01 · Measure
What does this measure?
The clock starts at the displayed cue and stops at your tap. It measures the interval in this exercise, on this device. It does not assess your health or reflexes.
The page clock: W3C High Resolution Time.
Measuring the body carefully
Health: what does a test measure?
Start with a simple signal. Then see what tests can and cannot tell us about the body and access to care.
Tap when the button lights up. Five tries; the interval also depends on the screen and device.
Ready
Choose “Start” and wait.
This is a measurement exercise, not a medical test or reflex standard. The interval can include the delay before the browser displays the cue and the input device responds; it also depends on attention. Do not compare it with other people’s results.
02 · Signals
One signal does not tell the whole story
Hearing, vision and attention can be explored through different experiments. Each has its own instrument and limits; read a project’s sources before interpreting a result.
Another measurement
What Happens If You Don't Sleep for 24 Hours?
After one night without sleep, the brain doesn't switch off — but attention becomes unstable. Follow hour by hour what we know and what we don't: adenosine, reaction time, the alcohol comparison and the glymphatic debate.
Another measurement
What You Can No Longer Hear
Listen to six tones between 9 and 16 kHz and compare the shape of your threshold with 632 ears measured in a clinic, alongside the uncertainty introduced by headphones.
Another measurement
The Blind Spot in the Middle of Your Vision
A fist at arm's length covers ten degrees of sky — the amateur astronomer's rule. The same ruler, turned on your own eye, finds a real gap in your vision: 6.28 degrees wide, over twelve times wider than the full moon. The instrument lets you measure your own angle, with one eye.
03 · Access
Care also depends on routes
Access to a service depends on organisation, information and place. The projects below map routes and measurements in Romania; check each one’s date and scope.
A service to explore
Need a psychologist, an MRI or sick leave in Romania?
Pick what's happening to you — a psychologist, pregnancy, cancer, an MRI, sick leave, a dentist — and follow the route through Romania's health system, door by door: today's rule, checked at CNAS, and what Sorana Stănescu documented in 53 editions of Foaia de observație, each linked. In Romanian and English.
A service to explore
Screening at your age: benefits, limits and access
Choose your country, age and sex to explore screening tests, their benefits and limitations, and access conditions. A guide for adults without symptoms, with test-specific evidence and decisions to discuss with a clinician.
A service to explore
How far are emergency units from your street?
Search for a Bucharest street and compare straight-line distances to adult and paediatric emergency units separately on the 3D map. The map does not calculate routes or travel times. In an emergency, call 112.
Body and health · 180 projects
The complete collection
Search titles, descriptions and topic terms, or choose a theme.
180 projects
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How the body works
Frontal crash stars are earned with a male dummy at the wheel. What the tests show when a small woman drives
NHTSA crashed 14 cars with the small female dummy at the wheel, in tests that award no stars. By NHTSA's own formula none reaches five. Pick any car tested in the US since 2011 and see who sat in each seat.
How care reaches people
Newborns with “major problems” in Romanian DRG reports, 2018–2026, by maternity unit
In 2025, 50 in 100 admissions of newborns weighing at least 2.5 kg were assigned “major problems” in Romanian DRG reports, up from 29 in 2019. Pick a maternity unit and see how its cases are classified.
How care reaches people
Leg amputations and arterial reconstructions in Romanian hospitals, 2018–2025
For every hospital in Romania: how many stays with a leg amputation and how many with an arterial reconstruction it reported in 2025, and the drive to the nearest hospital that does reconstructions.
How care reaches people
Caesarean rates by maternity: 192 hospitals in Romania
The caesarean rate of every Romanian maternity unit reporting in the DRG system, 2018–2026, set beside the rate predicted from what is known about its patients. Pick one on the map.
Health across communities
The tiger mosquito in your backyard: where it has been found in Romania
The Asian tiger mosquito has been found in 71 Romanian communes in 23 counties. See the nearest record to your home and how mild January has become there.
How care reaches people
How long does cooked food keep in the fridge? 2–3 days, 3–4 days, and the rice day
Choose the dish, the cooking day and how it was cooled: see the European 2–3 day advice and the US 3–4 day chart, the one-day rice rule, and the two-hour cooling condition.
How care reaches people
Child in the front seat in Romania: the 135 cm line and the airbag rule
Choose the child’s height, seat and restraint. In a family car, up to 135 cm a child restraint belongs on the rear seats. In front, the maker must permit fitting, and the corresponding front airbag must be deactivated by the driver or be absent.
How care reaches people
Is my referral ticket still valid in Romania? 30, 60 or 90 days
Pick the kind of ticket (specialist, tests, MRI/CT), enter the date on it and your appointment date, and see the term in the CNAS rules: 30, 60 or 90 days, with the last safe day and the last possible day. A table shows the same dates across every category, with hospital stays and booking explained. In Romanian and English.
How care reaches people
Time is brain: a real stroke on MRI, and the drive to thrombectomy from every place in Romania
Twelve real strokes on the admission and follow-up MRI: paint the brain you think is lost, then see the real scar. Then the drive from every Romanian locality to the 14 hospitals that perform thrombectomy, and what is known about night cover.
How care reaches people
Robotic and laparoscopic liver and pancreas surgery: what 20 randomised trials show
Laparoscopic and robotic liver and pancreatic surgery, 2017–2026: 20 randomised trials on one map, from OSLO-COMET and LEOPARD-2 to DIPLOMA-2 and PORTAL. Every number links to the exact sentence in the abstract and to PubMed.
How care reaches people
Deaths from infection in Romania: the rate rose by more than 60% in six years, against 8% in 18 other EU countries
Pneumonia, sepsis and C. difficile recorded as the cause of death, 2017–2023, age-standardised: in Romania, from 50.1 to 81.5 per 100,000 people; at 50–64, almost six times the rate of the comparison EU countries.
How care reaches people
Sepsis without a fever: 2,506 real intensive-care charts, hour by hour, before sepsis was dated
The charts of 40,335 intensive-care stays in two US hospitals. In 65% of the patients with sepsis, no temperature charted in the 12 hours before sepsis was dated reached 38 °C.
How care reaches people
Case of the day: one real patient a day, for doctors and medical students
Every day, one real case from open medical datasets: a stethoscope recording, an ECG, an X-ray, a lung CT or a labour CTG. One question, one minute, then what was actually found in that patient.
How care reaches people
The brain seen by ultrasound: how far the tumour is from where neuronavigation shows it
Real ultrasound volumes from glioma operations, set beside the MRI the navigation screen shows: in 22 patients, the same anatomical landmark appears on the two images 3.5 mm apart on average for the patient in the middle of the group, and up to 19.7 mm. Move the probe, decide where you would stop the resection, then compare with the MRI taken in theatre.
How care reaches people
The baby’s heart on the monitor: what doctors saw on the trace, and how the babies were born
The last hour before full dilatation in 506 real births from Brno: the CTG trace, what nine obstetricians said and the baby’s pH at birth. When most called a trace pathological, 29 of 55 babies had a normal pH.
How care reaches people
Laparoscopic ultrasound on a real patient’s liver
Hold the probe on the liver of a patient operated on for metastases: Doppler, guided puncture with indocyanine green and your resection line beside the real operation.
Health across communities
Tuberculosis in Romania: a quarter of the EU's deaths, many at working age (2011–2025)
In 2023, 705 of the 2,819 people who died of tuberculosis in the EU lived in Romania. The age-standardised rate is 8.5 times the rest of the EU's, and most die at working age. County by county.
Health across communities
Infant pneumonia: Romania has more than half of the EU's deaths (2011–2025)
In 2023, 159 of the 282 children under one who died of pneumonia in the EU were Romanian, with 4.4% of births. What the certificate says, what remains, and county figures.
How care reaches people
The medicines that left Romania: 3,231 shortage notices rebuilt, 2015–2026
55 prescription medicines were withdrawn from Romania by every maker, with no other authorised product of the same substance and form. 3,231 shortage notices rebuilt, searchable by medicine.
How the body works
The vitamin D winter: when the sun is too weak for vitamin D, for every town in the UK and Europe
In an average year, London’s sun is too weak for vitamin D from 13 October to 11 March. Dates for every UK town and any town in Europe, from 22 winters estimated by satellite.
Health across communities
Heatwave deaths in Romania: excess deaths in every county, week by week (2015–2026)
In two weeks of heat in July 2024, 11,486 people died in Romania, about 3,300 more than usual (about 2,550 on the most cautious calculation). The health ministry reported nine deaths from hyperthermia. Excess deaths in every Romanian county, week by week, since 2015.
Health across communities
People your age: how often people die in Romania compared with the rest of the EU, by age and cause
How many people of your age and sex die in a year in Romania and in the rest of the EU, and which causes make up the difference. Men aged 45–59: more than twice.
Health across communities
Children who do not grow up: deaths of children and teenagers in Romania compared with the rest of the EU
How many children and teenagers die in Romania compared with the rest of the EU's rates, by age and cause: pneumonia, transport accidents, drowning. About 330 extra a year.
Health across communities
Cirrhosis without a name: people in Romania die of liver disease three times as often as in the rest of the EU, and the statistics rarely say why
People in Romania die of chronic liver disease 3.3 times as often as in the rest of the EU, and only 14% of cirrhosis deaths are coded as alcoholic; almost all the others as “unspecified cirrhosis”. Country by country and county by county.
How care reaches people
Tested on patients in Romania: which new medicines are reimbursed there, and how long it took
200 new medicines were tested in trials with sites in Romania before EU approval. 113 are on Romania’s reimbursed list, usually after years of waiting. Every city and every medicine, with dates.
Health across communities
Romania's tap water that failed health-authority tests in 2025: nitrate, E. coli and arsenic, network by network
Romania's county public-health reports for 2025, read zone by zone for the whole country: in Constanța and Tulcea, 79 public water-supply zones had nitrate above the EU limit of 50 mg/l, and for 55 the report records no fix before the end of the year.
Health across communities
Measles in Romania, 2016–2025: who died, and who could have protected them
Two measles epidemics in Romania, 55,940 confirmed cases and 94 deaths. Of those whose age was published, 43 of 89 were babies under one. Romania's schedule gives the first vaccine dose at 12 months; until then, their protection depends largely on the people around them. All from the reports of Romania's National Institute of Public Health. In English and Romanian.
How care reaches people
Retracted medical studies that are still being cited: 2,731 clinical studies, 11,142 citations after retraction
Since 1980, journals have retracted 2,731 papers classed as clinical studies, almost all on patients. Later papers cited them 11,142 times at least a year after the retraction, 1,528 of them in systematic reviews, meta-analyses and guidelines. Look up a condition, medicine or supplement, read the sentences in later guidelines and reviews that still lean on a retracted study, and follow the case of the Japanese anaesthetist Yoshitaka Fujii: a committee found fabricated data in 172 of 212 of his papers. In English and Romanian.
Health across communities
Bonfire Night: the night UK air monitors most often record their dirtiest hour of the year
Each of the UK's national fine-particle (PM2.5) air monitors has one dirtiest hour a year. Since 2009 it has fallen on Bonfire Night, 5 November, in 282 of 1,206 cases (one monitor in one year): more than ten times as often as on the next-worst night (27). At Liverpool Speke, in 12 of 14 years. An hour-by-hour smoke map of 17 Bonfire Nights across 165 monitors, and a page for the monitor nearest you. In English and Romanian.
How care reaches people
Resident posts in your town’s hospital, 2016–2026
Every list of resident posts from the Ministry of Health, 2016 to 2026, on a map, with the day each post was taken in 2020–2025. A post is an open-ended employment contract with the unit that advertises it; in 2021–2025, 49% of posts were taken after allocation day one, against 24% of places. Look up a county, town or specialty.
Health across communities
When to open the window in winter
In winter, Romanian town air is dirtiest between 7 and 11 p.m. at 98 of 112 official stations; the afternoon is the time to air a room. The best hour for the station near you.
How the body works
The normal resting pulse: 50,249 measured adults against the 60 and 100 limits
The United States health examination survey measured 93,334 people's pulses by hand, seated, between 1999 and 2018. Plotted one dot per adult, 86% fall inside the conventional 60–100 range, and about four of every five outside it are below 60: 15.3% of men rest under the 'slow' fence, and the middle of the crowd sits at 70 (men) and 74 (women). The 50–90 range proposed by cardiologist David Spodick in 1996 and never adopted holds about 92% of adults. Measure your own pulse on the page and see it among people your age.
How care reaches people
Dementia in the family: a care plan and rights in Romania
A daily care plan and an A4 sheet for the family. Check the wording on a valid disability certificate, then read certificate benefits, the personal-assistant choice and the pension companion allowance separately. Conditions and amounts checked on 16 October 2026.
How care reaches people
Stroke warning signs and calling 112 in Romania
Recognise sudden stroke warning signs and prepare what to tell Romania’s 112 dispatcher. Includes an A4 reminder and the dated legal list of 13 hospitals named for thrombectomy. The list does not establish current service availability. Sources checked on 16 October 2026.
How care reaches people
The first appointment after a cancer diagnosis
Prepare documents, questions and the next step in Romania’s healthcare system. Choose up to five questions for your own sheet, or download the complete 23-item checklist with room for notes. Sources checked on 16 October 2026.
Brain, sleep and attention
The dream before the alarm: when your longest REM period comes
Enter when you fall asleep and wake, see a schematic model of your night with its longest REM period, then what a large REM-and-disease study really measured.
How the body works
The stripes of your skin: dermatomes, the embryo that drew them, and where organs send their pain
Each strip of skin reports to one nerve of the spine. On an adult the strips look scrambled; with arms out and thumbs up they fall into order, as on a five-week embryo. The page shows that order on a figure that lifts its arms as you scroll, and uses it to explain why the diaphragm is felt at the tip of the shoulder, the heart in the arm and the appendix first at the navel.
How the body works
Where the organs sit: textbook vertebral levels against 1,226 CT scans
Anatomy books give each organ and landmark one vertebra. 1,226 hospital CT scans, each lined up on its own spine, show the book's vertebra holds for a median of 45% of people and one vertebra either way for 91%. Drag a plane through them, then find where yours probably are, in centimetres from landmarks you can feel.
How the body works
Bucharest noise map by address: modelled road-noise levels around every building, school and park
The City's official noise maps existed only as PDF images. Type a street and number to see the modelled level around the building, at night and as a 24-hour average, against the WHO limit of 45 dB. Nearly 9 in 10 homes exceed it at night.
How the body works
How far are emergency units from your street?
Search for a Bucharest street and compare straight-line distances to adult and paediatric emergency units separately on the 3D map. The map does not calculate routes or travel times. In an emergency, call 112.
How the body works
Malaria lived in Romania. We killed it in thirteen years.
In 1948 Romania recorded 338,198 malaria cases; in 1961 the last indigenous case was reported. The map, the numbers and the people of the eradication campaign.
How the body works
Same image, a different eye jump
A study shows that eye movement changes which details remain visible in the same image; the effect depends on the movement’s angle.
How the body works
Wet-bulb temperature: how much heat the human body can take, and how hot your city gets
In the lab, bodies stopped coping at about 31 °C wet-bulb in young adults and 29 in older ones, well below the famous 35. Climb the thermometer, see who heat kills, and where your city's hottest hour lands.
How the body works
How many more times will you see your parents? A calculator of the time you have left, from Romania's life tables
Work out how many visits and days you have left with your mother, father or grandparents, from your ages, how often you meet and Romania's 2024 life table.
What a test can measure
Need a psychologist, an MRI or sick leave in Romania?
Pick what's happening to you — a psychologist, pregnancy, cancer, an MRI, sick leave, a dentist — and follow the route through Romania's health system, door by door: today's rule, checked at CNAS, and what Sorana Stănescu documented in 53 editions of Foaia de observație, each linked. In Romanian and English.
How the body works
Older Than Earth: which stars made you?
Nearly every atom in your body is older than the Earth: about 63 in 100 are primordial hydrogen, older than the stars. Follow one gold atom from the Big Bang to you, weigh your own stardust, and find where gold comes from. In Romanian and English.
How the body works
The tongue taste map: the sugar test
The textbook tongue map (sweet at the tip, bitter at the back) is wrong: every part of the tongue with taste buds tastes every taste. The test on your own tongue, a whole-class moment, and how four tables from 1901 became a map in 1942. In Romanian and English.
How the body works
In Romania, cervical cancer kills four times as often as in Sweden
The free HPV test in Romania, explained: enter your year of birth, last test and county to see when you are due, which route makes it free (a contracted gynaecologist, the CLARA project or a Pap test on referral) and whether the vaccine is free at your age. Plus what HPV positive means. In Romanian and English.
What a test can measure
Screening at your age: benefits, limits and access
Choose your country, age and sex to explore screening tests, their benefits and limitations, and access conditions. A guide for adults without symptoms, with test-specific evidence and decisions to discuss with a clinician.
How the body works
How tall was your great-grandmother?
Put your family on the door frame: each year of birth gets a pencil mark at the average height of Romanians born then, 1896–1996, fainter the less is known. Today’s children beside their great-grandparents, and 200 countries, from NCD-RisC data. In Romanian and English.
How the body works
How many ancestors did you have in the year 1000?
The places in your family tree double every generation. By the year 1000 they need billions of people, in a Europe of about 36 million. Put your grandparents' towns on the map, follow your ancestors generation by generation and compare them with a classmate's. In Romanian and English.
How the body works
The middle of your eye is made of carbon from the air of the year you were born
Nuclear tests in the 1950s and 60s nearly doubled the carbon-14 in the air, and every human body kept the mark. Put your family's birth years on the curve and see which year each part of you is made of: lens, tendon, heart, blood. In Romanian and English.
How the body works
Your earlobe doesn’t obey Mendel
Attached or free earlobes, tongue rolling, clasped hands, blue eyes: test school biology’s dominant–recessive rules on yourself and your family, see what a century of data shows, and meet the one visible trait that really follows a single gene. In Romanian and English.
How the body works
The Great Smog
London, 5–9 December 1952: five days of yellow fog in which, at night, you could not see your feet — and three months of dying after the sky cleared. You walk the blind street, lift the lid yourself, and put the influenza alibi to the arithmetic. In Romanian and English.
How the body works
Which medical specialties are in short supply in 2026: two join after two years without changes
The official 2026 list names 25 shortage specialties, up from 23 in 2024–2025: geriatrics and child psychiatry join, nothing leaves, and 11 of the 25 concern children or newborns. What the label means for patients, parents and residents — in Romanian and English.
How the body works
You carry DNA from people nobody has ever found
The river of your ancestors, two million years deep: the bottlenecks they went through, the Neanderthals and Denisovans they had children with, and ghost populations known only from our genes. Pick where your grandparents were from and see what is in your genome.
How the body works
Your body next to a chimpanzee’s: what each difference is for, and why your legs are older than your brain
A walking skeleton changes from a chimpanzee to a human through three fossils: legs and feet change first, the brain last. Then, part by part: walking that costs you a quarter of a chimpanzee’s oxygen, the Achilles tendon, sweat glands, the throwing shoulder, the thumb, the face, birth, and the chin nobody can explain.
How the body works
Most of your atoms are 13.8 billion years old: where each part of your body was made
Six in ten of your atoms are hydrogen from the Big Bang. Your oxygen came from exploding giant stars, much of your carbon from dying stars, half the calcium in your bones from exploding white dwarfs, your iodine from colliding neutron stars. Set your weight and watch your body come apart.
How the body works
A Romanian doctor timed a protein's journey through the cell and won a Nobel Prize
In 1953 George Palade described the grains on the cell's membranes, the ribosomes, and with Lucien Caro and James Jamieson he measured how many minutes new proteins take from the ribosome to the granules. The name ribosome was proposed at a 1958 meeting, and the year he left for America depends on the source. The story, in nine chapters, with games.
How the body works
All the DNA in you would reach the Sun and back. How many times?
About 21 times: 6.2 billion kilometres of DNA in 3 trillion nucleated cells. Guess first, then redo the sum with your own numbers and learn why the 600-trips myth no longer stands.
How the body works
The Test Said No
Why a test used in Bunia missed Bundibugyo, and the limits of vaccines and treatments developed for Zaire. DR Congo’s National Institute of Public Health reports 10,920 confirmed cases and 5,323 deaths through 7 November 2026; the tally may be revised. Tumaini began on 23 October; starting the trial does not establish vaccine efficacy.
How the body works
A blue whale’s heart can beat twice a minute
The heart preserved in Toronto was weighed at 175 kg and is about a metre across, far less than the car it is said to match. Stand beside it, put your hand in its aorta and hear it beat, from 2 a minute in a dive to 37 at the surface.
How the body works
What Paulescu discovered before the Toronto team
Paulescu published the animal evidence in 1921; Toronto achieved effective clinical treatment in January 1922. The day-by-day record, documented.
How the body works
The air machines of the Carpathians: when architecture was the only prescription
In the 1930s, when tuberculosis had no chemical cure, Romania erected a network of machine-like buildings across the Carpathian Mountains and deep underground. From −240 metres underground to +1,010 metres on the ridge, five monumental structures rendered obsolete by a single molecule.
How the body works
The Clock Inside Your Inner Ear
Spin in a chair and stop dead: you feel a rotation that isn't there. Keep turning instead, and the sensation disappears entirely — an interactive physical model of the inner ear shows why, and how a pilot ends up in a graveyard spiral believing they're flying straight.
How the body works
The vessel that was supposed to disappear
An artery in the forearm is supposed to regress before birth. In a cadaveric study, it persisted in 43% of limbs, and in 15% it could become, via the carpal tunnel, the sole blood supply of a finger.
How the body works
What Romanians die of
Of every thousand deaths in Romania, 545 come from diseases of the heart and the blood vessels. Counted as years of life lost before 75, the same diseases come to 297, and where the red used to be there rise the liver, the road and the first days of life.
How the body works
Retatrutide: what changes in the body
An anatomical atlas of retatrutide evidence: 24 research records and 110 reported findings on weight, liver fat, blood sugar, pain, sleep and other effects. Explore the studies, doses and limitations behind each finding. Human research, animal experiments and unanswered questions are identified separately.
How the body works
How full is a hospital?
For 198 hospitals, the published CNAS percentage can be reproduced with a 290-day denominator. Change the duration, keep patient-days fixed and inspect every record.
How the body works
The Falling Ruler: Can you catch it in mid-air?
A 30-centimetre workshop ruler drops under gravity at an unpredictable moment. Tap the screen the instant it moves: the mechanical jaws clamp down to the millimetre, turning gravitational acceleration into an exact reading of your visual reflex in centimetres and milliseconds.
How the body works
Sixty-Six Times: Oxygen Held by Haemoglobin
At full saturation, 15 g of haemoglobin per decilitre can bind 20.1 mL of oxygen. Clinical formulas give 0.30–0.31 mL dissolved at 100 mmHg: a ratio of about 66.
How the body works
Zero symptoms in common? It depends what you count.
The same diagnosis can encompass very different experiences. Compare manifestations and shared criteria, check the combinations and explore the limits of a feedback model.
How the body works
Ninety Millimetres of Mercury: The Calf's Second Heart and the Pressure Drop in the Ankle
In a standing adult, the hydrostatic column raises ankle pressure to 90 millimetres of mercury. The direct-cannulation finding is summarized as a fall towards approximately 25 millimetres after six to seven steps through the soleal valves.
How the body works
Twenty-Five Percent in Cold Water: The Mammalian Dive Reflex and the Vagal Brake on the Human Heart
Compare illustrated heart responses under different conditions on screen. Model values are not measurements of your heart and do not form a home test.
How the body works
Twenty Minutes for a Bubble: The Biophysics of Knuckle Cracking and the Cavitation Refractory Period
MRI links the crack to rapid cavity inception under negative pressure in <310 ms; the refractory period is about 20 minutes, while the precise acoustic mechanism remains debated.
How the body works
The Yawn's Thermal Window
The tiredness-and-oxygen explanation for yawning was tested directly in 1987 and falsified. Contagious yawning follows a narrow temperature window — 18.3% in Vienna at 1.4°C, 41.7% at 19.4°C, 45% in Tucson at 22°C, 24% at 37°C — and a 2007 lab experiment found that nasal breathing and a cold forehead pack cut contagious yawning almost to zero.
How the body works
Three Hundred Thousand to One: The Two-Hundred-Micrometre Barrier That Stops the Stomach From Digesting Itself
In the gastric lumen, acid at pH 1.5 would dissolve muscle tissue and light metals. Just 200 micrometres away, epithelial cells maintain a neutral pH of 7.0 via an active mucus-bicarbonate barrier.
How the body works
Your Ear Has Its Own Amplifier
The inner ear is not a passive sensor, but a piezoelectric mechanical motor: 12,000 outer hair cells pump force at over 20,000 cycles per second using the motor protein Prestin, adding 40 decibels to faint sounds (a 100-fold boost in amplitude and 10,000-fold in energy).
How the body works
Why Do You Hiccup?
A hiccup starts with an involuntary diaphragm contraction, followed in the classic description by glottic closure after about 35 milliseconds. See the reflex arc, the 4–60 hiccups-per-minute range and count an episode already in progress.
How the body works
One Second Without Air
During a swallow, breathing enters a mean pause of 0.75 ± 0.14 seconds. In a meta-analysis, the exhale–swallow–exhale sequence appeared in 77.4% of thin-liquid swallows.
How the body works
Three Micrometres of Water Between Air and Sight
The tear film is about 3,282 nanometres in its muco-aqueous region and 52.7 nanometres in its surface lipid layer — a 62.3-fold difference. Count your blinks and simulate how quickly the film thins.
How the body works
The Body Stands Like an Inverted Pendulum
When you stand still, the body behaves approximately like an inverted pendulum controlled through the ankles. For a 1.75 m person, a no-correction model takes 0.72 seconds to grow a 0.5° sway to 5°. Calculate your time and test your balance on one foot.
How the body works
One Volt per Centimetre: The Skin's Epithelial Battery and the Electric Field That Heals Wounds
Intact human skin acts as a living bioelectric battery maintaining a 20 to 50 millivolt transepithelial potential. A cut short-circuits the barrier, generating a 100–200 V/m lateral electric field that guides keratinocytes directly to the wound bed via electrotaxis.
How the body works
Fifty Grams in the Skull
How cerebrospinal fluid helps support the brain, and what sleep research shows. An idealised buoyancy model with its limits explained.
How the body works
Tens of Picoamperes in the Dark
In darkness, rods sustain a dark current on the order of tens of picoamperes, while direct human recordings measured flash-evoked photocurrents up to about 20 pA. Light acts as a metabolic brake that reduces ATP expenditure.
How the body works
The Blind Spot in the Middle of Your Vision
A fist at arm's length covers ten degrees of sky — the amateur astronomer's rule. The same ruler, turned on your own eye, finds a real gap in your vision: 6.28 degrees wide, over twelve times wider than the full moon. The instrument lets you measure your own angle, with one eye.
How the body works
Walking is controlled falling
Human walking behaves like an inverted pendulum: potential and kinetic energy exchange above the stance foot, with mechanical recovery reaching about 65% at moderate speeds. The instrument uses leg length and time over 10 metres to calculate speed and the Froude number.
What a test can measure
Pupil squared
When the pupil moves from 2 to 8 millimetres, its diameter grows fourfold while the circular opening grows sixteenfold. Simulate the pupillary light reflex and calculate your own aperture.
How the body works
One Kilogram at Arm's Length
At 50 centimetres from the elbow, a one-kilogram object creates 4.9 N·m, ten times the torque of the same object held 5 centimetres away. Move the mass and distance, then estimate equivalent biceps force in a static model.
How the body works
How your eyes stabilise your gaze
When you move your head, your eyes compensate. Change frequency, amplitude and delay in a vestibulo-ocular reflex simulator; results describe the simplified model and do not measure an individual’s eyesight.
How the body works
Why You Don't Deafen Yourself Talking
When we speak or chew, internal vibrations reach the inner ear through tissue and bone. The human studies cited for vocalisation show that stapedius activity can begin before the vocal sound; attenuation depends on frequency and conditions, while 20 decibels remains an explicit model example.
How the body works
Thirteen Nanometres: The Biophysics of Fingerprints and the Nanoscale Limit of Touch
A static press resolves two separate points only at 1.6 millimetres, but sliding a finger detects nanoscale grooves of just 13 nanometres. Fingerprints act as an acoustic grating converting spatial texture into 250 Hz shear vibrations tuned to deep Pacinian corpuscles.
How the body works
Five Hundred and Eighty Calories per Gram: The Extreme Biophysics of Sweat and the Human Heat Engine
Every gram of evaporated sweat extracts 2,418 Joules (580 calories) of internal heat. During exertion, muscles produce over 1,000 watts of waste heat. An idealized no-dissipation model gives roughly 20–25 minutes to 42 °C; the real heat balance includes other losses. Explains why runoff sweat loses evaporative latent cooling and how wet-bulb thresholds govern survival.
How the body works
Forty-Three Degrees on the Tongue: Why Chili Pepper Activates the Fire Receptor at Body Temperature
The thermal pain receptor TRPV1 responds probabilistically to heat, with an operational range around 42–43 °C. Capsaicin shifts the activation curve toward lower temperatures, so 37 °C can trigger a scalding alarm.
How the body works
Two Millinewtons per Metre: The Surface Tension of Lungs and the 480-Million-Bubble Paradox
Across 480 million alveoli, 130 square metres of wet membrane should collapse under Laplace's law. Surfactant drops water surface tension to 1–2 mN/m at expiration, stabilizing breathing.
How the body works
One Hundred and Fifty Millilitres: Anatomical Dead Space and the Alveolar Ventilation Paradox
In every breath, 150 millilitres of air remains trapped in the trachea and bronchi without reaching the alveoli. In shallow breathing, 6 litres of air are ventilated per minute yet alveolar delivery is strictly zero.
How the body works
One and a Half Watts: The Hydraulic Mechanics of the Human Heart
The human heart pumps 7,200 litres of blood daily across 100,000 continuous pressure cycles at a mechanical power output of just 1.33 watts — less than a nightlight LED.
How the body works
Why fine detail is clearest at the centre of your gaze
Explore acuity falloff in a model with an explicitly chosen E₂ = 2.5°: at five degrees, one third of central acuity remains. Calculate the diameter of a 1.5° circle; the illustrations are not calibrated eye tests.
How the body works
Why You're Taller in the Morning Than at Night
In the classic study of eight men, stature varied by a mean 19.3 mm, with 80% of the loss occurring in the first 3 hours after getting up. Measure your morning-to-evening difference and see an illustrative even-share value across 23 intervertebral discs.
How the body works
Nine Degrees Under Your Fingertip: Why Metal Feels Colder Than Wood
Aluminium and wood can share one temperature, yet skin initially meets them at roughly 20.6 °C and 29.2 °C. Simulate the difference and test it with two objects from the same room.
How the body works
Ten Oscillations a Second: The Hand's Physiological Tremor
The acceleration of a healthy adult's outstretched hand often carries energy between 8 and 12 Hz. Record two 12-second runs and see how the measuring phone enters the mechanics itself.
How the body works
The Two-Hour Nostril: The Hidden Asymmetry of Breathing
One nostril usually carries more air, and the dominant side switches every few hours. Test your own breathing and explore an illustrative model; the ratio and timing vary widely between people.
How the body works
Four Grams in the Entire Bloodstream: Why the Body Lives on a Single Teaspoon of Glucose
Across all 5 litres of human blood, only 4.5 grams of glucose circulate at any moment — a single teaspoon of sugar that the brain oxidizes in 54 minutes.
How the body works
Ten Microseconds Between the Ears: How the Brain Computes Sound Location
The human brainstem detects sound arrival time differences down to 10 microseconds between the ears — 100 times finer than a single action potential.
How the body works
Sixty kilograms a day? How much ATP your body really makes
Your body holds only 50–100 grams of ATP, yet remakes 36–47 kg of it a day at 2,000 kcal. Turn the machine that makes it with your finger, and find out where the famous 21,000 rpm comes from.
How the body works
Half a Millimetre per Second: Why Blood Nearly Stops in the Capillaries
At a resting cardiac output of 5 L/min, Q = A × v gives about 185 mm/s in the aorta and 0.19–0.24 mm/s across a 3,500–4,500 cm² capillary bed.
How the body works
Forty-Three Dioptres: Why We See Completely Blurred Underwater and Where the Eye's True Lens Really Is
Over 70% of human eye focusing power (+43 of 60 dioptres) occurs at the air-cornea interface. Underwater, this lens vanishes instantly, causing extreme hyperopia that a dive mask fixes with zero lens curvature.
How the body works
Nine Photons in the Dark: The Quantum Limit of Human Vision
In darkness, Hecht's estimated threshold is 5–14 absorbed photons; 9 is representative. In an intact rod, one photon activates roughly 2,000 cGMP molecules.
How the body works
The Forbidden Left Hand: left-handedness, measured with real data
A survey of 1,177,507 Americans and British film footage from 1900–1906 independently place the same historical low for left-handedness; school pressure may explain part of the later recovery. Take the real Edinburgh handedness test yourself.
How the body works
One Million to One: The Stomach's Impossible Acid Gradient
The H⁺/K⁺-ATPase creates a more-than-million-to-one gradient between parietal-cell cytosol and the secretory canaliculus. A 200 µm mucus-bicarbonate shield protects the epithelium.
How the body works
Eight Nanometres per Step: Kinesin's Invisible March
Compare kinesin transport with diffusion: eight nanometres per step, 125 million steps per metre and times calculated for explicit coefficients. At 10 µm the examples give about 55 or 500 seconds; explore how they grow with distance.
How the body works
One Hundred and Eighty Litres a Day: The Kidney's Invisible Recycling Loop
In the 180-litre-per-day model, reducing reabsorption from about 99.167% to 98.167% raises urine output from 1.5 to 3.3 litres: 2.2 times the baseline. This is a one-percentage-point change at fixed filtration, not an individual prediction.
How the body works
Forty Millimetres on the Back, Two on the Fingertip
On the fingertip we resolve two points at 1.6 millimetres, but on the upper back two points fuse into one even at 42 millimetres. The biophysics of Weber's two-point threshold, cutaneous mechanoreceptor density, and the sensory homunculus.
How the body works
Ten picometres: how sound reaches the inner ear
Compare pressure, energy and air motion in an acoustic model: two geometric ratios give about 22.5× pressure gain. At 0 dB SPL and 1 kHz the calculation gives 7.7 pm for an air particle, without measuring eardrum motion.
How the body works
Ten Million Volts per Metre
In a resting-neuron example, 70 mV across 7 nm gives 10 million V/m. Change voltage and thickness, then compare the ideal plate capacitance with the chosen specific value used for membrane energy.
How the body works
The Two Speeds of Pain
When you stub your toe, the reflex arrives in 80 ms, while the dull ache takes 1.60 s. A 1.5-second pause between two biological cables.
How the body works
Thermodynamics of the Tongue and Blood: Butter and Margarine
The solid-fat fraction depends on formulation and temperature. Two puff-pastry margarines measured in 2018 show the difference between melting point and remaining solid fat; the page also explains the EU trans-fat limit.
How the body works
Eight Point Four Kilograms
When you lose ten kilograms of fat, 8.4 kilograms leave through your lungs as invisible carbon dioxide, and 1.6 kilograms become water. An interactive exploration of respiratory mass biochemistry.
How the body works
The Two-Degree Point
Out of 180 degrees of human vision, only a tiny two-degree window sees the world in full sharpness and color. The brain reconstructs the rest through four saccades per second.
How the body works
The Clock of Birth
Human biology naturally schedules birth between 03:00 and 06:00 AM. Modern medicine concentrated deliveries at 09:00 AM, and Sunday births drop by 35%. Explore the 24-hour birth clock.
How the body works
The Billion Heartbeats · How Heart Rate Relates to Lifespan
Compare mammalian heart rates and lifespans, then try a constant-rate calculation. Cross-species estimates describe patterns; they do not establish a fixed lifetime number of heartbeats for any individual.
How the body works
Blood Doesn't Choose
You do not choose your blood type, but it determines who you can donate to and receive from. Pick a type to see its compatibility and frequency in Romania and twenty other countries.
How the body works
801,543,976,648,704 ways to write the same chain
The insulin B chain has 30 amino acids. Under the standard genetic code it has 801,543,976,648,704 possible RNA encodings; change any of the 30 codons and watch the message move while the chain stays fixed.
How the body works
By nine, genes already explain more than family
By age nine, genes already explain 41% of intelligence differences between children, and family only 33%. By adulthood, the split reaches 80% against 10% (Haworth et al., 2010; Bouchard, 2013).
How the body works
Two Hands, One Rhythm
A four-finger pattern can switch abruptly from 180° to 0° as tempo rises. The 20-second test tracks whether and when your hands change pairs.
How the body works
Seven Metres per Second: Why the Pulse at Your Wrist Is Not the Blood Flowing
The pulse at your wrist arrives in 80 milliseconds, yet the pumped blood takes over two seconds. A 35-to-1 dissociation between arterial wall waves and fluid mass.
How the body works
Eleven Joules at the Heel
The Achilles tendon can return 11.3 J in fast running, while a historical 35 J estimate used a different model. Compare walking and running, then calculate the mechanical work of your own jump.
How the body works
Two Hundred Milliseconds: Why You Can't Tickle Yourself
In an experiment with 16 participants, touch produced by one's own movement was rated as less ticklish; at 200- and 300-millisecond delays, ratings did not differ significantly from external stimulation.
How the body works
Water Wrinkles Begin in the Tiny Vessels of Your Finger
Immersion wrinkles appear as tiny vessels in the fingertip pulp constrict. In an experiment with 516 participants, force rose 1.35 times faster with wet, smooth fingers than with wrinkled fingers.
How the body works
Why brain freeze hurts your forehead
In a trial of 145 schoolchildren, headache was 2.2 times as common in the fast-eating group (27.4% vs 12.5%). A Doppler study of 77 adults measured blood flow velocity; the pain mechanism remains incompletely understood.
How the body works
The Two Clocks Inside the Menstrual Cycle
In a study of 612,613 cycles, 13% lasted exactly 28 days. Group averages vary both before and after ovulation, with larger differences before it.
How the body works
Why Menopause Shifted Thirteen Times More Than Puberty
Between Norwegian women born in 1936-1939 and those born in 1960-1964, age at menarche fell by 0.18 years. Age at menopause rose by 2.42 years — roughly thirteen times more, according to a 2020 study of 312,656 women.
How the body works
Three Centimeters of Border
Estimated heights for men born in 1930 are close in North and South Korea; for the 1996 cohort, the estimated gap is 2.9 cm for men and 3.4 cm for women. Compare two countries on the growth wall.
How the body works
Atlas of Medical Deserts
Doctors, family doctors, dentists, pharmacies and hospital beds per 10,000 residents, for each of Romania's 3,181 localities, today and twenty years ago. Doctors per 10,000 residents rose from 21.2 in 2004 to 34.0 in 2024, but towns have 56.4 and communes only 5.8; 315 localities lost their last doctor, and 566 have never had a pharmacy or a hospital.
How the body works
Hospitals and mortality: what the map can tell us
A comparison between administrative units: deaths in 2014–2022, registered-domicile population and distances between geographic centres towards units with hospital beds in 2024. The 87 units beyond 30 km contain 1.1% of the analysed population. It does not measure each person’s journey or establish an individual risk threshold.
How the body works
Spare Parts · An inventory of a body that never stops
What your body makes in a second, a day and a lifetime. A live inventory of bodily rhythms and tissues that renew slowly.
How the body works
Your Population — a census of the human body
The human body hosts roughly 68 trillion cells in total — 30 trillion human cells (mostly red blood cells) and 38 trillion bacteria — shown as an interactive census by category, including the 2016 correction of the old "ten bacteria per human cell" estimate.
What a test can measure
When Ambient Heat Becomes Dangerous in Pregnancy | The Heat Threshold
A systematic synthesis of epidemiological evidence on ambient heat during pregnancy. How local climate, humidity, and gestational timing shape risk thresholds at 30.55°C, 34.11°C, and 39.07°C.
How the body works
Your eyes have a stabilizer · A moving explanation
Turn the virtual head and see how the vestibulo-ocular reflex keeps your gaze in place.
How the body works
The last signal | A 900-second EEG recording
An evidence-led visual reading of a rare 900-second EEG recording around cardiac arrest. One case, four windows, and a careful boundary around what the signal can show.
How the body works
Magnesium citrate vs. malate vs. glycinate: which one actually absorbs better
Ten forms of magnesium, one named study behind each claim: who paid for it, how many people it studied, what it actually measured. For bisglycinate, malate, and taurate, this research found no independent human trial in healthy adults of comparable size to the ones behind citrate.
How the body works
Diseases treated once, not every day
How CAR-T cell engineering went from a last-resort leukemia treatment to early evidence that some cancers and autoimmune diseases might be reset rather than managed for life.
How the body works
Thermal baths in Romania: Felix, Sovata, Herculane, Covasna, Tușnad — prices, verdict
5 spa resorts compared: water type, entry price, treatment base and measured access from Oradea, Cluj, Brașov, Bucharest. Official tariffs.
How the body works
What Happens If You Don't Sleep for 24 Hours?
After one night without sleep, the brain doesn't switch off — but attention becomes unstable. Follow hour by hour what we know and what we don't: adenosine, reaction time, the alcohol comparison and the glymphatic debate.
How the body works
Blood Pressure Numbers Explained: What 120/80 Really Means
Enter 138/84 and see what the cuff is measuring: the peak and trough of one arterial pressure wave, pulse pressure, why ESC 2024 and AHA/ACC 2025 disagree, and how to measure at home.
How the body works
Stay-Awake Brain: 24-hour timeline, BAC comparison cards, PVT, caffeine calculator
Sleep-deprivation research as an interactive 24-hour timeline: the wake-hours slider, BAC comparison cards, a PVT reaction-time distribution, a caffeine calculator — the science of “17–19 hours ≈ the drink-driving line” and its limits.
How the body works
The brain changes its immune guard after 50
In the hippocampus of 40 donated brains, resident microglia thin out between about ages 50 and 75. Cells with a blood-lineage signature appear. The evidence comes from tissue, not a clinical test.
How the body works
DRD4-7R and "wanderlust gene"
A critical synthesis of DRD4-7R, novelty, migration, culture and the only direct tourism study found in this research register.
How the body works
The Moving Target
Statistics promise a boy born in Romania today 72.8 years. Follow 100,000 people born in the same year and see how the target moves as the years pass.
What a test can measure
The cause we couldn't name
A reading of recorded causes of death in Romania from 2018 to 2022. How many identify the disease that began the chain, and how many leave the question open?
How the body works
A Hundred and Five Names for One Ibuprofen
Ibuprofen appears in the register of authorised medicines under 105 commercial names, coming from 40 firms. Where the public catalogue sets identical boxes side by side — same substance, same strength, same tablet count — the dear box costs 1.56 times the cheap one at the middle of the list, and at least double in close to a third of cases. Type the name on the box in your drawer and see the molecule, the other names and the price rule. Medicines register: 6 November 2026; prices: 4 August 2026.
How the body works
What You Can No Longer Hear
Listen to six tones between 9 and 16 kHz and compare the shape of your threshold with 632 ears measured in a clinic, alongside the uncertainty introduced by headphones.
How the body works
Power After Midnight
A source-graded dossier of leaders associated with three, four or five hours of sleep, including the naps and recovery hidden by the legend.
How the body works
What If You Didn't Need to Sleep?
A mouse experiment induced selected cortical functions of sleep locally during wake; this explainer shows what worked, what remains unreplaced and who might claim eight extra hours.
How the body works
Cold as medicine, debunked
What remains of ice-bath and cold-shower claims when each effect is moved back to the dose actually used in the study.
How the body works
Avoidable death
In 2023 Romania recorded the EU's highest standardised treatable mortality rate: 199.7 against an EU average of 86.8 per 100,000 inhabitants under 75.
How the body works
The complete guide to perimenopause and menopause
A calm, evidence-based guide to perimenopause, menopause, symptoms, diagnosis, treatment options and appointment preparation, with three dedicated pages: blood tests, HRT risks per 1,000 women, and weight.
How care reaches people
The Night That No Longer Cools Down
Tropical nights (≥ 20°C) are warming faster than daytime highs. An interactive explainer about recovery, Europe, Bucharest on the chart and mortality.
What a test can measure
The Unseen Spectrum
An interactive documentary about colour-vision deficiency: prevalence, types, a simulator and educational and professional impact.
How the body works
Sepsis Clarity
A bilingual guide to recognising sepsis, emergency care, post-sepsis syndrome and recovery.
How the body works
Living Atlas of Endometriosis
A bilingual atlas of endometriosis: diagnosis, options, daily life, support, recent research and access in Romania, with sources and evidence limits in view.
How the body works
ADHD Treatment Map
Treatment, evidence, costs and access in the US, UK, EU and Romania, in a bilingual documentary. Regulatory update: 6 November 2026; comparative evidence: June 2026.
How the body works
The Thermometer & the Mind
A multidisciplinary dossier about how heat affects sleep, mood, learning, decisions and aggression, with interactive visualisations.
How the body works
The faintest sound you can hear moves your eardrum less than an atom
Go down into your own body, order of magnitude after order of magnitude: from a candle seen kilometres away, through two needles on the skin, a red cell and a 10-nanometre turbine, down to an atom. At every step, a measurement from 43 other pages.
How the body works
Cholera in the Romanian lands — The quarantine that stopped the fairs
Three cholera waves — 1831, 1848, 1873 — faced with no cures, by cordons on the Prut and the Danube, quarantines and closed fairs. The 1848 wave is dated from the pandemic chronology and the 1847 reopening of the quarantines; no complete toll survives.
How the body works
Balance in your ear — The three canals that sense rotation
Why you feel dizzy after spinning and stopping dead: fluid in the three semicircular canals keeps moving, and the brain reads a rotation that is no longer there. Interactive simulator with the mechanism explained.
How the body works
A sleeping foot: why sitting on it brings pins and needles
Sit on your foot for a few minutes and it prickles when you stand. The pricking comes from the nerve restarting its signal. A short simulation shows the order in which feeling returns.
How the body works
What a baby hears in the womb: your mother's voice as you first heard it
For months before birth, you could hear. Listen to a mother's voice the way it reaches the child inside her, rebuilt from studies that placed microphones in the womb, then record your own.
How the body works
What a newborn can see: your face through a baby's eyes, week by week
A newborn can see you, but not the way you think. Let your own face be filtered through measurements of newborn vision, then watch it come into focus over the first three months.
How the body works
The face she can no longer see is yours: a visit through aging eyes
Look at a family visit through your grandmother's eyes, rebuilt from measurements of aging vision. The light dims, the small print escapes — and the face she turns towards dissolves into the spot her brain paints over.
How the body works
How slowly a hand has to move
Draw one finger along an arm. The average firing of slow forearm nerves was highest at a slow stroke and at skin temperature, and a separate group rated that speed highest.
How the body works
How many pension years will you get? Retirement-age calculator with the years left
Enter your birth month and find your retirement month under Law 360/2023, the years after it and how many are free of limitations — on Romania's 2024 life tables, with a wall of bricks for all your years.
Health across communities
What you breathe on your street
A snapshot of PM2.5 on Bucharest streets on 30 September 2026 at 16:30. Distinguishes station readings from model estimates; it does not show current air quality.
Health across communities
What the numbers on fruit stickers mean: 4011, 94011 and other PLU codes
Type the sticker number to see the item in the official IFPS list, what a leading 9 means (declared organic) and what the code does not say. A leading 8 does not mean GMO: that meaning was dropped in 2015, never used in shops.
Brain, sleep and attention
When anxiety passes for conscientiousness: perfectionism, control and worry that never switches off
Ten portraits of the conscientious person, written in the words of someone who would never call themselves anxious, then the seven GAD-7 questions in their official wording. At the end each portrait sits beside the question it was written from, with both your answers. In the WHO surveys only 41.3% of people with an anxiety disorder in the past year felt they needed help. Nothing leaves your device.
What a test can measure
Your ears make sound: ten measured facts about the nervous system
Ears that make sound, a toe that can hurt twice, a man blind from strokes who walked a cluttered corridor without a collision: ten published results about the nervous system, each with its source and a note on how it was checked.
Health across communities
In 1993 a midwife on her own delivered one baby in eight in Romania’s maternity wards. In 2023, one in 66
How many midwives Romania has (from 12,479 in 1989 to 2,785 in 2024), how many babies they deliver without a doctor (one in eight in 1993, one in 66 in 2023), what is left in each county, and why the 2024 figures can no longer be compared.
Health across communities
Five antibiotics tracked, hospital by hospital
Which antibiotics did Romania’s public hospitals buy in 2025, and what infection rates did they report? The analysis tracks five names and may include combination products or multi-drug purchases; it does not cover WHO’s full Reserve category.
Health across communities
The week after Easter: more people died in Romania than usual
In the week after Orthodox Easter, on average 5.7% more people died in Romania than the reference level, some 270 extra deaths in that week, in eight of nine years (2015–2025). The rise moves with the date of Easter. Greece shows the same; Bulgaria less so, and the pre-set check against Bulgaria failed, in plain view.
Health across communities
Well water: why it looks clean and what may be in it
Nitrate in well water is tasteless: the 50 mg/L reference value, the section from latrine to bucket, the evidence map and search across 15,418 localities — plus the exact lab panel to request.
About the collection
This collection brings together relevant projects from the site’s library. Each entry has a title, a description and a link to its available edition. The complete projects carry their sources and evidence limits.
Reviewed · Collection as text
Sources
- W3C High Resolution Time
Describes the monotonic clock used for measuring an interval within a page; exposed resolution can depend on the browser.