Articles, Blog

Hacking the Nature of Reality

February 4, 2020

In particle physics we try to understand reality
by looking for smaller and smaller building blocks. But what if that has been the wrong philosophy
all along? The year is 1925 and the young Werner Heisenberg
is striving to understand the mechanics of the newly-discovered electron orbitals of
hydrogen. His approach is strange and radical – rather
than trying to map the detailed inner workings of the invisible atomic structure – the traditional
reductionist approach – he sought a model that ignored the fundamentally unobservable
internal mechanics. His mathematical description should depend
only on observable quantities – in this case, the mysterious frequencies of light produced
as electrons jump between orbitals. This philosophy led to a series of seemingly
miraculous mathematical insights, with the final result being the birth of modern quantum
theory and first complete formulation of quantum mechanics – matrix mechanics. Other representations of quantum mechanics
soon followed – for example, the wave mechanics driven by the Schrodinger equation and Paul
Dirac’s notation representing evolution in a space of quantum states. These became better known than matrix mechanics,
but the underlying philosophy of the Heisenberg representation was not forgotten. In fact the great Neils Bohr passionately
advocated it, insisting that matters are the observables – the measurable start and end
points of an experiment. According to this philosophy, the unobservable
details that happen in between are not only irrelevant, it may be meaningless to even
talk about those details as real, physical events. Despite its importance in the foundation of
quantum mechanics, and being championed by Bohr and Heisenberg, most physicists over
the following decades did not subscribe to this philosophy – at least not in practice. They remained reductionists, and the quest
continued for a detailed, mechanical description of the hidden inner workings of atoms and
of the universe. This search for the underlying clockwork of
reality led to quantum field theory, in which all particles are described by vibrations
in elementary fields that fill the universe, and all interactions are calculated by adding
up the exchanges of infinite number of virtual particles. But one ignores the wisdom of Heisenberg and
Bohr at great peril. Early quantum theory was plagued by
problems – for example, how do you compute infinite interactions? And how do you avoid the infinite interaction
strengths produced by some of those infinite sums? Some clever hacks – perturbation theory and
renormalization – worked in many cases to tame the infinities and yielded the incredibly
accurate predictions of quantum electrodynamics, which describes the interactions of the electromagnetic
field. But problems returned when we started to peer
into the atomic nucleus. At the beginning of the 1960s the atom was
understood as fuzzy, quantum electron orbits surrounding a nucleus of protons and neutrons. Those nuclear particles were originally thought
to be elementary – to have no internal structure, just like the electron. But new experiments were revealing that they
seemed to have some real size – as though they were made of yet-smaller particles. These were scattering experiments – particles
were shot into atomic nuclei, and the internal structure was probed by the way those or other
particles emerged. Such experiments revealed that the forces
binding these sub-nuclear particles together must be so strong that space and time should
break down at those scales, and our even best field theory hacks seemed to fail. And so a number of physicists turned back
to Heisenberg’s old idea. What if it was possible to understand a scattering
experiment – like those used to probe the atomic nucleus – not by modeling all the cogs and
wheels of the field theory of the internal nucleus, but rather by understanding the observables
only. In this case the observables were the particles
that entered and left the nucleus in a scattering experiment. In fact, Heisenberg himself was way ahead of the game. He’d already laid the groundwork in the
early 40s with his work on something called the scattering matrix, or S-matrix. The S-matrix is a map of the probabilities
of all possible outgoing particles, or out-states, for a given set colliding particles – in-states. The idea was invented by John Archibald Wheeler
in the late 30s as a convenient way to express the possible results of a quantum interaction. In fact, it’s still a very important tool in
quantum mechanics today. But Heisenberg took it in a very different
direction. In standard use, the S-matrix can be calculated
if you understand the forces in the interaction region – for example, in the nucleus of an
atom. But what if you don’t know those internal
interaction forces? Heisenberg sought a way to ignore that internal
structure and, rather, treat the S-matrix itself as fundamental. The S-matrix was to become the physics of
the interaction, rather than an emergent property of more fundamental, internal physics. Heisenberg’s made some progress in the 40s,
but the approach came into its own 20 years later when the atomic nucleus refused to give
up its mysteries. Through the 60s and 70s Geoffrey Chew and
others took Heisenberg’s work on the S-matrix and his anti-reductionist philosophy and developed
S-matrix theory. At the time, nuclear scattering experiments
were producing a startling variety of different particles. For example, many different mesons were discovered,
which we now know to be composed of two elementary quarks. But at the time, prior to the discovery of
quarks, no point-like, elementary nuclear particles were known. Rather than searching for smaller and smaller
particles, Chew and collaborators promoted a “nuclear democracy”, in which no nuclear
particle is more elementary than any other. They attempted to build scattering matrices
with no elementary particles at all, and with no details of nuclear structure. But how is this even possible? Remember, that quantum field theory fastidiously
adds together a complete set of virtual interactions that contribute to the real interaction. S-matrix theory sought to avoid this, and
instead tries to model a scattering experiment – to build an S-matrix – by applying some
general consistency conditions and then looking for the only scattering results consistent
with those conditions. These conditions include things like conservation
of energy and momentum, the behavior of quantum properties like spin, and the assumption of
a family of particles that can be involved in the interaction. But in order to avoid those sums of Feynman
diagrams, S-matrix theory also relies on symmetries between those virtual interactions. In particular something called crossing symmetry. An example of this is the fact that antimatter
can be treated as matter traveling backwards in time – that folds together large sets of
Feynman diagram and helps us ignore the actual causal structure within the interaction region. And here’s another example of crossing symmetry. Imagine two particles scattering off each
other. Two go in, and two go out – the out particles
could be the different to the in particles, or they could be the same just with different
momenta. There are two broad ways this can happen as follows:
1) the ingoing particles exchange a virtual particle which deflects or transforms them
into the outgoing particles – this is called the S-channel; or 2) the particles annihilate
each other, briefly forming a virtual particle, which then creates the two outgoing particles
– that’s the T-channel. In regular quantum field theory you’d need
to add up all the different versions of both these two channels separately. Before quarks and their interactions were
properly understood, doing that sum seemed impossible in the case of strong force interactions. But in 1968, italian physicist Gabriele Veneziano
figured out a hack. It had been postulated that the S-channel
and the T-channel should lead to identical scattering amplitudes. That fact enabled Veneziano to ignore the
fiddly details of the separate channels and derive a scattering matrix, which in turn
allowed him to explain the peculiar relationship between the mass and the spin of mesons. The S-matrix approach to solving problems
in quantum mechanics based on these global consistency conditions and taking advantage
of symmetries is also called a bootstrap model – from expression “pull yourself up by the
bootstraps” – the idea of raising yourself up without concrete starting point to push
off of. So S-matrix theory looked extremely promising
… until it didn’t. It presented severe challenges on par with
those plaguing quantum field theory – and, as it happened, physicists solved the QFT
challenges first. Breakthroughs in our understanding of the
behavior of quarks and gluons revealed that the strong nuclear force does not actually
approach infinite strength as was once feared, and so a full quantum field theoretic description
of the strong nuclear force was possible after all. The result is quantum chromodynamics – our
modern description of sub-nuclear physics. QCD deserves its own episode, so I’ll skip
the details for now. But the results was that S-matrix theory was
sidelined, and quantum field theory reigns supreme to this day as our reductionist description
of the subatomic world. So do we really now have a perfect mechanical
description of the smallest scales of reality? Well, not so fast. Standard QCD employs sums over large numbers
of intermediate virtual states. And as we discussed in our episode on virtual
particles, the physical-ness of these states are questionable at best. Quantum field theories like QCD surely gives
us insights into the nature of the fundamental workings of the universe. Given their astounding predictive success,
S-matrix theory now seems less fundamental – it seems like an emergent set of relationships
– what we call an “effective” theory – but it turns out that it has led to deep insights
that even quantum field theories could not reach. So I said that S-matrix theory got sidelined
– that’s not exactly true. Remember that clever little bit of work by
Gabriele Veneziano? It turned out that the Veneziano amplitude
for meson scattering represents something rather more profound that just predicting
the results a scattering experiment. Other physicists quickly realised that it
was telling us that mesons could be described by a very particular type physical system:
a vibrating string. And so string theory was born – at first as
a description of strong nuclear force interactions before quantum chromodynamics took over – but
then as a theory of quantum gravity. So our leading, and perhaps only current contender
for a theory of everything was first derived as a bootstrap model, an S-matrix theory. Oh another example of bootstrapping a scattering
experiment without understanding the internal physics, Steven Hawking’s derivation of Hawking
Radiation. And physicists are bringing the S-matrix back. Here’s an especially awesome example. We think that the largest structures in the
universe today – galaxies and galaxy clusters – as collapsed from quantum fluctuations in the
extremely early universe. Those fluctuations sometimes caused by individual particles. Princeton’s Nima Arkani-Hamed and collaborators
have performed what they call a cosmological bootstrap to understand the nature of those
early subatomic scale interactions based only on current observations – which in this case is the distribution of gigantic galaxies on the sky. That’s a cool result, but Arkani-Hamed’s
work on something called the amplituhedron has hinted that the S-matrix approach can
be taken much, much further. The amplituhedron takes Heisenberg’s old
philosophy to the extreme – “only consider the observables”- the amplituhedron doesn’t
just eliminate the fiddly mechanics of quantum field theory, it removes the very concepts
of space and time. These only emerge later as a consequence of
spaceless, timeless particle scattering. But all of these new efforts deserve their
own episodes, then we’ll see how a simple insight by a young scientist back in 1925
allowed us to pull ourselves up by our bootstraps towards a better understanding of the quantum
weirdness of space time. Before we jump your questions, I just want
to mention that the best and fastest way to get smart people answering your questions
is to join the Space Time discord channel. It’s hopping with lively conversations about
everything space, physics, or things that spacey physicsy people are into. The discord is open to anyone who joins us
on Patreon, even at the lowest $2 a month tier. OK, so previously we talked about a compelling
new idea for how black holes might merge – perhaps they’re captured and then brought together
in the searing hot accretion disks of quasars. Persona non grata asks whether migration traps
are like Lagrange points. Not really – in fact we covered Lagrange points
last week. Migration traps are different. If you place any massive body in an accretion
disk it will both tug on and be tugged by the surrounding gas. In some places it gives up angular momentum
– it’s orbital energy – to the gas, causing it to migrate inwards, while in other places
it steals angular momentum, migrating outwards. And between these inward and outward migration
regions are places where no angular momentum is exchanged. And, well, the black hole is trapped. Adam Wulg asks whether gas surrounding a pair
of merging black holes might significantly affect the gravitational wave signature. Well, the answer is that those waves would be affected – but not by much. Gas causes the black holes to merge faster,
so that should increase the frequency of the those waves and to a lesser extend the actual shape
of the waves. But the fact is, almost all gas is going to
be ejected from the near region of these merging black holes before they actually collide,
and LIGO only sees the merger in the last second, so the effect would be weak. LIGO is unlikely to have the sensitivity to
distinguish a gassy from a non-gassy merger for any individual merger. It may be easier with neutron star mergers,
which we see a LIGO signal up to a minute before the merger. “Q” suggests that it’s oxymoronic to say that
“All you need is a little quasar” to catch black holes. Suggesting that there’s no such thing as a little quasar. Well actually, that’s not quite true. Active galactic nuclei come in many sizes
– quasar is the name we use for the largest and most powerful, where you can actually
see the accretion disk. Full-blown quasars our powered by supermassive
black holes a few tens of millions to 10 billion times the mass of the sun – and the small
end of that range is indeed a “little” compared to the insane top end. And below the quasar range we have weaker
active nuclei. Those “little” accretion disks are still very
capable of capturing even smaller black holes – and may in fact be better at it because densities
can be higher in the centers of small galaxies where those weaker active nuclei
are found. But you should take all of this with a grain of salt; as rjw elsinga notes: there are a lot of holes in this theory

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  • Reply temp1029 January 29, 2020 at 8:55 pm

    At some point we’ll all just be watching a slideshow of previous episodes, lol

  • Reply Stefan Alenius January 29, 2020 at 9:15 pm

    Looking forward to your episode on Quantum Chromodynamics.

  • Reply 🐱‍👤 January 29, 2020 at 9:15 pm

    what… in… the… actual…˙˙˙lɐnʇɔɐ ˙˙˙ǝɥʇ ˙˙˙uᴉ ˙˙˙ʇɐɥʍ

  • Reply Nick Ames January 29, 2020 at 9:23 pm

    I think Our "Universe" is just SOMEWHERE within the Scale Of Particles, I guess you could call it. How do we know if Our Universe just a "Particle" or Sub Particles ?!

  • Reply Existenceisillusion January 29, 2020 at 9:26 pm

    4:24 is that a secret message? 10:55 that description sounds like 'effective theory' should be renamed 'what-if theory'. 13:08 based on observables but removes space and time? Isn't Space Time an observable, as in the video I'm watching?

  • Reply No-Body-Cares January 29, 2020 at 9:27 pm

    "Reality"? Each clique of humans have their own versions of what is reality. We view theories, ideas, and hypothesis, as being either very possible or extremely delusional. Especially when it comes to science & history. My possible/delusional theory is we are alone in (at least), the Milky Way. The farther back we look, the less advanced civilizations, the farther ahead (near the continuing spread of the universe), the more advanced life is. My theory, Not another's theory.

  • Reply JohnjacobsJHS January 29, 2020 at 9:42 pm

    Your way to smart.

  • Reply fluentpiffle January 29, 2020 at 9:43 pm

    The solution is to realise that there can be only one instance of 'infinitude' (the existentially correct description)..which leads to only one conclusion..

    The Wave Structure of Matter (WSM) explains Werner Heisenberg Uncertainty Principle as caused by incorrect 'particle' conception of Matter.

  • Reply Shiwaz January 29, 2020 at 9:53 pm

    "Wave after wave after wave"…

  • Reply Bogdan Veringa January 29, 2020 at 10:08 pm

    In particle physics or all of the physics you should take electrical into account, otherwise it's just rubbish

  • Reply John Marksman January 29, 2020 at 10:18 pm

    The Atom is like an Adult child or a catdog

  • Reply Ewan Grantham January 29, 2020 at 10:19 pm

    Will y'all be doing an episode on "Massive" Gravity? Is this really as big an idea as some of the media is suggesting?

  • Reply Carlos Castanheiro January 29, 2020 at 11:22 pm

    Have you guys seen this? Blew my mind.

  • Reply Carlos Castanheiro January 29, 2020 at 11:47 pm

    How can we have a particle exist outside of time? Particles, as everything else, are made of energy vibration in a given frequency and frequency is timed. Without time, there can't be frequency, therefore without time, we don't exist, actually nothing physical would exist. Great channel. Keep it up and thank you.

  • Reply ZappaBlues January 29, 2020 at 11:49 pm

    To quote Mr Gumby in the Monty Python Brain Surgeon sketch,… "MY BRAIN HURTS"

  • Reply Jesse Black January 30, 2020 at 12:07 am

    The contrast on this video looks all weird.

  • Reply Dah_Bard January 30, 2020 at 12:08 am

    Please do a video on plasma cosmology, whether it holds any bearing on the true nature of reality, or whether it’s quack pseudoscience.


  • Reply Nigel Healy January 30, 2020 at 12:18 am

    If a black hole event horizon is where time stops from our frame of reference, how can we see black holes merge? We'd see them get nearer and nearer?

  • Reply C Apt January 30, 2020 at 12:22 am

    Heisenberg? He'd be selling some good sh!t.

  • Reply Mike Foss January 30, 2020 at 12:30 am

    Reductionism is an effective yet problematic methodology because it occurs within a particular paradigm, where if the first principle or paradigm is false or flawed, then all of which follows studies the wrong things. Typically, such false methodologies are forced to conceive massive convoluted constructions – an artificial construction of reality – that project a top-down imposition on the subject matter. An example is found in social science, where behavioral science is forced to explain human behavior through artificially imposed empiricism and theories that exist in abstraction from the bottom-up evolutionary processes that are actually responsible. An additional liability of reductionism is that science is pursued, policies implemented, technology developed, ideological careerism chased, and growth-model industries prosecuted with impunity, which all occur in abstraction from systems-based accountability, responsibility, and consequences.

  • Reply pcantillano January 30, 2020 at 12:59 am

    can you talk about the gravitational waves detected recently near betelgeuse?

  • Reply Petersilius Zwackelmann January 30, 2020 at 2:12 am

    Okay what I got from this video ist that electrons are made out of LEGOs 😊

  • Reply Billy Seneczy January 30, 2020 at 2:21 am

    AHHH yes, NOW i understand.

  • Reply Player_1 January 30, 2020 at 3:24 am

    Lattice QCD is the best model

  • Reply joey15151 January 30, 2020 at 3:53 am

    Something I've been struggling with understanding lately is the non-specific reference point used when describing the passage of time after the big bang. We commonly hear phases like "1 quintillionth of a second after the big bang" but that is with respect to what object's frame of reference? If it is relative to the universe and all within it at the moment of the big bang then that implies there is, indeed, a universal clock against which all other events can be measured. Otherwise, it will have to refer to another frame of reference (such as the passage of time a human living on the Earth would experience) which should be dilated almost infinitely per Special Relativity. Its a moot point for our existence, but understanding how time was perceived within, and by, the universe might give us some context to the scales we are dealing with.

  • Reply Musky Elon January 30, 2020 at 4:09 am

    Nima is a sharp dude, like Penrose.

  • Reply Kenneth Hicks January 30, 2020 at 4:43 am

    Eagerly awaiting your QCD episode.

  • Reply Graham Reitz January 30, 2020 at 5:26 am

    More please. Fabulous.

  • Reply Abhishek samal January 30, 2020 at 5:55 am

    You say the sub nuclear particles where the space and times brake….means they are not 3dimensional as space brakes..also not 4 dimensional as time brakes….so they are 5th dimensional….???right matt???

  • Reply jonathan segel January 30, 2020 at 7:41 am

    this is the most 'uncanny valley' i've been in as the edits go, trying to fit so much information in there so quickly!

  • Reply Orwellian Horseman of the Apocalypse January 30, 2020 at 8:55 am

    Never going to be able to hear the name Heisenberg again and not hear Mr Cranston saying "You're goddamn right!"

  • Reply Logi Cian January 30, 2020 at 9:28 am

    The first principle is Allowance.

  • Reply Farhan Rafid January 30, 2020 at 10:16 am


  • Reply Geoffry Gifari January 30, 2020 at 11:16 am

    can S-matrix describe boubd states?

  • Reply 21guitarworld January 30, 2020 at 12:59 pm

    Can you do a video of "Is Science related to Math?"

  • Reply Brendon Brazier January 30, 2020 at 1:08 pm

    If all particles/information are destroyed in a black hole , then how do black holes get bigger?

  • Reply itchykami January 30, 2020 at 4:42 pm

    Maybe I don't understand; it seems one would use only the observable for a shorthand answer to the questions, but should find ways to reintroduce the unobservable when it's time to get down to the smallest detail; I.E. it seems like a breadth-first vs depth-first problem. Problem being that the depth is infinite.

  • Reply skOsH January 30, 2020 at 5:04 pm

    just let me know when it's possible to blast a hole in our universe that is safe to travel through, that allows me to go to another universe.

  • Reply Murphy deffa January 30, 2020 at 5:25 pm

    Some questions that arrised.
    1) If near black hole time is zero. Then if you teleport something massive inside black hole then effect will be never seen because increase of mass will be never seen as it would take infinite time to get out back hole.
    2) If 2 black holes merge then gravity waves are generated.
    Same should happen fast straight moving black hole. Like wave of boat.
    If so, then this wave carrys enery. Question now is where this energy came from. Dose it cause black hole reduce in speed or size.

  • Reply weylguy January 30, 2020 at 5:50 pm

    Take the expansion of the simple exponential e^x = 1 + x + x^2/2! + x^3/3! … It would seem that QFT is stuck on the right side, whereas reality says that reality is described by the left side. The amplituhedron appears to be a step in the right direction. It needs its own PBS Spactime episode!

  • Reply Dj Divide January 30, 2020 at 7:45 pm

    i'm not high enough to watch this. i'll come back in a minute.

  • Reply George Klinger January 30, 2020 at 8:01 pm

    This is one of your crappier videos.💩

  • Reply pingosimon January 30, 2020 at 8:39 pm

    "Fiddly details"

    …Matt, did someone challenge you to sneak "fiddly-dee" into a script?

  • Reply Stan A January 30, 2020 at 10:04 pm

    The information density in this video can produce a black hole

  • Reply Kram1032 January 31, 2020 at 12:23 am

    Ooooh I'm really looking forward to an explanation of the Amplituhedron. When that first became a thing a few years ago it definitely sounded very exciting.

  • Reply Tom Park January 31, 2020 at 1:46 am

    I think someone should do a spoof mashup of all the spacetime episodes, with a load of nice sciencey words accompanying lots of wavy particles bouncing around on sheets of wobbly netting… let's call it something like the Negative Thermal Temporal Short-Spin-Cycle Miele-Bosch (et al) Uncertainty Paradox…

  • Reply Julian Wright January 31, 2020 at 2:06 am

    Really wish you would visualize the math more.

  • Reply Александр Гончаренко January 31, 2020 at 2:22 am

    Spin networks! Next stop: quantum consciousness.

  • Reply Christopher Speirs January 31, 2020 at 2:26 am

    Please make an episode about PSR J1141-6545 and it's new angle to confirm Relativity.

  • Reply Derek Godzisz January 31, 2020 at 3:06 am

    could you make a video on condensed matter physics? thanks.

  • Reply Josiah Baker January 31, 2020 at 3:31 am

    Not true. The best way to get the answer you want online is by stating something incorrectly. I saw that in an online comic, Garfield I think.

  • Reply Alejandro Rojas January 31, 2020 at 6:11 am

    This guy goes to great lengths to get every fact in modern physics right and accesible… but that's nothing next to the dedication he puts in pronouncing international names

  • Reply DermiMatch Scalp Micropigmentation January 31, 2020 at 6:42 am

    I though we were going to hacking something here, now I just feel stupid.

  • Reply Lokartha Aeris January 31, 2020 at 7:27 am

    oops sorry, I thought this was a DR. Strange video

  • Reply Cameron Alexander January 31, 2020 at 8:36 am

    Up quark, down quark, strange quark, charm quark, top quark, bottom quark and of course, Lego quark.

  • Reply Sherlock Holmes lives. January 31, 2020 at 10:40 am

    Speaking as someone who basically knows absolutely nothing about theoretical physics, it seems to me that Einstein had a more pure, classical view of physics, closer perhaps to Newton, than the messier? work in quantum mechanics of Niels Bohr, Erwin Schrodinger and Werner Heisenberg.

  • Reply MetraMan09 January 31, 2020 at 3:39 pm

    if the speed of light is a speed limit, does that mean momentum uncertainty is constrained to plus or minus c which constrains location certainty? And does this mean it has to take time to get a precise location to allow for the position uncertainty to expand outward at the speed of light?

  • Reply Yojiv Iriak January 31, 2020 at 3:58 pm

    Arvin Ash was fabulous on this. Matt is awesome too.

  • Reply Salim Huerta January 31, 2020 at 4:19 pm

    Really want to understand confinement and asymptotic freedom

  • Reply John Farris January 31, 2020 at 5:04 pm

    👽Arvin Ash, YouTube👽

  • Reply ekszentrik January 31, 2020 at 5:36 pm

    My pet theory is that it's pointless to search for ever smaller fundamental particles because there will always be a smaller particle ad infinitum (it's turtles all the way down). Nature just generates such smaller particles on demand (whenever an interaction requires a smaller particle, including human observation). Physics are actually "designed" top-down rather than bottom-up.

  • Reply Sunny Sorout January 31, 2020 at 7:27 pm

    There is no meme in the Internet about this subject,
    Have a itch in the teath😊

  • Reply Joe Maldonado January 31, 2020 at 8:35 pm

    I'm pretty sure I will be able to understand all this when I have born in the next universe.

  • Reply Gary Crasher January 31, 2020 at 10:32 pm

    I wonder if parton distribution functions will be a topic for a future video

  • Reply JonathanH January 31, 2020 at 11:17 pm

    Sometimes I can understand him, but not in this video!

  • Reply Luke The Fluke February 1, 2020 at 1:06 am

    Besides the Australian accent, this guy looks like Peter Dinklage and it's very distracting.

  • Reply John B February 1, 2020 at 3:08 am

    You won't find the Answers in the Universe, it is merely an experience ("Story") produced through "The Processing System of LIFE".
    The reason why won't find the answers, is because "Doble Logic" resides in the human Genome, so you can't rely on human reason, as its processes are Corrupted by the nature of the human Genome.

  • Reply Superluminal February 1, 2020 at 4:23 am

    If you were a light year long then would you feel a gravity wave?

  • Reply Jelly no not that one February 1, 2020 at 5:26 am

    assuming that most of the budget in this video came from getting to use the legos …

  • Reply Ricardo González February 1, 2020 at 6:49 am

    Great video!

  • Reply PegaZeus 109 February 1, 2020 at 12:20 pm

    When I clicked on this video I thought it was going to be a tutorial on how to unlock godlike powers and bend The Universe to my will. I was of course mistaken in this assumption and have since transported myself to 14th Century Italy to became a Benedictine Monk.

  • Reply Cid Fafner February 1, 2020 at 1:57 pm

    Reductionism is cancer.

  • Reply Dr. Laird Whitehill's Fun with Astronomy Channel February 1, 2020 at 4:07 pm

    I didn’t know what I didn’t know. Now I know. I’m not happy.

  • Reply Robert Napnap February 1, 2020 at 4:48 pm

    Matt, what's an essmay trick?

  • Reply Max Power February 1, 2020 at 6:47 pm


  • Reply ZSTAR 1000 February 1, 2020 at 9:10 pm

    I NEED an Amplituhedron episode!

  • Reply Pat S February 1, 2020 at 10:35 pm

    what kind of bullshit is this?

  • Reply Graham Bourbon February 1, 2020 at 11:11 pm

    Despite the almost incomprehensible complexities of this talk, describing
    an alternative understanding of reality at the smallest cosmological scale…
    It's still more comprehensible than the current development of USA politics

  • Reply Brian Messemer February 2, 2020 at 12:18 am

    I love "tame the infinities" 😂 "Down boy, down infinity, sit, SIT, good boy, gooooood infinity." 😂

  • Reply Brian Messemer February 2, 2020 at 12:20 am


  • Reply mustafa razvi February 2, 2020 at 5:12 am

    What is the smallest space where infinite information can be stored ?

  • Reply dpactootle February 2, 2020 at 10:05 am

    In physics everything is really simple, but is the names that are too cool and seem complicated, like Heisenberg, buturonburber, shomborburger and sorontopongongier de Labrieseter. It is all German and some French for spiciness.

  • Reply Daniel Bojidarov February 2, 2020 at 10:17 am

    Here's an antichristic sad joke :"Please Ton 618 Me"

  • Reply sebastian gramano February 2, 2020 at 1:10 pm

    maybe we a grasping the simulation interface we are simulated on, just think about this, what a simulated being would see if they try to understand the simulation they are being run? such as a character in a utterly advance VR game.

  • Reply katzda February 2, 2020 at 3:05 pm

    If light cannot escape black holes, does it mean that beyond the horizon it can travel faster then it's maximum speed? How much force it needed to accomplish this? I guess it will need to be at least equal to the smallest theoretical black hole?

  • Reply Dan Rob February 2, 2020 at 7:07 pm

    Made it to 6:25 and realized that all I'm hearing is gibberish. I don't have the slightest clue. I'm going to bed.

  • Reply Tatenda Tambo February 2, 2020 at 11:00 pm

    Is it weird that 7min into this video my first thought was, "Oh yeah, now PBS Space Time is getting into the good stuff."? Also, thank-you for giving a Chemistry Minor like me a greater insight into what my professors were trying to get across to me… in retrospect, maybe I should have attended more of their lectures… But unless we find evidence of Tachyons, I regret nothing of spending my time partying instead. Did I mention Space Time is awesome?!!?

  • Reply Aqua Kugelschreiber February 2, 2020 at 11:42 pm

    Is it possible that black holes are the fundamental building blocks of the universe?

  • Reply John Scallan February 3, 2020 at 12:50 am

    Lego's! I knew they were the foundation of everything.

  • Reply John B February 3, 2020 at 1:06 am

    Don't waste your time guessing….
    Discover and operate "The Processing System of LIFE", and you will gain access, to any Manual, involving anything in your Universe.
    All this knowledge is Contained in The Permanent Libraries of "The Processing System of LIFE".
    NOT the BS invented through human Interpretation.,

  • Reply Johnathan Fullman February 3, 2020 at 6:34 am

    Spaceless and timeless scattering? Doesn't the concept of scattering imply both space and time? So confused.

  • Reply Pronto February 3, 2020 at 7:53 am

    Wait…if atoms are made of Lego…what is Lego made of…? If we can figure that out…then we will have the answer. [Books flight to Denmark] I'm going to get that Nobel Prize after all. Screw you, high school physics teacher…maybe I'll invite you to Stockholm to watch my acceptance speech!

  • Reply Morten Svendsen February 3, 2020 at 10:00 am

    Atoms are made up of Lego – I knew it! It all makes sense now!

  • Reply Pogi Barenio February 3, 2020 at 2:18 pm

    When you can travel back and forth from physical to spiritual plane, chances are you must be a supernatural or a god coming to this world.

  • Reply Nerdy Rodent February 3, 2020 at 4:23 pm

    Played it at 2x speed and 0.5x speed. Still couldn’t get it.

  • Reply Lalfo February 3, 2020 at 6:20 pm

    Can the entanglement of two 3d parts of a 4d particle preserve the wave function of the particle and maintain causality?

  • Reply thereisnospace February 3, 2020 at 10:16 pm

    ok this is the episode i am certain i cant follow spacetime anymore. its just getting too abstract. i watched the quantum theory videos multiple times. but i just have to admit i can't understand what matt is talking about for the last 1,5 -2 years.

  • Reply TheNoodlyAppendage February 4, 2020 at 12:59 am

    Oh good, for a second I thought you found a security f,law to exploit.

  • Reply John B February 4, 2020 at 5:36 am

    Forget the theory and analytics of the human species whose Anatomy is based on "DOUBLE LOGIC" in the structure of the human Genome and DISCOVER "he Processing System of LIFE".
    When you discover and learn about "The Processing System", you will gain access to Manuals on anything that has existed, in the Permanent libraries of "The Processing System of LIFE". These Manuals will dispel ALL human theory and guess work.

  • Reply Underscore Door February 4, 2020 at 10:12 am

    Do not use the Discord to get questions answered. You are better off using reddit or this chat. If you want to give to patreon to support better learning, more power to you. Just dont do it for discord. See the PBS Spacetime reddit for more info on why the discord is poorly run.

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