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

Today’s NYT Connections Hints, Answers and Help for May 18, #707

Hints and answers for Connections for May 18, #707.

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

Today’s Connections puzzle is a mix of difficult and easy. The purple category does what most purple categories do, and makes you really break down how you think about the words. Read on for clues and today’s Connections answers.

The Times now has a Connections Bot, like the one for Wordle. Go there after you play to receive a numeric score and to have the program analyze your answers. Players who are registered with the Times Games section can now nerd out by following their progress, including number of puzzles completed, win rate, number of times they nabbed a perfect score and their win streak.

Read more: Hints, Tips and Strategies to Help You Win at NYT Connections Every Time

Hints for today’s Connections groups

Here are four hints for the groupings in today’s Connections puzzle, ranked from the easiest yellow group, to the tough (and sometimes bizarre) purple group.

Yellow group hint: School days.

Green group hint: About there!

Blue group hint: Sure, let’s go.

Purple group hint: The Scarlett Letter.

Answers for today’s Connections groups

Yellow group: Tasks for a student.

Green group: Encouraging responses in a guessing game.

Blue group: Up for anything.

Purple group: What «A» might mean.

Read more: Wordle Cheat Sheet: Here Are the Most Popular Letters Used in English Words

What are today’s Connections answers?

The yellow words in today’s Connections

The theme is tasks for a student. The four answers are assignment, drill, exercise and lesson.

The green words in today’s Connections

The theme is encouraging responses in a guessing game. The four answers are almost, close, not quite and warm.

The blue words in today’s Connections

The theme is up for anything. The four answers are easy, flexible, game and open.

The purple words in today’s Connections

The theme is what «A» might mean. The four answers are area, athletic, excellent and one.

Technologies

Today’s NYT Strands Hints, Answers and Help for May 18, #441

Here are hints and answers for the NYT Strands puzzle No. 441 for May 18.

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 will probably be easier if you have some basic knowledge about a certain type of vessel. You don’t really need to have ever been on one, since the answers show up in books and movies all the time. 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: Riding the wind.

If that doesn’t help you, here’s a clue: famed song by Christopher Cross.

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:

DULL, TILE, TILER, SEER, GALE, GALES, HAIL, SAIL, LEEK, GLUE, HALL, TALL, HEAT

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’ve got 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:

HELM, HULL, KEEL, MAST, STERN, RIGGING, RUDDER, TILLER

Today’s Strands spangram

Today’s Strands spangram is SAILBOAT. To find it, start with the S that’s four letters down on the farthest row to the left, then wind across, up and down.

Technologies

Google I/O 2025: How to Watch and What to Expect

With Android 16 out of the way, Google I/O will certainly be all about AI.

Google I/O 2025 takes place on May 20 and 21 with Google’s big keynote happening on day 1. We expect Big G to talk about its myriad innovations across its ever-expanding portfolio of products — almost certainly with a huge focus on AI every step of the way. If we collectively cross our fingers, promise to be good and eat all our vegetables then we may even be treated to a sneak peek at upcoming hardware.

Read more: Android 16: Everything Google Announced at the Android Show

Google also hosted a totally separate event that focused solely on Android. The Android Show: I/O Edition saw the wrappers come off Android 16, with insights into the new Material 3 Expressive interface, updates to security and a focus on Gemini and how it’ll work on a variety of other devices.

By breaking out Android news into its own virtual event, Google frees itself to spend more time during the I/O keynote to talk about Gemini, Deep Mind, Android XR and Project Astra. It’s going to be a jam-packed event, so here’s how you can watch I/O 2025 as it happens and what you can look forward to.

Google I/O: Where to watch

Google I/O proper kicks off with a keynote taking place on May 20, 10 a.m. PDT (1 p.m. EDT, 6 p.m. BST). It’ll almost certainly be available to stream online on Google’s own YouTube channel, although a holding video is yet to be available. There’s no live link on the I/O website yet, either, though you can use the handy links to add the event to your calendar of choice. Expect links to a livestream to be available closer to the day.

What to expect from Google I/O 2025

Little chat about Android 16: As Google gave Android 16 its own outing already, it’s likely that it won’t be mentioned all that much during I/O. In fact at last year’s event, Android was barely mentioned, while uses of the term «AI» went well over a hundred.

Android XR: Google didn’t talk much about Android XR during the Android show, focusing instead on the purely phone-based updates to the platform. We expected to hear more about the company’s latest foray into mixed-reality headsets in partnership with Samsung and its Project Moohan headset, so it’s possible that this is being saved for I/O proper.

Gemini: With Android being spun out into its own separate event, Google is evidently clearing the way for I/O to focus on everything else the company does. AI will continue to dominate the conversation at I/O, just as it did last year (though hopefully Google can make it more understandable) with updates to many of its AI platforms expected to be announced.

Gemini is expected to receive a variety of update announcements, including more information on its latest 2.5 Pro update which boasts various improvements to its reasoning abilities, and in particular to its helpfulness for coding applications. Expect lots of mentions of Google’s other AI-based products, too, including DeepMind, LearnLM and Project Astra. Let’s just hope Google has figured out how to make this information make any kind of sense.

Beyond AI, Google may talk about updates to its other products including GMail, Chrome and the Play Store, although whether these updates are big enough to be discussed during the keynote rather than as part of the developer-focused sessions following I/O’s opening remains to be seen.