Ethan Siegel
@StartsWithABang
Followers
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Following
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Statuses
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"Some blogger who doesn’t even write a single paper in a decade." #Cosmology Science writer, astrophysicist, author, communicator. He/him or they/them.
Portland, OR
Joined April 2011
"Where can I buy Infinite Cosmos?" Yes!! Everywhere! Amazon: https://t.co/YNFhRYJECN Barnes & Noble: https://t.co/ZK59LnOpOp Disney: https://t.co/6a7PpNScMH Penguin/Random House: https://t.co/xBk0a2trVV Powell's city of books: https://t.co/KV6af2ZNjD
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Astronomers are on “Cloud 9” with a new, starless gas cloud Just 16 million light-years away is a massive cloud of gas, weighing in at around 1.4 million solar masses. And yet, there are no stars inside at all. Here's what that means. https://t.co/W8Hd7UsvfS
bigthink.com
Astronomers have found starless gas clouds before, but Cloud 9 might be the most pristine one of all, with big lessons for cosmic history.
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What does oxygen in JWST’s most distant galaxies really mean? JWST found oxygen in the second most distant galaxy ever spotted. That's not a surprise, however; that's all but inevitable once you've made stars for the first time. https://t.co/UDnL55ZRSi
bigthink.com
In a galaxy less than 300 million years after the Big Bang, oxygen's presence abounds. That's expected; its absence would truly be profound.
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Why is there no such thing as antigravity? #AskEthan In our Universe, everything that we know of experiences the influence of gravity. But if there are antiparticles, why isn't there any antigravity? https://t.co/Hb1PFWBfYN
bigthink.com
In General Relativity, the matter and energy curve spacetime, which we experience as gravity. Why can't there be an "antigravity" force?
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10 quantum myths that must die in the new year Quantum mechanics is bizarre, counterintuitive, and surprising in many ways. But not in every way that most people think. That's why, to start 2026, these 10 myths have got to go. https://t.co/WMVRegQc49
bigthink.com
The very word "quantum" makes people's imaginations run wild. But chances are you've fallen for at least one of these myths.
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Why scientists can’t stop searching for alien life No, we haven't yet discovered any good evidence for life beyond Earth, despite the breathless assertions of many. But we mustn't stop looking, and this is why. https://t.co/pFNgjzxaeq
bigthink.com
There will always be "wolf-criers" whose claims wither under scrutiny. But aliens are certainly out there, if science dares to find them.
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Prove Einstein’s relativity for yourself for under $100 Einstein's relativity has been misunderstood by more people than almost any correct physical theory ever. Here's how you can prove it for yourself, DIY-style, for cheap. https://t.co/dDj3djobad
bigthink.com
Particles are everywhere, including particles from space that stream through the human body. Here's how they prove Einstein's relativity.
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What is true that many don't accept? Ethan Siegel @startswithabang names 5 scientific truths that became unpopular in 2025, but remain vitally important. 🧵
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The trick to identifying JWST images in an instant Have you ever seen an image of space and wondered, "is this really from the JWST?" If so, this one cool visual sign is a dead giveaway, and once you see it, you'll always know. https://t.co/WyuZsWRlif
bigthink.com
If you can identify a foreground star, the spike patterns are a dead giveaway as to whether it's a JWST image or any other observatory.
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Why does something exist instead of nothing? #AskEthan We all know that the fact that the Universe exists has made a lot of people angry since the dawn of people. But how did our Universe come to have "something" instead of nothing? https://t.co/lmLWhTIKok
bigthink.com
Perhaps the most remarkable fact about the Universe at all is simply that it, and everything in it, exists. But what's the reason why?
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Does our physical reality exist in an objective manner? With quantum mechanics, we can keep the idea that an objective reality exists, Independent of observers, but there's a whole lot we have to give up if we do. https://t.co/XvVCfcwZXo
bigthink.com
We think of physical reality as what objectively exists, independent of any observer. But relativity and quantum physics say otherwise.
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Why ice skating is a miracle of physics Most animals slip on the ice, but put a pair of skates on, and you can control your motion on the ice like it's child's play. The unusual physics of ice is at fault. https://t.co/RSfib9DpK3
bigthink.com
While ice itself is slick, slippery, and difficult to navigate across under most circumstances, skaters easily glide across the ice.
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The simplest explanation for ultra-high-energy cosmic rays The highest-energy cosmic rays are too high in energy.... for bare protons. But if they're actually heavier ions instead, the simplest explanation is just plain iron-ic. https://t.co/zgyuJFpSlv
bigthink.com
The highest-energy particles could be a sign of new, unexpected physics. But the simplest, most mundane explanation is particularly iron-ic.
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How recently have we understood the Universe? The Universe has been around for 13.8 billion years. But it's really only over the most recent millennia, centuries, and decades that humanity has understood it at all. https://t.co/uxA2bn59dx
bigthink.com
While humanity has been skywatching since ancient times, much of our cosmic understanding has come about only recently. Very recently.
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Can stars form within the expanding Universe? #AskEthan The Universe, since the Big Bang, expands, cools, and gets less dense. How is it possible for gravity to form stars in such a dilute environment? https://t.co/7wbVWI3qat
bigthink.com
Our Universe doesn't just expand and cool, but the expansion itself is accelerating. Can stars form under such structure-erasing conditions?
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10 solstice facts for everyone to know "If you live at a higher latitude than the 43rd parallel, the Sun is lower during your winter solstice than it is at the opposite hemisphere’s pole." Weird but true; come see all 10! https://t.co/RO6Psot0Gx
bigthink.com
Earth orbits the Sun while spinning on its tilted axis, with two annual occasions marking that maximal tilt. That's where solstices arise.
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The USA’s Genesis Mission: moonshot or madness? The USA just announced the "Genesis Mission," an AI/quantum computing platform for all 17 national laboratories. Will it accelerate scientific discovery, or end it completely? https://t.co/MZiSaqPwEO
bigthink.com
The Department of Energy's newest mission seeks to make a unified AI platform across all national labs. Will it help US science, or kill it?
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As 2025 ends, the Standard Model still hasn’t cracked Here in 2025, many challenges have arisen to both Standard Models: particle physics and cosmology. As the year end, there's barely a crack in either. https://t.co/ErM28hd4jQ
bigthink.com
Our Standard Model of the Universe, for both particle physics and cosmology, remains intact for now. When will its foundations crack?
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Brightest-ever lensed supernova reveals astronomy’s coming revolution Astronomers found our first gravitationally lensed superluminous supernova. With the Vera C. Rubin Observatory now operational, hundreds, maybe thousands more should be coming. https://t.co/Nb1dg9CZ9p
bigthink.com
With the observation of SN 2025wny, a lensed superluminous supernova, astronomy's future comes into sharp, exciting focus.
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Starts With A Bang podcast #124 – Astrochemistry Everyone gets excited about astrobiology, but we've never found "biology" beyond Earth. Chemistry abounds, however, and that's why astrochemistry is so fascinating. Listen for yourself! https://t.co/1nZgjABTnX
bigthink.com
It takes a wide variety of processes in the Universe to make all the elements that populate space today. We're still discovering new ones!
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How do LLMs/chatbots impact students and cheating? #AskEthan Across all educational levels, students are outsourcing their assignments to LLMs like ChatGPT. Except for the ones who care about growing their own minds, they're unlikely to stop. https://t.co/1ZI3CQAeA5
bigthink.com
As technology advances, more opportunities for cheating arise. AI/LLMs aren't posing a new problem; they're how students cheat themselves.
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