Technologies

NASA’s Hubble telescope helps scientists solve mystery of dead galaxies

Why did some galaxies from the early universe suddenly stop making stars? Astronomers look back in time to find out.

As mere mortals, we yearn to travel back in time — an obsession nourished by iconic contraptions such as Marty McFly’s car, Hermione Granger’s time turner and Doctor Who’s police box. Often forgotten, however, are the real-life astronomers who kind of already do it.

Recently, one such research team tapped time travel to solve a space mystery from billions of years ago using a unique combination of super sensitive telescopes: Why did some of the early universe’s galaxies strangely stop popping out stars and become inactive, or quiescent?

Galaxies are thought to be at the pinnacle of their star manufacturing potential at this moment in time, so it’s especially puzzling when we discover any that are dormant. Right now, they should be making more stars than ever.

«The most massive galaxies in our universe formed incredibly early, just after the Big Bang happened,» Kate Whitaker, a professor of astronomy at University of Massachusetts-Amherst and lead author of a new study, said in a statement. «But for some reason, they have shut down. They’re no longer forming new stars.»

It turns out, some old galaxies merely ran low on star fuel, or cold gas, early on in their lifetimes. The results of the group’s study were published Wednesday in the journal Nature and could rewrite our knowledge of how the universe evolved.

But hold on, you’re probably still on that bit about astronomers going back in time. If they can swing that, why didn’t they show up to Stephen Hawking’s famous time-traveler-only dinner party?

You might have heard the term «light-year,» which refers to the distance light whizzes along in one Earth year. We need this term as a measurement because light doesn’t travel instantaneously. Of course, turning on your bedroom lamp leads to near-immediate brightness, but if someone turned on a flashlight while standing on the moon, about 238,900 miles (384,472 kilometers) away, its beam wouldn’t reach us for over a second.

That means moonlight has about a one-second lag for us Earthlings. In effect, when we glance at the moon, we’re seeing everything one second after it happens. We’re sort of looking back in time.

Astronomers scale that concept up by the billions. Using powerful telescopes as time machines, they look into deep space — like, billions of light-years away. For this study that mined the mystery of prematurely «dying» galaxies, for instance, the team looked at six cosmic bodies 10 billion to 12 billion light-years away in the universe.

So, it took 10 billion to 12 billion years for any illumination within the studied area to reach their telescope lenses. That means the astronomers were looking back in time far enough to watch the moments soon after the Big Bang — which occurred about 14 billion years ago — unfold in real-time.

Lo and behold, that’s how they solved the cosmic puzzle. The researchers say the galaxies either burned through their cold gas supply too quickly or are blocked from replenishment.

More specifically, Whitaker and fellow researchers demystified the issue by using a mixture of powerful telescopes: the Hubble Space Telescope and the Atacama Large Millimeter/submillimeter Array, or ALMA. The Hubble Space Telescope is sensitive to light across the spectrum — even the type humans can’t see.

And as if time travel wasn’t fantastical enough, the team took advantage of another tool called gravitational lensing to enhance the light collected. Basically, the lens’ viewpoint traveled along a line decorated by hundreds of other galaxy clusters.

Gravitational pulls of those galaxies were strong enough to warp beams of light coming from the team’s six galaxies of interest, stretching them while they traveled to Earth. That helped shed light — no pun intended — on juicy details that would have otherwise been missed within the galaxies.

ALMA, on the other hand, used those details to look for levels of the cold gas, or star fuel, needed by galaxies to make stellar bodies. «There was copious cold gas in the early universe, so these galaxies, from 12 billion years ago, should have plenty left in the fuel tank,» Whitaker said.

Now we know — thanks to the closest we’ve come to time travel — those tanks have been empty.

Technologies

Facebook Brings Back Local Job Listings: How to Apply

One of Facebook’s most practical features from 2022 is being revived by Meta.

On the hunt for work? A Local Jobs search is being rolled out by Meta to make it easier for people in the US to discover and apply for nearby work directly on Facebook. The feature is inside Facebook Marketplace, Groups and Pages, Meta said last week, letting employers post openings and job seekers filter roles by distance, category or employment type.

You can apply or message employers directly through Facebook Messenger, while employers can publish job listings with just a few taps — similar to how you would post items for sale on Marketplace.

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Facebook offered a Jobs feature before discontinuing it in 2022, pushing business hiring toward its other platforms. Its return suggests Meta is attempting to expand Facebook’s usefulness beyond social networking and to position it once again as a hub for community-driven opportunities.

«We’ve always been about connecting with people, whether through shared interests or key life events,» the press release states. «Now, if you’re looking for entry-level, trade and service industry employment in your community, Facebook can help you connect with local people and small businesses who are hiring.»

How to get started with Local Jobs on Facebook

According to Meta, Local Jobs will appear as a dedicated section in Facebook Marketplace starting this week. If you’re 18 or older, you can:

Tap the Marketplace tab on the Facebook app or website.
Select Jobs to browse available positions nearby.
Use filters for job type, category and distance.
Tap Apply or message the employer directly via Messenger.

Businesses and page admins can post jobs by creating a new listing in Marketplace or from their Facebook Page. Listings can include job details, pay range, and scheduling information and will appear in local searches automatically.

The Local Jobs feature is rolling out across the US now, with Meta saying it plans to expand it in the months ahead.

Technologies

Tesla Has a New Range of Affordable Electric Cars: How Much They Cost

The new, stripped-back versions of the Model Y and Model 3 have a more affordable starting price.

Technologies

Today’s NYT Strands Hints, Answers and Help for Oct. 22 #598

Here are hints and answers for the NYT Strands puzzle for Oct. 22, No. 598.

Looking for the most recent Strands answer? Click here for our daily Strands hints, as well as our daily answers and hints for The New York Times Mini Crossword, Wordle, Connections and Connections: Sports Edition puzzles.

Today’s NYT Strands puzzle is a fun one — I definitely have at least two of these in my house. Some of the answers are a bit tough to unscramble, so if you need hints and answers, read on.

I go into depth about the rules for Strands in this story.

If you’re looking for today’s Wordle, Connections and Mini Crossword answers, you can visit CNET’s NYT puzzle hints page.

Read more: NYT Connections Turns 1: These Are the 5 Toughest Puzzles So Far

Hint for today’s Strands puzzle

Today’s Strands theme is: Catch all.

If that doesn’t help you, here’s a clue: A mess of items.

Clue words to unlock in-game hints

Your goal is to find hidden words that fit the puzzle’s theme. If you’re stuck, find any words you can. Every time you find three words of four letters or more, Strands will reveal one of the theme words. These are the words I used to get those hints but any words of four or more letters that you find will work:

BATE, LICE, SLUM, CAPE, HOLE, CARE, BARE, THEN, SLAM, SAMBA, BACK

Answers for today’s Strands puzzle

These are the answers that tie into the theme. The goal of the puzzle is to find them all, including the spangram, a theme word that reaches from one side of the puzzle to the other. When you have all of them (I originally thought there were always eight but learned that the number can vary), every letter on the board will be used. Here are the nonspangram answers:

TAPE, COIN, PENCIL, BATTERY, SHOELACE, THUMBTACK

Today’s Strands spangram

Today’s Strands spangram is JUNKDRAWER. To find it, look for the J that’s five letters down on the far-left row, and wind down, over and then up.

Quick tips for Strands

#1: To get more clue words, see if you can tweak the words you’ve already found, by adding an «S» or other variants. And if you find a word like WILL, see if other letters are close enough to help you make SILL, or BILL.

#2: Once you get one theme word, look at the puzzle to see if you can spot other related words.

#3: If you’ve been given the letters for a theme word, but can’t figure it out, guess three more clue words, and the puzzle will light up each letter in order, revealing the word.