How do you take a photo of time?
I've been watching the track events at the Olympics since I was a wee lad. It was a tradition in our family. We'd gather around our ancient low-definition 19 inch CRT television and watch tiny blobs compete against other tiny blobs and root for our country.
It was a bit like watching YouTube on your phone in 144p.
Jackie Joyner-Kersee was amazing.
You can't forget about Flo-Jo.
And then the Olympics decided NBA players were allowed in the competition.
Which formed... The Dream Team.
Well... they won each game by an average of 44 points.
So... no. It was not fair.
Though it became more fair as time went on.
But, umm... yeah. The other teams looked like the Washington Generals and the US looked like the Harlem Globetrotters if they stopped screwing around half of the game.
But my absolute favorite Olympian was a runner named Michael Johnson.
For one thing... gold shoes.
But he also had this crazy, upright, Tom Cruise-ish sprinting style that just made him look like a running robot on the track.
And in the 1996 Atlanta games he just trounced EVERYONE. I mean, it wasn't even close.
Yikes. Those losing blobs are probably really embarrassed.
Last night I decided to invigorate my nostalgia and watch the track events again. And I got to see one of the wildest races in history.
It didn't even last 10 seconds but it was one of the most exciting sporting events I've ever witnessed. Almost every runner won the race.
After I saw that initially, I was like... who the heck won???
Even in slow motion I wasn't sure.
This was one of the closest finishes in history. There has never been a race where all 8 runners were within this margin.
The arena was silent as the winner was being confirmed. The runners just kind of paced around waiting for official word. My best guess was the Jamaican runner, Kishane Thompson. But then the loudspeaker announced Noah Lyles.
The last tiny morsel of American pride burst out of me with a big "Wooooo!"
I forgot what it was like to be proud of my country. I wish it happened more often. But this young man, despite being last place in the first 3rd of the race, turned on the afterburners and won in a photo finish.
And that's when my inner nerd took over.
Because when they showed the photo finish image, it looked super weird.
Why do all of the runners look all warpy like that QWOP game?
So I went down a research rabbit hole to figure this out.
Photo finishes are actually fascinating. The first photo finish captured the end of a horse race in 1890. But that was mostly luck and timing. The actual photo finish mechanisms weren't used until 1937.
Originally they would film the finish line through a physical slit.
And the first horsie head that appeared in that slit would be the winner. This technology ended a huge aspect of corruption in horse race fixing almost overnight.
But we have come a long way since then. And I'd like to introduce you to the Omega Scan 'O' Vision Ultimate.
This slow motion camera sits fixed on the finish line of every race. The concept of the photo finish has remained remarkably similar to the 1930s approach. The camera sensor is specially designed to only record a vertical slit.
Only the finish line itself is actually captured.
And because it limits what it records to only that slit, it can capture 20,000 frames per second to get amazing temporal resolution.
So why don't the photo finishes just look like, well... this?
That is because the camera takes a picture of time more-so than dimensional space. I guess it would be more accurate to say it *assembles* a picture of time.
As the runners cross the finish line, the camera combines all of the little strips of pictures into a single image.
It's almost like if you tried to reassemble a piece of paper after it had been shredded.
Imagine each strip of paper is a picture of ONLY the finish line, just at a slightly different point in time.
What if someone stopped on the finish line and didn't move... what would that look like?
Once they got there, the same part of their body would just be repeated.
So the right side of the photo finish picture represents earlier in time and it just assembles the image strip by strip as time passes and you literally get a picture of time itself.
Okay, but how do they determine the winner from the photo finish?
I mean, that shoe looks like it is ahead of Noah Lyles!
The IAFF rules state the foremost part of the torso must cross the finish line first. And the endpoint of the torso is the outer end of the clavicle.
So if you get this bone across the finish line first, you win the race.
The start of the race is actually just as carefully timed as the end of the race. There are sensors in the starting blocks of each runner.
The starting gun also has an electronic sensor.
They have determined the fastest a human can react to the sound of a gun is roughly 100 milliseconds. So if you start running before 100 milliseconds they know you didn't actually hear the gun, you just got antsy and started running too early.
And the final fun fact...
Did you notice the Omega logo at the top of the photo finish?
That isn't superimposed or added after the fact. That is captured by the camera.
But if this image is composed only of tiny little slivers, how did they get the Omega logo to show up?
That is a little display. And it is synchronized with the Scan 'O' Vision Ultimate to show a little sliver of the Omega logo for each frame captured.
So when the final image is stitched together, it looks like a cohesive logo at the top of the photo.
