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.
This video is part of Perimeter Institute's free educational resource Fields. Download the teacher's guide, modifiable worksheets, and supporting materials at: resources.perimeterinstitute....
Perimeter's educational outreach programs and resources like these are made possible in part thanks to our donors. Be part of the equation: perimeterinstitute.ca/donate.

[@robertschlesinger1342]

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

[@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 300000 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.

[@patitapabanpati5206]

Beautiful,,,,,, keep making such video

[@gilian2587]

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.

[@Guide504]

nice vid to show my son well done.

[@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.

[@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. www.academia.edu/5927513/The_Spacetime_Wave_Theory www.academia.edu/5038836/The_Unification_of_Physics Richard

[@jman8128]

it is a reasonable doubt, and a reasonable conclusion.spacetime is fundamental.

[@tomhammer802]

Space (where) and time (when) are the most important when determining physics? Plausible. Add the last four questions (what, why, how, who) and all of knowledge lies within these. "Who" is ofc the most important :) But most do not consider. Alas, we will come to know. Indeed, we will.

[@ty2010]

That's never been assumed, it's why we get gravitational lensing

[@jman8128]

@Dirk Knight To describe more, there is space in the universe which is not empty, it is a net, a pond; there are matiarials in the universe, they are knots of the net; there is time in the universe, which is simply the vibration of the net itself. That is so obviously to me, I will be surprised if it is not true.

[@jman8128]

@Dirk KnightWell, when matter burns, it release energy. it is like when a knot solved, producing ripples onto the net, turning into pure energy. Time is an universal clock, its only because everything is connected to the huge net of the universe, it also explained entropy well, this vibration keeps shaking us, shaking everything.

[@tncorgi92]

Music is too loud to hear what Burgess is saying.

[@discogodfather22]

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.

[@AvatarOfBhaal]

A gradient in space, rather than a point.

[@balasubr2252]

Ben Jacobs yes indeed the topological variations and the contours of such gradient make communicating with languages difficult and meaning and nuances might be miscued- so, even if field might be imaginary mathematical computing might enable more accurate deciphering and accounting for error free transmissions

[@juangonzalezpestano3544]

thanks i love astronomy

[@dougg1075]

Now you have your predictions go forth and dig deeper.

[@paulgibby6932]

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

[@blakes8901]

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

[@RagingGeekazoid]

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.

[@patitapabanpati5206]

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

[@andybeans5790]

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

[@RagingGeekazoid]

Gravity is different from other fields. It's the only known field whose mediating particle has to have spin 2.

[@4pharaoh]

@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

[@omkarchavan5940]

Rather than reflection, it's a perception of reality (and not reality itself)

[@4pharaoh]

@Dirk Knight Look again my friend, @0:50 a scalar temperature field is described. The issue with the word "real" is; that to some, the word is objective, and others want to make it subjective. I submit that although @0:55 the video "defines" the word field, it is nevertheless subjectively "real." and has *yet* to be proven objectively real. For the record, I understand the "field(s) very well, (and an inking of it's underlying reality.) Also: To state _"Since QFT does an excellent job describing that level of reality, quantum fields are "real"._ is just as valid as saying: _"Since the Luminiferous Aether does an excellent job describing that level of reality, it must be "real"._ That kind of "reasoning" was a Logical Fallacy before Michelson and Morley, and it is so now.

[@dnomyarnostaw]

@@4pharaoh Well expressed. Very important point.

[@balasubr2252]

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?

[@MarkAhlquist]

Paula Abdul did that already.

[@balasubr2252]

Mark Ahlquist Unlike Paula Abdul this one perhaps might: kzbin.info/www/bejne/enKmlKx4g5p9pMk

[@rayagoldendropofsun397]

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 .

[@stephsauve4569]

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

[@stephsauve4569]

Means I never get there into infinity?

[@RagingGeekazoid]

Not at all. You get there at (almost) the speed of light, and you haven't aged nearly as much as they have when you get there.

[@qwaqwa1960]

Yeah, right...aether...

[@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.

[@mattheww9656]

J Mark Morris So can NPQG make a prediction that can be tested and independently verified?

[@davidrandell2224]

No, all is expanding electrons. This standard theory model was dispensed with 19 years( not seconds,minutes,weeks or months); try to keep up.