Showing posts with label Astrophysics. Show all posts
Showing posts with label Astrophysics. Show all posts

Tuesday, 22 October 2013

Four space age technologies that already exist (kinda).


Yes, I know. You are all heartbroken because I haven’t posted an article in a while – unfortunately real life gets in the way of the internet. How awesome would it be to live as some sort of digital being floating amongst all the racism and cat pictures like some kind of electronic ghost of internet present?  Sneaking up on people and going “Well well well, what have we here?” when they open a private browsing window?


… anyway, moving on.


This week we bring you some space age technology that (kind of) already exists (a little). I’ll be honest with you, it’s not going to be my best work but I am working on a new article as you read this and it’s going to be a tour-de-force of whimsy and wonderment (It’s really not). As always, any complaints can be addressed to 123 Fake Street. As for the town? Just write down the town you live in and I’m sure it will find its way to me *snigger*.


Okay, let’s do this *cracks knuckles*

*Note: you will notice that, with the exception of the first image, my captions are somewhat lazy - this isn't a lack of creativity, but a fantastic new feature Google have added to their blogging service that makes captions of more than a few words take up several lines of the whole page - thanks Google! Making things easier through innovation!* 

A see-through phone 

 

I don’t know about you, but when I picture the future I see all computer technology being small, sleek, pretty and see-through, if not holographic or built into the brain in some sort of freaky melding of man and machine. If you go into any phone shop today you will notice that more and more advanced technology is being crammed into smartphones no bigger than a few square inches – so we are well on our way to downsizing the helpful technology we use every day.


Its a carrot! Not really, it's a see-through 
phone. (Source: Polytron)
As for the see-through part, a Taiwan-based company called Polytron has recently unveiled a prototype of the hardware of a transparent handset. The phone contains all the hardware you would expect from a modern handset: an expansion card slot, a battery, speakers and a microphone. Unfortunately the handset is currently unable to run an operating system such as Android or Windows 8 and is just a hardware prototype which is only currently capable of playing music. 


Polytron currently specialises in privacy glass – another neat item of technology which works by altering the alignment of crystals within the glass to alter the amount of light that gets though. When a current is applied to the glass it is clear and when there is no current the crystals align in such a way that lets less light though, making the glass appear cloudy. It is thought that this might be how the phone could display data.

Advanced humanoid robots

 

ASIMO (Source: Vanillase)
Walking, talking and thinking robotic pals are probably a big part of most people’s vision of the future and are a staple of science fiction’s vision of the future from HAL (crazy) to C3PO (annoying and technically from the past, somehow).  It turns out that there are several amazingly advanced robots in existence today that you might not know about.

Most people will have heard of ASIMO, first introduced by Honda in 2000. ASIMO stands for Advanced Step in Innovative MObility and the robot was designed (through 20+ years of research) to be able to walk with agility and interact with people and its environment and to improve the quality of life of humans. ASIMO can do several impressive things besides being able to run, walk, dance, climb, kick and conduct an orchestra: the 2011 model of ASIMO can work cooperatively with other ASIMO units, step aside when approached and return to its charger when it senses its batter levels are running low. 

ATLAS (Source: DARPA)


Unfortunately Honda doesn’t currently have any plans to market ASIMO. An interesting fact about ASIMO: his designers were so shocked by his lifelike movement that they travelled to Vatican City to ask whether it was cool with the man upstairs to make a robot that can walk like a person – luckily for ASIMO they gave the go ahead.

The most recent addition to the world of bipedal robots is Atlas – an adult-sized robot designed and produced by a US robotics company called Boston Dynamics contracted by the US Defence Advanced Research Projects Agency (DARPA). Atlas is perhaps less impressive than ASIMO as it is human controlled, but makes up for it with some other feats. Much like a coked-up gorilla made out of lead, Atlas is hard to knock down. It has been shown walking over rough terrain with perfect balance and balancing on one leg whilst being struck repeatedly with a large weight. Thankfully DARPA is not developing Atlas for combat applications, but to assist with search and rescue in hazardous environments.

Ion thrusters

 

It genuinely surprised me that this exists. If you remember last month’s article about interstellar travel, I talked about methods of jet propulsion to carry space crafts between stars alternative to current technologies. One such alternative method to generating thrust for space craft are ion thrusters, some examples of which already exist and have been used on the Deep Space 1 and Dawn space crafts. For some years NASA have been working on NEXT – the NASA Evolutionary Xenon Thruster – which aims to be three times more powerful than the NSTAR ion thruster used on Dawn and Deep Space 1.


The NEXT thruster: look at it shine! (Source: NASA)
In order to explain how NEXT (or any other ion thruster) functions, we have to talk about ionisation. That’s right folks – its chemistry time! (and after all, it is all about chemistry).  In their normal state, atoms exist without an overall charge – the negative charge of the electrons and the positive charge of the nucleus kind of cancel each other out (for a more detailed explanation of atomic structure, have a look at my previous article or this article at Howstuffworks.com). 


I will say first of all that I am over-simplifying this for the sake of making this article more interesting and easy to read and any sciency types going “HURURURUR  ACTUALLY, I THINK YOU WILL FIND…” will be summarily ignored. When an atom gains or loses an electron, the ‘balance’ between the negative charge of the electrons and positive charge of the nucleus is upset and the atom gains a positive or negative charge depending on what is lost or gained, becoming an ion. The reason why this happens involves the differing energy levels electrons occupy around the nucleus - I’m not going into detail because it isn’t really relevant here, but if you want to know more you can check out this excellent page on the subject.


In an ion thruster, a neutral xenon atom is released into a magnetic field along with a free electron. The atom and electron collide to produce a positive xenon ion which is accelerated through the magnetic field, propelling the craft forwards.


The NEXT thruster has recently set a record for remaining active for 5.5 years without any loss of function. The longevity and extreme fuel efficiency of this thruster gives hope for the success of more ambitious deep space missions in the future. 

Universal constructor/Cornucopia machine 


A 3D printer! (Photo by Bart Dring)
Okay, I will admit that this one is a stretch - but can't a nerd dream? You might have guessed from my previous articles (and this one) that I have no life am something of a fan of Sci-Fi. My favourite video game (and one of my favourite things too) is the 2001 masterpiece Deus Ex – and many people agree with me on this one. One of the fictional technologies featured in the game is a universal constructor, or UC. This is an example of a theorised device known as a molecular assembler – this is pretty much a machine that can construct anything by arranging atoms at the molecular level (in the case of Deus Ex this was achieved by using nanobots – nanoscopic robots).


You are probably thinking that no such thing exists – you would have heard of it. And you’d be correct.  The closest thing we have at the moment is a 3D printer. Again, I know it’s a bit of a stretch – but it is a step in the right direction. A 3D printer is an amazing device which takes a digital 3D model and constructs the object in the physical world by laying down thin layers of a material and building up a physical reconstruction of the 3D model. When you think about this for a minute, its pretty amazing – its kinda like having a magic crayon which you can draw something with and have it appear next to you (yes, I do write science articles). 


At the moment 3D printers can make things out of a wide variety of materials including metal alloys, plaster and ceramics. 3D printers are commercially available and it is possible to buy one for personal use, the cheapest ones being around £1000 (about $1600 USD) – you could buy something which you could use to make many of the simple everyday objects you might need.


Again, this is still quite far off from a machine that can make anything, but it is still amazing – and who knows? One day this technology could develop into a machine which could make literally anything and solve world hunger. So keep an eye on it.


That about rounds this one up (I know, only four items – you must feel cheated). Stay tuned for more sciencey goodness next week. In the meantime, check out the Facebook page from the link at the top of the page. 

As with every article I post here, this one has been thoroughly researched and a list of sources can be provided for anyone who is curious – just check out the contact page

Monday, 23 September 2013

5 mind-bending facts about the universe


Let me tell you a secret. Every biologist secretly wishes they had studied physics instead. I certainly do. As a science writer I also love to write about physics. Why? Because physics is sexy. And also images from NASA are free.

Physics is slowly becoming the new rock n’ roll – with celebrity popularizers of science like Brian Cox and Michio Kaku and historic scientific efforts such as the Large Hadron Collider becoming more and more popular every day. Everyone loves a bit of physics. It is a fascinating subject, after all.

Anyways, to round up the series of physics-heavy articles I give you a collection of five mind-bending physics facts about our happy little universe. Feel free to use them to impress people, get dates or satisfy your curiosity.  

1.All the matter that makes up the human race could fit in a sugar cube.

Don’t look at me like that. It will probably surprise you to know that 99.9999999999999% of matter is actually empty space. We most likely all learned about the structure of matter in school: all matter is made up of atoms which are made up of neutrons, protons and electrons. The protons have a positive charge and they group together with the uncharged neutrons to make a positively charged nucleus. This nucleus is kinda like the sun in the centre of our solar system and around the nucleus orbits the tiny, negatively charged electrons – kind of like the planets orbiting the sun. 

You can just about make me out - I'm about three billion atoms in © picsfive - Fotolia.com
If we were to somehow step inside an atom we would realise that the nucleus is like the head of a pin and the space in which the electrons zip around is like a football stadium and the electrons themselves would be the size of a bumblebee. If all this empty space wasn’t there, all of us would fit inside a single sugar lump. Considering the fact that all atoms are by far mostly empty space, why does all matter have mass? This is because of the Higgs field. The Higgs field is an invisible net of energy which exists through the universe associated with its own particle called a Higgs boson – famously discovered by the LHC supercollider in Switzerland last year. The Higgs field acts like a swamp – particles which travel through it are given the property of mass, just like a runner would be slowed down by running through a swamp. Different particles are slowed by the field to differing extents, which gives objects differing mass.
Of course, the sugar cube would still have mass so it would weight something like 5 billion tons – good luck putting that in your hot beverage of choice.

2.If the sun were to suddenly blink out of existence we wouldn't notice for eight minutes.
It's the sun! As far as I know it's still where it's supposed to be. You'll just have to take my word for it for 8 minutes. (Source: NASA)

The speed of light is about 300, 000, 000 meters per second and the sun is 149,600,000 km from planet Earth – that equates to about 8 light minutes. If the sun were to suddenly blink out while you were reading this (let’s say a star-hungry space whale had it for dinner) the light it was radiating at the moment of its disappearance would take 8 minutes to reach your eyes. That’s just long enough to have a sandwich before the world ends!


3. When things move they get heavier.

I discussed this one in my last article, but I thought it warranted a second mention – particularly if anyone hasn’t read the last one. Albert Einstein’s famous equation of relativity E=mc2 tells us that energy (E) and mass (m) are simply two different forms of the same thing – meaning that energy has mass. The faster something moves, the more kinetic energy it has (kinetic energy is the energy of movement) and therefore the more mass it has.

Obviously we don’t really notice this in real life, but it does happen – it is just that the percentage of energy which is turned into mass is incredibly tiny at the speeds we experience here on earth. At speeds approaching light speed this becomes much more dramatic, and if it were possible for something with mass to move at the speed of light it would, in theory, become infinitely massive.

4. There is a planet made out of burning ice.
 
Gilese 436b - ideal weather for... a fire breathing yeti? (Source: NASA)
Somewhere out there in space is, you guessed it, a planet completely coated in ice… which is on fire. A confusing place to say the least. The catchily-named Gliese 436 b is a Mercury-sized planet which closely orbits the star Gilese 436 near the constellation of Leo. The planet orbits the star so closely -4.3 million miles (it doesn’t sound close but that is 15 times closer to the star as Mercury is to our sun) – that its surface is constantly at the scorching temperature of 439°C. You might be thinking that it is impossible for frozen water to exist at such an insane temperature – and you would be 100% correct. But as with almost everything in science, there are exceptions to the rules.

In order to understand how 439°C ice can exist, we need to take a look at the difference in structure between ice, water and steam. As we all know, water exists in three states depending on its temperature. This is because the water molecules (made up of a single oxygen atom and two hydrogen atoms) have differing levels of kinetic energy. Ice molecules have very low levels of energy and therefore don’t move around much. This means that they are very ordered and still (but not completely) and very close together which gives ice its solid structure. As temperature increases the molecules become more energetic and move more – this gives rise to water and steam as the particles become more energetic and less ordered. In chemistry this is called entropy, which is a measure of the disorder of the molecules. Steam has higher entropy than water and water has higher entropy than ice.

On Gliese 436 b, most of the planet is made up of water surrounding a small core made of rock. Gravity from the planet core pulls the water molecules on the planet very close together into a more ordered, less entropic state called Ice X (ice ten or hot ice) which remains in a solid state regardless of the 439°C temperature of the entire planet surface. Don't touch it - your arm would be vaporized. So, y'know, wear sunscreen.

5. We really have no idea what is going on.

I think we can all agree that there is a lot of stuff in the universe. All this stuff – planets, stars, life – is made up of matter. Astrophysicists figure that all the matter that exists only accounts for about 4% of the universe. As for the other 96? Nobody knows apparently.

Mysterious, right? (Source: NASA)
Science proposes that 73% of the universe is made up of something called dark energy and the remaining 23% is made up of something called a dark matter. The Big Bang theory states that the universe ‘exploded’ out of an infinitely dense point at the beginning of time and has been expanding in size ever since. According to the laws of physics, the expansion of the universe should be slowing down– but this is not the case. The rate of the expansion of the universe is actually accelerating and nobody is really sure why. The leading theory as to why this happens is down to dark energy acting like an opposite to gravity, pulling matter apart. Dark matter on the other hand is something that science thinks exists but doesn’t really understand.

Basically it’s a fancy way of saying ‘Who knows?’

And that about sums it up. Join us next time for some fascinating critters!

Thanks for reading, remember to check out and Like the Facebook page (https://www.facebook.com/scienceunplugged) to support ScienceUnplugged and to see notifications of new posts, science news and interesting things.

As with every article I post here, this one has been thoroughly researched and a list of sources can be provided for anyone who is curious – just check out the contact page.

Tuesday, 17 September 2013

The Science of Sci-Fi: Getting around in space.



Now for part two of my epic sci-fi saga: getting around in space (I realise that that isn’t really a good name for a sci-fi movie… well maybe if it was on REALLY late at night). Or on the internet.

Anyway, moving on. 

A spaceship. Yup. Can't really think of a funny caption. Sorry. © innovari - Fotolia.com
Continuing the science of sci-fi series, I’m going to talk about interstellar travel. The ability to travel the vast distances between stars is a staple of most sci-fi universes, but what about our own? The concept of traveling to another solar system brings with it a lot of obstacles which need to be overcome.
The problem with interstellar travel is distance (who’da thunk it?). The distance between Earth and our closest star system, Alpha Centauri is about 25.6 trillion miles away, or 4.3 light years - that is to say it would take a beam of light 4.3 years to travel there from our sun.  So, y’know, It’s a long way. The human race has done some unmanned interplanetary travel within our own solar system and even technically outside its edges, but no human being has ever set foot on another planet – just our moon.

Science has been sending unmanned probes out into space since the launching of the first earth satellite, Sputnik-1, in 1957 which orbited earth for three months, sending radio pulses back to earth. I’m not going to get into the whole cold war space race thing because it’s not relevant here and when science wins, everyone wins (I know you can’t see it, but I just gave a thumbs up with a huge grin and one of my teeth twinkled with a PING). 

The Mariner 10 probe, brought to you by the high-tech 3D redering of the 1970s (source)
Since then there have been numerous probes sent throughout the solar system by various countries.  The Mariner 10 probe was launched by NASA in 1973 with the mission of investigating Venus and Mercury which are 38 million kilometers and 77 kilometers from Earth (at their closest orbits to Earth) respectively. The probe took several thousand photos of the surface of both planets along with collecting data about the atmosphere and magnetic field of both planets. The Mariner 10 finished its mission in 1975 and is thought to be currently orbiting the sun.



The infamous 'accidental' tracks left by the Spirit rover. You might say they made something of a boner
(source)
Perhaps better known are the Spirit and Opportunity rovers that were sent to Mars by NASA in 2003. Landing in 2004, the rovers surveyed the surface of Mars to look for signs of water activities. The Spirit rover became unresponsive in 2010 (maybe it became… SELF AWARE!! …no actually, they just lost contact with it), but the Opportunity rover is still rolling along the surface of Mars, nine years on from the start of the mission – not bad for a piece of equipment designed to last three months. Pros of this mission: it gave us insight into the geological history of mars. Cons: the spirit rover accidentally drew an *ahem* interesting shape on the surface of the red planet shortly after landing in 2004 – probably what it’s most famous for (welcome to the internet).

This blue dot is the first radio transmission from the first man-made object to leave our solar system. Or maybe its just something someone knocked up in Photoshop - who knows? (source)
So, it seems we have become quite adept at shooting robots into space – but what about beyond the limits of the solar system? Well, the closest we have come was when the Voyager 1 probe crossed over the outer limits of the solar system in August 2012 after 36 years in space and 11 billion miles traveled. In February 2013 a radio signal was received from the Voyager from beyond the orbit of our sun – the first signal to be broadcast from interstellar space. The signal was picked up by radio telescopes on earth as a tiny blue dot.

So why haven’t we gone outside our solar system? Traveling at the top speed of Earth’s current space shuttles (about 28,300 km/h) it would take 165,000 years to get to the Alpha Centauri system – several times longer than the written history of the human race - which makes for something of an inconvenient flight (Are we there yet?). And that’s only our closest star. Of course, one way we could go all over our galaxy (and beyond) would be travel very very very fast. Unfortunately this is never going to happen based on conventional jet propulsion systems as it takes 3,000,000 lbs of rocket fuel to send a shuttle just into Eath’s orbit, which is more than 15 times the mass of the shuttle itself, so you can imagine the amount of fuel required to take an interstellar star ship to Alpha Centuri. Engineers and scientists are working on this problem and there are several theoretical and proposed alternatives to conventional methods, but I will talk about those later – first we have to address perhaps the biggest obstacle to deep space travel.

The Speed Limit of the Universe

Much like the motorway/freeway/highway, everything in the universe has a speed limit but, unlike the speed limit on the roads, it is the speed of light and it cannot be broken. Well breaking the speed limit on the road is illegal but it is POSSIBLE – an act that I in no way endorse. Neither do I endorse breaking the laws of physics on the highway – that’s neither funny nor clever. Anyway, you guessed it folks – it’s time for the maths stick once again. In order to explain why nothing in the universe that has mass can travel faster in the speed of light we have to take a look at the most famous mathematical equation in history. You’ve guessed it:
E=mc

This is the equation for Albert Einstein’s famous theory of special relativity. In this equation E stands for energy, m stands for mass and c2 stands for the speed of light (300, 000, 000 meters per second ) squared. The c in this case stands for constant, as the speed of light in a vacuum which is always the same. Now – if you read my last article you might have guessed that I am not great at mathematics. In fact I suck at it (no – this is not an appropriate place to say ‘that’s what she said’) – so hopefully this explanation is satisfactory. 

Albert Einstein circa 1921, photographed Ferdinand Schmutzer (source)
The equation explains the relationship between mass and energy. I’m not a physicist and trying to explain this in detail would confuse everyone, most of all me, so I will keep it simple. Einstein’s theory states that mass and energy are interchangeable and are just two different forms of the same thing. The faster an object is moving, the more energy it has and therefore more mass. The closer an object gets to the speed of light, the more energy it has pushing it along which equates to more mass. 

So why don’t we notice this in real life? If energy has mass then why don’t we get heavier while we run? Why doesn’t a car get heavier as it gets faster? The answer is that it does happen – we just don’t notice it because it is so small – at the slower speeds we are used to on Earth the percentage of mass increase is tiny. It’s a different story close to the speed of light where the increase in mass would be colossal; in fact if an object moved at the speed of light it would become infinitely massive and have infinite energy. Even if the starting object has tiny mass, like a single electron, the end result would be the same.

So based on Einstein’s equation it would require an infinite amount of energy to travel at the speed of light, making it effectively impossible. So how might we overcome this obstacle if we are ever to travel to other star systems? Both science and fiction have several ideas to get over it.

Cheating Physics – Getting to Other Stars

As I mentioned earlier, our current technologies wouldn’t allow us to make the massive journeys between stars – even if we could get up to a decent speed, the amount of fuel required to power a large star ship would be a *ahem* $@#%load (scientific term). So one way we could approach being able to travel between stars is to develop more efficient propulsion systems.

There are several theoretical and proposed alternatives to current jet propulsion technologies. One such idea is using an antimatter rocket – a rocket engine which generates its thrust with antimatter. Antimatter is basically the ‘evil twin’ of matter particles in our universe – they are particles with the exact opposite properties of matter. For example, the antimatter equivalent of an electron is a positron. Electrons are negatively charged particles which are found in all atoms – their antimatter opposites have the same mass but the opposite charge. When a particle of antimatter meets a particle of matter they annihilate – a reaction which destroys both particles, converting them into the energy equivalent of the mass of both particles. Antimatter annihilation can produce an insane amount of energy from a tiny amount of matter which makes it an ideal rocket engine. Unfortunately antimatter is very hard to make and so far only 38 atoms of anti-hydrogen have been created, lasting only 0.2 seconds before annihilation. Another candidate for getting us close to light speed is nuclear fusion engines, which generate energy and thrust through the process of nuclear fusion – this is when two atoms fuse together to form a heavier element – releasing energy in the process. This is much more efficient than rocket fuel and could take us to (relatively) nearby stars with much smaller rockets.

So assuming we could use one of the many theoretical propulsion systems to get our space ships close to the speed of light and we wanted to travel to a star system a little less than 200 light years away, how would we deal with the problems of making the 200-or-so-year journey there? Again, there are several speculated solutions to this problem. A few of them are actually kinda weird. One proposal is a generation ship – a huge starship where the descendants of the original crew would be the ones arriving at the destination. Of course this would require building a ship capable of sustaining a functioning human society for 200 years, which I don’t think anyone knows how to even begin trying to do. Then we have suspended animation – this would work too for shorter journeys of a few years as well. This one has been in a good few Sci-Fi movies and shows – probably most recently in James Cameron’s 2009 epic, Avatar and the brilliant 2012 prequel to the Alien films, Prometheus by Ridley Scott. This method would involve slowing or pausing the aging process by freezing the passengers of a mission or putting them in deep sleep and waking them up at their destination – again unfortunately no such technology currently exists, but could offer a method of getting people to distant star systems in the future. Another idea is to send frozen fertilised human embryos into space and have them ‘revived’ by a robot (unfortunately not like C3PO) when they are within some years of their objective. Those are probably three of the least weird ideas – there are many more you can look up.

An almost-universally recurring staple of science fiction is faster than light, or FTL, travel. There are also many proposed mechanisms for this one and they are even more theoretical than the stuff I’ve mentioned before. Perhaps one of the more popular ideas found in sci-fi is that of using a wormhole to travel. This is another thing we have to thank Einstein for – working with a student by the name of Rosen he came up with the idea of Einstein-Rosen bridges – what have become known as wormholes. Wormholes are basically shortcuts through the fabric of space and probably the best way to explain it is the analogy which gives it its name. Imagine that the universe is a giant apple and you are at point A and want to get to point B which is on the other side of the apple. You would have to walk from point A to B which would take a few hours (it’s a really big apple) but a worm could get through the apple much more quickly (in less than one hour) by munching its way through the tasty tasty universe – by creating a wormhole. Unfortunately they are just theory at the moment and Einstein speculated that they would be very unstable and collapse almost immediately after coming into existence.  If we could work out a good way to create and stabilize wormholes (like a Stargate?) then we could, in theory, travel to distant stars and even galaxies almost instantaneously.

Well, that about wraps it up for this week. I know what you are thinking: ‘Adam, you should stick to the biological sciences.’ – if you have any complaints about the length, content or nonsensical-ness of this article, please write to our complaints department at 123 Fake Str… oh, sorry – we don’t have one. My mistake.

Thanks for reading, remember to check out and Like the Facebook page (https://www.facebook.com/scienceunplugged) to support ScienceUnplugged and to see notifications of new posts, science news and interesting things.

As with every article I post here, this one has been thoroughly researched and a list of sources can be provided for anyone who is curious – just check out the contact page.