The Speed of Light, is it a relative thing?

[Delasaurus]

1 hour ago, saac said:

Not sure I'd agree with time being a mere concept - not entirely sure what you mean by that. As for infinity, I have always looked upon it as a mathematical concept rather than an absolute physical state.

Jim

Take a peek at this wiki...

https://en.wikipedia.org/wiki/Time

It briefly describes the difference between various schools of thought.

It might be time Jim but not as you knew it

And have a look at some Hindu scriptures regarding time,  if you have the time. Pardon the pun!

As for infinity, a mathematical concept! Are you joking!

 

 

[Macavity]

*Science* will always "assimilate" any dissenters.

For folks interested in Physical Constants I used to get a Free (CERN) Book!
Perhaps reading for the "terminal nerd" but I could sit for (a few) hours? 

Remembering now... It's held on the LBL (Lawrence Berkely Lab website):
http://pdg.lbl.gov/ (They are openly available to the Public, I suspect...)

http://pdg.lbl.gov/2017/html/computer_read.html  Random, but...  stuff?

In past editions there was a PLOT of evolution of measured Speed of Light
with time... From (Galileo!) Roemer onwards. At the start the points (error
bars) vary hugely! Slowly the values close to the currently accepted value,
the error bars get smaller & smaller... then suddenly "boom" it all shifts! 

After that (certain) constants can become *defined* quantities... But such
things are an interesting study in the evolution of experimental technique.
Maybe there is a (Scientist) "Psychological" factor at work sometimes...  

[George Jones]

7 hours ago, MarsG76 said:

In theory all of those scientists who think that they're so "smrt" because they can come up with some BS theory in their "thought  experiment" because they were at some university, getting rubbish drilled into their heads that they just go around blindly repeating, trying to talk down and ridicule people who don't play into that fiction... key word trying... but in reality they end up looking like they're off with the ferries.... That mechanical engineer wierdo comes to mind... Bill Nye the science "wanna be " guy.

 

 

5 hours ago, MarsG76 said:

Yeah... see it basically like this, if you're some imaginative moron but have enough publicity by the media, you can push any theoretical rubbish that you can make up, and it'll be taught in universities for other sheeple science wannabes to repeat blindly... until some one challenges you theoretical fiction... Hawking vs Suskin battle over hawking radiation "debate" comes to mind, where first Suskin "proved" Hawking's made up "imaginary" story to be wrong?!?!?! Than Hawking "proved" that his fictional imagination was right after all and that black holes glow with "Hawkin Radiation" or what ever.. and get this, GET THIS.. he "DISCOVERED" (HAHAHAHAHA) that "Theory" when he "traveled" to the black hole in a thought experiment.. AAAA HAHAHAHAHA... Oh gimme strength.. my abs hurt from laughing...

This took me back to my child hood days (like when I was 8), when we were playing with Masters of the Universe dolls and, of course, Heman always had to win the battle, that WAS FACT, NOT A THEORY, FACT!!!!, but during play a friend had to win, basically due to his tears and crying that he was stuck with skeletor because his mum and dad won't buy him Heman, or man-at-arms (or whatever), SO I LET HIM WIN.... but than, of course Skeletor had to lose another day because "he is evil", and Theoretical fact is theoretical fact, can't argue with that, RIGHT?.... Suskin vs Hawkin much?? HAHAH  HAHA ah memories....  

 

3 hours ago, MarsG76 said:

Yes true, but I'm not bashing science... no, not in the slightest, "theoretical physics" is not a science, it's more fiction writing under the pretense of being science or physics, but it's at best a pseudo science... 

I didn't name any scientists... just merely a few guys who sit around all day, imagining themselves flying  around in space, inventing ways the universe should function according to them... LSD anyone?

and in the case of Bill Nye, actually say something stupid like "Bill Nye: Older people need to 'die' out before climate science can advance" or "Bill Nye is hopeful that the climate deniers will eventually die off"

That's not touching the holocaust crp he spewed put... kicker is, he has NO SCIENCE CREDENTAILS and allegedly 4 air conditioning unit s in his house!!!

Google is full of links...

All just propaganda pushing frauds...

You most surely are bashing science.

It is hard not to take this personally, as I put bread on the table by teaching physics. Yesterday, I got up at 4:30 am so I could finish marking assignments and preparing material on introductory quantum theory for a 10 am lecture. Last week, I taught material not in the text on Hawking radiation. It seems that I made this effort with some nefarious purpose in mind.

 

[saac]

1 hour ago, Delasaurus said:

Take a peek at this wiki...

https://en.wikipedia.org/wiki/Time

It briefly describes the difference between various schools of thought.

It might be time Jim but not as you knew it

And have a look at some Hindu scriptures regarding time,  if you have the time. Pardon the pun!

As for infinity, a mathematical concept! Are you joking!

 

 

To be honest I think the wiki take on time owes more to philosophy than it does to science. To draw from your earlier sentiments concerning the real world practicalities of engineering,  were time an abstract concept, then wither the engineer in his/her pursuit of: bridges, engines, flight, medicine, power (generation), in short advancement. For all of these and our successes therein, the property of time is without question real. Indeed without time and its constant flow nothing can happen, the universe ceases to exist. I'm sure if I dig far enough we could seat this in the 2nd law of thermodynamics; as an engineer (the slower younger brother of physics)  this is where I place my fulcrum to coin a phrase   So no, no new age philosophy here, time is real and infinity is hokum  

Jim 

 

 

[Stub Mandrel]

2 hours ago, Delasaurus said:

Isn't wild speculation though part of the 'what if' scenario and excitement in moving forward? Surely 'what if's' and 'wild speculation'  are perfectly satisfactory to air? It's a way of striking out new ideas is it not? New theories? If we get too rigid in our thinking, then we surely may as well just recite some passages from Moore or Hawkins; chapter 10;verse 5?

I can't see the connect between that view and mocking Hawkin for coming up with a theory about black holes sitting in his wheelchair.

FWIW I spent three years studying a scientific discipline at university and I would still venture to call myself a scientist, having taken a scientific approach in much of my professional work. I really don't recognise the criticism of academia you make as valid.

I have no problem with people inventing their own theories and ideas, witty or otherwise, but accompanying them by blanket and hackneyed criticism of scientists as ruthless ivory-tower glory seekers doesn't make those ideas valid.

 

[saac]

1 hour ago, Macavity said:

*Science* will always "assimilate" any dissenters.

For folks interested in Physical Constants I used to get a Free (CERN) Book!
Perhaps reading for the "terminal nerd" but I could sit for (a few) hours? 

Remembering now... It's held on the LBL (Lawrence Berkely Lab website):
http://pdg.lbl.gov/ (They are openly available to the Public, I suspect...)

http://pdg.lbl.gov/2017/html/computer_read.html  Random, but...  stuff?
 

Chris wonderful, you've just given me my Christmas reading list  I love this type of thing (yes appeals to my inner nerdy nature). I remember at school encountering Physics for the first time and being given a copy of the then Scottish Education Board Data Booklet for Physics, Chemistry  and Mathematics.  I loved just getting lost in it, each new physical constant being the subject of tomorrow's reading. I still have my copy some 30 plus years on.  

Jim

[andrew s]

Wild speculation, guesses, hunches and blinding insight are all fine. However, on their own they are meaningless. What is needed is hard work to focus them on unsolved problems or anomalies to come up with a coherent theory that does all the old theory did plus fix some issues etch.

Saying mass bends spacetime means nothing unless you predict, say, that the Sun will deflect the light of a star by x.

Regards Andrew 

[George Jones]

Sometimes experiment is ahead of theory, e.g., perihelion shift in Mercury's orbit was observed before it was explained by the theory of general relativity, and spectral lines were observed before they were explained by quantum theory.

Sometimes theory is ahead of experiment, e.g., Peter Higgs published his theory in 1964 and Steven Weinberg and Abdus Salam (using Higg's result) published electroweak theory in 1967, and it was years before these theories received any experimental backing.

When a theory has no experimental backing, it is difficult to know if this is because experiment has not caught up with theory, or if it is because the theory is not Nature's way.

I like Steven Weinberg's description of the scientific method:

" scientific research is more honestly reported as a tangle of deduction, induction, and guesswork "

[MarsG76]

2 hours ago, George Jones said:

 

 

You most surely are bashing science.

It is hard not to take this personally, as I put bread on the table by teaching physics. Yesterday, I got up at 4:30 am so I could finish marking assignments and preparing material on introductory quantum theory for a 10 am lecture. Last week, I taught material not in the text on Hawking radiation. It seems that I made this effort with some nefarious purpose in mind.

 

That's 2 different things... you're making living and you most likely mostly teach lab tested fact... the other mob basically make up crap and, from a distance via media, insult who ever doesn't believe them by one saying that the one's who disagree should die than equate the "deniers" with holocaust denial.. (doesn't make sense to me either)... while being a hypocrite by living in a very resource hungry style,  the other basically in a round about way insulted people's faith who didn't agree with his made up bull. Those kind of cult/nazi like "scientists" (big mouth hypocrite nye hasn't even got that credential) deserve zero respect.

Excuse me if I refuse to see a "theory" and anything not lab/experiment tested as fiction... I love science, but real science.

 

Now back to speed of light perhaps.

[MarsG76]

31 minutes ago, George Jones said:

When a theory has no experimental backing, it is difficult to know if this is because experiment has not caught up with theory, or if it is because the theory is not Nature's way.

I like Steven Weinberg's description of the scientific method:

" scientific research is more honestly reported as a tangle of deduction, induction, and guesswork "

Didn't say any thing about using the media to insult or ridicule anyone who disagrees with the propaganda some pretend scientist wannabes are obviously being paid to peddle. :-)

[Delasaurus]

23 minutes ago, George Jones said:

Sometimes experiment is ahead of theory, e.g., perihelion shift in Mercury's orbit was observed before it was explained by the theory of general relativity, and spectral lines were observed before they were explained by quantum theory.

Sometimes theory is ahead of experiment, e.g., Peter Higgs published his theory in 1964 and Steven Weinberg and Abdus Salam (using Higg's result) published electroweak theory in 1967, and it was years before these theories received any experimental backing.

When a theory has no experimental backing, it is difficult to know if this is because experiment has not caught up with theory, or if it is because the theory is not Nature's way.

I like Steven Weinberg's description of the scientific method:

" scientific research is more honestly reported as a tangle of deduction, induction, and guesswork "

Yes, there are many factors to consider, social, economic, technological, cultural and religious values to name a few which either restricts or advances theories or scientific experiments, or indeed anything in our world.

Many astronomers or 'astrologers' as they were called in the classical days were tortured and abused at the hands of the religious fraternity, were they not, for holding on to a belief system that they questioned and mocked?

The classic one being does the Earth go around the Sun, or does the Sun go around the Earth? Without those brave souls, 'mocking' the establishment of their day, we would still be concluding that the Moon belongs to the Goddess Luna and woe anyone who disputes that claim, as it has been written in stone and that this is the truth and only truth and to dispute it will bring the wrath of the Gods upon the firmament.

We must keep in mind that modern day science is not the be all and end all of the answer to the Universe..it will change, always has done and always will do.

Today x=y, tomorrow it might =z, that is the way theory is. As hard and as fast as we might like to believe that we are mortal, we all know we are not, same with science, things change. Old beliefs die and new ones evolve, nothing in science has ever been written in stone.

 

[Delasaurus]

2 hours ago, saac said:

To be honest I think the wiki take on time owes more to philosophy than it does to science. To draw from your earlier sentiments concerning the real world practicalities of engineering,  were time an abstract concept, then wither the engineer in his/her pursuit of: bridges, engines, flight, medicine, power (generation), in short advancement. For all of these and our successes therein, the property of time is without question real. Indeed without time and its constant flow nothing can happen, the universe ceases to exist. I'm sure if I dig far enough we could seat this in the 2nd law of thermodynamics; as an engineer (the slower younger brother of physics)  this is where I place my fulcrum to coin a phrase   So no, no new age philosophy here, time is real and infinity is hokum  

Jim 

 

 

That is exactly my point. It ceases to exist! It's called Metaphysics. We don't necessarily require the 2nd law of thermodynamics to realise that perhaps this whole kaboodle is nothing but an illusion. I know that if I walk into a bridge girder, it will still hurt. But there is nothing to say otherwise that the whole Universe is nothing but an illusion, which many Yoga gurus and Bhuddists have maintained for centuries. And no, I don't smoke weed if your thinking that!

[ollypenrice]

50 minutes ago, MarsG76 said:

That's 2 different things... you're making living and you most likely mostly teach lab tested fact... the other mob basically make up crap and, from a distance via media, insult who ever doesn't believe them by one saying that the one's who disagree should die than equate the "deniers" with holocaust denial.. (doesn't make sense to me either)... while being a hypocrite by living in a very resource hungry style,  the other basically in a round about way insulted people's faith who didn't agree with his made up bull. Those kind of cult/nazi like "scientists" (big mouth hypocrite nye hasn't even got that credential) deserve zero respect.

Excuse me if I refuse to see a "theory" and anything not lab/experiment tested as fiction... I love science, but real science.

 

Now back to speed of light perhaps.

You use the phrase I've highlighted. Lee Smolin expressed his doubts about string theory rather differently - by writing The Trouble With Physics.

The only string theorist I know personally is Marcel Vonk and he expressed admiration for Smolin's critique. Since he still researches in the string theory field I can only assume that Smolin didn't persuade him, but the key thing to notice is the considered dialogue between doubters and researchers. 

Science is a world in which a dissenter like Smolin can express himself and expect to tbe read and taken seriously. His critique not only attacks string theory on intellectual grounds but explores the way science politics has, in his view, encouraged it beyond its worth.

In my view your are attacking straw men and straw science.

Olly

PS For a serious investigation of time there's The Labyrinth of Time by  Michael Lockwood.

[andrew s]

Not sure if anyone is interested in this any more but I found this:

The best observational data we have shows the Universe is spatially flat. There is also no indication that it has a topology more complicated than Euclidean 3 space (R3).

Given this the only solution to the GR  FWR equations that are spatially flat with R3 topology are spatially infinite.

(Paraphrased from a PhysicsForum post by Peter Donis) 

Regards Andrew 

[saac]

2 hours ago, MarsG76 said:

That's 2 different things... you're making living and you most likely mostly teach lab tested fact... the other mob basically make up crap and, from a distance via media, insult who ever doesn't believe them by one saying that the one's who disagree should die than equate the "deniers" with holocaust denial.. (doesn't make sense to me either)... while being a hypocrite by living in a very resource hungry style,  the other basically in a round about way insulted people's faith who didn't agree with his made up bull. Those kind of cult/nazi like "scientists" (big mouth hypocrite nye hasn't even got that credential) deserve zero respect.

Excuse me if I refuse to see a "theory" and anything not lab/experiment tested as fiction... I love science, but real science.

 

Now back to speed of light perhaps.

As a fellow educator in the beautiful subject I find myself with much in common with George on this. Although I plough my trade lower down the foothills at secondary school, I've always thought that what we really teach in science/Physics at school is the power of the scientific method rather than just facts (already proven). It's the methodology of science and importantly the development of critical thinking that is important not so much recall of facts. I've always thought that the ability to interpret, analyse, discriminate and justify are among the critical skills school science promotes. While I personally will never push forward the boundaries of science, there will be no law or theorem carrying my name, I am nonetheless confident that what I do in the classroom contributes to the discipline in the wider sense.  I earn my keep.

I wouldn't think too harshly of the bunfights that scientists engage in, there is a rich tradition in trashing reputations and theories, all the greats at some stage engaged in this - Newton v Hooke  was particularly fraught.

As for theory as fiction, I'm sure Newton, Einstein etal will not be too perturbed in their slumber; they were both masters of the theoretical and their position as scientific luminaries  needs no defence.

Jim 

[saac]

2 hours ago, andrew s said:

Not sure if anyone is interested in this any more but I found this:

The best observational data we have shows the Universe is spatially flat. There is also no indication that it has a topology more complicated than Euclidean 3 space (R3).

Given this the only solution to the GR  FWR equations that are spatially flat with R3 topology are spatially infinite.

(Paraphrased from a PhysicsForum post by Peter Donis) 

Regards Andrew 

Ok, I'm nervously moving away from my shallow end of the pool here, would I be correct in thinking that the "topology" arises from the influence of mass but the general "plane" of the universe is flat?   

Jim

 

 

 

 

 

[George Jones]

11 minutes ago, saac said:

Ok, I'm nervously moving away from my shallow end of the pool here, would I be correct in thinking that the "topology" arises from the influence of mass but the general "plane" of the universe is flat?  

Actually, topology alone gives us no information about the curvature of space or spacetime. In order to talk about curavture, we need more structure, like a metric, which is a way of making local measurements of space and time.

With topology alone, we can talk about whether a universe is spatially finite or infinite. If space is compact, it is finite; if space is not compact it is infinite.

"Compact" is a technical maths term within the subject of topology, but it has somewhat of the flavour of its use in everyday English.

Sorry if I have been too technical, but my wife (a high school maths and science teacher) is auditing (for fun) a uni math course that includes an introduction to topology, so I have brushing up on this stuff.

[saac]

6 minutes ago, George Jones said:

Actually, topology alone gives us no information about the curvature of space or spacetime. In order to talk about curavture, we need more structure, like a metric, which is a way of making local measurements of space and time.

With topology alone, we can talk about whether a universe is spatially finite or infinite. If space is compact, it is finite; if space is not compact it is infinite.

"Compact" is a technical maths term within the subject of topology, but it has somewhat of the flavour of its use in everyday English.

Sorry if I have been too technical, but my wife (a high school maths and science teacher) is auditing (for fun) a uni math course that includes an introduction to topology, so I have brushing up on this stuff.

What influence if any (hindrance or otherwise) does our position within the universe have on our ability to assess its geometry, does it impose any limitations.  By that I mean can we draw an analogy on the difficulty we had determining the nature of the Earth vice the intuitive conclusion from our senses telling us it was flat. What is the key?

Jim

[andrew s]

23 minutes ago, saac said:

What influence if any (hindrance or otherwise) does our position within the universe have on our ability to assess its geometry, does it impose any limitations.  By that I mean can we draw an analogy on the difficulty we had determining the nature of the Earth vice the intuitive conclusion from our senses telling us it was flat. What is the key?

Jim

JIM, There is no evidence we live in a special place. Once corrected for our peculiar motion the CMB is smooth to about 1 part in 10^4 if I remember correctly. What limits us is the size of the observable Universe.

Regards Andrew 

[saac]

Andrew, I'm used to reading about the uniformity (smoothness) of the CMB as supporting evidence for the Big Bang but am I understanding correctly that the shape of the universe would in turn influence how we would perceive the CMB?  Or is that actually the same thing! 

Jim

[andrew s]

9 minutes ago, saac said:

Andrew, I'm used to reading about the uniformity (smoothness) of the CMB as supporting evidence for the Big Bang but am I understanding correctly that the shape of the universe would in turn influence how we would perceive the CMB?  Or is that actually the same thing! 

Jim

It means that at the time of creation of the CMB the Universe was very close to isotropic and homogenous and since we see it as such we can't be in a special place. 

We still assume that at large scales it still is homogenous and isotropic and it does seem to be. (Not at home so can't look up the details.)

One of the reasons we think it is flat is due to the CMB plus other data. The paper on Cosmology I posted covers some of this.

Regards Andrew 

[saac]

1 hour ago, andrew s said:

It means that at the time of creation of the CMB the Universe was very close to isotropic and homogenous and since we see it as such we can't be in a special place. 

We still assume that at large scales it still is homogenous and isotropic and it does seem to be. (Not at home so can't look up the details.)

One of the reasons we think it is flat is due to the CMB plus other data. The paper on Cosmology I posted covers some of this.

Regards Andrew 

Thanks Andrew. We talk about the CMB in the Higher Physics course but it is quite superficial, used in context of supporting the Big Bang. This is a good opportunity to broaden my understanding it may offer something else to talk about in class so I'll take a closer look at the paper.

 

Jim 

[SilverAstro]

The topic = "  The Speed of Light, is it a relative thing? "

( ignoring for now, the allusion to Albert's General and Special thingies)

299 792 458 m/s would - to me, an experimental physicist (amongst other things) in a previous life, suggest that "we" collectively have got the value of a    m    a tad wrong ? or maybe the value of a second is wrong ?

either way I would suggest that 300,000,000 NewM/s would make more sense ?

I think redefining the m would cause less havoc to space-time (and the standard model(s) )than re-defining the second ? perhaps ?? > debate

[SilverAstro]

5 hours ago, andrew s said:

at the time of creation of the CMB the Universe was very close to isotropic and homogenous

and ever so very tiny, (Tony) like a very very tiny Planck thing (/Baldrick), so how come it is now (perhaps) infinitely big,

maybe the period of exponential inflation never ended ?

[Delasaurus]

6 hours ago, SilverAstro said:

The topic = "  The Speed of Light, is it a relative thing? "

( ignoring for now, the allusion to Albert's General and Special thingies)

299 792 458 m/s would - to me, an experimental physicist (amongst other things) in a previous life, suggest that "we" collectively have got the value of a    m    a tad wrong ? or maybe the value of a second is wrong ?

either way I would suggest that 300,000,000 NewM/s would make more sense ?

I think redefining the m would cause less havoc to space-time (and the standard model(s) )than re-defining the second ? perhaps ?? > debate

 

We know 'scientifically' that m varies around certain parts of the Earth, as does 'WEIGHT' due to local gravitational changes, which is why the 'standard' metric measure is kept under lock and key somewhere, in Belgium? Where all measurement is referred to it.

So, quite simply from that fact alone, if we have m in any one of our equations, the result will always be a variable. For example, SoL will not be the same in Skegness as it  will be in Tokyo say.

The same with t , it is not a constant as Einstein himself points out, so again if we have t in any part of our equation..the result, again must be a variable and not a constant. The best we can do is 'average' out the differences from around the globe and agree to accept a certain agreed 'number' to work into our equations.

Nothing travels faster than the Speed of Light maybe, but that is not to say that it is a fixed entity.