Iridium magic — how to fool believers

By Frederic Friedel

I have a friend named Sergey. He is a very intelligent, very talented person, a top international chess grandmaster who travels the world and sends me wonderful cultural pictorials of the places he visits. He is a lucid and interesting conversationalist whose company I enjoy. But: Sergey believes in magic, he believes in paranormal phenomena — and he believes in aliens and UFOs, as I have mentioned elsewhere.

One day Sergey was coming to Hamburg and I wanted to put him up in our company flat. “No, I want to stay at your home,” he said, “because so many famous people have stayed there.” — “But we will argue all evening,” I said. It didn’t matter, he actually enjoys fighting with me.

Well, Sergey turned up and our debates were well under way long before the pizza dinner arrived. And continued during the meal. Sergey kept coming up with new and incredible things he had seen on his travels, he had photos and even videos, described unexplained objects and supernatural events. Many I could explain ad hoc — people doing simple, well-known conjuring tricks. But Sergey inevitably demurred: the people he had seen (and photographed, or videoed) were the real thing, they were not using tricks, like the charlatans I was describing. “Frederic, I am an expert, I have so many years of experience. I can catch tricks and cheats!” Really?

At some stage I said: “Okay, Sergey, I will show you something. I will perform a feat of magic that is a thousand times more difficult than anything you have told me about so far. I will do it without any supernatural forces, just using tricks. And you will of course immediately be able to catch me.” Sure, Sergey was quite confident that he would be able to do so.

My son Tommy was spending the evening with us, and I turned to him: “Tom, get the star exploder, and set it up for us.” He look a little puzzled, so I pulled it out from the drawer for him. It was a small electronic device, about half the size of a TV remote control, and I handed it to him together with a little post-it tab under it. On this were a few numbers and letters: 22:10:46, 22°NNE, 49°. Tommy looked at it and understood: “Okay, let’s do it,” he said.

So we took Sergey into the front garden. It was a beautiful, dark night, the sky was very clear and full of twinkling stars, no moon to disturb anything. I pointed upwards and said: “Pick a star. Any star.” Sergey, a bit mystified, pointed upwards and said: “Okay, that one.” “Right,” I said, “Tommy, blow it up!” And Tommy started fidgeting around with the little black device.

Suddenly Sergey cried out in surprise: “It is moving!” You could clearly see a dot in the sky slowly moving against the background. “Okay, Tom, let’s do it,” I said. “Yes,” he replied, “I am setting the parameters. Wait a sec. Okay, ready? Go!” He pressed a button and within a few second the moving dot in the sky lit up, shining much brighter than any of the neighbouring stars. Then brighter, brighter, until it was a beacon in the sky, around thirty times brighter than the surrounding stars. No, correct that: thirty thousand times brighter! Really. Forty times brighter than the planet Venus at its brightest, at its most dazzling. Absolutely stunning.

At this stage I said to Tommy: “Okay, switch it off, we don’t want to destroy all the planets circling the star!” He furiously tapped the keys on the device, and immediately the star started diminishing in brightness, until after about a minute it disappeared from view. “I think we blew it up,” Tommy said, “we increased its brightness too much and for too long.”

“So how did I do that, Sergey?” I asked the stunned chess grandmaster. He pondered over it for a while: what he had seen was clearly not a plane, which has blinking lights, or a balloon. In any case: why would they light up in this way, and how could I be controlling this? He thought and thought, and after a few minutes his face lit up, he had found the solution: “Laser!” he said. Come on Sergey, that is only a word, and it doesn’t even make sense. Actually it was simply his way of saying “Magic!” to a militant skeptic.

Of course some of you reading this piece will know the solution, the answer to the question of how I did it. If you don’t, think about it for a minute. What is the most likely explanation?


Actually the trick I had used on Sergey was completely extemporaneous. During dinner I had “gone to the bathroom”, but in reality went upstairs and visited the astronomy site Heavens Above (links given below). There I discovered that there would be an Iridium Flare in our location at, say, 22:10:46 that evening, at 22° NNE at an elevation of 49°. This I jotted on the post-it — 22:10:46, 22°NNE, 49° — and put it in my pocket. And did nothing for a while.

At around ten p.m. the conversation very naturally turned back to miracles and tricks, and then to my challenge to do something really spectacular. Tommy was not in any way initiated — that is not necessary, he figures these things out on the fly. When I said “get the star exploder” he did not know what I was talking about or what I intended. And when I handed over the device, which was a digital compass that also displays the time, he glanced at the post-it below it. And when we went outside and I started my “pick a star” shtick he finally understood what we were doing. I glanced at Tommy’s hand — he was holding the device pointing to 22°NNE — and I pointed in that direction. Of course Sergey picked a star in the general area I was pointing. Tommy simply monitored the time on the compass and pretended to type in commands. He knew exactly what was needed, and twenty seconds before flare time he pretended to initiate the star explosion. It was all unprepared, but it went like clockwork.

Before I tell you about Iridium Flares and exactly what we were doing let me show you a picture and a video of such an event:

This time lapse picture was taken by astrophotographer James Young in California. The peak brightness of the Iridium satellite flare was about –6 magnitude. The bright star at the top, at magnitude 2.5, is the star Alpha Pegasi.

Even more impressive is the following video recording of an Iridium Flare:

That is what Sergey was exposed to, that is what we had pretended to have done with our little “star exploder”. But what exactly are Iridium Flares?

Iridium is a satellite communication system that provides voice and data coverage to phones, pagers and integrated transceivers over the world. It is done with a constellation of 66 satellites, plus a few spare ones to serve in case of failure. The satellites are in low Earth orbit, about 500 miles up, and have an orbital velocity of 17,000 mph (27,000 km/h).

Iridium satellite [image courtesy Calvin College]

Iridium satellites have two large solar panels and three polished door-sized antennas, at 40° angles to the main body of the satellite.

These antennas reflect sunlight directly down at Earth, creating a quickly moving illuminated spot on the surface below. The light track is about ten km wide and to an observer it looks like a bright flare in the sky. The brightness can reach a magnitude of –9 and can last from 5 to 20 seconds. Iridium Flares occur on average from zero to four times a night for any given location.

The site I mentioned is Heavens Above, a marvelous service that is also available as a must-have app for Android phones. It is all free, but you should donate to the maintenance. Heavens Above tells you everything you need to know about the current night sky, like the moon, planets, constellations, comets, asteroids, etc, but also the passes of satellites for the next ten days — literally hundreds of them. It is particularly impressive to watch an overpass of the International Space Station, which is bright and majestic. Oh, and don’t miss watching this interactive 3D visualization of ISS.

So, anyway, that is how I scammed a true believer in magic, and I hope you will do the same to your friends, for entertainment. Incidentally, Sergey has been the victim of two of my skeptical articles to date, and I feel a bit guilty of using him in this way. But I met him recently and told him I was going to do it. His reaction was: “That is unfair, it makes me look stupid. But on the other hand it is all very interesting, so go ahead, Frederic, tell the stories!” And quickly posted links to my articles on his Facebook page.