Ethan Siegel

Ask Ethan: How and when will the Universe die? As the Universe ages, it continues to gravitate, form stars, and expand. And yet, all this will someday end. Do we finally understand how?

How and when will the Universe die?

#AskEthan

Ever since the discovery of dark energy, astronomers have been secure in predicting the heat death of our Universe.

But if dark energy is changing, as DESI data suggests, are all bets off?
bigthink.com/starts-with-...
#space #cosmology #astro

You can learn more about journalism, ethics, and the world of reporting by reading Karen Attiah than you can by reading everything else by everyone working at the Washington Post today.

What do distant observers see when they look at Earth? From here on Earth, looking farther away in space means looking farther back in time. So what are distant Earth-watchers seeing right now?

What do distant observers see when they look at Earth?

If a distant observer takes a look back at Earth, what would they see?

They'd see a more primitive version of our planet, of course, and beyond a certain distance, no Earth at all.
bigthink.com/starts-with-...
#space #astro #Earth

YouTube video by The Well Jane Goodall on death, her next great adventure #shorts

RIP to the one and only Jane Goodall, who has finally embarked on what she promised just a short while ago would be her "next great adventure" here: www.youtube.com/shorts/XeXNK...

Thousands of NASA employees to bid farewell to the NASA they knew As October begins, thousands of longtime NASA employees are leaving the agency. 4000+ will exit by January 9, 2026, changing NASA forever.

Thousands of NASA employees to bid farewell to the NASA they knew

Yes, NASA science is being destroyed, and the NASA we know is actively in the process of being gutted.

Here are the receipts.
bigthink.com/starts-with-...
#space #astro #nasa #usa

The "atom" lost its original meaning, and that's good for science Invented over 2000 years ago by Democritus, the word atom literally means uncuttable. Revived in 1803, today's "atoms" can indeed be split.

The “atom” lost its original meaning, and that’s good for science

First proposed more than 2400 years ago, the idea of the "atom" was an uncuttable, indivisible building block to all reality.

So why do we still call our composite structures atoms, then?
bigthink.com/starts-with-...
#physics #atom

So happy that my undergrad nerd colleagues and my grad school nerd colleagues are finding each other!

Want to make a game together, lol?

The 5 biggest mysteries about the origin of our Universe From the Big Bang to a prior period of cosmic inflation, our cosmic origins are clearer than ever. Yet these 5 big mysteries still remain.

The 5 biggest mysteries about the origin of our Universe

We know more than ever before about the beginning stages of our Universe's history.

But five huge puzzles, from the first stars to the origin of matter to the nature of inflation, still remain.
bigthink.com/starts-with-...
#space #bigbang

It's really too bad. Masks are supposed to be about public health and protecting one another.

These days, you have to protect yourself and plan for yourself, alone, almost everywhere you go.

(In the USA. There are plenty in Japan!)

Mark is one of my favorite illustrators, and I use (and link to) his work in my newsletter often. Ethan is also a great writer, so I expect this book will be wonderful.

As the author of the book that @markgarlick.com and Jon Lomberg co-illustrated, the opportunity to get a free, frameable art masterwork along with the extraordinary book is a bonus that will catch your eye, day after day, and make you ponder both the remarkable knowns and unknowns of existence.

Ask Ethan: Where are we located relative to the Big Bang? If you think of the Big Bang as an explosion, we can trace it back to a single point-of-origin. But what if it happened everywhere at once?

Where are we located relative to the Big Bang?

#AskEthan

The Big Bang didn't occur at a single location in space, but rather, everywhere at once.

If we assumed it was a big ka-boom, we'd be shockingly close to its origin point.
bigthink.com/starts-with-...
#space #astro #bigbang #notanexplosion

Cover of the book The Grand Cosmic Story with pre-order now text beneath it, and a beautiful galactic background behind it.

Now is absolutely the perfect time to preorder my newest book, The Grand Cosmic Story from National Geographic, coming out in just 2 weeks!

Do it now at this link - promo.porchlightbooks.com/pages/promot... - and get a FREE bonus frameable print of the unique artwork in the book!

Was too good of a joke for me to be the only like!

Even before the Big Bang, space wasn't truly empty All of the matter that we measure today originated in the hot Big Bang. But even before that, and far into the future, it'll never be empty.

Even before the Big Bang, space wasn’t truly empty

Before the Big Bang, space was inflating, devoid of matter and antimatter particles.

But even still, it wasn't truly empty, and the existence of a cosmic horizon explains why.
bigthink.com/starts-with-...
#space #bigbang #physics #astro

The strongest evidence for a Universe before the Big Bang The hot Big Bang is often touted as the beginning of the Universe. But there's one piece of evidence we can't ignore that shows otherwise.

The strongest evidence for a Universe before the Big Bang

Louder, for those of you in the back who've been willfully covering your ears: the Big Bang wasn't the beginning, and we have some damn good evidence supporting that conclusion!

bigthink.com/starts-with-...
#space #physics #bigbang

The Big Bang doesn't mean what it used to As we gain new knowledge, our scientific picture of how the Universe works evolves. This is a feature of the Big Bang, not a bug.

The Big Bang doesn’t mean what it used to

Some legit scientists argue that the Big Bang never happened.

The only way that holds any water at all is if they use an outdated definition: one that's been obsolete for decades.
bigthink.com/starts-with-...
#space #astronomy #bigbang #cosmology

Tod you are someone who values learning in every instance, except if someone claims that a name you share in pronunciation with them is better spelled with two ds.

They close their eyes and ears when information that counters their narrative appears.

Not just tobacco or climate science anymore. It's all of science. It's arguably anything that's for the collective brightening of the light of human civilization.

Finding good information is hard.

A study done on 2.5M pregnant women who took Tylenol during pregnancy showed no adverse fetal effects.

However, pregnant women with untreated fevers had increased fetal risk of:

Neural tube,
Heart,
And abdominal wall,

Defects.

Plus cleft palate and more!

Yes it was spectroscopically confirmed by JWST. The galaxy is real!

The "most distant explosion ever" turned out to be rocket debris The universe is filled with unlikely events, but is also full of ways to fool ourselves. The case of galaxy GN-z11 shows us the peril.

The “most distant explosion ever” turned out to be rocket debris

In 2020, a team of astronomers saw a brilliant, temporary flash in the then-most distant galaxy, GN-z11.

Now the culprit has been identified: glinting space debris from a proton rocket.
bigthink.com/starts-with-...
#space #physics

There fished it out and responded.

We're all the result of cosmic contamination.

Maybe "enrichment" is the more poetic way to think about it?

Ha there we go!

Yes to both.

You've heard the phrase "one astronomer's noise is another astronomer's signal?

Well one astronomer's contamination is another astronomer's enrichment!

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@ashleybvigil.bsky.social Hey I don't know if you saw, but your last email to me got me thinking so hard you just became the latest #AskEthan!

Ask Ethan: What is the true purpose of scientific peer review? Just because a paper passes peer review doesn't mean that what's written, or what the author asserts, is true. Here's why it still matters.

What is the true purpose of scientific peer review?

#AskEthan

Passing peer review isn't "crossing the finish line" where every claim inside has now been verified to be correct.

Instead, it's "crossing the start line" by science's high standards.

bigthink.com/starts-with-...
#science #space

Ownership has been replaced with subscription-as-a-service.

As someone who grew up in the "d00d wArEz" era of the internet, this is a dystopia.