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Space Science

The Universe is Expanding Faster Than it Should Be (nationalgeographic.com) 157

It's one of the biggest puzzles in modern astronomy: Based on multiple observations of stars and galaxies, the universe seems to be flying apart faster than our best models of the cosmos predict it should. Evidence of this conundrum has been accumulating for years, causing some researchers to call it a looming crisis in cosmology. Now a group of researchers using the Hubble Space Telescope has compiled a massive new dataset, and they've found a-million-to-one odds that the discrepancy is a statistical fluke. From a report: In other words, it's looking even more likely that there's some fundamental ingredient of the cosmos -- or some unexpected effect of the known ingredients -- that astronomers have yet to pin down. "The universe seems to throw a lot of surprises at us, and that's a good thing, because it helps us learn," says Adam Riess, an astronomer at Johns Hopkins University who led the latest effort to test the anomaly.

The conundrum is known as the Hubble tension, after astronomer Edwin Hubble. In 1929 he observed that the farther a galaxy is from us, the faster it recedes -- an observation that helped pave the way toward our current notion of the universe starting with the big bang and expanding ever since. Researchers have tried to measure the universe's current rate of expansion in two primary ways: by measuring distances to nearby stars, and by mapping a faint glow dating back to the infant universe. These dual approaches provide a way to test our understanding of the universe across more than 13 billion years of cosmic history. The research has also uncovered some key cosmic ingredients, such as "dark energy," the mysterious force thought to be driving the universe's accelerating expansion.

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The Universe is Expanding Faster Than it Should Be

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  • by gweihir ( 88907 ) on Friday December 24, 2021 @02:14PM (#62112515)

    The current theories we have are broken. No surprise. Unless we eventually get quantum-gravity, I will regard all predictions about how large-scale or very small scale Physics "will" behave as speculation until experimentally verified.

    • Unless gravity turns out to be even more fundamental than quantum mechanics.

      • That it may be more fundamental than quantum mechanics is entirely possible (And I've always felt likely), and QFT hints at this (In that it requires SR to work, confirming the postulates that lead to GR)
        The problem of course is that GR breaks down at quantum scales.
        Does the universe truly contain singularities? Seems unlikely. But really, who knows. Maybe it really does.
        It seems that GR needs some revisions for small scale gravitational interactions, even there aren't gravitons.
        So far, the most success
        • Does GR break down at quantum scales or does quantum break down at very high energies? Both work fine under all experimental and observable conditions except for the very early universe.

          I'm very much not a theorist but is it possible for quantum mechanics to no longer apply at extremely high energies, without violating any known experiments? Then the universe is just relativistic quantum mechanics (with some high energy cutoff) operating in curved space time.
          • Does GR break down at quantum scales or does quantum break down at very high energies? Both work fine under all experimental and observable conditions except for the very early universe.

            Not just the very early universe.
            Any GR singularity is a problem for QM.

            I'm very much not a theorist but is it possible for quantum mechanics to no longer apply at extremely high energies, without violating any known experiments? Then the universe is just relativistic quantum mechanics (with some high energy cutoff) operating in curved space time.

            Absolutely.
            The current universe, described by QFT is "Just relativistic quantum mechanics"
            With 1 major exception: Gravity.
            Most QM physicists want gravity to be a force, but Einstein's postulates still remain true- Gravity isn't a force, and all attempts of describing it as one have failed.
            Loop Quantum Gravity keeps General Relativity, but allows QM to not break down at high energies, but making more complicated spacetimes.

            • As far as I know the only observable singularity is the big bang. What happens in black holes stays in black holes ;) And of course there is very little, if any, experimental data describing the universe before the end of inflation. The equivalence principal is so fantastically well tested that curved space seems a far better explanation than treating gravity as a traditional force. But just "seems" the question is what self, and data consistent theories can be generated.
              • As far as I know the only observable singularity is the big bang.

                That's fair.

                What happens in black holes stays in black holes ;)

                Not quite, but the technicality isn't worth getting into the Blackhole Information Paradox over.

                • Yes - information and black holes is a whole different of worm...holes? But what really matters here is that the only situation near a singularity where we have experimental evidence is the big bang. We also don't have any other experimental evidence anywhere near Plank energy.

                  So the question is whether there is a theory that looks like QM in curved space at "low" energies (eg
                  Can I have quantum mechanics operating as waves on some "classical" medium that doesn't obey the uncertainty principal, but
        • Yes GR's Singularities are a problem but QM also has problems, one of them being the "Black Hole Information paradox," quantum state information being lost once a black hole evaporates, breaking QM's time-reversal symmetry.
          • Well since the universe is expanding, going forward in timespace 1 second is a longer distance than going back 1 second, making time-reversal symmetry sketchy except in limited fringe cases.

            • That's not T-symmetry. A physical system is time reversal invariant if its underlying laws are not sensitive to the direction of time. QM equations are time invariant. You can say the rock hit the pond causing the waves or you can say the waves kicked the rock out of the pond. Without specifying a direction of time then either exploitation is valid. Not so with a evaporated black hole. You can't specify a backward (from our perspective) direction of time from a system with no quantum information to a syst
          • Absolutely.
            But that problem only exists because Black Holes apparently evaporate, which is a bizarre effect of a bizarre confluence of GR and QM already.
            I.e., the BIP is already 3 layers deep in hypothesized problems existing in theories with known open questions.

            Personally, there's enough evidence suggesting T-symmetry is nothing but a postulate that made some early physicists feel better, that I wouldn't lose a lot of sleep over violations of T-symmetry in GR. Particularly as long as there is actual o
      • So am I wrong to think that what is more fundamental than what is a matter of perspective?

    • Did Einstein have any theories on this? He seems to be proven right on things many years later.

      • by znrt ( 2424692 ) on Friday December 24, 2021 @06:33PM (#62113257)

        "einstein de sitter space-time"

        einstein believed the universe is static. he forced this belief into his own equations by introducing a "cosmological constant" with a very specific value so they allowed for a static universe.

        when other scientists showed that the field equations pointed at a dynamic universe anyway he found the idea preposterous and dismissed it as wrong interpretations or directly miscalculations. only after hubble brought up hard evidence did he reconsider, and presented a theory with de sitter for a continuously expanding universe. he didn't live to know that the expansion was actually accelerating.

        the funny thing is that he could have realized all that from his own groundbreaking discoveries a decade earlier, had he not been so stubborn about that particular. even the brightest among us can only see that far.

    • Unless we eventually get quantum-gravity, I will regard all predictions about how large-scale or very small scale Physics "will" behave as speculation until experimentally verified.

      So you are disregarding every prediction of Einstein then? After all General Relativity cannot explain what happens inside a black hole. The Milky Way does not rotate around a super massive black hole. It rotates around your mom. Thanks I'll be here all week.

      • After all General Relativity cannot explain what happens inside a black hole.

        Sure it can, we just don't think it's correct.

        • No, the mathematics of General Relativity requires division by zero for inside black holes. General Relativity describes everything else about black holes including how they form.
          • No, the mathematics of General Relativity requires division by zero for inside black holes.

            Which is a description of what happens inside. It's a singularity. A point of infinite density, the effects of which are limited only by the fact that spacetime has a maximal speed limit of time and space.

            General Relativity describes everything else about black holes including how they form.

            Yup. And it describes what's inside. We just don't think it's correct.

            • That's not how 'division by zero' works. If you get a division by zero, then not only is the answer *unknown* (not wrong, or right, *unknown*), it also means the mathematical model you are using is not usable in that situation.

              The *model* has a singularity at the center of the black hole. Because of that, it tells us nothing about what is actually at the center of a black hole.

              • That's not how 'division by zero' works.

                That's entirely incorrect.

                If you get a division by zero, then not only is the answer *unknown* (not wrong, or right, *unknown*),

                Wrong again.

                it also means the mathematical model you are using is not usable in that situation.

                Wrong for the third time. I'll give you a caveat that it's a good indication that the model is incomplete.
                There's no rule that says a singularity cannot be real, we just have strong suspicions that they are not.

                The fact that the Schwartzchild Metric is over radius does not imply that it's not a valid physical description of spacetime.
                In fact, the GR term for it is an incomplete geodesic.
                Spacetime ends at the singularity.
                There's no rule that says spacetime cannot e

                • There's no rule that says a singularity cannot be real, we just have strong suspicions that they are not.

                  And that is not how science works. By that logic, no one has proven Bigfoot does not exit therefore they must exist? Is that your logic? There's no rule that says spacetime cannot end. It just doesn't "smell right"

                  “Smells” right also is not science. Quantum mechanic principles also do not “smell right” either. Should we also discount them too?

                  • And that is not how science works. By that logic, no one has proven Bigfoot does not exit therefore they must exist? Is that your logic? There's no rule that says spacetime cannot end. It just doesn't "smell right"

                    You just reduced the most successful forward-predictive theory of all time with Bigfoot sightings?
                    You're a fucking joke.

                    “Smells” right also is not science. Quantum mechanic principles also do not “smell right” either. Should we also discount them too?

                    Quite a bit of science is based on smell. When something doesn't smell right, you go looking for correct answers.

                    No one is discounting anything. They're looking for possible better answers.

                    Back to school, fuckwit.

                    • And while you're there, have your prof teach you to calculate the local time for a photon.

                      Then I want you to boldly exclaim to him that it must be wrong, because of the singularity in the calculation.
                      When you're done with that, go explain to the QM guys how the quanta for the electromagnetic field actually doesn't live forever, thus photons decay, because there's a singularity in the math.

                      Congratulations, you've just disproven modern physics. Because singularities mean something's wrong.
                      You've just di
                    • You just reduced the most successful forward-predictive theory of all time with Bigfoot sightings? You're a fucking joke.

                      No, you did. Your argument is a triple negative argument: "There's no rule that says a singularity cannot be real, we just have strong suspicions that they are not." Something cannot exist because no one has proven that it cannot be real?

                      Quite a bit of science is based on smell. When something doesn't smell right, you go looking for correct answers.

                      Again wrong. Science is not based on smell. Science is based on evidence. Hunches, guesses point to possible answers. Answers still require evidence.

                      No one is discounting anything. They're looking for possible better answers.

                      Except you just did. Did you scroll up?

                      Back to school, fuckwit.

                      So you are the type of person to resort to insults when challenged. That is who you ar

            • The supermassive black hole in our galaxy is speculated as 146 million miles acress. We can't _measuer_ what is inside it, but there is no reason to suspect it is a point mass.

              • Other than that is how General Relativity predicts it? Other than every other observation shows it has no observable volume?
                • What part of general relativity says _anything_ about the interior density or structure of a black hole. Even popular science magazines like Discover have gotten this right, see https://www.discovermagazine.c... [discovermagazine.com] .

                           

                  • What are you talking about?
                    At the point of collapse, it will collapse infinitely.
                    The only possible result is a single mathematical point.

                    Even popular science magazines like Discover have gotten this right, see https://www.discovermagazine.c... [www.discovermagazine.c] [discovermagazine.com] .

                    FTA:

                    At some point, the collapsing core will be smaller than an atom, smaller than a nucleus, smaller than an electron. It’ll eventually reach a size called the Planck Length, a unit so small that quantum mechanics rules it with an iron fist.

                    This is the quantum mechanical argument.
                    GR is quite clear- it's a single mathematical point. GR doesn't observe the planck length.
                    Until there is an accepted theory of quantum gravity, GR is the only real model we have, and it says it's a point.

              • Incorrect.
                GR absolutely predicts that it is a single point.
                That's why it's called a singularity.
      • by dcw3 ( 649211 )

        But your mom has a black hole. Thanks I'll be here all week.

      • > After all General Relativity cannot explain what happens inside a black hole.

        It doesn't need to. The boundaries of a black hole are not a sharp cutoff. They describe a time-space that we can't reacive any more information from, but there is no reason to think it is unique, especially since black holes can _evolve_ from collecting matte together, such as a large enough star cooling down and compressing below the Swarzschild radius.

    • by gtall ( 79522 )

      The current theories are mathematical constructs. For them to be broken can only mean they are inconsistent. Newton's theory of gravity is not inconsistent, it works great inside its boundaries. Same for Einstein and quantum theory.

      If you mean the current theories are incomplete, then duh, who knew?

      • by gweihir ( 88907 )

        Nope. Quantum theory and General relativity apply to the same subject and are really one theory. And that theory _is_ inconsistent.

    • The difference between speculation and science is measurement. That's obvious.

      What's a little more subtle is that not all measurements are created equal. Most of the more famous verifications of relativity were made from Earth or very near the Earth.

      I would exclude things like empirical verification of the Shapiro delay because it made a radar measurement of the travel time to a different planet at two different phases of its orbit, so the measurement spanned a bigger baseline than Earth or its gravity well

    • Unless we eventually get quantum-gravity, I will regard all predictions about how large-scale or very small scale Physics "will" behave as speculation until experimentally verified.

      Physics is an experimental science: you should always regard any prediction about how physics will behave as speculation until experimentally verified. No matter the scale and regardless of whether we discover a theory of quantum gravity, this will still remain true.

      • by gweihir ( 88907 )

        Physics is an experimental science: you should always regard any prediction about how physics will behave as speculation until experimentally verified. No matter the scale and regardless of whether we discover a theory of quantum gravity, this will still remain true.

        Well, if the get the theory fixed, I am willing to regard predictions made with it as "good initial hypotheses". Sure, that is just a different way of saying "speculation of higher quality".

    • Every theory is broken. What gets people noble prizes is figuring how and why it is broken. Is just a matter of domain, such as modeling mercury with Newtonian physics. Or is fundamental, like the ultraviolet catastrophe. Or an assumption like aether. If we assumed things were broken we would have learned nothing. But in proving the disconnect between model and observations and then showing why changed the world. Not I said observations and not reality. That is because we only know and San model what we
    • by AmiMoJo ( 196126 )

      Even the statement "the universe is expanding" isn't quite right. We can see things moving further away from each other, but we can't see the edge of the universe. There probably isn't even an edge at all, just the furthest point any part of the big bang has reached.

      • by gweihir ( 88907 )

        Indeed.

      • You seem to be trying to conceive of the expanding universe as if it were an inflating balloon you are looking at from the outside, where thinking of it of it from the inside like measuring the moon's orbit to the Earth with measuring sticks that are shrinking and clocks that are slowing down would be a better model of reality.

  • Should? (Score:5, Insightful)

    by byromaniac ( 8103402 ) on Friday December 24, 2021 @02:33PM (#62112555)

    The Universe is Expanding Faster Than it Should Be

    Ha! I love how whenever there is a disagreement between model and reality, people tend to blame reality for not doing what it should.

    I mean, 'Universe Expanding Faster Than Models Predict' or 'Models Underestimate Expansion of Universe' would be far more accurate.

    • Ha! I love how whenever there is a disagreement between model and reality, people tend to blame reality for not doing what it should.

      But we wouldn't know there was anything interesting going on, were it not for the fact that we had a theory, that fails to predict reality. In this case, a "failed" theory conveys information. It is worth noting that Newton's laws of motion are a "failed" theory under the extreme conditions that result in relativistic effects, but scientists and engineers continue to use the old theory, because it is not obsolete, but merely incomplete. Relativistic effects only make sense with respect to Newtonian mechanic

  • Otherwise it couldn't keep up with yo mama!
  • by bb_matt ( 5705262 ) on Friday December 24, 2021 @02:50PM (#62112601)

    ... so here's the content:

    The universe is expanding faster than it should be
    The latest measurements with the Hubble Space Telescope suggest the universe is expanding faster than scientists' models predict—a hint that some unknown ingredient could be at work in the cosmos.

    BYMICHAEL GRESHKO
    PUBLISHED DECEMBER 17, 2021
    10 MIN READ

    It’s one of the biggest puzzles in modern astronomy: Based on multiple observations of stars and galaxies, the universe seems to be flying apart faster than our best models of the cosmos predict it should. Evidence of this conundrum has been accumulating for years, causing some researchers to call it a looming crisis in cosmology.

    Now a group of researchers using the Hubble Space Telescope has compiled a massive new dataset, and they’ve found a-million-to-one odds that the discrepancy is a statistical fluke. In other words, it’s looking even more likely that there’s some fundamental ingredient of the cosmos—or some unexpected effect of the known ingredients—that astronomers have yet to pin down.

    “The universe seems to throw a lot of surprises at us, and that’s a good thing, because it helps us learn,” says Adam Riess, an astronomer at Johns Hopkins University who led the latest effort to test the anomaly.

    The conundrum is known as the Hubble tension, after astronomer Edwin Hubble. In 1929 he observed that the farther a galaxy is from us, the faster it recedes—an observation that helped pave the way toward our current notion of the universe starting with the big bang and expanding ever since.

    Researchers have tried to measure the universe’s current rate of expansion in two primary ways: by measuring distances to nearby stars, and by mapping a faint glow dating back to the infant universe. These dual approaches provide a way to test our understanding of the universe across more than 13 billion years of cosmic history. The research has also uncovered some key cosmic ingredients, such as “dark energy,” the mysterious force thought to be driving the universe’s accelerating expansion.

    But these two methods disagree on the universe’s current expansion rate by about 8 percent. That difference might not sound like much, but if this discrepancy is real, it means the universe is now expanding faster than even dark energy can explain—implying some breakdown in our accounting of the cosmos.

    The researchers’ findings, described in several studies submitted last week to The Astrophysical Journal, use specific types of stars and stellar explosions to measure the distance between us and nearby galaxies. The dataset includes observations of 42 different stellar explosions, more than double the next-biggest analysis of its kind. According to the team’s work, the tension between their new analysis and results from measurements of the early cosmos has reached five sigma, the statistical threshold used in particle physics to confirm the existence of new particles.

    Other astronomers still see room for possible errors in the data, which means it’s still possible the Hubble tension is just an artifact.

    However, “I do not know how this large of an error is hiding at this point, and if it is, it’s just something no one has suggested,” says team member Dan Scolnic, an astronomer at Duke University. “We’ve checked every idea that’s been presented to us, and nothing’s doing the trick.”

    Cosmic microwaves and the distance ladder
    The Hubble tension comes from attempts to measure or predict the universe’s current rate of expansion, which is called the Hubble constant. Using it, astronomers can estimate the age of the universe since the big bang.

    One way of getting the Hubble constant relies on the cosmic microwave background (CMB), a faint glow that formed when the universe was just 380,000 years old. Telescopes such as the European Space Ag

  • Really? (Score:2, Insightful)

    by the_skywise ( 189793 )

    Reality doesn't match our model so reality must be wrong?

    Is this what we've regressed to now?

    • Reality doesn't match our model so reality must be wrong?

      I think quite a common reaction to unexpected outcomes is "this cannot happen". Prudent software engineers trap errors that logically cannot happen, based on code analysis, but nonetheless, impossible things have an annoying tendency to occur. This is where you can indulge in a little witticism, such as "This error is logically impossible. Please adjust your universe."

  • Things to do, people to kill...

  • by kbahey ( 102895 ) on Friday December 24, 2021 @03:05PM (#62112623) Homepage

    Wait ... Hear me out ...

    Subir Sarkar [ox.ac.uk] is a professor of theoretical physics at Oxford. He has done important work in providing evidence that the expansion of the universe is not accelerating.

    Instead, he is saying that there is a dipole effect because earth, and the galaxy cluster that we are in, are all moving in space, and that gives the effect of accelerating expansion.

    He provides compelling evidence (for a non-specialist at least) for what he says. He also casts doubts on the evidence for acceleration by analyzing their data (supernovae as standard candles, and their red shift), since a dipole effect is observed on that.

    Watch his lecture at Oxford [youtube.com] , or his shorter talk with Sabine Hossenfelder [youtube.com] (no slides though).

    If his findings hold up to scrutiny, this will lead to the Nobel Prize for the acceleration no longer being true. Saul Perlmutter and Adam Reiss jointly got it for the discovery of dark energy. The latter is the one quoted in the article and summary.

    Reiss has dismissed Sarkar's finding, so far.

    This is exciting, since it removes one mystery about dark energy. More importantly, it shows the rigors of the scientific method.

    • I was about to dismiss your comment as "crank," but then I saw Sabine Hossenfelder's name. So now I'm listening!

    • by burtosis ( 1124179 ) on Saturday December 25, 2021 @01:27AM (#62113783)
      The short of it is Sarkar is saying the red shift on one side and blue on the opposite written across the sky in the cosmic microwave background maybe isn’t all due to us moving through space. Right after the CMB was discovered, it became a universal cosmic speed indicator because it was assumed on large scales, maybe 100x average galaxy spacing, space was the same everywhere and therefore you could be at rest with the rest of the visible universe. Since ours had this dipole, or red blue side in the sky, it made sense you could just zero it out like in all the maps of it where they show all the little very slight differences in the CMB across the sky. That would be a simple way of measuring our velocity through space relative to most everything else. The original assumption that space was uniform at large scales is possibly not correct and there could be lumpiness at the largest scales and thus movement on them. I haven’t read his papers but in the video he talks about examples of large red shift differences at large scales in several sources. If true, this would make us need to back up and re-examine many things like the influence dark energy (simply a positive cosmological constant) has. Not sure of the validity, but this isn’t really any kind of quackery but the typical probing around the edges of certainty because that’s what eventually, with enough tries, brings progress.
  • by dcw3 ( 649211 ) on Friday December 24, 2021 @03:40PM (#62112713) Journal

    The universe is expanding exactly as fast as it should be. It's our understanding of it that isn't expanding fast enough.

  • "The Universe is Expanding Faster Than it Should Be"

    No, I guarantee you it isn't.

    It's just expanding faster than we think it should, which means we're missing something or that we have a faulty model.

    In reality, it's expanding at exactly the rate it "should" be.

  • The Universe is expanding at exactly the rate it should be, Scientific theory though just has a lack of understanding and data to explain it.
    • Scientific theory though just has a lack of understanding and data to explain it.

      This is precisely the driving force behind scientific discovery. Before we can discover that the universe is expanding faster than we expect, we have to have an existing theory of an expanding universe. We discover interesting stuff to study, which is interesting because it is not what we expected. If we just blundered about without any theory at all, I would suggest that we would not discover anything.

      I come to this as an engineer, not a scientist. I like lots of theory. I work out what I think an electron

  • by logicnazi ( 169418 ) <gerdesNO@SPAMinvariant.org> on Friday December 24, 2021 @04:03PM (#62112785) Homepage

    Is it possible that this apparent acceleration could also be explained by the visible universe (or a large part of it) being in a region of unusually low density in the universe (so the effect of gravity from the more densely packed parts of the universe we can't see is stretching our part of the universe out)?

    I'm curious if this would explain the observations and if so whether this explanation would require more or less change to our existing theories. I'm guessing there is a good reason (not just the assumption we are in a typical part of the universe) why this explanation isn't considered (I think maybe something to do with CMB) but I'm hoping someone can explain why.

    • by tomthepom ( 314977 ) on Friday December 24, 2021 @11:41PM (#62113687)

      No, and for two reasons.
      Firstly, the universe is expanding symmetrically - all points are moving away from all other points. Any 'outside' force causing that would have to be symmetrical, but since gravity is an inverse square force, a spherically symmetrical amount of mass outside the sphere of the observable universe would have zero net gravitational effect on anything in that sphere. e.g., if the earth was a hollow sphere, you would feel no net gravitational force inside it because the gravity from one side would cancel the gravity from the other side.
      Secondly, just as the light from outside the observable universe will never reach us because that region of space is expanding away from us faster than the speed of light, so will any gravity from outside never reach us, since gravity also moves at the speed of light. Everything outside the cosmic horizon is causally disconnected from our region of space. But the expansion of the universe is uniform everywhere, from regions far distant (and closer to the cosmic horizon), to regions closer to us that are causally disconnected from anything outside the observable universe.
      Well, that's my understanding of it anyway..

  • Then it should be. Just like my wife.

    Thank you, thank you. I'll be here all night. Tip the veal and try your waitress.
  • Observing the Universe makes it expand faster, due to a quantum quirk. We have to shut out all telescopes or risk the Great Rip, tearing matter apart, which some scientists say is even worse than Covid.

  • Dark energy is more properly, "invisible energy" and dark matter is really "invisible gravity."

  • So much astrophysics/quantum physics in particular and science in general (ignore all the nanotech and the spikeviruses --- spike proteins are really good for you, just like Sarin gas) is such bunkem today, without supporting proof, theory built upon theory built upon theory with nonâ"reprodicable studies!
    Fred Hoyle's Steady State Theory and black holes ---- there's your answer!
  • You do realize that the universe is asymptotically contracting, right? I donâ(TM)t understand why this concept is so hard for people to grasp, this is relativity 101. We exist within the event horizon of a black hole, so the equation would be (E)^2 = (m(s^2 + t^2))^2

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