Stop the hacker! If you own a laptop, take great care if keeping data you wouldn’t want to lose—or have read by someone else—on its hard drive, because a laptop can easily be stolen. And keep backups at home.
2. Software attack
If your computer is connected to the Internet, there can be vulnerabilities (mistakes!) in its software that could allow a hacker to gain access remotely, through the network. Some of these mistakes could allow a hacker to run programs on your computer without even having to trick you into doing something first, and if hackers find out about these security holes before the people who write the computer software do, they can exploit them before anyone has time to fix the problem: these attacks are known as “zero-day” exploits because they take place on zero-day of the vulnerability becoming generally known.
Stop the hacker! Updates (patches) are made available by the software company to fix vulnerabilities. Nowadays, your computer will usually let you know if a patch is available, and you should always install these—ask your parent or guardian to do so, or help you to do so, if it is their computer—otherwise the computer, the data on it, including any of your private information, may be at risk. Additionally, make sure any computer connected to the internet has its firewall turned on—a firewall is a barrier that can block uninvited connections to the computer from the internet.
3. User attack
A hacker may try to trick the computer user into doing something for them. For example, you could receive an email asking you to click on a link, or open an attachment, or a link might send you to what looks like the genuine web page of your favorite site. But email is totally insecure—in fact, anyone can send a message that claims to be from someone else, and can attach a link that looks genuine. So an unexpected message like this could be from a hacker, and the attachment could be a nasty piece of malware.
Stop the hacker! Never open a strange attachment—even if the message appears to come from someone you know and looks like it would be a lot of fun to look at! Would your friends really just send you a link without a message too? Watch out too for fake web pages and never enter your username and password on any site unless you are positive it is the genuine site. Don’t even click on a link that comes out of the blue, because the link itself may contain malicious code that your web browser will then execute. Beware!
Don’t make it easy for hackers! Passwords are really important. Weak passwords (less than ten characters long, or containing obvious words like part of your name, or no punctuation characters) can often be easily found with modern computers. So always choose a good password—never just use “password,” for instance, and don’t be guilty of using the same one for everything!
Annie looked on in amazement. “How did they get in?” she wondered.
“I told you,” said George, who had given in and collapsed back into the armchair, where he was being warmly embraced by his two little sisters. Ebot was copying his movements in a very awkward manner: the poor robot had no one to hug and no chair to sit on, which made him look most peculiar. “They get everywhere.”
Annie’s mom stuck her head round the door. “Hello, everyone!” she said cheerfully. “My goodness! What is that robot doing? What a funny way to stand.”
“Don’t ask, Mom,” said Annie. Susan wasn’t an enormous fan of science and technology: they seemed to have taken over her life more than she had bargained for when she married Eric as a graduate student.
“How sweet of you to bring your sisters round, George,” she said. “But don’t you think it’s getting a bit late for little ones? Perhaps you should take them home now… . And, Annie, don’t you need to get on with your vacation project?”
George tried not to look too disappointed. He had been really looking forward to working out how to operate Ebot—and having a chat with Annie about what had happened in Foxbridge earlier. Now, thanks to his sisters, it didn’t look like he’d get the chance to do either. He stood up, holding one sister under each arm, their fat little legs kicking wildly, while behind him, Ebot produced an exact copy of his actions.
“Gracious me!” said Susan, noticing Ebot properly this time. “That robot looks just like your father!”
“We know.” Annie sighed. “Seriously, Mom, please don’t ask me to explain.”
“Well, it’s not my fault that I’m always the last to know,” she said huffily. “No one in this house tells me anything!”
“C’mon, George,” said Annie. “Let’s take the little ones back to your house.”
“Straight back when you’re done,” her mother warned. “You need to get that chemistry project under way. You know why… .”
Annie sighed again.
George plonked his sisters down on the ground, and he and Annie set off for his house, each holding a small hand; Ebot followed behind, guiding an imaginary child as he did so.
Annie was quiet as they walked through the garden. She looked a bit glum at the prospect of going home alone to work on her project.
“At least you’ve got Ebot to keep you company now,” said George, trying to cheer her up. “I’d rather have a robot in the house than twin sisters.”
“But a robot is just a machine,” said Annie sadly. “It’s not like Ebot will grow to love us, is it?” As she spoke, she heaved Juno through the hole in the fence and hopped through after her.
“Unless you program him to,” said George. “You could see if your dad could get Ebot to have feelings. You can probably download ‘robot emotions’ from the Internet.”
“But it wouldn’t be the same as being loved by your sisters. They aren’t programmed to love you; they just do it naturally.” Annie caught Hera as she stumbled through the hole in the fence and hugged her before setting her gently down on the ground. “Look, babies!” Annie pointed up to the clear evening sky where two stars blazed. “That’s Castor and Pollux, the twin stars. That’s you, if you were stars.”
The twins gazed upward, plump hands outstretched as if they could grasp a star each and bring it down to Earth. “Reach a star?” they asked Annie hopefully.
“Sorry, girls,” she said. “Even I can’t make a star fall to Earth for you. You just have to look at them in the sky.”
The duo toddled toward their house, followed by Annie and George.
“It’s spooky,” said George, turning to look behind him. “Ebot really does look just like your dad.”
“Except that he’s not alive,” said Annie. “He’s just like Dad, except that Dad is living and Ebot isn’t… .” She paused. “I know!” she exclaimed, jumping up and down in excitement. “That’s what I’ll do!”
“What?” asked George.
“For my project!” She was bouncing around on her toes. “Why is Ebot not alive when Dad is alive? What’s the difference between the two of them? What is Life? That’s my vacation project.”
“Your vacation project is ‘Life’?” asked George. “Are you serious?”
“Yeah!” Annie looked absolutely delighted, her earlier gloom forgotten. “But not just that,” she said. “I already know the first bit—how life developed on Earth and how Charles Darwin sailed on the Beagle and found all that out. Now I’m going to do how life came to Earth from space! I’m going to do the Cosmic Chemistry of Life! Ha! Take that, Karla Pinchnose … ,” she muttered.
George stared at her in amazement. “Isn’t that, like, a bit overambitious?” he hazarded.
“Have you forgotten about my outstanding IQ?” she asked him. “C’mon, Ebot. We’ve got work to do… . Can I have those gloves back, George?”
He handed them over and, with a cheery “Good-bye!” Annie headed back toward her house, Ebot following, leaving George to babysit the twins.
Great, he thought. Annie’s off to do a superexciting science project without me. That’s just great. When I grow up, he grumbled, I really am going to live only with robots—no people whatsoever … except perhaps Annie occasionally. But no one else. Muttering under his breath, he turned and walk
ed back into his house.
THE HISTORY OF LIFE
Professor Michael J. Reiss
When we look at the animals and plants around us, the sheer diversity of life seems amazing. Even in a busy city a single walk brings us into contact with dozens of species, from insects so small we can hardly see them, to trees and large animals like birds and mammals. In the countryside there are literally thousands of species in even a small bit of forest, grassland, or marsh.
We still don’t know how many species there are in the world. About 1.2 million have so far been carefully identified by scientists, described, classified, and given a name—but the total figure is much bigger than that. The best current estimate is that there are about eight or nine million species in all, though some biologists think the figure could be much higher than this. This means that the great majority of species on our planet haven’t even yet been given a name. They could go extinct and we wouldn’t even notice!
Where do all these species come from? This is a question that humans have often asked. Many of the world’s religions have an answer. They talk about God creating life. This answer isn’t enough for scientists, though. Even if God did make species—including us—we want to know when and how!
It was Charles Darwin in the nineteenth century who provided the answer that we still think is correct. Darwin was a wealthy man and was happily married. He and his wife, Emma, had servants and his wife ran the household. That gave Darwin time to do his scientific work, even though he and Emma had ten children, most of whom loved nothing more than to rush into their father’s study and try to get him to play with them.
Darwin realized that just as farmers can produce new breeds of farm animals by selectively choosing to use only certain individuals to produce the next generation, so nature can produce new species by what he called “natural selection.” Suppose, for example, that a widespread species of seed-eating bird occurs in some places where plants produce mainly small seeds and in some places where plants produce mainly large seeds. Suppose too that there is inevitably some variation in the size of the birds’ beaks and that how large a bird’s beak is partly depends on the size of its parents’ beaks, so that birds with small beaks tend to produce offspring with small beaks and birds with large beaks produce offspring that typically also have large beaks.
Nothing very surprising, so far. But Darwin realized that if beak size is important for a bird’s survival and reproduction—for example, because food is sometimes in short supply—then natural selection would gradually lead to changes in beak size. Over time, birds that live where the plants have large seeds would come to have large beaks, and birds that live where the plants have small seeds would evolve small beaks. Given enough time, the original single bird species might evolve into two new species, each one well adapted to its food source.
Darwin published his theory in 1859 in a book called On the Origin of Species (the full title is On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life—the Victorians liked long book titles). This is one of the most important scientific books ever written. It changed the way we see our world and has never been out of print. It is a long book but still very worth reading.
Darwin was the first to admit that his theory didn’t explain everything. In particular, how did the first species come into existence? After all, his theory may explain how species can change over time and evolve into new species but doesn’t say anything about how the whole process gets going.
Darwin was a bit of a genius. Actually, he was more than a bit of a genius; he was a total genius. The tentative answer he came up with for the origin of the very first species is pretty much what many of today’s scientists still think might be the case. On February 1, 1871, Darwin wrote to his close friend and fellow scientist Joseph Hooker:
It is often said that all the conditions for the first production of a living organism are now present, which could ever have been present. But if (oh and what a big if!) we could conceive in some warm little pond with all sorts of ammonia & phosphoric salts,—light, heat, electricity &c. present, that a protein compound was chemically formed, ready to undergo still more complex changes, at the present day such matter would be instantly devoured or absorbed, which would not have been the case before living creatures were formed.
We still don’t know for sure how life started. It might well have been in one or more of Darwin’s warm little ponds, much as he suggested. But once it got going, there was no stopping life. As millions of years went by, life gradually reached more and more of the Earth’s surface. Species got bigger and hardier.
They colonized the land and took to the air. Eventually, three to four billion years after the process started, we have whales and hummingbirds and giant redwood trees and beautiful orchids and all the other eight or nine million species there are today, including us.
And we are still discovering some of these species. Maybe you too might one day find yourself journeying to a part of our wonderful Earth and being the first person to identify a new species!
The next morning George woke late, to an unusually quiet house. He could hear none of the normal angry screams as the twins acted out their morning pantomime of outrage and horror that anyone could expect them to eat breakfast. He stretched and wiggled his toes under the warmth of his comforter. And then he remembered! Annie and the Cosmic Chemistry of Life—how life came to Earth from space … And then he also remembered the bank machines going crazy and spewing out money all over the world. He had to find out what was going on! He leaped out of bed, threw on his clothes, and ran downstairs.
The scene that greeted him was surprising in its normality. The twins sat meekly in their high chairs, placidly eating their breakfasts without spattering food onto the walls and floor; George’s mother and father smiled at him. He was bewildered by this change of pace—breakfast was usually an infant war zone—and startled to find his sisters looking angelic rather than demonic.
Catching his shocked expression, his mother said, “We told you they’d grow up one day, didn’t we?”
“Overnight?” queried George. Surely that wasn’t actually possible… .
“Kids,” said his father smugly. “They change so fast!” He sighed. “You were the sa—”
But at that moment a home-baked muffin hurtled through the air and thwacked him squarely on the jaw. The impact sent crumbs flying across the kitchen while the twins dissolved into peals of laughter. One muffin was followed by a second, until George’s poor father was being bombarded, like a young solar system full of colliding debris.
George used that moment to escape out the back door. “Off to Annie’s!” he shouted back to his parents.
He hopped through the hole in the fence and sprinted up to the back door of the next-door house. As usual, it was open, so he let himself in with a cheery “Halllloooo!”
A second later, a corresponding “Hallooooo!” told him that Annie was in her father’s study—the room that housed Cosmos, the extraordinarily intelligent computer that Eric used to help him with his work. The sound of a violin drifting down from upstairs—the same phrase over and over again—also told him that Annie’s mom was at home, practicing for a concert. When Annie was younger, her mom had worked as a music teacher, but recently she had returned to her original career as a concert musician and was away from home more and more often, performing with her orchestra.
Sure enough, George found Annie perched on several cushions in front of Cosmos, who had been their friend and helper on so many adventures now. It hadn’t always worked perfectly—on one occasion, Cosmos had struggled to make their homeward journey possible alone, and needed to be linked up with another supercomputer in order not to leave the two friends stranded in a distant exosolar system—that is, a planetary system that orbits a star other than our Sun. On another, Cosmos had nearly exploded with the effort of rescuing Annie’s dad when he fell into a black hole. The computer could still be unpredicta
ble and erratic when he chose… . And today looked like it was one of those days.
“He’s being really tricky,” said Annie, wrinkling her nose.
Cosmos said nothing, which was unlike him, but sneezed instead.
“Has he got a cold?” asked George.
“He’s being really off,” said Annie. “He says he feels ill, but that sounds really weird to me.”
“Yeah, not like Cosmos at all! What were you trying to do with him?” George pulled up a chair to sit next to her.
“Well, I’m working on my project!” Annie explained.
“Let’s see!” said George immediately.
“Okay—here it is …” She brought up a screen that showed two pictures of Eric, side by side.
“One of these is real Dad, a.k.a. Eric,” she said, pointing. “And one is robo-Dad, or Ebot.”
WHAT IS A SUPERCOMPUTER?
What is a flop? Or a megaflop?
As time goes on, more and more powerful computers become available. One way (not the only way!) of measuring the power of a computer is to measure the maximum number of floating point operations per second (usually abbreviated to “flops”) that it can perform.
One big system
Whatever the power of today’s processors may be, there is a simple idea for making a much more powerful machine—put lots of them together! A supercomputer is a computer specially constructed to achieve exceptional performance by linking many processors together into a single big system. Each processor can then work on a part of a task simultaneously—in parallel.
Linking multiple processors means connecting them to some sort of network, and often it is enough to have computers connected across large distances through networks like phone networks, or via the Internet.
An embarrassing problem?
If the work can be broken up into separate pieces, each processor working completely independently of the other pieces, the problems to be solved are called embarrassingly parallel problems. In these cases, the network is only really needed to tell each processor what it should be doing and to collect the results at the end.
George and the Unbreakable Code Page 6