Dark matter is only detectable by the gravitational pull it exerts on visible objects, like stars and galaxies.
If physicists had a “Most Wanted” list, dark matter particles would be right at the top.
Dark matter is an invisible material that lurks throughout the cosmos. In fact, it makes up about 85 percent of the matter in the universe. Unlike the ordinary matter inside you, your computer, the planet and all the stars in the sky, dark matter doesn’t produce or reflect any light. For decades, physicists have tried to identify the particles that make up this mysterious substance. But so far, all searches have come up empty.
Understanding light and other forms of energy on the move
Hold on, you might say. If dark matter is invisible, how do we even know it exists? Dark matter is detectable because of the gravitational tug it exerts on visible objects. This is similar to the way you can tell it’s windy outside without being able to see wind. You know there’s wind because you can see it rustling the leaves on trees.
The first clues that dark matter exists came in the 1930s. An astronomer named Fritz Zwicky peered at a distant swarm of galaxies and found something odd. The galaxies were moving fast. In fact, they were moving so fast that the galaxy cluster should fly apart. So there must have been some unseen material hiding among the galaxies, holding the cluster together with its gravity.
See all the entries from our Let’s Learn About series
In the 1970s, astronomer Vera Rubin found that stars swirl around spiral galaxies much faster than expected. At such high speeds, these stars should fly apart. To avoid shredding themselves, galaxies must be held together by dark matter’s gravity.
Most scientists are now convinced that dark matter exists. But they still have no idea what it is. Many different types of particles have been proposed to explain dark matter. Yet experiments designed to search for those particles have so far only ruled out contenders. As a result, some physicists have an alternate idea. Maybe dark matter doesn’t exist at all. Maybe at very large scales, gravity simply behaves in strange ways we do not yet understand.
Want to know more? We’ve got some stories to get you started:
Spin in this Milky Way bar may show cosmic dark matter does exist The gravitational pull of dark matter may be slowing down a rotating bar of stars at the center of our Milky Way galaxy. (7/19/2021) Readability: 7.4
If dark matter particles could kill us, they would have already The fact that dark matter hasn’t killed anyone yet puts limits on how large these mystery particles can be. (8/6/2019) Readability: 7.7
Strange X-rays point to possible ‘dark’ matter Since dark matter can’t be directly observed, scientists have to come up with creative ways to find it. One method is searching for X-rays from deep space. (2/20/2017) Readability: 7.9
Scientists Say: Dark matter
Explainer: What is a planet?
The dark side of the universe
Distant galaxy seems filled with dark matter
Ancient light may point to where the cosmos’ missing matter hides
Cosmic mystery: Why are many galaxies dark?
Some white dwarf stars point to possible dark matter
Mapping the invisible
Having a hard time imagining how scientists “see” invisible dark matter? Try this at-home experiment from NASA. Drop some beads or other small items into two plastic bottles, then fill one bottle up with water. Like dark matter, the water is transparent, but its effects can still be detected. You can see this when you compare how the motion of visible objects, such as beads, differs between the two bottles.
Billy Maxwell, a feisty, gritty competitor who won seven PGA Tour titles with the help of a lethal 4-wood and precise short game, died Monday at the Brooks Rehabilitation Hospital in Jacksonville, Florida, at the age of 92. He had suffered a stroke on Sept. 5. In addition to a golf career that included eight top-10s and 19 top-25s in major championships and a 4-0 record in the 1963 Ryder Cup, Maxwell also owned the Hyde Park Golf Club, long considered one of the top public-golf experiences in the area. He loved nothing more than to set up shop at the practice range, hit balls, tell golf stories or give free tips to customers. “That’s all he ever wanted to do, was play and talk golf,” said his daughter Melanie Bevill. “I asked him one time, ‘do we always have to talk...
Written By Sierra Powell / Reviewed By Ray Spotts So, you've finally gotten to the point where you've accepted that your fitness game isn't all that great, and you want to take some steps to change it. One major factor in this is building lean muscles - a process that can seem daunting at first - but if you put in the effort, it is much easier than you think! Here are five ways you can build and up your fitness game. Take Supplements That Work The following are some essential supplements to take for building lean muscles and upping your fitness game. Whey Protein...
There are two meetings to look at on Wednesday, with my attention being at Melton and Redcliffe. Below are the best bets for the respective programs. Melton Best bet: Race 3, Number 4, Carnera It has been a little while since he has greeted the judge, but he gets a great chance to change that here. This horse is on the back-up after a game effort last Friday at Geelong when leading and fighting on pretty well when fourth. This horse drops a bit in grade and depth here, should find the front and prove hard to get past. Next best: Race 2, Number 1, Crafty Old Fox He loves the sit/sprint set-up and has drawn the pole. That should eventuate here. The rub of the green didn’t go his way last start at Shepparton...
Punchy Korean flavours done taco-style in these Spicy Korean Chicken Tacos. This weeknight taco dinner is great for your family or a party dish.
The post Spicy Korean Chicken Tacos appeared first on Sugar Salt Magic.
Vision actor Paul Bettany is ready for another season of WandaVision if it happens. While WandaVision didn’t score any major Emmys on Sunday night, that doesn’t take away from how well-received Marvel Studios’ first television show was. The show competed under the limited series category at the Emmys and Kevin Feige has made it clear there will not be another season of the series. Elizabeth Olsen Says That ‘WandaVision’ Will Likely Remain A Limited Series It seems Marvel’s plan for their shows is for some like Loki to get multiples seasons, and others, like WandaVision, to get a limited run. However, Paul Bettany shared with Entertainment Weekly that if a second season of WandaVision were to ever...
Car insurance is an oft-overlooked aspect of car ownership. Most customers see advertised prices and deals in TV commercials and just assume that’s how much they’re going to pay per month. However, cars need to...
The article How Much Does it Cost to Insure a BMW versus a Tesla? appeared first on BMW BLOG
Since Gwen Stefani and Blake Shelton officially tied the knot in early July, there’s been non-stop headlines about possible pregnancy rumors. With the number of varying stories, it’s tough to separate fact from fiction. Gossip Cop has investigated a lot of pregnancy rumors for Stefani and Shelton, so let’s take a look at the latest. Gwen Stefani Desperately Wants A Baby Girl? According to HollywoodLife, Gwen Stefani and Blake Shelton were “talking about having a baby” in July. The outlet noted that starting a family was a natural next step for the newlyweds. After having three sons with her ex Gavin Rossdale, Stefani thought “it would be incredible to have a little girl,” one source leaked. “It’s...
Thanksgiving is my favorite holiday, and there are a few reasons why. I get to see a ton of family members and spend all day with them. We watch a lot of football and play extremely competitive board games. And no matter what we are doing, there’s always some delicious food involved. When it comes down to it, Thanksgiving is really all about appreciating the many blessings in our lives while enjoying the heck out of a traditional turkey dinner and all the fixin’s that come with it. Turkey, dressing, mashed potatoes, gravy, creamed corn, stuffing—these are the ultimate comfort foods. And it’s that’s just the beginning. There’s also cranberry sauce, green beans, sweet potato pie, rolls with butter… just talking about these yummy dishes puts a smile on my face....
If you purchase an independently reviewed product or service through a link on our website, we may receive an affiliate commission. Dancing With the Stars is back for its 30th season, premiering on Monday night (Sept. 20) with an all new, star-studded cast. Longtime judge Len Goodman will return to the panel after missing out on last season due to COVID-19 travel restrictions. His replacement last season, Derek Hough, will continue his judging gig alongside Goodman, Bruno Tonioli and Carrie Ann Inaba. See below for everything you need to know and how to watch Dancing With the Stars. Dancing...