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

Tinder Users Must Start Logging In With Their Faces, Starting Nationwide

The social app now has new US requirements including face identification to help quell longstanding problems with catfishing and more.

US Tinder users will find a new feature when they open up the dating app starting Wednesday: A mandatory Face Check on their phones will be required before they can log into their profiles.

The Face Check step will begin with a new request to record a video of your face, a more casual version of setting up Apple’s Face ID login. Tinder will then run checks comparing your face data to your current profile pics and automatically create a small face badge for your profile. We already know how it works, because Tinder has already launched the feature in Canada and California before the full US rollout.

The technology, powered by FaceTec, will keep biometric data of the user’s face in encrypted form but discard the scanning video for privacy. Tinder will be able to use the face data to detect duplicate accounts, in an effort to cut down on fake profiles and identity theft.

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Tinder’s facial recognition rollout is also made to prevent catfishing, or people pretending to be someone else on Tinder to scam or blackmail them. But that also points to a deeper problem on the rise in dating apps — a growing number of bots, many controlled by AI, are designed to glean personal information or fool users into scammy subscriptions, among other problems.

Tinder’s working against these bots on several fronts, including this Face Check push as well as ID Check, which requires a government-issued ID and other types of photo verification.

The dating app also recently released a feature in June to enable double-dating with your friends, which Tinder reports is especially popular with Gen Z users. If you’re worried about the latest hazards on Tinder, we have guide to safety practices.

A representative for Tinder did not immediately respond to a request for comment.

Technologies

Today’s NYT Mini Crossword Answers for Thursday, Oct. 23

Here are the answers for The New York Times Mini Crossword for Oct. 23.

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

Need some help with today’s Mini Crossword? Read on. And if you could use some hints and guidance for daily solving, check out our Mini Crossword tips.

If you’re looking for today’s Wordle, Connections, Connections: Sports Edition and Strands answers, you can visit CNET’s NYT puzzle hints page.

Read more: Tips and Tricks for Solving The New York Times Mini Crossword

Let’s get to those Mini Crossword clues and answers.

Mini across clues and answers

1A clue: Like some weather, memories and I.P.A.s
Answer: HAZY

5A clue: Statement that’s self-evidently true
Answer: AXIOM

7A clue: Civic automaker
Answer: HONDA

8A clue: What fear leads to, as Yoda told a young Anakin
Answer: ANGER

9A clue: Foxlike
Answer: SLY

Mini down clues and answers

1D clue: Verbal «lol»
Answer: HAHA

2D clue: Brain signal transmitter
Answer: AXON

3D clue: Hits with a witty comeback
Answer: ZINGS

4D clue: Sing at the top of a mountain, maybe
Answer: YODEL

6D clue: Name of the famous «Queen of Scots»
Answer: MARY

Technologies

Today’s NYT Strands Hints, Answers and Help for Oct. 23 #599

Here are hints and answers for the NYT Strands puzzle for Oct. 23, No. 599.

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 might be Halloween-themed, as the answers are all rather dangerous. Some of them 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: Please don’t eat me!

If that doesn’t help you, here’s a clue: Remember Mr. Yuk?

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:

POND, NOON, NODE, BALE, SOCK, LOVE, LOCK, MOCK, LEER, REEL, GLOVE, DAIS, LEAN, LEAD, REEL

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: