Ask any question you want about Physics

Thanks Arbitrageur.

No conclusive answer. But the links were interesting.

I too was puzzled by the comments about cooling being a dominant way.

I did however, just come across this

'Earth's magnetic field is powered by the heart of the planet. At its centre is a solid inner core surrounded by a fluid outer core, which is hotter at the bottom. Hot iron rises within the outer core, then cools and sinks. These convection currents, combined with the rotation of the Earth, are thought to generate a "geodynamo" that powers the magnetic field.'

From this link www.bbc.com...

I'm not sure if it could be related to the Exoplanet comment.

You also question the lack to mention the irregularity of magnetic flips;

Maybe they're not actually irregular.

From the link. 'Now the most detailed analysis of the geological evidence to date suggests that the field really is slowly destabilising. Whereas in the distant past it reversed direction every 5 million years, it now does so every 200,000 years.'

This seems like they're becoming more frequent. Not necessary irregular.

Cooling may have something to do with the frequency of flips perhaps.

The earth has changed a lot from the early more stable periods.

This link about Cratons is interesting because it's a completely different earth than we know now.
en.wikipedia.org...

Delbertlarson.

I hope you get a reply to your letter.

originally posted by: toysforadults
What is time?

It is the thing that clocks measure. This is what Einstein said and it is not flippant, it is a critical feature of the structure of the laws of physics as an initial state differential equation, the concept of which goes to Newton.

How does gravity work?

Energy & momentum in the form of the "stress energy tensor", apparently those quantities of all physical origins summed up (from hadrons, to leptons to photons) alters the shape of space which results in apparent forces and changes in spacetime which affect all physical entities equally.

What is consciousness?

It is what goes away with general anesthetic.

a reply to: blackcrowe

From the link.

The link is wrong. Which is not unusual for "consumer science." As far as can be determined, reversals never happened every 5 million years. Or every 200,000 for that matter.

This seems like they're becoming more frequent. Not necessary irregular.

There has never been any regularity to polarity reversals. They have always occured at irregular intervals and persisted for irregular periods of time.


Hulot

a reply to: Arbitrageur

You guess? Lol.
Wonder if it dawns upon you that iss is orbiting the earth?
Or are you talking about launching a rocket from the earth?

a reply to: delbertlarson

'Yes experiment is King'
So where is your experiment to your new theory?

originally posted by: Phage
The link is wrong. Which is not unusual for "consumer science." As far as can be determined, reversals never happened every 5 million years. Or every 200,000 for that matter.

I agree the link is wrong about the every 5 million and every 200,000 years. However it's right about the last time there was a reversal

"The last major reversal was 781,000 years ago".

If reversals were happening every 200k years, there should have been another three reversals at 581kya, 381kya, and 181 kya, which I wouldn't expect to be at those exact intervals perhaps but the fact that none of those three have happened at all kills any idea of regular 200,000 year intervals. In that respect alone the link appears to debunk its own claim of every 200k years.

originally posted by: Hyperboles
a reply to: Arbitrageur

You guess? Lol.
Wonder if it dawns upon you that iss is orbiting the earth?
Or are you talking about launching a rocket from the earth?

ISS orbiting the earth without operating any thrusters is a kind of freefall where gravity is the only influence on it, where "g" aboard the ISS reference frame is effectively zero.

ISS orbiting the earth when operating thrusters is not freefall any more because gravity is the not the only influence on it, the thrusters result in a force on the ISS when they are operating, resulting in a non-zero "g" on the ISS reference frame as you can see from the astronauts "falling" inside the ISS.

These are not hard concepts, so I don't know why you have so much trouble distinguishing between them.

a reply to: Arbitrageur

Is everything we see and experience in our 3d world a shadow of the 4th dimension?

Like a 3d object is a dot in 2d but if you add time it becomes a curve, circle, ...? What would we have to add to make the 4d visible?

originally posted by: Hyperboles
a reply to: delbertlarson

'Yes experiment is King'
So where is your experiment to your new theory?

The ABC Preon Model undergirds quarks and leptons, agreeing with a monumental experimental record. But it goes further to propose 18 additional experimental tests, 9 of which have been qualitatively, and 8 quantitatively, verified. The absolute theory without a length contraction will allow for a non null result of a group velocity equivalent of Michelson-Morley, but the test has yet to be done. The aether model predicts that atomic clocks immersed in radio waves should run slow, but to my knowledge no such test has been done. The new high velocity quantum mechanics (HVQM) formulation should agree with all spectral results of experiments done on hydrogen, including the Lamb shift. However, since HVQM allows for the free fitting of parameters (the electron size and the proton size are parameters that could be fit), the Lamb shift could just be used to fit parameters, and that isn't really experimental proof at that point. The HVQM formulation could also be used for other predictions, and that is where the experimental verification (or, possibly, refutation) would come in.

Without experiment we don't have science, we only have philosophy. Philosophy can be important too, but good philosophy will eventually become science once tests are shown to be possible. In science, experiment is king.

a reply to: Phage

Thanks Phage.

So. My link was wrong.

And. After asking if wiki was reliable. LOL

I didn't think a BBC link would be an issue.

This is really disappointing.

Here in the UK. We have to pay for the privilege (not optional) to have our BBC.

The license fee is for tv, radio and all other media.

But. Thanks for your link.

I am finding the subject quite interesting.

If you, Arbitrageur or anyone else wants to post me some more links. I would appreciate it.

I did like the nuclear fission idea in Arbitrageurs 2nd link.

But. That 2nd link is more technical. And. There are in between bits that i need to read up on to help me.

a reply to: blackcrowe

It's not just the BBC. Trust me.

It's consumer grade science in general. It has a way of mucking up the actual science.

a reply to: Phage

Thanks Phage.

As i said.

Disappointing.

But. Thanks to the good posters on here.

I might be able to learn something.

originally posted by: blackcrowe
I did like the nuclear fission idea in Arbitrageurs 2nd link.

But. That 2nd link is more technical. And. There are in between bits that i need to read up on to help me.

I can post the abstract to a paper claiming to confirm the fission via geoneutrino detection, but I don't have the full paper:

Partial radiogenic heat model for Earth revealed by geoneutrino measurements

...radiogenic decay can be estimated from the flux of geoneutrinos, electrically neutral particles that are emitted during radioactive decay and can pass through the Earth virtually unaffected. Here we combine precise measurements of the geoneutrino flux from the Kamioka Liquid-Scintillator Antineutrino Detector, Japan, with existing measurements from the Borexino detector, Italy. We find that decay of uranium-238 and thorium-232 together contribute 20 (+8.8)(-8.6) TW to Earth’s heat flux. The neutrinos emitted from the decay of potassium-40 are below the limits of detection in our experiments, but are known to contribute 4 TW.

This scientific American article explains more, and is probably more reliable than the BBC but I've seen some interpretation errors even in scientific American, so again if you want to know what the scientists really said, their actual paper is a better source.

Nuclear Fission Confirmed as Source of More than Half of Earth's Heat

Jupiter's core is heated by a process called the Kelvin–Helmholtz mechanism, whereby as the surface cools and shrinks about 2cm per year, which heats the core as a result, so this limits the core cooling.

As long as the core stays relatively hot by whatever means, the dynamo that generates the magnetic field can continue for relatively long periods of time, in fact Earth may be swallowed by the expanding sun in 5 billion years without its core ever cooling completely. The larger the planet or moon, the better the chances of retaining the magnetic field.

Mars and even the moon used to have magnetic fields soon after they formed, but without heat sources for the cores to maintain the dynamos they only lasted a limited time. The moon's lasted perhaps a billion years maybe with some tidal heating help from Earth when it was a lot closer, while mars may not have had a good heat source to maintain the dynamo so its magnetic field may have been shorter-lived than the moons, even though Mars is larger. My guess is, bigger planetary mass is generally better for longer-lived magnetic fields, but it's not the only factor affecting how long the dynamo and resulting field lasts. Maybe tidal heating effects allowed the moon to maintain its magnetic field as long as it did, and this might lend credence to tidally locked exoplanets being able to maintain magnetic fields with help from tidal heating.

Ancient moon’s mega magnetic field explained

Mars' Ancient Dynamo and Crustal Remanent Magnetism

As if all that isn't complicated enough, then we have the mystery of how Venus can be so similar to the earth and not have a magnetic field (yet it's even closer to the sun and still has an atmosphere!). This article suggests it might be because Venus didn't get whacked by a giant impact like Earth did:

Earth and Venus are the Same Size, so Why Doesn’t Venus Have a Magnetosphere? Maybe it Didn’t Get Smashed Hard Enough

Maybe that's the reason or maybe not, but when we have a hard time figuring out mysteries like this in our own solar system with all the data we have available, I try to keep in mind how speculative comments about expolanets really are.

originally posted by: Peeple
a reply to: Arbitrageur

Is everything we see and experience in our 3d world a shadow of the 4th dimension?

Like a 3d object is a dot in 2d but if you add time it becomes a curve, circle, ...? What would we have to add to make the 4d visible?

Walk across the room, and you have observed the 4th dimension, time. If it weren't for time you wouldn't be able to walk from one side of the room to the other, and time is the 4th dimension in relativity.

Could there be more dimensions? String theory hypothesizes more dimensions, but from my limited understanding, they would be much smaller than the size of a proton and you can't even see a proton so you're not going to see those even if they exist, which they may not since string "theory" isn't confirmed by any experimental evidence I know of.

I hear some UFO researchers talking about a possible "interdimensional" origin of some UFOs, but to be honest I have absolutely no idea what they are talking about or what theory or model those statements are based on, if any. I don't think they know either.

a reply to: delbertlarson
It's not surprising you are having problems making a theoretical model for the aether since that's been the experience of everyone who has attempted it, as far as I know. Thanks for the update and good luck with your letter to Dr Hamed.

a reply to: Arbitrageur

Thanks Arbitrageur.

That's really cool.

I'm still reading Phages.

It's an easier read and very interesting and detailed. But. Very long.

I'll get round to your links next.

Although i do understand it is not a complete or definite model.

a reply to: Arbitrageur

Any computation of time aboard the iss has to take in the g (due to earths gravity) at that altitude too, so pendulum wont do its job as the point of suspension is free falling

originally posted by: Hyperboles
a reply to: Arbitrageur

Any computation of time aboard the iss has to take in the g (due to earths gravity) at that altitude too, so pendulum wont do its job as the point of suspension is free falling

OK then please show the computation of time aboard the ISS using your model and math, for
1. The ISS in freefall (when the pendulum doesn't work), and
2. The ISS with thrusters operating when the period of an attached pendulum is say 45 times longer than the same pendulum would have on Earth's surface.

If you're not using relativity or the pendulum for the computations, then exactly how do you make the computations for time aboard the ISS?

originally posted by: Arbitrageur

originally posted by: Hyperboles
a reply to: Arbitrageur

Any computation of time aboard the iss has to take in the g (due to earths gravity) at that altitude too, so pendulum wont do its job as the point of suspension is free falling

OK then please show the computation of time aboard the ISS using your model and math, for
1. The ISS in freefall (when the pendulum doesn't work), and
2. The ISS with thrusters operating when the period of an attached pendulum is say 45 times longer than the same pendulum would have on Earth's surface.

If you're not using relativity or the pendulum for the computations, then exactly how do you make the computations for time aboard the ISS?

fairly trivial which you can do yourself.
apply the values of g for both conditions at that altitude ( do not invoke any sheites like reference frames ), to your pendulum equation

a reply to: Hyperboles

fairly trivial which you can do yourself.

Good answer.

originally posted by: Hyperboles
fairly trivial which you can do yourself.

If I do it myself I come up with what Wikipedia shows per the relativity model:

Gravitational Time Dilation


So if your answer is whatever I come up with when I do it myself, then you must agree that relativity is correct. If you are asking me to do it myself using the alternate math you provided for your model, the only thing I can come up with is something like this, since you never provided any math:

hyperboles/0 = undefined, but possibly infinite trolling

You remind me of electric universe cranks: lots of hot air, but never any quantitative predictions to back any of it up. No mainstream models are being challenged by your model, you apparently don't have one if that's all you can say.

a reply to: Arbitrageur

Lol are you not capable of reading my entire post? rather than cherry pick.
Alas AIs drawback, it figures

a reply to: Arbitrageur

Thanks Arbitrageur.

As you and Pharge gave me so much to read. I didn't think i would have much to add for a while.

Hopefully this link is better than the BBC disappointment.

It's about new findings on Venus' weird spin.

www.space.com...

It's rotation is very slow. And in the opposite direction of Earth.

'Orbital characteristics
If viewed from above, Venus rotates on its axis the opposite way that most planets rotate. That means on Venus, the sun would appear to rise in the west and set in the east. On Earth, the sun appears to rise in the east and set in the west.

The Venusian year — the time it takes to orbit the sun — is about 225 Earth-days long. Normally, that would mean that days on Venus would be longer than years. However, because of Venus' curious retrograde rotation, the time from one sunrise to the next is only about 117 Earth-days long. [Gallery: Transit of Venus from June 5, 2012, when the planet transited in front of the sun for the last time until the year 2117.

Taken from link within posted link. www.space.com...

Where it is said 'Venus takes 243 Earth-days to rotate on its axis, by far the slowest of any of the major planets, and because of this sluggish spin, its metal core cannot generate a magnetic field similar to Earth's.'

It does however mention a magnetic field.

'Magnetic field: 0.000015 times that of Earth's field.

Internal structure: Venus' metallic iron core is roughly 2,400 miles (6,000 km) wide. Venus' molten rocky mantle is roughly 1,200 miles (3,000 km) thick. Venus' crust is mostly basalt, and is estimated to be six to 12 miles (10 to 20 km) thick on average.'

This is from another link from link.

'Inside of Venus

Venus is a rocky planet, much like the Earth. Given its similar size, mass, and density to our planet, scientists think that its interior is much like Earth's own. In addition to a crust significantly older than Earth's constantly changing surface, Venus likely also sports a mantle and a core. The mantle is probably rocky, and the core is probably somewhat liquid.

But despite the planets' similarities, the magnetic field of Venus is far weaker than on Earth's. The reasons for that may have to do with the core. Part of it could simply have to do with motion. The planet spins very slowly — once every 243 Earth days — and the core may not spin fast enough to create a magnetic field the way the core of Earth and other planets do. The core may also be completely solid, or may not even exist at all. Taking readings on the interior of another planet is a significant challenge.'

From here. www.space.com...

Also from same link above.

'Early in the history of the solar system, while planets such as Venus were forming, the cloud of dust and rock orbiting the sun was a chaotic place. Giant rocks pounded the surface of the newly created planets and their moons. So how did Venus escape unscathed? While Venus could have been extraordinarily lucky and missed any significant damage in the turbulent young system, it is more likely that the surface of Venus has been completely redone by volcanic activity, smoothing over the scars of its early life. The planet has significantly more volcanoes than Earth, several of them the size of Earth's largest system, the Big Island of Hawaii.'

Which would then fit with the moon smack as a trigger to shake things up.

It's very interesting. And so much to learn.