---
title: 'Nobel Prize Under Fire: Is Dark Energy Real?'
source: 'https://youtube.com/watch?v=xeFaOY2UCEk'
video_id: 'xeFaOY2UCEk'
date: 2026-08-04
duration_sec: 431
---

# Nobel Prize Under Fire: Is Dark Energy Real?

> Source: [Nobel Prize Under Fire: Is Dark Energy Real?](https://youtube.com/watch?v=xeFaOY2UCEk)

## Summary

The video discusses the ongoing controversy in physics regarding the accelerating expansion of the universe and the existence of dark energy. It highlights a recent challenge to the 2011 Nobel Prize-winning discovery, the rebuttals, and the scientific infighting that followed, concluding that current data is insufficient to settle the debate.

### Key Points

- **Controversy over universe expansion** [00:00] — Physicists disagree on whether the universe's expansion is accelerating. A group last year claimed it does not speed up, implying the 2011 Nobel Prize was awarded in error. The Nobel winners pushed back, but their rebuttal was also rebutted.
- **Basics of expansion and dark energy** [00:30] — The universe is expanding, which everyone agrees on. In the 1990s, supernovae observations suggested the expansion is accelerating, requiring dark energy with negative pressure, comprising 2/3 of the universe's energy.
- **Controversies of the Nobel Prize** [01:10] — The 2011 Nobel Prize was controversial because evidence was initially weak, and the two discovery groups were not independent, sharing results, which could introduce bias.
- **New challenge to acceleration** [02:06] — A 2023 paper claimed a systematic mistake: the apparent acceleration is due to the age of galaxies affecting supernova appearance, not actual acceleration. After correcting for this, dark energy is unnecessary.
- **Rebuttal by Nobel winners** [03:16] — A group including two Nobel laureates argues the new paper overestimated the galaxy age effect, and standard corrections account for it. They maintain the expansion is still accelerating, with a press release calling it a 'crisis averted'.
- **Rebuttal of the rebuttal** [03:58] — The original authors rebutted the rebuttal in March, and a third group using a different dataset found no acceleration, but this did not get a press release, likely due to infighting.
- **Scientific infighting and data insufficiency** [04:38] — The speaker notes that scientists questioning the status quo often lose in departmental politics. The data is insufficient to make a strong case either way; galactic environment models are not well understood.

### Conclusion

The debate over dark energy and cosmic acceleration remains unresolved, with current data insufficient to settle it. The scientific process is influenced by biases and infighting, but the mystery of the universe's accelerating expansion persists.

## Transcript

Strange things are happening in physics. It seems  that physicists can't agree what's up with the   expansion of the universe. Last year, a group  claimed that the expansion of the universe does   not, as we thought, speed up. That would mean that  the 2011 Nobel Prize in physics was awarded in  
error. The Nobel Prize winners have now pushed  back, but their rebuttal was also rebutted,   and it's somewhat of a mess really. But here's  the brief summary. The universe is currently  
expanding. This part everyone agrees on. It  expands simply because it contains matter and   energy. However, in the 1990s, observations  of supernovae seem to show something more.   The universe doesn't just expand. The expansion is  getting faster. Normal matter and energy does not  
do it. This why physicists had to introduce energy  with negative pressure which is called dark energy   and not small amounts of it. 2/3 of the energy  in the universe would have to be dark energy to  
fit the observations. The physicists who made the  discovery were awarded a Nobel Prize in physics   in 2011. This Nobel Prize has been controversial  for several reasons. One reason is that at the  
time many thought it was awarded prematurely. The  evidence was not particularly strong back then.   And that's true. But then again, the statistical  significance has much improved since then and the   results seems to have held up. Or maybe it's  just confirmation bias. Another reason is that  
the results partly looked convincing because  the discovery was made by two different groups.   However, if you do as much as read the author  lists or the acknowledgements of the papers, it's  
obvious that the two groups were in contact with  each other and shared results. These were clearly   not independent analyses. This doesn't mean the  results are wrong, but it's a way that biases can  
enter. Then last year, a completely different  group looked at the supernovi data again, and   they said there's a serious systematic mistake in  both of the data analyses. You see, the way that  
one usually infers the accelerated expansion is  to look at how supernovae look different depending   on how far away they are. And since light moves  well with the speed of light, the more distant the  
supernovi, the further back in time they happened.  Looking at supernovae at different distances then   tells you how the expansion of the universe  has changed. The paper from last year then  
said actually the different appearances of the  supernovae have nothing to do with the accelerated   expansion. It's just that the further away the  supernovae are the younger the galaxies where the  
supernovi happened on average and the age of the  galaxy influences how the supernovae look. They   redid the analysis and found that if one properly  removes the effect from the age of the galaxy, the  
expansion of the universe no longer accelerates  and dark energies are necessary. Bold, because   unnecessary is not a word physicists usually apply  to invisible things that explain everything. The   news is now that a group which includes two of  the original Nobel Prize winners say that the  
argument fails. They say that the New Dark Energy  paper overestimated how much the age of the galaxy   affects the supernova and that whatever's left is  accounted for by standard corrections. The bottom  
line is they say the expansion of the universe  is still speeding up. The university put out a   bombastic press release that was widely picked up.  According to the press release, lead author Dr.  
Phil Wiseman said, "The previous and well-accepted  measurements were in fact fine and our current   understanding of the page of the universe remains  robust. Thankfully, we have averted this crisis,   but the mystery about why the universe is still  accelerating in size remains." A press release  
does not mention that this rebuttal was rebutted  already in March by the authors of the original   paper who well defend their own analysis. At  the same time, another paper was published by  
a third group which redid the analysis using a  different data set of supernovae and found again   that the acceleration is not there. This did not  get a press release because that would have made  
the Nobel Prize winners very unhappy. This isn't a  joke. It's almost certainly what happened. There's   a lot of infighting in departments about whose  research will be publicly mentioned and scientists  
who question the status quo are usually on the  losing end. What are we to make of this? These   aren't calculations you can check with a pen on a  paper. So I can't tell you whose analysis is wrong  
or right. But I want to offer a general comment  about the existence of this discussion. Obviously,   the result depends on what you assume happens in  the environment of the supernovae and how that   enters the observations. This in return depends  on how you think galaxies form and develop,  
which in return depends on our model for the  universe. We know that these galaxy formation   models are difficult to get right. They have loads  of parameters to twiddle that'll give you whatever   you want. And still, they somehow managed to screw  up the predictions for the earliest galaxies. My  
takeaway here is therefore that the data is  simply insufficient to make a strong case one   way or another. Galactic environments are not well  understood enough. Not today, and they certainly   were not in the 1990s. So those papers all get a  five out of 10 on my [ __ ] meter. But thankfully,  
the crisis was averted by the people whose Nobel  Prize depended on averting it. Always reassuring   when the universe checks with the committee first.  I'm always looking for new product recommendations  
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