Science

Science

The Three Levels of Smartness: Why the Sharpest People Often Look Dull
I At the east end of the wet market, Old Chen sells tofu. He never finished school and cannot read every character. Give him a string of numbers, and he will quote you the total while cutting tofu, round off the change cleanly, and tie the plastic bag before you have finished calculating on your phone. When he sees which daughter-in-law is not getting along with which mother-in-law, he can tell from the distance they stand apart. As he hands over the tofu, he gives one of them an extra line: “This batch is tender, eat it while it’s hot.” Both women’s faces soften a little.
By Jina day ago in FYI
The 3-second UFO claim that falls apart at the division stage
2.4 kilometers in 3 seconds. Average speed: 800 meters per second, or Mach 2.35. That number is not absurd for a fighter jet. An F-15 can dash to about Mach 2.5. But it gets there by accelerating the whole way, and it has exhaust, intakes, shock waves, and heat signatures. It also does not go "absolutely silent" a few kilometers from an observer. The reported object, by contrast, supposedly starts from a hover and covers 2.4 kilometers in 3 seconds. Speed is only the first issue.
By Jin3 days ago in FYI
The Mercury-to-Gold Startup Has a Spectrum, a Preprint, and a Very Long Road
A spectrum and a cold cup of coffee In Marathon Fusion’s lab, the gamma-ray spectrometer printed a curve with several crowded peaks. One peak sits at the characteristic energy of mercury-197. Co-founder Kyle Schiller put that image into the public release. Next to it: no sample mass, no neutron flux, no blank-control spectrum.
By Jin3 days ago in FYI
The Nautilus Never Lied. We Did.
1 You have probably heard the claim: The growth lines on a nautilus shell record the number of days it takes the Moon to go around the Earth. A modern nautilus has about 30 growth lines per chamber, exactly matching a 30-day month. But in nautilus fossils from the Ordovician, more than 400 million years ago, each chamber has only 9 growth lines. So at that time the Moon went around the Earth in only 9 days, and a month had only 9 days.
By Jin3 days ago in FYI
Humans Probably Didn’t Feed Wild Animals to Domesticate Them
1. A distinction that matters “Feed the chickens, and later you will get more eggs.” That sentence treats an outcome as a purpose. Chickens may lay more after feeding. Early humans scattering grain around a camp did not necessarily have eggs in mind. A behavior can help domestication without having domestication as its function.
By Jin4 days ago in FYI
The White Powder on the Lab Bench
Many years later, lab people will probably still remember a scene like this. On a gel-casting day, a bottle of white powder sat on the bench. The bottle was not locked. The drawer was not locked either. Anyone who needed to run SDS-PAGE would scoop a little out with a spoon, weigh it, and put it back. The spoon handle had last week’s gel residue stuck to it, and nobody wiped it off. No one asked, “How many grams did you scoop today?”
By Jin4 days ago in FYI
I'm Blind. The Raised Dots on the Floor Walked Me Back to Class.
When I took a class at the Chaoyang District Disabled Persons' Federation, everyone went to the restroom during the break. I came back last. The voices moved ahead of me, shoes on tile getting quieter, and my cane tip hit the base of the wall, then a metal doorframe. I had never walked that corridor. The floor was polished, and the tip slid, the tap coming back hollow.
By Jin5 days ago in FYI
The Surgeon Said “Clean Margins.” The Cancer Didn’t Get the Memo.
“The surgery was very successful.” Cancer patients want to hear that sentence. They also tend to misread it. When a surgeon says “successful,” the meaning is concrete: the visible lesion was completely removed, the margins were negative, and the lymph node dissection was adequate. In that sense, the surgery really was successful. Biological cure is a different claim. A patient whose pathology report says “negative margins” may still carry millions of tumor cells that no scan can see. Those cells sit in the bone marrow, the liver, or the lung microenvironment and wait for a gap in immune surveillance.
By Jin5 days ago in FYI
Retrocausality: Is This the Ultimate Debunking of Retrocausality?
Picture the scene. You are knee-deep in a late-night rabbit hole, watching an episode exploring mind-bending temporal mechanics, anomalous data, and the fringe edges of human consciousness. A guest or a theory drops a line that completely short-circuits your usual way of thinking: If you say, "I will practice for this two weeks after the test," it implies you are learning future facts—remembering information that you actually learnt in the future.
By Lewis Smith7 days ago in FYI
AI Has No Envy. That Is Why It Will Change Mathematics.
At two in the morning, B crumpled the third sheet of draft paper and threw it into the wastebasket. The paper ball bounced once and landed beside the bin. He did not pick it up. The tea on the desk had been brewed at ten; a film had formed on its surface. He stared at A’s preprint on the screen. Lemma 3.2 on page four used the same technical route he had thought of last week. Even the choice of constants was similar. He closed the PDF, opened his own draft, and the cursor stopped after half a line of formula. It blinked for seven minutes. Then he closed the laptop, went to the kitchen, boiled water, came back, and opened the laptop again. The draft was still there. He deleted the half-line, rewrote it, and deleted it again at the third line. The streetlight outside shone in. The edges of the pothos leaves were turning yellow. He should have watered it last week.
By Jin7 days ago in FYI
The World's Heaviest Pumpkin Record Fell Twice in One Week. The New Giant Weighs 3,156 Pounds. AI-Generated.
Picture a pumpkin so big that you could not wrap your arms around it, not even close. A pumpkin that weighs more than a small car. Now picture two of them breaking the world record in the same week.
By Mitsuru Satou7 days ago in FYI
The Same Breath Kills a Candle and Feeds a Fire. Here’s the Physics.
If exhaled air were pure carbon dioxide, a walk in the woods would be a health hazard. A person’s average exhaled breath is about 3.6–4% CO₂, not 100%. Alveolar gas is higher, around 5.3%, but the air that leaves the mouth is diluted on the way out. The gap between alveolar gas and exhaled breath sits in the trachea and bronchi, the anatomical dead space. During inhalation, fresh air first fills these non-exchange airways and mixes with old gas before reaching the alveoli. During exhalation, the lungs do not squeeze out every last bit of alveolar gas; they push out a portion, and that portion mixes with gas from the dead space. Average exhaled CO₂ therefore lands well below alveolar concentration.
By Jin8 days ago in FYI