Fotini Markopoulou - What is Space-Time?

Einstein showed that space and time are essentially the same thing, a single entity called ‘spacetime’. But space and time seem so radically different. How could space and time be literally the same thing? How would spacetime change our understanding of space and time? What are the implications?




Fotini G. Markopoulou-Kalamara is a Greek theoretical physicist interested in foundational mathematics and quantum mechanics. She is a faculty member at Perimeter Institute for Theoretical Physics and is an adjunct professor at the University of Waterloo.


Closer to Truth, hosted by Robert Lawrence Kuhn and directed by Peter Getzels, presents the world’s greatest thinkers exploring humanity’s deepest questions. Discover fundamental issues of existence. Engage new and diverse ways of thinking. Appreciate intense debates. Share your own opinions. Seek your own answers.

[markberman]

What a great interview and so wonderful to hear someone who is obviously deeply involved in working on the issues talking about what we don't know and about what we think we know and obviously trying to work t he angles of the questions from every perspective. Hopefully there's a longer interview on the website. This is yet another short interview where you want to take notes and think on some things a bit. She's wonderfully open minded.

[td]

“You are a function of what the whole universe is doing in the same way that a wave is a function of what the whole ocean is doing.”
"You and I are all as much continuous with the physical universe as a wave is continuous with the ocean."

― Alan Watts

[sgs]

Lot of comments on here already from people almost certainly less qualified, but apparently more certain, than a scientist who is humble enough to admit 'I do not know'!

[TheTroofSayer]

Something about the synthesis of space with time into the Einsteinian "spacetime" that makes me uncomfortable, and so I tread gingerly when going there. But I am much more confident about how the body wires the neuroplastic, DNA entangled brain; and here, what Markopoulou says is relevant.

*Everything* that we know about space and time, we learn from the moment, as infants, we begin crawling through it, reaching into it with our infant hands; and we continue to learn about it as we grow into adults. Indeed, the brain begins self-organising into its functional specializations within the womb - when the heart begins to beat it wires the medulla oblongata, and the reaching, kicking limbs begin to wire into the homunculus sensory and motor cortex.

Humans with human mind-bodies will attribute very different meanings to their experiences of space and time compared to birds-in-trees with wings or fish-in-water with fins. An earthworm surrounded by soil, or a snail confined to moving within two-dimensional contexts will likewise attribute very different meanings.

The question "What is Space-Time" is well-founded, integral to the subjectivity/objectivity debate, and perhaps pivotal to what the established, physicalist narrative is getting all wrong with bottom-up causation.

[plasticfantastk]

Every conversation with Mrs Markopoulou is always a pleasure

[universalparadoxes]

As we take a step closer to the truth, it feels like truth gets ever further away. Another great mindbending interview. thx for persevering.

[youtubetrailerpark]

Everybody gives the same non-answer and like she said some even say not to ask the question which is bull. Leaving time out of it for now, there has to be something that is warped/curved by matter whether that be a physical substance or an energy "field". Space is something.

[andrewbrodis]

1. Origins-lack of spacetime (also known as equilibrium).

2. Substitution of equivalence (also know as formation of symmetric pairs. This makes equilibrium dynamic.

3. Cycle of existence-equilibrium fails-expansion into symmetric pair (points of contrast separated by space for a duration), which is acted on by equilibrium and removed. This is a history of a one dimensional spacetime (expansion, transition, contraction).
4.build this hierarchy by further expansion of the cycle using 2 pairs vs. one pair. One dimensional spacetime is a transient period of existence. ( +X), ( -X )= 0
But two dimensional spacetime is 2 transient spacetime existences in a cycle of expansion, transition, contraction. (+X, +Y), (-X, -Y) = 0
One dimensional annihilates existence on contraction of one dimension short duration of cycle. Two dimensional expands existence cycle.
5. This is the crux of development. Synchronization of contraction from annihilation to bypass thus creating a spacetime continuum of expansion, transition, contraction.
6. Maturation of the cycle of moving spacetime towards and away through cycle creates our current spherical quantum expansion and also the contraction creates Dark Matter.
7. Our spherical quantum expansion spacetime matrix has the quality of Differential Expansion of matter & space. Matter expands radially @ c because its internal relativity resists expansion in 3 dimensions whilst it radiates (this is Mass). Since we are radiating at constant speed unilateral trajectory all we sense are relative deviations from the flow. At each quantum position of radiating trajectory, we have a probability of receiving or discharging energy from surrounding spherically expanding spacetime.



The light source & receiver are co-moving along a shared radial trajectory at a fixed relative distance.
When their radial trajectory distance traveled from the point of transmission equals their relative distance the space will have expanded spherically enough to reach receiver.

This is how quantum, SR & GR are inter-related. Each point of radial expansion is a quantum position. As matter continually radiates through these positions in all radial trajectories it creates "many worlds" with no paradox. Each moment a new sphere of entangled energy is expanding spherically in every direction. The spherical design also accounts for observed relative cosmic expansion that is explained by trajectory not acceleration.
GR-action between co-moving components in radial expansion
SR-differential expansion of matter and light
Quantum-Higgs relativity in cycle of expansion, transition, contraction controlled by a specific matrix that expands energy spherically @ a constant relativity thus creating entanglement through spherically expanding each quantum position

[suesimmons]

Remember soap bubbles? If a region of soap film is analogous to a region of space-time, then perhaps the foam that accumulates here and there is a analogous to matter. The surface tension in the film or foam is potential energy analogous to E=mcc. Somebody clever will flesh out the details.

[rodolforesende]

there are speculations about whether spacetime and matter might be derived from more fundamental entities or concepts, or if they represent different manifestations of the same underlying reality. However, it's important to note that these ideas are highly speculative and theoretical, and there is currently no experimental evidence to support them.

[GradyPhilpott]

Well! I'm glad we got that cleared up.🥴

[wallyr.]

I don’t know about a world without space and time, but how about a “place” without space and time? Wouldn’t that be the center of a black hole? 🤔

[ToddDesiato]

She gets it! Guv is what we measure with rulers and clocks, described by Tuv and governed by the laws of quantum mechanics. It's the material rulers and clocks that give us "space-time".

[alanbooth]

a beautiful lady with beautiful ideas and supreme intelligence - I think she's right!!!

[brothermine]

Two of the most interesting, unanswered questions about spacetime are (1) whether it's continuous or discrete, and (2) what kinds of nonlocal phenomena (wormholes, "spooky" quantum action at a distance, etc) does it support?

[evilferris]

Matter tells space and time how to curve and it's the curvature of time that's mostly responsible for telling matter how to move.
– Matt O'Dowd, @PBSSpacetime

[NondescriptMammal]

Thank you for asking the right question in a straightforward way. This kind of explanation is too hard to find.

[pinchopaxtonsgreatestminds]

Space-time is a way to say "I don't know.". It replaces the Aether backdrop that scientists are supposed to use.

[zakirhussain-jsku]

Before trying to understand spacetime, we need to understand space & time individually. Can anyone explain what is space & what is time?

[rhcpmorley]

Motion, motion, motion. Space and Time are ONLY connected by (relative) MOTION.

Both the word Space and the word Time have multiple meanings - why do you never differentiate??
Space (in this context) is the (abstract) dimension of relative position (hence xyz-axis), and Time (in this context) is the (abstract) dimension of change (calibration of rate, e.g. per hour, and indexation of event, using dates etc). So merge the two and space-time is the (abstract) dimension of changing position aka Motion.

The maths might be complex, the contextualising is not....but somehow you've got the hard bit, bit missed the easy bit.

The words Time and Space both have multiple meanings - not that you would guess that by listening to most scientists on the topic. Both meanings of Time are abstracts, one meaning of Space is:-

1. ‘Space’ has several (related) meanings. A space could be a gap e.g. in a car park, for example. Space also refers to the dimension of position, i.e. the three vectors of xys axis. Or Space might mean ‘everything not on earth’ as in ‘outer space’.
And sometimes Space refers to the entire known universe.
But science is so often not specific when it uses the words. It liberally, lazily conflates these different meaning of these words.
In the context of dimension, space is the dimension of position. That is the three sub-dimension of length, breadth and height (xyz-axis), calibrated in standard units, allow us to overlay an abstract framework that calibrates and indexes position, and relative position.
2. ‘Time’ has two core meanings…to expand on this:-
The ONLY empirical evidence of Time is change / change events (look around you - earth spinning, you breathing, quarks decaying - all change event series). Change can be quantum or compound, depending on your reference-frame. Time represents TWO distinct contexts of change:
1.The calibration of change (i.e. the dimension of change - hence 'rate' e.g. miles PER HOUR - the calibration of change of position aka motion) i.e. Time is to change what temperature is to heat, a dimension/calibration set. Temperature is abstract, heat is real, Time is abstract, change is real; and
2. Time is the collective 'flow' of change. Time is to change-events what 'River' is to water molecules - a collective term. Is a river real? Well yes, on one level; but, fundamentally the word River is an abstract collective, water molecules are real. So too Time is a collective abstract, change-events are real - Time, the 'flow' of change.

We think we perceive time passing, we actually see change happening...the illusion of time. Time, one word, two distinct meaning, both reference change.


Hence Space (in this context) is the (abstract) dimension of position, and Time (in this context) is the (abstract) dimension of change. So merge the two and space-time is the (abstract) dimension of changing position aka Motion.
I hope this helps www.time-defined.com