How an X-ray sees through you
Inside the tube, 60,000 volts hurl electrons from a white-hot tungsten filament at nearly half the speed of light into a spinning tungsten target, where some of their lost energy leaves as X-rays. Soft tissue lets many of those X-rays through; dense, calcium-rich bone stops far more. The screen shows what the detector measured the way old film did, more X-rays meaning darker, so the white on your X-ray is a shadow where most X-rays never reached the detector. A typical hand X-ray's dose is comparable to less than three hours of natural background radiation.
- 0:00 Paradox cold open
- 0:05 Inside the tube
- 0:12 Across the gap
- 0:18 How X-rays are made
- 0:40 Measured, then shown
- 0:53 A small dose
- 1:02 Their shadow