Fields: The Reality of Fields

Physicists discuss the central role that fields play in modern physics as well as how they use fields in their area of study.

[robertschlesinger]

Excellent overview of field theory for outsiders. Now you need a set of sequel videos to get into the details of QFT for pedestrians.

[johnZarkov]

Time 2:10 .. "a filed created by this magnet". If the field created by the magnet, or is a pre-existing field modified by the magnet. That is, is there a field permeating space without the presence of nearby charges or magnets? Carlo
Rovelli seems to indicate the latter.

[NeilRieck]

IIRC, Michael Faraday was proud of the fact that his publications contained almost no mathematics. The opposite was true with the work of James Clerk Maxwell who used mathematical field theory to re-describe Faraday's observations which also brought two new facts: electric fields and magnetic fields are aspects of the same phenomenon (they were thought to be different forces before then) -AND- and that the speed of these waves was approximately km/s (186000 mi/s). The truth is this: science and mathematics have proceeded hand-in-hand ever since Galileo. You can't have one without the other.

[discogodfather]

Great, but what is a field exactly? What is it made of? Seems as if the geometry concepts have not played out well (string theory). It's ironic that this entire video passes without acknowledging that we have only the vaguest idea of what "fields" are.

[pharaoh]

@3:00 “So, so we talk about fundamental forces but what we really mean is fundamental fields”
When you talk about ‘fields’ in QFT you are really talking about the math.
The math may describe all observations beautifully but this is still purely a mathematical abstraction, like a mirror’s reflection of the underlying reality.
Temperature for example is NOT “a field as a collection of ‘data points’ in space time…” @4:11

[paulgibby]

2:48 (buzzer) using a term without defining it: "charge"

[OpenWorldRichard]

I just have a doubt about the idea that fields are fundamental and represent basic physical reality. Take for example the recent observation by LIGO of gravitational waves from the merger of two neutron stars at a distance of 130 million light years. It was found that the speed of the gravitational wave and the speed of the light and gamma rays from the merger travelled at the same speed and arrived together. This is very significant as we know that gravitational waves travel as a wave disturbance of spacetime so the medium for the transmission of gravitational waves is spacetime itself.


Consider also that the light and gravitational waves have been travelling through a region of space where space itself has been expanding and still they arrived together. This strongly suggest that the medium for the transmission of light is spacetime itself and we should consider light as a wave disturbance of spacetime travelling at speed c. We can still think of light as a wave in the electromagnetic field just like a radio wave but we should not assume that the field is the medium for the transmission of light.


In summary, fields are not fundamental, spacetime is fundamental.




Richard

[Keaggan]

That magnet and iron filings illustration is the same as a rock in the pond. We are are seeing what something does not what something is.

[tncorgi]

Music is too loud to hear what Burgess is saying.

[gilian]

Explanations and visualizations of scalar and vector fields. It would have been interesting to see explanations and visualizations of spinor and twistor fields. Not here, though; not today. C'est la vie.

[Raging.Geekazoid]

And all of those fields coexist in the same space. Which makes you wonder, what are they and how do they work? They can't be "fundamental building blocks of the universe", because they're distributed through all of space. And they don't really act like "liquids", they act more like properties of a solid. An extremely complicated solid. It's even possible to model gravity as a field without having to curve spacetime.

[dougg]

Now you have your predictions go forth and dig deeper.

[balasubr]

Could we not, then, for example apply quantum theories to the societal fields of realities ? Are the forces of societal relationships not computable just as the forces of gravitational field? Are not the forces of societal relationships expressed through the words and the languages? Could we not use quantum mechanical engineering to societal mechanics and use such technologies to augment human capabilities of communications and understanding? Why is quantum mechanics not yet applied outside of physics to help solve societal and language space time miscommunications?

[andybeans]

If spacetime is a field that causes gravity and QFT describes fields, why doesn't it describe gravity?

[Dwayne-hv]

id cut off my right hand to be able to participate in this kind of research

[stephsauve]

If I travel fast to an alien world, I age little while the people on the alien planet age thousands of years. Does this mean that if I travel at the speed of light, to the people on the alien planets

[patitapabanpati]

Sonali Mohapatra ma'am r u from good to know that

[rayagoldendropofsun]

The Higs field of individual particles floating around without MOLECULAR MOTION is not possible when all gas rise from it's molecules in motion fired up by it's electrons creating an upwards ENERGY FLOW, and a single atoms wellbeing is like that of trapped gas molecules solid objects, they're always GROUNDED by way of it's electrons connected to the earth surface ENERGY CONSERVATION SYSTEM .

[ChristophePochari]

Without the aether a field is meaningless

[EmergentUniverse]

Until physicists abandon the idea of beautiful mathematical spacetime, fields, and general relativity - they will be LOST. It's not really that hard to figure out what is going on. Yes, there are fields, but there is a medium that is carrying them. That medium is a superfluid that implements spacetime. What makes the superfluid? Particles of course. Two fundamental particles just below the standard model that combine in various ways to make the standard model composite particles. The superfluid of spacetime is most likely low energy photons and low energy neutrinos and whatever they combine into at that low energy (a graviton?) and they are incredibly dense and permeate everything in the universe (except it gets a bit more complicated at high energies in a NS or BH). Once you understand the idea that everything is based on discrete particles that generate and carry fields, then everything else simply falls out. If you want to understand how the universe really works, I invite you to read my blog articles at johnmarkmorris.com. There you will find that this logic solves most of the major open problems in physics and also sorts out a lot of the really bad narrative from physicists and cosmologists. However, physicists and cosmologists appear to be incapable of extracting themselves from this nightmare of their own creation that has caused lack of significant progress in 45, 90, or 130 years depending on where you start counting. Yes, their math still works at the scale they operate upon, but not below that where the reality of nature is discrete like our macro world.