as one of its sides is long, and connect all of its corners to corresponding corners on the other square. This creates eight new edges, for a total of 12. To move to 4 dimensions and get a hypercube, you create another cube, one side-length away, in the new dimension, adding 12 new edges. Then connect all the 8 corners to corresponding corners on the other cube, adding 8 edges for a total of 32. Hypercube projections in three dimensions can be mind-warping, but this projection is probably the easiest to comprehend:

The fact is though, our universe doesn't show any signs of interacting with a fourth spacial dimension, and so arguing about whether one exists is a lot like arguing about the existence of God.

https://www.youtube.com/watch?v=iGO12Z5Lw8s

Dodo's dont exist (now), how do we know unicorns have never existed? You could argue no fossil record, but then how come we still havnt found the missing link?

The fact its called the missing link means it is believed that there must be one, but as yet we havnt discovered it.

Once upon a time we lived on a flat earth, only we didnt did we.
until fairly recently things like the Bosen higgs didnt exist, and to be fair, if you believe in string theory etc then they didnt exist.

So take that further, in quantum physics and string theory, its possible for things to exist and not exist at the same time. Or it exists because we thought it into existence.

As for God, surely thats an open question until it can be proved one way or the other. The fact we dont know just means we dont have all the information.

How old are black holes? rare as rocking horse shit, except turns out every galaxy has at least one. So we have gone from not knowing they existed to finding them all over the place.

So do we have 3 dimensions or more than 3? I dont buy the argument that its the same as arguing god, as i said it wasnt that long ago not a single person would have entertained the idea of a black hole.

You cant prove god dosnt exist or 4 dimensions dont exist, the best you can manage is to say we dont know and dont have what it takes currently to prove or disprove.

I dont believe or disbelieve in 4 dimensions, i am open minded about it. I will remain open minded until its proved or disproved.

As for unicorns............how can you draw something that dosnt exist? If you draw a unicorn then what are you drawing? How do you know the excepted form of a unicorn is correct?

So i would argue your drawing isnt of a unicorn but of something other people tell you, represents a unicorn. So your taking someone word for it that a unicorn would indeed look like that.

Or the sheeple theory!

Dont be offended by anything I said, after all i cant see a reason to get upset about something you dont think even exists. If it helps, i dont think they are actually pink though

mayko - 9-11-2017 at 07:45

Dodo's dont exist (now), how do we know unicorns have never existed? You could argue no fossil record, but then how come we still havnt found the missing link?

The fact its called the missing link means it is believed that there must be one, but as yet we havnt discovered it.

You might want to read this:
https://en.wikipedia.org/wiki/Transitional_fossil#Missing_li...

Pay special attention to the last paragraph:

Quote:

"Missing link" is still a popular term, well recognized by the public and often used in the popular media.[59] It is, however, avoided in the scientific press, as it relates to the concept of the great chain of being and to the notion of simple organisms being primitive versions of complex ones, both of which have been discarded in biology.[5] In any case, the term itself is misleading, as any known transitional fossil, like Java Man, is no longer missing. While each find will give rise to new gaps in the evolutionary story on each side, the discovery of more and more transitional fossils continues to add to our knowledge of evolutionary transitions.[5][60]

wg48 - 9-11-2017 at 07:55

So you categorize children in the same group as physics students!!! No wonder you think its ok the pass off fairy tales to both.

To suggest I am studying the subject would be an oversimplification. I am attempting to produce a version of the expanding space animation shown below. I don’t want to oversimplify it so I want to get the dimensions and expansion rate unoversimplified. The hope is it may help undo some oversimplifications. But apparently I have oversimplified the task LOL.

Yes oversimplified sounds much better than wrong, false, fake incorrect or lie. You could also use misunderstanding, inaccurate and famously in the UK, economical with the truth. Like the speed of light in SR, in my frame BS is BS and its never good in the long term to BS children, physics students or anyone else.

cphotons.gif - 146kB

from http://www.astro.ucla.edu/~wright/photons_outrun.html

Edit: added gif reference, move a pic to correct thread

[Edited on 9-11-2017 by wg48]

Melgar - 9-11-2017 at 11:01

@NEMO I'm almost entirely sure that you wrote that with the intention to create as much confusion as possible.

However, since we're floating theories here, how about I float my "Big Flush" theory?

In sci-fi, wormholes are a popular concept, because they allow for travel between dimensions. But "real" theoretical wormholes could really only exist in a really massive black hole, where spacetime is stretched to its tearing point. Nobody has any idea how much mass it'd take to open up a hole in spacetime. Except me! See, I've theorized that if a black hole gets big enough, it tears open a tiny hole in spacetime, and flushes its contents down the hole, only closing when its mass is no longer enough to keep the hole open. Where does that mass go though? Nowhere. It's flung outside of time and space, where it quickly establishes order in its own right, as a new universe. This theory is actually testable. Wormholes should not be able to exist in our universe, because its combined mass isn't even enough to tear spacetime. And if anyone ever figures out how much mass is needed to warp spacetime enough to tear it, and other wormhole dynamics, it would correspond to our universe having been flushed through one.

Or how about my "Mxyzptlk" theory?

Mister Mxyzptlk is a Superman villain who lives in the fifth dimension. There, things happen for no reason. It's rather chaotic, but its residents have adapted. Effects don't necessarily have causes. Mister Mxyzptlk likes to come to our dimension (he's a criminal in his own dimension too) and wreak havoc by making it more like his own. Superman can't hurt him physically, though. To make him go back to his own dimension, Superman has to trick him into saying his name backwards. Anyway, it's already agreed that time is the fourth dimension, which is why Mister Mxyzptlk's dimension is the fifth one. However, if he lives in the fifth dimension and can come to our dimension, then that means that our universe exists within his. And since cause and effect aren't linked in the fifth dimension, then there's every reason to believe that a universe where cause and effect ARE linked, could come into existence for no reason at all. You may be wondering where the fifth dimension came from, but that implies a cause and effect, neither of which exist in the fifth dimension. Duh.

aga - 9-11-2017 at 14:42

X, Y, Z, Time, Gravity, Electric, Magnetic ... Oh ! and maybe Energy. Forgot that one.

That's 7 (or 8) dimensions already.

Which one is the 5th dimension ?

NEMO-Chemistry - 9-11-2017 at 14:57

@NEMO I'm almost entirely sure that you wrote that with the intention to create as much confusion as possible.

However, since we're floating theories here, how about I float my "Big Flush" theory?

In sci-fi, wormholes are a popular concept, because they allow for travel between dimensions. But "real" theoretical wormholes could really only exist in a really massive black hole, where spacetime is stretched to its tearing point. Nobody has any idea how much mass it'd take to open up a hole in spacetime. Except me! See, I've theorized that if a black hole gets big enough, it tears open a tiny hole in spacetime, and flushes its contents down the hole, only closing when its mass is no longer enough to keep the hole open. Where does that mass go though? Nowhere. It's flung outside of time and space, where it quickly establishes order in its own right, as a new universe. This theory is actually testable. Wormholes should not be able to exist in our universe, because its combined mass isn't even enough to tear spacetime. And if anyone ever figures out how much mass is needed to warp spacetime enough to tear it, and other wormhole dynamics, it would correspond to our universe having been flushed through one.

Or how about my "Mxyzptlk" theory?

Mister Mxyzptlk is a Superman villain who lives in the fifth dimension. There, things happen for no reason. It's rather chaotic, but its residents have adapted. Effects don't necessarily have causes. Mister Mxyzptlk likes to come to our dimension (he's a criminal in his own dimension too) and wreak havoc by making it more like his own. Superman can't hurt him physically, though. To make him go back to his own dimension, Superman has to trick him into saying his name backwards. Anyway, it's already agreed that time is the fourth dimension, which is why Mister Mxyzptlk's dimension is the fifth one. However, if he lives in the fifth dimension and can come to our dimension, then that means that our universe exists within his. And since cause and effect aren't linked in the fifth dimension, then there's every reason to believe that a universe where cause and effect ARE linked, could come into existence for no reason at all. You may be wondering where the fifth dimension came from, but that implies a cause and effect, neither of which exist in the fifth dimension. Duh.

Wrote it with a smile, i have no idea about space, black holes, worm holes(except garden ones), or space stretching.

To me it is what it is, i find all the theories fascinating, but honestly i wouldnt know where to start to even begin to try and understand how it all works.

But I am offended about unicorns and the easter bunny

Melgar - 9-11-2017 at 22:01

Have you ever heard of the "Gish Gallop"? It's a technique used by this Australian young-earth creationist to throw as much crap out there in as short of a time as possible, to make it impossible to refute all the crap in any reasonable time frame. It's essentially "starting ten fires in ten minutes", and then making it someone else's job to put them out. Well, I just thought you should know that your post would make even the great Duane Gish jealous.

[Edited on 11/10/17 by Melgar]

Melgar - 10-11-2017 at 09:21

Quote: Originally posted by aga

X, Y, Z, Time, Gravity, Electric, Magnetic ... Oh ! and maybe Energy. Forgot that one.

That's 7 (or 8) dimensions already.

Which one is the 5th dimension ?

First off, energy isn't a dimension. It's a quantity, equal to mass times the speed of light squared. So matter and energy are theoretically interchangeable. Though, to do it directly would require antimatter. Gravity can be thought of as a field or a force that exists within the three spatial dimensions (and time, of course). Not a dimension in its own right. There are four primary forces in our universe: gravity, electromagnetism, the strong force (holds protons together in an atom's nucleus, so their electrostatic repulsion doesn't send them flying apart), and also the weak force, which has something to do with neutrinos and isn't especially important to understand unless you care a lot about subatomic particles.

Magnetism and electricity are actually the same force, electromagnetism, but magnetic fields and electrical fields are perpendicular to each other. Moving an electrical charge creates a magnetic field, and moving a magnetic field will exert a force on electrical charges. You know how the sun has all these magnetic storms on it, and solar flares that are tightly bound to magnetic field lines? Have you ever wondered why? After all, the sun is almost entirely made of hydrogen and helium, neither of which we think of as being strongly magnetic. Well, it's because the sun is a plasma, made of ionized gas. And ions are charged. So when an ion moves, it generates a magnetic field. And since the sun is constantly churning, all those ions generate enormous magnetic fields, sometimes even strong enough to cause EMP-like problems on Earth.

aga - 10-11-2017 at 11:48

First off, energy isn't a dimension. It's a quantity, equal to mass times the speed of light squared ... Gravity can be thought of as a field or a force ... Magnetism and electricity are actually the same force ...

Personally i disagree with all of that, apart from possibly the energy thing.

How the dimensions appear to us (and can be quantified/analysed) is entirely defined by our existence in the first four, which is all i am trying to convey.

Basically we cannot usually see or imagine much beyond what we evolved in, which does not make that the Absolute Truth about reality.

I missed my meeting around Proxima Centuri by the way.

Melgar - 10-11-2017 at 13:16

But I guess the point is, you can quantify a field in terms of its strength, but you can't describe a dimension as having strength. You might be thinking about how "gravity wells" are sometimes drawn as though they exist in another dimension, but that's really just a way of depicting a field that perhaps isn't the most accurate. A more accurate depiction might be as a vector field:

Electromagnetism is even more confusing because of the perpendicular electric and magnetic field lines, but it's pretty much a proven fact that electricity and magnetism are inseparable, and are just different manifestations of the same force.

Have you ever read Richard Feynman's "Cargo Cult Science" speech? It's very good, and I read it several times a year just to remind myself what science should be like, even if it doesn't always meet these standards. I highly recommend everyone in this thread read this, actually:

http://www.sciencemadness.org/talk/viewthread.php?tid=76734&...

I should probably ask for permission to edit the wiki or something, so I can add this to it. It's somewhere else on the web, but there are random spaces missing in the text that makes it hard to read so I edited it, but then never quite found a good home for it.

aga - 10-11-2017 at 13:54

Just U2U zts16, who founded the excellent wiki (if i recall correctly) and access is granted, if granted.

Your notions of what energy, magnetism, electricity and gravity are, could quite easily be incorrect.

I Know that mine are totally wrong, as i can only observe/measure their Effects based on my own reality-references, which i know cannot be their entire existence.

NEMO-Chemistry - 10-11-2017 at 15:09