from the world's big
Remodeling the Universe
David Z Albert the is Frederick E. Woodbridge Professor of Philosophy and Director of the M.A. Program in The Philosophical Foundations of Physics at Columbia University. He is the author of "Time and Chance," "Quantum Mechanics and Experience," among others. He received his B.S. in physics from Columbia College (1976) and his doctorate in theoretical physics from The Rockefeller University. He lives in New York City.
Question: Can you give a brief overview of quantum mechanics?
David Albert: Quantum mechanics is supposed to be a completely general account of the behavior of the physical world. The way quantum mechanics emerged historically was that around the end of the 19th century, the beginning of the 20th century, there were more and more reasons to be worried that the prevailing classical physics -- that is the physics of Newton and later of Maxwell, who incorporated electromagnetic phenomena into Newton's theory -- that the Newtonian/Maxwellian model of the world that we had was apparently going to be unable to account for atomic structure, was going to be unable to account for things as simple as the stability of matter.
A famous problem that very much worried people just in the period immediately before quantum mechanics emerged was that people had experimentally seen that the atom apparently consisted of a small positively charge core with electrons rotating around it, and it's easy to show from Maxwell's equations that electrons going in a circular orbit around a core like that are going to produce huge amounts of electromagnetic radiation; they're going to lose all of the energy of their orbits to this radiation; they should very quickly crash into the nuclei, and matter should cease to exist. So there was a very acute problem about how matter could be stable at all. The more this and other related problems were looked into at the beginning of the century, the more -- the less it looked as if there was any hope at all of an explanation of these phenomena along the lines of Newtonian and Maxwellian classical physics.
It looked like this was going to call for nothing less than a global revolution in our fundamental theories of physics. And over a period of 10 years or so -- centered on the period between 1920 and 1930, say -- a new fundamental theory of the world was developed, called quantum mechanics. Quantum mechanics, then, aspires to be a complete replacement for Newtonian mechanics. It now proposes to be understood as the fundamental laws of the evolutions of the physical states of every kind of physical system. But, as it surely should have, quantum mechanics was engineered in such a way as to essentially reproduce the predictions of classical mechanics for those systems, human-size systems, macroscopic and larger systems, for which Newtonian mechanics was known to do a good job, okay? And the way it worked out was that the predictions of quantum mechanics differed significantly from those of Newtonian mechanics only for very small kinds of physical systems, subatomic systems, so on and so forth, which is exactly where we needed it to differ.
So it's important to separate how the theory was discovered and what it was originally developed for from what it proposes to be once it's there. It was originally developed to account for new phenomena that we had discovered at the subatomic level, okay? But it would be a serious misunderstanding to interpret it therefore as merely a specialized theory of subatomic objects. It's supposed to be the theory of the entire physical world, but its discovery was prompted by failures of the previously existing theory in the subatomic realm.
What is quantum mechanics? A philosopher of science explains how it emerged as the necessary response to classical physics.
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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."
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.
A new study looks at what would happen to human language on a long journey to other star systems.
- A new study proposes that language could change dramatically on long space voyages.
- Spacefaring people might lose the ability to understand the people of Earth.
- This scenario is of particular concern for potential "generation ships".