Holy Shit, the Speed of Light!

If you know a little bit about physics, you know that the speed of light is around 300 million meters per second. If you know a bit more, you know that the exact figure is 299,792,498 meters per second. If you know just a bit more, you know that neither of those are necessarily true.

Here's the problem: "The Speed of Light" is a bit of a misnomer, which is probably one of the reasons scientists tend to just call it c. A more accurate definition of c would be "The Speed Limit of the Universe," because 299,792,498 meters per second is the fastest that any energy, matter, or information can possibly travel. It so happens that light is the only thing we know of that can reach that speed.

There are contenders, but we haven't quite gotten there yet.

What that doesn't mean, however, is that light always travels at c. In fact, light only travels at "light speed" in a vacuum. You'll note that the entirety of Earth is not, to our great benefit and relief, a vacuum. We have a whole atmosphere that lets us breathe and stuff.

That's not to say we don't have some perfectly nice vacuums on Earth

The effect of the atmosphere on light is relatively small. It shaves off about 90,000 meters per second from light speed, which is a drop in the bucket. "So what's the big deal," you might say, "that's more or less the same. What's the difference?" To which I'd respond, "Are you inside?"

"Always."

Because if you are inside, the light you're seeing is traveling significantly slower. Even if it's natural light coming through a window. Glass alone will slow down light by almost a third. These are just natural processes that slow light down. If you put some effort into it, you can make light practically crawl. Physicists at Harvard University, led by Lene Hau, used a bizarre state of matter with densely packed, super-cold atoms to slow light to 17 meters per second. That's 38 miles per hour. That's like you're morning commute, if you don't take the highway. You could beat light to work, depending on the traffic.

A few years later, those same physicists succeeded in turning light into matter and making it just stop. They then revived it and started it moving again a short distance away. So, congratulations. Any time you move, you are travelling faster than light...given the right conditions.

Holy shit.





"Bolt200" by Jmex - Own work. Licensed under CC BY-SA 3.0 via Commons

"Робот пылесос Roomba 780" by Nohau - Own work. Licensed under CC BY-SA 3.0 via Commons

"Sacrumi". Licensed under CC BY-SA 3.0 via Wikipedia - No offense intended :-)

Holy Shit, James Harrison!

In 1951, a 14-year-old Australian kid named James Harrison underwent major chest surgery. There were no major complications, and he ended up fine, but it struck him as incredible that he required almost 3.5 gallons of donated blood in order to survive the ordeal. From that moment, he made a personal vow to donate as much blood as he possibly could once he had fully recovered. As soon as he turned 18, he started giving plasma every 2-3 weeks.

Which I guess was exhausting? This pictogram is weird.

Once he had one or two donations under his belt, there was an interesting development. It turns out James Harrison's blood contained an antibody called Rho(D) immune globulin. That probably doesn't mean much to you, but to OB/GYNs and medical researches, finding this antibody in someone who was vowing to donate as much blood as humanly possible was like planting a garden and finding El Dorado in your backyard as a result.

I have a sudden urge to start gardening...in November.

To understand why, you need to know a bit about blood types and pregnancy complications. If a pregnant woman has a negative blood type but the fetus is positive, the mother's blood often treats the baby as a disease. The medical term for that situation is Rhesus Disease, but it's also known as "Bad News Bears." In the best case scenario, the baby is born anemic. More often than not, it could cause miscarriage or stillbirth.

Rhesus Disease used to be one of the most common causes of pregnancy and birth complications. But then James Harrison came around. When his fancy-pants antibody is given to pregnant women, it essentially hides the part of the baby's blood that causes the mother's body to treat it as a parasite. Thousands of babies were born and lived because Harrison was constantly donating. It wasn't long before researches developed RhoGAM, which is essentially a vaccine that protects at-risk pregnancies from Rhesus Disease.

James Harrison is still around and donating, and he's become a major voice for blood donation. He currently holds the world record for lifetime blood donations -- which, by now, is well over 1,000. It's estimated that his blood has saved over 2.4 million babies.

Well that's just ungrateful.

I don't usually get personal on this blog, but in this case I'm going to make an exception. My daughter is quite possibly alive today because of James Harrison. Her blood type is Rh positive and her mother's is Rh negative. My daughter is easily the single best thing that's ever happened to me. She's brought immeasurable happiness into my life, and I owe that happiness, in part, to James Harrison.

There is nothing like this.

Holy shit.




By the way, you ought to consider donating blood yourself. You've got a ton of it, and it's not like you're using it all. Might as well, right? The Red Cross is a good place to start, but a quick Google search for "donate blood" should show you what your options are.



James Harrison with two babies. Australian Red Cross.

"Muisca raft Legend of El Dorado Offerings of gold" by Andrew Bertram - World66. Licensed under CC BY-SA 1.0 via Commons

"Human-Male-White-Newborn-Baby-Crying" by Evan-Amos - Own work. Licensed under Public Domain via Commons