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Now and then a bottle of vino stops me being sensible. That, and other things.

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Now and then a bottle of vino stops me being sensible. That, and other things.

Old 3rd Mar 2019, 14:23
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Now and then a bottle of vino stops me being sensible. That, and other things.

I posted this on Quora where there are some very good PhD's answering questions. Now and then I should disqualify myself from the forum. Like now.

I deleted this answer because I was outside a bottle of fine claret when I wrote it, but hey, it’s not as daft as some posts, so here it is again, but please don’t let my ramblings alter your exam results.



It was in 1958 that a friend handed me a book on Special Relativity. I was hooked.

circa 1980, I realised no one knew how gravity worked. Galileo, Newton and Einstein, along with many other fine minds, gave us a description of its functions - breathtakingly intuitive and exquisitely accurate but still no one knows how gravity actually works. The world makes use of General Relativity and I think it’s true to say it’s the most tested theory in the history of science. For the most part, it is not explainable to the layman.

The answers on this thread show everything from a deep understanding of fields and formulas, through to bewildered confusion. Who am I to make such a statement? I hear you ask. Just a bloke of average intelligence who has climbed into a judge’s chair and reviewed the case for 40+ years. Like a lot of judges, I have to make decisions based on other people’s knowledge, and like a lot of judges, I’m probably totally confused. We have a universe that is slowly revealing its mysteries but we’re on the first page. Let’s look at what conclusions I’ve come to.

Size. Well, we may just as well take Douglass Adams’ answer: “You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space.”

At least that was funny, but I find it very un-funny to realise that no one knows the extent of our physical reality. Deeply disturbing in fact. Neil deGrasse Tyson told us that a professor had complained that he was distressing his audiences. In short, they went in all happy at the prospect of one of Tyson’s lectures but came out depressed upon realising how insignificant we humans must be. Tyson slumped across the stage imitating his depressed audience. That was also funny, for a while, but when people seriously talk of an infinite universe, I feel more turmoil inside than just a little insignificance.

We don’t even know how big it is? That’s bad enough, but we don’t even know what the stuff is that’s so big we don’t know how big it is!

The best brains on Quora differ in their opinions, and while most people accept an expansion, just what is expanding is very difficult to extract from the arguments put forward. Spacetime as a noun seems to be accepted, but quite what this means is strongly disputed. Generally, fields - Yes. Fabric - No. Okay, I’ll hold that thought for a while.

Gravity waves. Mostly, this gets corrected. Gravitational waves are what LIGO is all about. LIGO, and right back from Einstein’s concept of a spacetime - that at first didn’t need an ćther - as it was ‘Imponderable’ . . . but not for long. Clearly, Einstein did a lot of pondering about an ćther. How he visualised this I’m not sure but he did predict gravitational waves and the energy predictions make me wonder if a Deity didn’t plant more than a few geniuses on Earth in the 1800’s.

So, whatever spacetime is, it seems to accept long wavelength disturbances in its what? Fabric? Curvature? Springy stuff. Whatever . . . years ago when I protested to a professor that any detector would also be altered by the wave - so that the waves could not be detected, I didn’t know they would be transverse. Gosh, nature’s clever. These waves were begging to be detected.

Detecting the them was a huge achievement, but predicting them in the first place, and the energies involved, was . . . is, mind boggling. But let’s get something out of the way: Gravitational waves do not cause gravity. You could almost say they have little to do with gravity, except that vast gravitational disturbances created them in the first place. This wobble in spacetime then travels in a quite ordinary wave-like way at the speed of light - given they like to be transverse. Just after the wave arrives, we get some photons turning up from the last gasps of the event. Handy time markers to asses the speed. Thanks again for these little clues that allow us to progress science.

But wait! We can justify Maxwell’s electromagnetic energy travelling to us without some medium to wobble, but gravitational waves would surely need something to wobble in. It’s about now I call for further expert witnesses as I don’t want to reveal my ignorance. By good fortune I get an appealing professor who’s figure puts me in mind of non-rotating binary masses. It gave her opening statement about the Big Bang certain colour.

‘At just ten to the minus forty seconds, quantum gravity split from . . .’

The real science was lost on me, but I did realise the significance of gravity being separated from other energies at such an early stage.

Gravity is quite different. Gravity does not have to be related to anything else, except that it eventually gained the power to manipulate other products and spin-offs of the Big Bang. It shaped the formation of clouds of newly invented matter, and quite a while later, when the clouds turned to clumps, cause some of them to light up. The Universe was on its way, but gravity still remained aloof.

Someone put forward the argument that matter curves spacetime and causes gravity. Fair comment, but are we sure? Chicken and egg. Not one expert witness could explain exactly what was taking place. Matter. Curvature. There was a lot of Hurrumphing and sorting of paperwork before someone protested that the measurements were spectacularly accurate. ‘A given mass,’ they siad, ‘M.’ they added, ‘A known curvature and a known g. We even have a known escape velocity!’ They rested their tenuous case.

‘But what actually happens at that junction of spacetime and matter?’ I repeated.

In my imaginary courtroom I was told I couldn’t possibly understand. The curvature is just a mathematical concept. “Stress energy tensor”, someone piped up, but he was told to be quiet because he was only the tea boy. It only describes what would be, by applying ten mathematically descriptive examples of the Greek alphabet to each point of space.

‘Ah’, said I, and adjourned for lunch. I invited the expert witness to my table but was distracted by the tea boy’s conversation with a lad with a broom.

‘Something is missing’, the boy said, ‘Something so obvious that no one has ever realised what it is. Everyone in the canteen knows that matter is not real - just a different form of energy. So I think spacetime just distorts to representative Plank length points and forms into quark-gluon structures that dictate the atomic forces needed to fabricate the nucleons and the associated electrical fields. The lad with the broom replied that that’s just what his mum had told him.

I picked that moment to ask the tea boy if he thought that spacetime flowing into matter could be the missing ingredient. I’d thought for years it might be the answer. He looked askance at me. ‘No, your honour, that’s bollox. You should stick to the judgin’* and forget astrophysics’.

I turned to my expert witness who’s Martini was dropping down the little umbrella stem at an exponential rate - more due to her thirst than the geometry of the glass. She undid her top button, loosed her hair and swung it so that it fanned out into a blond arc. It put me in mind of the water in Newton’s bucket and I wondered if it would centrifuge like that if the mass of the distant stars were to vanish. I then tried to calculate what gravitational waves her figure might be creating, and picked that moment to suggest to the usher that tomorrow would be quite soon enough for the answer to the universe.

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Old 3rd Mar 2019, 16:02
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-snip- Just a bloke of average intelligence who has climbed into a judge’s chair and reviewed the case for 40+ years. Like a lot of judges, I have to make decisions based on other people’s knowledge, and like a lot of judges, I’m probably totally confused. We have a universe that is slowly revealing its mysteries but we’re on the first page.
-snip-
Douglass Adams’ answer: “You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space.”
-snip-
At least that was funny, but I find it very un-funny to realise that no one knows the extent of our physical reality.
So what?
Two hundred years ago they knew even less about this stuff and they didn't all leap over the cliff like the proverbial lemmings.
You spent 40 years in a profession and are upset, it seems, that you don't understand a complicated subject as well as people who spent 40 years in that profession.
Of course you don't. I don't either, and like you I am a bloke of average to above average intelligence and interest in ... just about everything.
You and I are not gods; we are limited mortal humans.
Let the 15 pound brains continue their pursuit of knowledge and understanding. Cheer them on, but don't be upset that you don't know it all. You can't know it all.
It is in the pursuit that knowledge, and of that understanding, that great progress and great learning is made.
I would think that a man of your advanced years would have arrived at that level of wisdom already. The cumulative understanding of the human race is greater than it was the day you were born, and greater than it was ten years ago. (Cumulative, not collective, since we the human race average out to a pile of madmen and fools collectively).

PS: when serving as a juror, is has been frustrating to discover how little we are allowed to know before we render a verdict. The jury do not get to render a verdict with all of the facts, it gets offered a few selected facts as presented by the attorneys and the judge. (And the rules of the game).

For the far less advanced undertaking that is simple human endeavor, crime, and error, you (well, the position you held) are part of the problem that your ranted about: having to make a decision with incomplete information.

Welcome to the human race, rivets.

We all make decisions with incomplete information because that is the human condition. We don't, and can't, know it all.
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Old 3rd Mar 2019, 16:34
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Originally Posted by Lonewolf_50 View Post
So what?
Two hundred years ago they knew even less about this stuff and they didn't all leap over the cliff like the proverbial lemmings.
You spent 40 years in a profession and are upset, it seems, that you don't understand a complicated subject as well as people who spent 40 years in that profession.
Of course you don't. I don't either, and like you I am a bloke of average to above average intelligence and interest in ... just about everything.
You and I are not gods; we are limited mortal humans.
Let the 15 pound brains continue their pursuit of knowledge and understanding. Cheer them on, but don't be upset that you don't know it all. You can't know it all.
It is in the pursuit that knowledge, and of that understanding, that great progress and great learning is made.
Wise words indeed.

The genuine 15 pound brainers ( by whom I mean the likes of Einstein, Bohr, Feynman, et.al.) with the imagination and free thinking that 99.9999999999% of us can't even begin to comprehend.....how many of us would have looked at the wobble on a spinning plate that someone had thrown into the air and had the insight to see something in it's behaviour that led to a Nobel Prize...

It's darned frustrating but I try not to lose sleep about it...
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Old 3rd Mar 2019, 16:57
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L - R - I don't know what you are smoking, but at your age you should really give it up and have a nice cup of cocoa instead.
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Old 3rd Mar 2019, 18:02
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I spent my whole career working in applied science (very applied, almost engineering at times). From time to time I worked with pure scientists. They were like aliens. 90% of what they said went over my head, even if it was within my field. The biggest single issue was that whenever a theory was proposed, I'd want to test it with an experiment, trial or wind tunnel test, whereas the pure science bods wanted to test it with math. Always seemed bonkers to me. My basic philosophy has always been that if you can't physically test something several times, independently, to prove, or disprove it, then it probably isn't true.
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Old 3rd Mar 2019, 21:03
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and are upset, it seems, that you don't understand a complicated subject as well as people who spent 40 years in that profession.
Yes and no. I'd be upset if someone suddenly did find out how everything was working . . . and my inflow proposal was wrong. But for the moment, it's an open game. All bets are on. Well, not all, because some of them are seriously bonkers.
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Old 3rd Mar 2019, 23:42
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Nature can be remarkably simple in essence.

My guess is that we don't understand it all because (like the blind man and the elephant) we're looking at it the wrong way.

And we may never figure how to look at it the right way...!
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Old 4th Mar 2019, 08:11
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Originally Posted by er340790 View Post
My guess is that we don't understand it all because (like the blind man and the elephant) we're looking at it the wrong way.
https://dilbert.com/strip/2019-03-03
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Old 4th Mar 2019, 09:02
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Hmmm . . . a good punchline.
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Old 4th Mar 2019, 09:27
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Really enjoyed the opening thread, couldn't even detect a hint of claret, thanks for sharing LR.

Now one thing about gravity confounds me. We can make it in a centrifuge, but why don't all the objects on the planet go flinging off into space as the Earth rotates?
Does mass displace gravity, that is, does having a big ball like Earth create some gravity IOU stemming from the middle that gets stronger at the surface?
If we drilled a hole from one end of Earth to the other and threw a ball down there where would it come to rest?
Maybe gravity is like heat, a product all its own with a fixed supply of it throughout the universe, and the constant push/pull is what we call gravity waves.
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Old 4th Mar 2019, 09:56
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Devil

Most interesting thread, Loose rivets.

But speaking for myself only...."How does gravity work?"

To use a rather crude expression common here in my part of Australia,
DILLIGAF

All I know is that it does, and that it is far far beyond my comprehension as to know why. Furthermore, as long as I have a bottle of a good Barossa Shiraz handy I will have no particular desire to question such imponderables!

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Old 4th Mar 2019, 12:43
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Originally Posted by cattletruck View Post
Really enjoyed the opening thread, couldn't even detect a hint of claret, thanks for sharing LR.
Now one thing about gravity confounds me. We can make it in a centrifuge, but why don't all the objects on the planet go flinging off into space as the Earth rotates?
That's simple...gravity is a myth...the Earth sucks....

( Joking aside....simple answer is that Gravity is much much stronger than the perceived outwards flinging force so nothing flies off....but FWIW the spinning has a measurable effect and it does mean that if you weigh less at the equator than you do at the poles.)

Does mass displace gravity, that is, does having a big ball like Earth create some gravity IOU stemming from the middle that gets stronger at the surface?
Mass doesn't displace gravity, it actually produces gravity.

If we drilled a hole from one end of Earth to the other and threw a ball down there where would it come to rest?
It wouldn't. Conveniently ignoring the effects of air resistance and the Earth's rotation, and assuming we have a straight hole from one side of the Earth to the other, passing through the Earths centre, what would happen is:

The ball would accelerate down the hole towards the centre of the earth.. pass though the centre at it's maximum speed.. then carry on outwards/upwards but now decelerating... until it popped out the far side, eventually come to a halt at some height above the surface (how high being dependent on how fast you threw the ball to start with), and then reverse direction and start heading back down the hole again, accelerating towards the Earth's centre, and so on, and so on, back and forth....it would simply carry on oscillating, a bit like a pendullum...

Last edited by wiggy; 4th Mar 2019 at 12:53.
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Old 4th Mar 2019, 14:38
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Yes, and it would take about 40 minutes to fall through, no matter how the hole was drilled. In other words, the time taken to fall through a hole going straight through the centre, with a length of about 8000 miles, would be the same as the time taken to fall through a hole that missed the centre by a considerable margin, say with a length of only 6000 miles.

Reduced to absurdity, rolling a frictionless ball along a perfectly level trench cut along a few miles of surface, would yield the same time - about 40 minutes.

Schuler Tuning?
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Old 4th Mar 2019, 14:52
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As far as gravity is concerned, maybe it’s just a reaction to the expansion of space time? Matter acts as a ‘concentrator’ of this reaction, inasmuch as the matter itself doesn’t expand. This concentration then gives rise to mass, inertia, etc.

As you can tell, I wasn’t much good at physics.....
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Old 4th Mar 2019, 15:11
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Quora,
I know Loose likes Quora but I have found that over the past months there seems to be a lot of excuses for people to write soft porn answers rather than sensible ideas, many of the posts seem factually untrue.
I took myself off of the forum but continue to get daily messages in my emails.
FF
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Old 4th Mar 2019, 15:19
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For my money, Quora has an unfavorable signal to noise ratio.
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Old 4th Mar 2019, 15:59
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For someone who could not get beyond p 15 of Hawking's book, it falls to me to give you all the answer.

42
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Old 4th Mar 2019, 17:09
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4 T two. I know the answer's in there somewhere.

For my money, Quora has an unfavorable signal to noise ratio.
That's a good way of putting it.

There was however, a superb post by the PhD son of a Phd, both of whom had worked on the modelling of Neutron stars. They had access to Cray time, and his description of some of their findings was breathtaking.

Now, here's the thing about Quora. If it were laid out as an ordinary forum, like this one, I could have readily put a link to his post. Oftimes however, I just can't find things again and of course I can't turn up and suggest they reformat the entire site. Oh, wait, I have . . . but very politely, just a hint here and there that I wish the responses were not dynamic, and skid about according to 'Upvotes'. Mind you, the few times I've been shoved to the top does feed one's ego.

It seems the site lusts after question quantity. It is said one can earn huge sums, multi-thousands, asking questions. A family member surprised me by saying he'd worked hard to feed questions in, and after some weeks, found his top earnings were 38p.

What is surprising is that a few PhD's from top universities occasionally give time. Several of them are very, very good writers, and this is true of Viktor T Toth, who puts a huge amount of work into replies. However, he is one who turns off the 'Comment' button, so there is no chance of progressing his thoughts except by using one's SINGLE answer to bring his post into your own argument. Such a shame.

I got threatened by excommunication by mods on one American physics site. Generally a good science forum. My crime was 'theory development' and all my protests about just wanting the 'Inflow' hypotheses discussed, was to no avail. Shut up about spacetime inflow, or you're history. It was my sole reason for being there.

Must stop rambling and pour the first wine of the evening. But if you don't already know the science, and want to get a hint of why gravity is so exciting, google Cox, vacuum chamber, feather and bowling ball, and give a lot of thought to his statement that there is NO force being applied to the items while they are accelerating towards the planet.

BTW, any preconceived ideas you may have about Brian . . . have a look at him teaching in a graduate class. Calm and knowledgeable, is how I found him, unlike several of the big names who are dreadful lecturers.

Oh, he also said, at the end of one of his TV things, 'This is why it's such an exciting time'.

I feel this. We're almost touching the answers; almost tasting them, yet no one knows what made the brick that just fell on your toe, head the way it did.
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Old 4th Mar 2019, 20:06
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The other day Richard Attenborough said that there was a chance that all the Dolphins would die out.
Is there a problem with this? Why not let any species die out?
Does the fact that they have attractive eyes make them worth of saving.
Come to that, if the human race died out in one week's time would this be any different to the human race dying out in 1000 years time? We wouldn't worry as we would all be dead.
In fact the problem with escalation of global warming is the human race itself. Us dying out as a species would cure the problem. Is this 'Save the Planet' thing really 'Save the Planet - for us'?

FF
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Old 4th Mar 2019, 20:09
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LR is nearly my age. Do we now agree that a daily dose of a good wine (plus some fine spirits) is the key to a long and healthy life.
I would add that a regular consumption of Beef is another positive aid.
FF
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