Dark Energy and Non-Conservative Forces

[DLTherrien]

20 minutes ago, StringJunky said:

It does gradually make sense in the end. If you keep reading and asking here you'll get used to the ideas and language of relativity, which helps a lot.

I already get a lot of it and it makes sense although it should not but only because I do study the known facts as we see it. Definitely bizarre but it is what it is. Learning the math is something I aspire to and thanks for the book suggestion. That should help .I study in my spare time online but I have had to even revisit algebra. Been a long time so brushing up from there. 

[StringJunky]

4 minutes ago, DLTherrien said:

... it is what it is. 

I think you have the right attitude for going right into it. I hope you enjoy it, amidst the testing moments .  

[DLTherrien]

2 minutes ago, StringJunky said:

I think you have the right attitude for going right into it. I hope you enjoy it, amidst the testing moments .

I am the type of person who gets easily bored with things. Once I get to the point I feel there is nothing more to learn, I move on. This is why I believe I am so drawn to this science. I will never run out of things to learn.

[StringJunky]

3 minutes ago, DLTherrien said:

I am the type of person who gets easily bored with things. Once I get to the point I feel there is nothing more to learn, I move on. This is why I believe I am so drawn to this science. I will never run out of things to learn.

It will keep you busy for a very long time if you want. There's plenty of Relativists here to help when you get stuck.

[Markus Hanke]

1 hour ago, DLTherrien said:

Definitely bizarre but it is what it is.

It initially appears bizarre only because it runs contrary to how we as humans, in our human domain of everyday life, experience the world. It’s a habit of perception that keeps us “stuck” in a particular world view. But it is possible to transcend that Newtonian paradigm, and with a bit of practice the relativistic world view becomes quite natural after a while.

[DLTherrien]

8 minutes ago, Markus Hanke said:

with a bit of practice the relativistic world view becomes quite natural after a while.

And I believe then we go insane. That is why I find this so interesting. I have seen and experienced Newtonian physics. They are all around us and come naturally over time to the point they are routine and nondescript. I need things that stimulate my thinking. This definitely helps with that to the point I come up with all sort of craziness but that is the fun part. Once I learn the math which I will, then I can try to prove my insanity which will then make me better at the math and the cycle continues. .What else do you do at 49? Watch football, sit on the couch and complain? Not his guy. Knowledge for me is like a toy. Every time I learn something, I get a new version of my toy. 

1 hour ago, StringJunky said:

There's plenty of Relativists here to help when you get stuck.

And I greatly appreciate all of your support. You are very patient people. 

[studiot]

4 hours ago, StringJunky said:

Have you read  A most incomprehensible thing by Peter Collier? I have it but I haven't read it yet. It's a layman's mathematical introduction.

https://www.amazon.com/Most-Incomprehensible-Thing-Introduction-Mathematics-ebook/dp/B008JRJ1VK

No I haven't, though I have heard of it.

 

Looking at the contents I wonder how anyone needing tensor calculus and differential forms (a chapter on each early in the book) can call it a gentle introduction.

Einstein knew neither of these when he developed relativity. That came later.

He started with Physics Principles.

I'm sure he once said something to the effect that if you need the symbolism and can't explain without it, you don't fully understand it.

 

Read carefully the reviews on Amazon's site. They are mostly favourable but most also suggest you need much more than algebra to work with this book.

Edited July 10, 2018 by studiot

[swansont]

35 minutes ago, DLTherrien said:

And I believe then we go insane. That is why I find this so interesting. I have seen and experienced Newtonian physics. They are all around us and come naturally over time to the point they are routine and nondescript. 

One advantage of having really good clocks is that you don't have to go particularly fast to experience relativistic effects. I have colleagues who have to account for time dilation when they go on trips.

http://blogs.scienceforums.net/swansont/archives/6

There's also someone I know that measured gravitational time dilation while he went camping

http://leapsecond.com/great2005/

 

[DLTherrien]

I have an experiment of my own in mind where I will run it and leave it for a month or so and see the results. You just reminded me to pick up two identical time pieces.

10 minutes ago, studiot said:

ou need much more than algebra to work with this book.

I'm not scared.  I can figure out anything if I put my mind to it. 

One question I have before I really dive into the math meaning calculus and try to understand it is this. I am aware that the symbols used are just variables; that I am familiar with being a programmer; we use them all the time. Integer, Boolean, float etc,. I will use Plank's constant as an example of what I ask. It's value is 6.62607004 × 10^-34 m² kg / s ... copied from the web; which is supposed to be the smallest possible thing in our universe if I understand it correct. The variable .. h .. Still there are many more which all appear to be variables holding different values which makes sense because the values are difficult to write on their own. Same reason we use them in programming.  Do you guys meaning math experts actually remember what they all mean or their values and if not how would you do calculations if you didn't? I hope you understand my question. @swansont,, @Marcus, @studiot and anyone else who reads this. 

 

[studiot]

Here is a good lesson in several things Physics for you.

Planck's constant is

[math]h = 6.6261x{10^{ - 34}}Js[/math]

That is the units are Joule -seconds or energy times time.

Not energy divided by time as you have written it

This is an important distinction as what you have written is is the time rate of change of aereal density or metres squared- kilogrammes per second.

(The hyphen refres to multiplication, the slash refers to division)

 

Planck's constant so often qppears divided by 2pi that a new constant called Planck's reduced constant is recognised

[math]\hbar  = \frac{h}{{2\pi }} = 1.0546x{10^{ - 34}}JS[/math]

Note the bar through/over the h.

 

I don't know if you have done any dimensional analysis but energy has dimensions ML2T-2

Multiplying this by time gives ML²T^-2 * T = ML²T^-1

 

Dividing it by time gives ML²T^-2 * T^-1 = ML²T^-3.

 

Here is a good writeup of Dimensions and a useful table in PDF

http://i1.dainikbhaskar.com/web2images/education/phy_unt_13659.pdf

 

I have ordered Peter Collier's Book and will report further thoughts when I receive it.

Get the third edition if you do as it has a new 2018 chapter.

 

 

 

[DLTherrien]

45 minutes ago, studiot said:

Planck's constant so often qppears divided by 2pi that a new constant called Planck's reduced constant is recognised

 

That would be what is called h bar then? An h with a bar through the top.That is how I have seen it described. As far as the way I wrote it, I didn't copied from the web just to show how the variable h holds that information  but thanks for the detailed explanations. They help anyway. Sorry for the huge image.. Just copied the first one I saw and pasted. The hbar is so we don;t have to write  h divided by 2π, A shortcut because it is used so much is what I remember reading. Just notice you already mentioned H bar. Sorry. Little busy here at work still trying to beat the coming rain.

Edited July 10, 2018 by DLTherrien

[studiot]

1 hour ago, DLTherrien said:

That would be what is called h bar then?

Yup, that's it.

 

And did you understand the Dimensional Analysis and why your quoted/stated units were wrong?

Edited July 10, 2018 by studiot

[DLTherrien]

Just got home from work. I will look them over in more detail in a little while. I was at work when I first responded. Little time to be thorough. It is 4:04 PM here. Dinner time.

 

[swansont]

38 minutes ago, studiot said:

Yup, that's it.

 

And did you understand the Dimensional Analysis and why your quoted/stated units were wrong?

They aren't wrong

m² kg / s 

 

A joule is m² kg / s² so the units are indeed J-s

4 hours ago, DLTherrien said:

I will use Plank's constant as an example of what I ask. It's value is 6.62607004 × 10^-34 m² kg / s ... copied from the web; which is supposed to be the smallest possible thing in our universe if I understand it correct. 

Not the smallest thing. It's the quantization of angular momentum — that can only change by this amount.

It doesn't make sense to compare bigger or smaller if they are some other quantity. Energy, or momentum, or mass, etc.

An electron's mass is 9.11 x 10^-31 kg, for example. It makes no sense to compare that directly to Planck's constant.

[studiot]

25 minutes ago, swansont said:

They aren't wrong

m² kg / s 

 

A joule is m² kg / s² so the units are indeed J-s

Yes you are quite right.

Thanks for pointing that out.

[DLTherrien]

1 hour ago, swansont said:

It doesn't make sense to compare bigger or smaller

I wasn't sure really when I posted. Going by memory which was obviously flawed. Now though I have gotten some cool answers with good explanations of the math.

 

1 hour ago, swansont said:

An electron's mass is 9.11 x 10^-31 kg

How do we know the mass of an electron. Last time I checked, we cannot actually see one and looking as we all know is detrimental to the experiment so is it just the math that states that and how if so did we come up with that conclusion. I am about to finish "The Grand Design" tonight so perhaps it will answer that question for me. 

[swansont]

28 minutes ago, DLTherrien said:

How do we know the mass of an electron. Last time I checked, we cannot actually see one and looking as we all know is detrimental to the experiment so is it just the math that states that and how if so did we come up with that conclusion. I am about to finish "The Grand Design" tonight so perhaps it will answer that question for me. 

You can trap them  — they respond to electric and magnetic fields. There are different types, but the one used for this is called a Penning trap. The motion in the trap is cyclical and the resonances can be measured accurately, and depend on the mass and charge of the particle.

Or you can measure the e/m ratio from deflection in a known field, and determine the charge separately.

To name two well-documented methods.

[DLTherrien]

47 minutes ago, swansont said:

Or you can measure the e/m ratio from deflection in a known field, and determine the charge separately.

Cool. I went looking for some more on this and I stumbled across this. This seems to be a good way for me to get started on the math and from MIT. What do you think? https://ocw.mit.edu/courses/mathematics/18-01sc-single-variable-calculus-fall-2010/1.-differentiation/ It appears to be all free. Cool. The link is the page where it all starts. It seems like all I will need to get up and running will be here. Not just some you-tube video.

[DLTherrien]

12 hours ago, swansont said:

To name two well-documented methods.

MIt's web site is very cool. You can essentially take any of their courses. Physics, Quantum mechanics etc. etc. 

[studiot]

On 10/07/2018 at 7:41 PM, studiot said:

I have ordered Peter Collier's Book and will report further thoughts when I receive it.

Get the third edition if you do as it has a new 2018 chapter.

Having received the book I can now definitely recommend it.

 

However the proviso that you need a bit more than just just algebra definitely stands.
Experts often overlook just how much subject lore they use unconsciously.

 

It is also refreshing to see such an offerening from a small independent publisher, and at such a reasonable price.

 

[DLTherrien]

54 minutes ago, studiot said:

Having received the book I can now definitely recommend it.

 

However the proviso that you need a bit more than just just algebra definitely stands.
Experts often overlook just how much subject lore they use unconsciously.

 

It is also refreshing to see such an offerening from a small independent publisher, and at such a reasonable price.

 

Thanks. I will check it out. I am getting a better understanding of the math although the process is slow. I am a busy guy with work and school but Little by little I will get it. I find many people use the same math in their explanations so just by reading I am starting to understand it. I can see why it takes such intensive study.