Is Dark Energy Getting Stronger?


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The power of Dark Energy may be increasing as the universe ages. Subtle clues are emerging that the accepted model for the nature of dark energy and dark matter may not be all that. We saw the first such clue recently in our recent episode on the Crisis in Cosmology. Today we’re doing a Space Time Journal Club to reveal another clue. We’re looking at a new paper in Nature Astronomy, “Cosmological constraints from the Hubble diagram of quasars at high redshifts” by Risaliti and Lusso. It hints that the cosmological constant may not be so constant after all. In fact it may be increasing. If this is true, then our prediction for the future of our universe looks VERY different, and may involve the entire universe tearing itself to shreds at the subatomic level in the Big Rip.

On this edition of Space Time Journal Club we look at:
Risaliti & Lusso (2019) “Cosmological Constraints from the Hubble Diagram of Quasars at High Redshifts”

#darkenergy #darkmatter #spacetime

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100 comments on “Is Dark Energy Getting Stronger?

  1. Tim Beaton on

    If the Big Rip™IS coming, does this feed into the possibility of Penrose's Conformal Cyclic model? I admit, i tried to read his book, but i failed miserably to understand the details (my brain is getting too old!). A universe that expands to the point of nothing left but photons, should that be what might happen in a Big Rip, seem stop be exactly what Penrose was hypothesising.
    Please, for dunderheads like myself, could you at Space Time do a video on Penrose's CCC? Even if he is wrong, it would still be an interesting video.

  2. Zerotech on

    If Dark Energy can't be measured because it's changing, does that mean that we can only see one type of dark energy, or there exists more than one type of dark energy?

    If so how would you measure 2 types of dark energy?

  3. Ralph Hope on

    I've asked this before on a similar video but was not lucky enough to have my comment used. I'll have one more go then give up;

    Surely using the standard inverse square law (which you appear to show on this video) for supernovae/quasar distance is incorrect?

    If space itself is expanding then spread of light as it travels out in a sphere from its source would be stretched (and therefore dimmed) by the expansion of space – the same effect that causes red-shift, but it the x and y axis rather than z. Ie if space grew 5% in the up/down, left/right dimensions you need to expect an 11% lower brightness than the inverse square alone law would predict due to space itself expanding.

    Using the inverse square law alone would surely lead us to believe that things were further away than they actually were. The missing piece of the maths?

  4. Andrew Driffill on

    So, I have a theory I’ve been trying to get to you guys, I’m not going to go into it here, but it doesn’t have an interesting relation to this topic, so I’ll try and explain what I can here..

    To me, the problem here is that the ‘information’ we obtain from these light based phenomena (such as red shift) can only infer to us information relevant to moment the ‘light’ was emitted from its given source..

    So in this case, a standard candle that is 1000Ly away will give us an accurate snapshot of the Hubble constant and the like at time the light was emitted – 1,000years ago, the problem with the math is we use this information in relation to the ‘time now’ thus causing an ‘increasing’ error as you include more candles from further distances.

  5. Subscribe to Pewdiepie on

    Hey guys, we don’t mean to be bothersome, but the top youtuber position is in danger of being overtaken by a corporation (T-Series). We aren’t asking you to care about or watch Pewdiepie’s videos, we are asking you to preserve the #1 youtuber spot for actual solo youtubers. Youtubers don’t want to be represented by a company, and I’m sure you don’t either. Please subscribe to Pewdiepie and thanks for your time

  6. jason jones on

    I think this is completely biased ……what about white energy ……seriously……. and you can call me racist but I think it was actually a white man that came up and coined the phrase dark energy……..

  7. Michael Palin on

    So, can someone explain why the expansion of the universe only occurs on the cosmic scale? From the explanations I had read or watched of this phenomenon, I understood that it was already occurring at every scale at the same time and I'm confused now. Isn't dark energy everywhere already? And why is it not pushing away all our atoms as it pushes away galaxies? Maybe I don't understand the concept of space expanding. When dark energy expands space, does matter move with it or stays in place if there are other forces around? That is, if two atoms in a molecule are, say, 5 Å away from each other and space doubles in size, would they be 10 Å away now or would they stay at 5 Å because of the molecular forces?

    And by the way, I know I'm overstating my welcome here, but, what kind of force does dark energy even exert? It expands space itself so, does it work like a negative form of gravity?

  8. Brama Ryder on

    If light is the fastest car on the track, what good is the = side of MC 2. As mass will never break one light barrier, never mind breaking it 299 792 458 in one second. So its M & 99.99 times the speed of one light barrier.

  9. Bae Lavery on

    Hi PBS Space Time,
    Can you please adressed Mike McCulloch's – Quantised Inertia. It stands to correct much of the mathematics in relation to dark matter, and dark energy; as well as provides solutions for bridging quantum mechanics with general relativity. QI is strong, but relatively recent breakthrough with a lot of verified mathematics and reliable peer review among the arvix community etc.

    Thank you for the always amazing content.

  10. Stuart Wine on

    Do the effects of dark energy permeate from the cosmic level into the subatomic level? It's amazing to think the same force that tears apart galaxies can tear apart an atom. Doesn't that suggest dark energy is more powerful than the powerful nuclear force?

  11. MrKafein on

    According to the Janus Cosmological Model, the extra stretching of the light from these distant stars would come from a high concentration of negative matter getting in the way, showing them more redshifted than they really are, a negative lensing effect, if you prefer. That would mean there is actually NO acceleration of the expansion of the universe.

  12. Alex Weinstein on

    Not one to comment (honestly you do the best job out of many of these videos, great stuff!), but virgin orbit will be using cosmic girl, a repurposed Virgin Atlantic 747. I got a job there so I know enough to be dangerous :).

  13. joe humphrey on

    Meh propaganda, it in no way was that ever accepted , except by those that wish propagate some strange black box 'science' that can seemingly pay off multiple mortgages. All while never providing an answers, primarily the answers that would negate it's own continuation.
    You want a study? Find how many evidentiary papers get published that negate the hypothesis being explorered?

  14. Circadianarchist on

    What about the geometry of the universe? Isn't Lambda the one that makes the universe flat? If it is true it changes would that mean the universe's geometry changes too and we are seeing it as flat now by pure coincidence?

  15. Mike Doonsebury on

    Your arguments are impeccable, but your conclusion is imbecilic. "The expansion effects things on the largest scale, but isn't strong enough to effect things inside a galaxy." Of course not. Because if you had some sort of accelerated expansion inside the galaxy effecting stars, then you'd have some sort of mysterious, unexplained force that caused the stars in the outside of the galaxy to rotate faster than a Keplarian model would predict.

  16. Brook Parsons on

    Would xrays and visible light from quazars be affected and similarly by disruptions in the space in between? We track the changes in visible light from stars to find their composition, exoplanets, life and/or future tech. Isn't there a high probability that the dust between us and Tabby's star or other astrophysical phenomena we don't fully understand yet could be affecting one or both of our light values?

  17. Random Rant on

    Way to sell, and feed at the same time, our collective existential dread. Dagnabit and too bad. Any idea if there is some way to pluck a star from the sky (Or better yet all of them to burn for fuel to re-engineer the universe.) and change things? The math in my head doesn't match that idea (Even astronomically remotely…) but after following the solid logic (No sarcasm again.) of a black hole bomb I realize that maybe there are alternatives. Any ideas even if they are currently impractical?

    I had to pause first out on this video (Which I am sure will be informative and amazing. Seriously no sarcasm intended. I genuinely enjoy most videos. Even most of the ones that kill probabilities and theories that would be cool… Like certain types of alternative universe theories… Thanks gravitational waves.) to remark that while I like the Deadpool shirt I miss Luna.

  18. Dave Hammond on

    Part of the problem with your calculations is that once you are finished with negative and imaginary numbers, you try to make sense of your results with only positive and real numbers.


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