from the world's big
What Dark Matter Reveals About the Structure of the Universe
We know that the dark matter has to be pretty cold - moving so slowly that its motion hardly matters - and that allows us to predict in great detail the large scale structure of the universe.
Dark matter is the vast majority of the mass of the entire universe. It’s the mass that holds all galaxies together, and in fact, led to the formation of galaxies. And it also holds clusters together and it made the most important contribution to the organization of the structure of the universe.
We already know that the dark matter is cold. I invented this terminology back in 1983, calling the dark matter hot, warm or cold depending on how rapidly it’s moving in the early stages of the Big Bang. Hot if it’s moving at nearly the speed of light, cold if it’s moving so slowly that its motion hardly matters, and warm is an intermediate case.
We know that the dark matter has to be pretty cold, but it could be a little bit warm. And that would make a great difference to what we call small scale structure, the amount of satellite galaxies and things like that. We don’t yet know the real nature of the dark matter beyond that it’s pretty cold.
Being pretty cold is enough to allow us to predict in great detail the large scale structure of the universe, the organization of the galaxies and to some extent the satellites of the galaxies. But the small scale structure of the universe really depends in more detail of the nature of the dark matter. Also, the dark matter can possibly interact with itself and annihilate and two dark matter particles come together and then make a lot of other stuff. And this could have played an extremely important role in the early universe, and it could still be producing effects that are sensitive detectors in space and on the ground can find experimentally.
We haven’t yet seen clear evidence for any of these things, although there are a number of experiments that are reporting tentative detections. So, it feels very much like we’re on the verge of major breakthroughs in trying to understand the nature of the dark matter. If we finally do figure out the nature of the dark matter, we will then have a single unified picture of the origin and evolution of the entire universe. One that scientists all over the world have contributed to and that can become the basis for a shared origin story that could possibly solidify the bonds of humankind. We’ve never had a single picture, thoroughly supported by scientific evidence, and we’re coming close to it now.
So I think we scientists are feeling very hopeful that we’re about to cross this threshold and have a complete understanding of the origin and the evolution of the universe. And of course, we’re also coming to a much better understanding of the evolution of life. So these last decades of the 20th century and the first decades of the 21st century are a real turning point, I think, in our understanding of how we got here.
In Their Own Words is recorded in Big Think's studio.
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Sallie Krawcheck and Bob Kulhan will be talking money, jobs, and how the pandemic will disproportionally affect women's finances.
Men take longer to clear COVID-19 from their systems; a male-only coronavirus repository may be why.
- A new study found that women clear coronavirus from their systems much faster than men.
- The researchers hypothesize that high concentrations of ACE2-expressing cells in the testes may store more coronavirus.
- There are many confounding factors to this mystery—some genetic, others social and behavioral.
Where is coronavirus hiding?<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzE1NTgxNy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0ODY4NzkxMX0.D84W6ZUOhv6Q-Ki7ddiF3zmDLK_Z6vuXtzfB9R8zLAA/img.jpg?width=1245&coordinates=0%2C179%2C0%2C180&height=700" id="1cc38" class="rm-shortcode" data-rm-shortcode-id="b4e083fb45357e1fb56a8571e8cdc553" data-rm-shortcode-name="rebelmouse-image" />
A laboratory technician at Queen Elizabeth University Hospital, Glasgow, holds a container of test-tube samples from people tested for novel coronavirus.
Further research required<div class="rm-shortcode" data-media_id="z9vH49bb" data-player_id="FvQKszTI" data-rm-shortcode-id="7ef1ab8ca2f90b28543d580c408ed25f"> <div id="botr_z9vH49bb_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/z9vH49bb-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/z9vH49bb-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/z9vH49bb-FvQKszTI.js"></script> </div> <p>The Montefiore-Einstein study is currently preliminary, and further research will be required before researchers can determine what, if anything, its results illuminate.</p><p>The study is currently published on <em>Medrxiv</em>, a <a href="https://www.aje.com/arc/benefits-of-preprints-for-researchers/" target="_blank">preprint</a> distributor. This means the study has been shared publicly before undergoing the <a href="https://undsci.berkeley.edu/article/howscienceworks_16" target="_blank">peer-review process</a>.</p><p>Preprints allow researchers to communicate their findings before official publication, which can take months if not a year or longer. This pre-publication can lead to early feedback, increased visibility, and new collaborations. It's especially helpful for <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6400415/" target="_blank">early-career researchers</a> trying to establish themselves.</p><p>However, given the speed at which coronavirus is spreading, researchers have leaned on preprints as a means of disseminating data to other experts faster than the peer review allows. As a result, <em>Medrixiv</em> has seen a <a href="https://www.nytimes.com/2020/04/14/science/coronavirus-disinformation.html" target="_blank">surge of preprint studies</a>, but they must be read within the context of their preliminary status.</p><p>The Montefiore-Einstein also has its limitations. The study had an initial sample size of only 68 subjects (48 males, 20 females) and a further examination of three families. And the connection of coronavirus to ACE2 enzymes in the testes came from database research, not direct observation.</p><p>The researchers acknowledge the need for further investigation. In particular, Shastri stresses the need to confirm the coronavirus's ability to infect and multiply in testicular tissue. If other researchers find their data promising, they could move forward with new research to build upon the study and see if this clue fits into the mystery.</p>
One clue among many<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzE1NTc5NS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNTQ3NjEzMX0.G-p4KniVRhsHXoIOyFfzEARdN5nGXWWkkQa85x6_ooM/img.jpg?width=1245&coordinates=0%2C281%2C0%2C298&height=700" id="d50c6" class="rm-shortcode" data-rm-shortcode-id="938d51b21df264aae5e883e5f1f9c894" data-rm-shortcode-name="rebelmouse-image" />
Coronavirus protesters in Los Angeles. Men are more likely than women to disregard health warnings from officials.
The word "learning" opens up space for more people, places, and ideas.
- The terms 'education' and 'learning' are often used interchangeably, but there is a cultural connotation to the former that can be limiting. Education naturally links to schooling, which is only one form of learning.
- Gregg Behr, founder and co-chair of Remake Learning, believes that this small word shift opens up the possibilities in terms of how and where learning can happen. It also becomes a more inclusive practice, welcoming in a larger, more diverse group of thinkers.
- Post-COVID, the way we think about what learning looks like will inevitably change, so it's crucial to adjust and begin building the necessary support systems today.
The coronavirus pandemic has brought out the perception of selfishness among many.
- Selfish behavior has been analyzed by philosophers and psychologists for centuries.
- New research shows people may be wired for altruistic behavior and get more benefits from it.
- Crisis times tend to increase self-centered acts.