“Isn’t… that… a … Tyrannosaurus Rex?” Markus stutters.
”Yes, I think so,” Mariana whispers.
“Do you think… Uncle Albert has been eaten…?” Markus is afraid to ask.
Instantly Uncle Albert appears from the rocket hatch and calls to the children:
“There you are! Hurry up and get in and I’ll pull in the hose. We have to get going right now. In a hurry!”
”But what about the giant lizard?” asks Markus and points to the Tyrannosaurus Rex.
“Oh that,” says Uncle Albert. “No problem at all. He is sound asleep and won’t wake up for ages yet. I had to subdue him when he started chewing on the Moona-Lisa. Lucky I had built-in some defence mechanisms in the rocket’s shell, just in case we would land somewhere dangerous.”
“But why are we in such a hurry?”
“I have made all the observations I need and if my calculations are correct, a giant rock from space, a meteor or maybe an asteroid, will hit the Earth any minute and it is best we are not here when it does.”
The Moona-Lisa is ready for take-off in record time and off they go. Only a few minutes after they leave the Earth they see an enormous boulder pass them and start to burn as it travels through the layers of the atmosphere. As the asteroid hits Earth, the space travellers can see the explosion all the way to the moon and a big black cloud begins to spread over the Earth’s surface.
”Wowwee. That was one big explosion,” says Mariana.
“But what about all the dinosaurs?” asks Markus distraught.
“They will die out now, soon enough,” replies Uncle Albert. “It has long been suspected that the dinosaurs became extinct approximately sixty five million years before our time after an asteroid or comet hit Earth. It was what I was afraid of when I found out what time we had landed in. And now we know that it’s true. Amazing how much we’ve learned on this trip, isn’t it?”
Uncle Albert is elated, but Markus and Mariana are sad. They think of all the poor dinosaurs they just met that are now doomed. But Uncle Albert explains that if the giant reptiles had not become extinct, mammals never could have evolved and thrived. And neither could humans, since humans are mammals. So without the Earth’s collision with the asteroid, neither Uncle Albert nor the children would have existed!*19
”But Uncle Albert,” asks Mariana, ”what if an asteroid were to hit Earth in our time?”
“That would be bad indeed. The chances are very small, but we must learn to keep watch around the Earth so we can solve such problems in time should we discover them.”
“Maybe we could move to Mars for a while, if we needed to.” Markus suggests.
”Perhaps, perhaps.”
”Peep, peep,” Max whimpers.
“Max! We’ve forgotten Max. Markus, we have to care take of his cuts and bruises and give him some really tasty cheese.”
Helping Max makes the children forget about both dinosaurs and dangerous asteroids. Instead they suddenly notice how hungry they are after all the adventure. So hungry that even Uncle Albert’s tinned foods taste great.
12
Uncle Albert’s mood improves for each day they get closer to the Earth. As usual he observes everything he can see and spends his time with calculations and equations. Markus and Mariana spend their time looking out into space and finding fun stuff on the rocket’s computer. One night, a few days after leaving the Earth of the dinosaurs, Uncle Albert exclaims:
“Now, dear friends, I can tell you…”
“…that if my calculations are correct,” Markus and Mariana finish his sentence for him.
”How did you know I was going to say that?” says Uncle Albert surprised. “Anyhow, yes if my calculations are correct, we should be home tomorrow after breakfast. Our breakfast time here, that is. Which is just before dinner your time. Just in time to make it home as you promised! Sleep well.”
It all sounds a bit confusing to Markus and Mariana, but the children are happy to be home soon and are soon sound asleep in their beds.
KRACKADONG!
A giant bang wakes everyone and the whole spaceship shakes. Red and yellow lights are blinking on the instrument panel and a warning siren is heard. Uncle Albert is up in the blink of an eye and starts pressing and turning every knob and button on the ship. Markus and Mariana, still half asleep, are lifted from their beds and hover up towards the ceiling.
“Hmm,” says Uncle Albert, “it seems that we have been hit by a small meteor rock, a micro meteor. It has punched a hole in the antiproton engine’s cooling system, and it has shut down. An excellent precautionary measure, if I do say so myself.”
”I’m sure,” says Mariana unhappily as she floats in the air, ”but what do we do now?”
“So that’s why we’re weightless again! But I’d rather be back on Earth and be heavy than float around here like a butterfly for the rest of my life,” Markus complains.
But Uncle Albert isn’t listening. He dives into a hatch in the floor with his legs sticking out and flailing about. He looks so funny that the children can’t help but laugh, despite their predicament.
“Ha!” Uncle Albert backs up out of the hatch and does a somersault in the air. “Look here! I knew I had brought spare parts.”
In his hand he holds a piece of hose, about half a meter long.
“Put your spacesuits on. I have to climb down to the engine on the outside to change the hose.”
“Space walking, yeah!” says Mariana, excited.
”Yes, but you two will have to stay in here. I need your help here and it is taking an unnecessary risk to send more than one of us outside.”
“Boring,” says Markus. “So why do we have to wear the suits?”
“Oh Markus,” sighs Mariana, “if we open the hatch all the air will be let out!”
It is harder to put the spacesuits on without gravity. There is no good way to hold on to anything. The three space travellers spin around each other whilst struggling with their suits, but finally everything is ready and Max is once again perched on Mariana’s shoulder. Uncle Albert fastens a toolbox to his stomach and opens the hatch and climbs out. Slowly and carefully he hovers down towards the antiproton engine.
”In position,” he announces to the children over the radio.” I am starting to remove the broken hose.”
“A red light just went out here,” says Mariana after five minutes.
“Precisely. I have removed the faulty hose. Here comes the new one.”
Markus and Mariana hear how Uncle Albert whistles to himself as he works. Something that sounds like an ABBA song. Then he grunts:
“Arggh! That wasn’t good at all.”
“What is it?
”I dropped the wrench!”
Through the window the children watch as the tool slowly floats away into space.
“Uncle Albert!” they groan.
“It’s hard to work with these big gloves. But Markus, look in the other box under the pantry. It says “Tools” on it. I may have a good old wrench with me as well. Did you know, by the way, that it was a Swede who patented the wrench at the end of the 19th century?”
Markus couldn’t care less about patents right now, but he is relieved when he finds a wrench.
“Uncle Albert, I’ve tied the wrench to a string so that you won’t lose this one as well.”
“Good idea! I’ll do that with all tools from now on.”
A few minutes pass before Uncle Albert, slightly worried says:
”Done. Mariana, press the button that says ’Cooling’!”
A buzzing sound is heard.
“A green light is showing. It says ‘Pressure’,” she says. Uncle Albert hollers as if Sweden had just won the world football championship:
“Yes! We made it! Victory is ours! Yippee!”
13
Markus and Mariana are once again glued to the windows of the Moona-Lisa, watching the Earth growing closer. And now it looks as it should, with all its continents in the right pl
ace.
Uncle Albert steers in over Europe and up toward Scandinavia and Sweden.
“This will be tricky,” he says. “I have to steer just right to land in my launch tower. My rocket garage you might call it,” he chuckles.
But the precision landing in the mansion’s tower is not entirely successful, and Uncle Albert collides with a wall. The Moona-Lisa falls the last few meters with a crash. The proud space travellers have to crawl out of a rocket that looks about ready for the junkyard.
“Poor Uncle Albert! Your wonderful spaceship, look at it,” says Mariana.
”Yes, yes, well. You take things as they come and what will be will be. We aren’t going on any more space trips any time soon, ” says Uncle Albert philosophically. “Anyway you two better be off home right away, so you aren’t late for dinner. It was at six, wasn’t it?”
Markus and Mariana look at the big clock on the wall of the rocket room. It shows five minutes to six.
“Is it really possible that it is the same day as when we left?”
“Yes of course! And if you don’t believe me now, you will when you find Rufus behind the steel door, safe and sound.”
Markus and Mariana throw themselves on the heavy door and after some pushing manage to open it. There is Rufus, barking happily and jumping at them. He seems to be just fine. But he is less happy to see Max.
”Uncle Albert, please, can’t you take care of Max? We can’t bring him home. Neither Rufus nor Mum would accept it. Not without a lot of complaining anyway.”
“Okay, I guess I’ll take care of the mouse.”
”Thanks! Now we have to run home. Thank you for a super-exciting trip. We’ll be back as soon as we can, in a day or two.”
And with those words Markus and Mariana run off with Rufus in tow. Uncle Albert and Max are left behind, eyeing each other suspiciously.
“Well I guess I’ll be stuck with you for a while then,” mutters Uncle Albert. “Come on, I’ll see if there’s some cheese left in my fridge.”
Markus and Mariana come running into their house just as the clocks strikes six.
“Just in time, I must say,” they hear their mother mutter in the kitchen. “The food is ready and on the table.”
As she enters the dining room and sees Markus and Mariana she exclaims:
”What have you done? Your clothes are filthy. There’s always something when you’ve been to Albert’s. Filthy pigs! Go put on some clean clothes and wash up before we eat.”
”Oops, maybe we should have thought of how dirty our sweaters were after all that rock-slinging,” whispers Mariana to Markus as they run up the stairs to their room.
At the dinner table their father asks if Uncle Albert had anything particular up his sleeve, or if he’d come up with some new crazy scheme during the summer.
“Naaahh. He has redone the roof of the tower,” Markus and Mariana reply innocently.
”Really? That’s unlike Albert,” says their father. Their mother gives the children a pensive look:
“What have you done with your hair? You cut it just a week ago, but it looks like it’s been a month…”
Everything grows faster in the summer…” Markus says and winks at Mariana.
Then they hungrily devour the best food they’ve had in weeks. Or was it 65 million years?
THE END
FACT and FANTASY
1. Protons, neutrons and electrons
build up atoms and all matter
Everything around us here on Earth is built up of tiny balls which are called atoms: air, water, earth, metals, plastic, plants, animals … yes, EVERYTHING. In nature there are barely a hundred different types of atoms, but they can “glue” themselves together in a tremendous variety of ways. That’s why there are so many different materials and substances. When atoms “glue themselves together”, we call them molecules and the “glue” is really called chemical bonding. An atom isn’t more than a tenth of a millionth of a millimetre in size. And it takes several thousand billion billions of atoms to make up one single gram (one thousand billion billions, written in figures, is a one followed by 21 zeros – mathematicians and others write this as 1021).
The atoms consist of an atomic nucleus and electrons that spin around the nucleus in different orbits – kind of like the way the planets spin around the sun. The atomic nucleus, itself, consists of protons and neutrons. It is the number of protons that tell us what type of atom it is. The tiniest and simplest atom is hydrogen, which consists of just one single proton and only one electron. Another very important atom for life on Earth is oxygen. Its atomic nucleus has eight protons and eight neu¬trons and around it spins eight electrons. Water, for example, consists ofwater molecules which are composed of two hydro¬gen atoms and one oxygen atom that have “glued” themselves together.
This is a model of an oxygen atom with a nucleus consisting of 8 protons (blue) and 8 neutrons (red). Around the nucleus spins 8 electrons (green) in two shells; the innermost shell holds only 2 electrons.
As Uncle Albert said, the protons are positively charged, the electrons are negatively charged and the neutrons are electrically neutral. An atom always has as many protons as it has electrons and is therefore neutral. But sometimes, an atom can lose an electron or take an electron from another atom; then it’s charged and called an ion.
2. Antiprotons and other antimatter
There are antiparticles as well. Every particle has its antiparticle: the proton has an antiproton; the neutron has an antineutron, while the electron’s antiparticle has its own name: positron. A particle and its antiparticle weigh exactly the same, and they also share several other properties which are exactly the same, but their charges are opposites. So, the antiproton is negatively charged and the proton is positively charged. If a particle and its corresponding antiparticle would come into contact with each other, they would be destroyed. All the energy that has been stored in their mass would be unleashed, according to Albert Einstein’s famous formula E=mc2.(Where E means the energy we get, m is the mass and c is the speed of light.) Therefore, in principle, antiprotons would be the ideal rocket fuel if they were mixed with protons, which you can easily extract from hydrogen (you just have to remove the only electron). But, in reality, it is incredibly hard to produce any greater volumes of antiprotons; it’s just as hard to manage to store them in such a way that they won’t come in contact with the any of the protons before they get to the rocket’s engine.
Many antiparticles fly around in space (although they are less numerous than ordinary particles), and they can be produced in laboratories for particle physics, like CERN. In laboratories, the antiparticles are produced in the same way Uncle Albert does it: you accelerate the particles to a very high speed in particle accelerators, which is the equivalent of high energy, and make them crash into something. Then, with Einstein’s formula E=mc2 in reverse order, you can create antiprotons. However, it is tremendously ineffective: it takes tens of thousands of protons to create every single antiproton.
3. Relative time – time dilation
The nature of reality is in fact such that time passes at different rates depending on how fast you are moving. Time passes quickest if you are perfectly still; then, the clock runs exactly as we are used to. But when something moves really fast time passes more slowly. To achieve a notable difference you have to travel at a velocity near the speed of light. And at the very speed of light (300 000 km/s), time stands absolutely still. Even in rockets spinning around the Earth at only 8 km/s, the difference is minimal; however, there are extremely accurate clocks that can measure it. And what’s more, nothing can move faster than the speed of light – it is impossible to build a rocket that goes faster than light.
To be exact: if you should travel past me at a high speed, I would see that your clock runs slower than mine. But to you, in your spaceship, it would look like I’m moving at a high speed in comparison to your vessel, and you would see that my clock runs slower than yours; that is, the very opposite.
There is no “right” or “wrong” time; on the contrary, time runs at different speeds when measuring it for things that pass by at different velocities. And it is not the case that a clock runs slower due to some technical cause; it is time itself that moves slower. In fact, the heart beats slower; people age slower. The difference in the speed of time is actually called time dilation.
The clock with the little green astronaut in the spaceship has run slower thanthe clock with the little red astronaut on Earth.
But if Uncle Albert travels from Earth at a high speed he will see, as we know, that time on Earth runs slower than his time, while they who remain on Earth will see that their clocks run faster than Uncle Albert’s. But what will it be like when he returns? Who will have aged the most? There is a decisive difference between Uncle Albert and the people on Earth: Uncle Albert changes his speed later, when he turns around and goes back. As a result, it is his clock that runs slowest, and his clock that shows the least passing of time, when he lands back on Earth again. So Uncle Albert can go away and return after spending just a few weeks in his spaceship, while on Earth a thousand years have passed. This is not fantasy: it is fact. But, to build a rocket that can handle the necessary speed is as yet a fantasy.
Does the idea of different time in different places sound weird? It might seem strange because we are not used to such things. But reality is the way it is, and to understand something is, to some extent, just the same thing as becoming used to it. We believe that we understand that the Earth has gravitation, that balls thrown up in the air will come down again, just because we are so used to it. But, the actual reason for there being gravitation might be equally hard to understand as the reason for time passing at different rates in different places.
The Space Journey Page 4
