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New study says cosmic acceleration and dark energy don't exist
An Oxford scientist claims a Nobel-Prize-winning conclusion is wrong.
- Paper by Oxford University physicist Subir Sarkar and his colleagues challenges how conclusions about cosmic acceleration and dark energy were reached.
- Physicists who proved cosmic acceleration shared a Nobel Prize.
- Sarkar used statistical analysis to question key data, but his methodology also has detractors.
Is our Universe's expansion speeding up? The 2011 Nobel Prize went to three scientists for proving just that. But what if the evidence they used to come up with this conclusion was wrongly interpreted and the supposed cosmic acceleration is simply an artifact of our movement through a local part of the Universe? In the big picture, there's no speeding up. What's also not there is the mysterious dark energy, thought to be creating that acceleration, says a new paper from a group of physicists who take issue with the supernovae-related evidence that was used to come up with the original Nobel-worthy conclusion.
The Nobel Prize for the cosmic acceleration idea, if you're wondering, was won by Saul Perlmutter, Brian Schmidt, and Adam Riess for "for the discovery of the accelerating expansion of the Universe through observations of distant supernovae". They used evidence from exploded stars called "la supernovae" or "standard candles" to show that the Universe's expansion was getting faster. These kinds of supernovas are so bright that we actually know their absolute brightness. This fact allows scientists to calculate the distance of these explosions from Earth, while studying the red shift in the light they emit points to the Universe's rate of expansion. In 1998, groups led by Perlmutter and Schmidt found light from 50 supernova to be dimmer than it was supposed to be, leading them to conclude that cosmic expansion was actually accelerating (thanks to dark energy – a yet-to-be-directly-observed enigmatic force that supposedly takes up 68% of all mass-energy in the Universe while causing it to expand).
But while the expansion has become accepted as science fact, there have been some who see things differently. Following up on his 2015 paper on this subject, Oxford University physicist Subir Sarkar and his colleagues at the Niels Bohr Institute and the Paris Institute of Astrophysics now published a second study taking issue with the idea of a Universe growing with acceleration.
As explained in Physics World, by statistically analyzing a sample of 740 la supernovae in their 2015 paper, Sarkar's team found "only marginal" support for cosmic acceleration with low statistical significance. The difference in their approach was in how they looked at the procedures used to calculate the absolute brightness of supernovae and how their light is absorbed by dust that gets in the way.
2011 Nobel Laureates in Physics, Saul Perlmutter, Brian P. Schmidt and Adam G. Riess2011 Nobel Laureates in Physics, Perlmutter, Schmidt and Riess, describe how an assumed error turned into the surprise discovery that the universe is expandi...
Critics of that paper abounded, taking issues with their methodology and pointing to other data that showed acceleration. Now, in the second paper, to be published in Astronomy and Astrophysics, the scientists continue to assail the supernovae evidence and the idea of cosmic acceleration by pointing to anomalies in the red-shift data and how calculations with respect to the Cosmic Microwave Background (CMB) are carried out.
"If you look at supernovae in only a small part of the sky, it would look like you had cosmic acceleration," Sarkar says. "But we are saying that it is just a local effect, that we are non-Copernican observers. It has nothing to do with the overall dynamics of the universe and therefore nothing to do with dark energy."
Riess disagrees with Sarkar's conclusions and data, calling it outdated. His team used data from 1,300 supernovae in their latest study and came up with clear-cut support for the acceleration's existence. Furthermore, he stated, "The evidence for cosmic acceleration and dark energy are much broader than only the supernovae Ia sample."
Who would argue with a Nobel Prize-winner? Subir Sarkar, who believes that "The CMB does not directly measure dark energy," adding "That is a widely propagated myth."
You can check out his new paper for yourself at arXiv.
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The team caught a glimpse of a process that takes 18,000,000,000,000,000,000,000 years.
- In Italy, a team of scientists is using a highly sophisticated detector to hunt for dark matter.
- The team observed an ultra-rare particle interaction that reveals the half-life of a xenon-124 atom to be 18 sextillion years.
- The half-life of a process is how long it takes for half of the radioactive nuclei present in a sample to decay.
Gender and sexual minority populations are experiencing rising anxiety and depression rates during the pandemic.
- Anxiety and depression rates are spiking in the LGBTQ+ community, and especially in individuals who hadn't struggled with those issues in the past.
- Overall, depression increased by an average PHQ-9 score of 1.21 and anxiety increased by an average GAD-7 score of 3.11.
- The researchers recommended that health care providers check in with LGBTQ+ patients about stress and screen for mood and anxiety disorders—even among those with no prior history of anxiety or depression.
Study findings<p>For the study, <a href="https://link.springer.com/article/10.1007/s11606-020-05970-4" target="_blank">published in the Journal of General Internal Medicine</a><em>, </em>Flentje and her team evaluated survey responses from nearly 2,300 individuals who identified as being in the lesbian, gay, bisexual, transgender, and queer (LGBTQ+) community. Most of the participants were white, while nearly 19 percent identified as a racial or ethnic minority. Multiple genders were represented with cisgender women (27.2 percent) and men (24.6 percent) making up a majority of the participants. Sixty-three percent had been assigned female at birth. For the most part, participants identified their sexual orientations as queer (40.3 percent), gay (36.5 percent), and bisexual (30.3 percent).</p><p>The JGIM study participants were recruited from the 18,000-participant <a href="https://pridestudy.org/" target="_blank">PRIDE Study</a> (Population Research in Identity and Disparities for Equality), which is the first large-scale, long-term national study focusing on American adults who identify as LGBTQ+. It conducts annual questionnaires to understand factors related to health and disease in this population. </p><p>Participants filled out an annual questionnaire (starting in June 2019) and a COVID-19 impact survey this past spring. Flentje noted that on an individual level, some people may not have experienced a big change in anxiety or depression levels, but for others there was. Overall, depression increased by a <a href="https://patient.info/doctor/patient-health-questionnaire-phq-9" target="_blank">PHQ-9 score</a> of 1.21, putting it at 8.31 on average. Anxiety went up by a <a href="https://www.mdcalc.com/gad-7-general-anxiety-disorder-7" target="_blank">GAD-7</a> score of 3.11 to an average of 8.89. Interestingly, the average PHQ-9 scores for those who screened positive for depression at the first 2019 survey decreased by 1.08. Those who screened negative for depression saw their PHQ-9 scores increase by 2.17 on average. As for anxiety, researchers detected no GAD-7 change among the study participants who screened positive for anxiety in the first survey, but did see an overall increase of 3.93 among those who had initially been evaluated as negative for the disorder. </p>
Risks among gender and sexual minorities<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="fc3fd1ae68b77bbbf58a6995638d6d65"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/EnUqDjCqg0A?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>The LGBTQ+ community is a vulnerable population to mental health concerns because of their fear of stigmatization and previous discriminatory experiences.</p> <p>Previous research by the Human Rights Campaign has found "that LGBTQ Americans are more likely than the <a href="https://medicalxpress.com/tags/general+population/" target="_blank">general population</a> to live in poverty and lack access to adequate medical care, paid <a href="https://medicalxpress.com/tags/medical+leave/" target="_blank">medical leave</a>, and basic necessities during the pandemic," said researcher Tari Hanneman, director of the health and aging program at the campaign.</p> <p>"Therefore, it is not surprising to see this increase in anxiety and depression among this population," Hanneman said in the release. "This study highlights the need for <a href="https://medicalxpress.com/tags/health+care+professionals/" target="_blank">health care professionals</a> to support, affirm and provide <a href="https://medicalxpress.com/tags/critical+care/" target="_blank">critical care</a> for the LGBTQ community to manage and maintain their mental health, as well as their physical health, during this pandemic."</p>
What should health care providers do?<p>The authors of the study recommend that health care providers check in with LGBTQ+ patients about stress and screen for mood and anxiety disorders in members of that community—even among those with no prior history of anxiety or depression.</p><p>As cases of COVID-19 continue to mount, the sustained social distancing, potential isolation, economic precariousness, and personal illness, grief, and loss are bound to have increased and varied impacts on mental health. Effective treatments may include individual therapy and medications as well as more large-scale coronavirus support programs like peer-led groups and mindfulness practices. </p><p>"It will be important to find out what happens over time and to identify who is most at risk, so we can be sure to roll out public health interventions to support the mental health of our communities in the best and most effective ways," said Flentje.</p>
What we know about black holes is both fascinating and scary.
- When it comes to black holes, science simultaneously knows so much and so little, which is why they are so fascinating. Focusing on what we do know, this group of astronomers, educators, and physicists share some of the most incredible facts about the powerful and mysterious objects.
- A black hole is so massive that light (and anything else it swallows) can't escape, says Bill Nye. You can't see a black hole, theoretical physicists Michio Kaku and Christophe Galfard explain, because it is too dark. What you can see, however, is the distortion of light around it caused by its extreme gravity.
- Explaining one unsettling concept from astrophysics called spaghettification, astronomer Michelle Thaller says that "If you got close to a black hole there would be tides over your body that small that would rip you apart into basically a strand of spaghetti that would fall down the black hole."