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Monthly Archives: December 2012

Bacteria – The Ultimate Survivors

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Judgment Day – The human race is dying off. The rivers are drying up, crops are failing and the soil barren. The atmosphere is so thick with pollutants and dust that the sun no longer penetrates to the surface of the earth, cutting off the main energy source of the biosphere. Man is doomed, the world an inhospitable environment. There is no food, no water and the very air is a deadly poison. Death is the only fate for the race…. but what if it didn’t have to be?

What if we could preserve the race in suspended animation to return only when the environment has recovered and can again support life? Even if this takes centuries to happen and in the mean time you are exposed to unbearable heat, toxic chemicals, drought, starvation, nuclear radiation exposure and the wear and tear of time as the years pass. Wishful thinking. This is impossible and can never happen. Well, maybe not for us human beings but for two gram positive genera of bacteria this is a reality. Both the Clostridium and Bacillus genera have the amazing ability to ensure the survival of their kind by preserving their DNA in an impenetrable and almost indestructible capsule called an endospore.

This last resort is only used when absolutely necessary, after all other attempts at survival are unsuccessful. When a bacterium can no longer survive in an environment, it copies it’s DNA and creates the enduring endospore to protect it. This DNA can survive for years until conditions are favourable outside again. It is a sacrificial process whereby if the bacterium does begin the process of sporulation, it will die in the process. The organisms DNA is preserved however, ensuring the survival of the strain. The resulting germinated bacterium is merely a clone of the original.

Endospore

With Bacilli being aerobic and Clostridium being anaerobic, these spores are produced by a wide range of bacteria. A major problem with endospores, in regard to everyday life for humans, is in the preservation of food. Scientists have had to develop ways of destroying endospores present on food or ways of ensuring they cannot germinate. Unfortunately, the majority of endospore forming bacteria are pathogens. Therefore, the consumption of endospores creates a health risk as there is no better environment to bring about germination than the warm, moist intestines of a mammalian body. Infant botulism is a prime example of this. The endospores of Clostridium botulinum can be found in honey where they are unable to germinate due to the excessive sugar levels. If an adult consumes the spores in the honey they are unaffected because the spores cannot tolerate the strong acid in the stomach and the abundance of intestinal flora already present. If an infant under twelve months were to eat the honey however, the spores would find themselves in the ideal environment for germination as the stomach acid is weaker and the natural flora not yet established. Infant botulism can lead to respiratory failure and even death if not treated.  Another high profile case of the dangers of this property of endospores than the anthrax scare in the USA in 2001. There was widespread panic when endospores of Bacillus anthracis were posted in envelopes causing several deaths as the inhaled spores quickly germinated and led to respiratory failure. One worry is that as well as Bacillus anthricis, many of the endospore producing bacteria can be used in biological warfare, including Clostridium Botulinum. The Bacillus anthracis also has a habit of lying dormant in soil for years until it unexpectedly germinates causing damage to livestock and humans alike.

It is widely accepted that some endospores can lay dormant for centuries waiting for conditions to become favourable again but there are cases of germination in the lab of endospores dating back several thousand years. Using the appropriate growth medium and aseptic technique scientists have been able to germinate Clostridium endospores found in the ancient tombs of Egypt. These tombs are approximately 4000 years old. Even more amazingly in 1995 the scientist Raúl Cano managed to germinate Bacillus sphaericus endospores found in the gut of a 30 million year old bee preserved in amber found in Dominica.

Whereas this is a significant scientific find, it does not quite signal the time for a real life Jurassic Park being made possible. It is the bacteria which come back but there is no DNA from other organisms which could be used to clone and grow new creatures (or old creatures as the case may be) even if the technology to do so was available. Unbelievably some scientists even claim to have germinated endospores that date back 250 million years though these claims have been met with scepticism and need to be verified (Vreeland, R. H., W. D. Rosenzweig, and D. W. Powers. 2000).

But what is an endospore? How can an organic specimen endure such rigours for such a long time with next to no metabolic activity and still maintain life to return and go on as normal? To answer this it’s important to understand the structure of an endospore. An endospore is a dry, non-dividing, metabolically almost inactive and dormant cell that is produced to preserve DNA by a moist, metabolically active, vegetative bacterial cell when it detects that it can no longer survive in its current environment.

It is amazing to think that a bacterium can become almost invincible in just eight hours, survive like that potentially for centuries and then return to normal in a mere hour.

With this remarkable resilience to survive almost any kind of attack added to the bacterial arsenal, is it any wonder they are found in almost any environment in the world. They can get energy from a variety of sources, through both heterotrophism and autotrophism. From the sun to volcanic springs at the bottom of the ocean under extreme pressure. They can live straight off raw chemicals in the case of chemotrophs. They can survive in the absence of oxygen, mutate almost on demand if they encounter any new problems. This includes new food sources and new powerful antibiotics. The bacteria can simply alter their DNA to resist the drug and to produce new enzymes that can break down the new food source. Is it any wonder bacteria are referred to as “The Ultimate Survivors”?

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Posted by on December 17, 2012 in Biology

 

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Dragons – Who Says They’re Fantasy Creatures?

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I recently saw the film ‘The Hobbit: An Unexpected Journey’ and was very excited at the prospect of seeing Smaug the dragon, a character I loved reading when I was younger. After writing a post on how Star Trek technology is not so science ‘fiction’ as it was when it was written, I began to think if dragons are creatures of ‘fantasy’.

Obviously, if there were dragons somewhere in the world we would know about it but the fact is many different cultures from around the world have described the dragon in one form or another without coming into direct contact with each other.

A fascinating New York Times article explains:

“Dragon images have been found on the Ishtar Gate of Babylon, on scrolls from China, in Egyptian hieroglyphs and Ethiopian sketches, on the prows of Viking ships, in bas relief on Aztec temples, on cliffs above the Mississippi River and even on bones carved by Inuits in climates where no reptile could live.”

Bearing this in mind, it is not outside the realm of possibility that dragons are/were a reality. They are usually depicted as magic creatures in modern literature but if you think about it, there is no aspect of dragons that cannot be explained by science. I’m not saying dragons did exist but there is no reason that they couldn’t have existed.

The quintessential dragon trait is fire breathing. A store of fire in the belly is highly unlikely as it would cook the meaty muscle of the dragon but there are two means of fire production that stand out as genuine possibilities. The first being the combustion of methane gas, a by-product of digestion. Many animals today are known for producing large quantities of methane gas. Most notably cattle have gotten a bad name for producing vast amounts of the gas, which is driving on the greenhouse effect.

Whereas cattle release methane as an unwanted nuisance, dragons may be able to store it in some sort of third lung or bladder-type organ. The body is already adept at transporting gas around the body, so if the blood was modified to carry methane gas from the intestines to a storage organ, much like it carries oxygen from the lungs, the fuel for the fire is sorted.

It could then force a flow of the gas through the nostrils or mouth. A spark would be needed to ignite the gas. This may be achieved by either grinding particularly hard teeth like a flint or, more likely, by producing an electric charge much like an electric eel. Thus we have all the requirements to make fire. Presumably there would be a valve type feature to prevent burning methane from being drawn back into the body and blowing the whole gas store.

The second means of creating fire is to mix two chemical solutions together which then react violently with each other and spontaneously combust, i.e. burst into flame without an ignition spark. A possible combination would be a hydrocarbon solution mixing with a strong oxidizing agent. Reactions such as this are used in rocket propulsion.

A similar action is used by the bombardier beetle, which squirts a combination of chemicals producing high levels of heat.

A small alteration to the chemical mix of the bombardier beetle could plausibly produce a combustible mixture. Picture a method similar to the spitting cobra but with each tooth releasing streams of different chemicals which collide mid air and burst into flame. Or a different mixtures being expelled from each nostril.

As regards to the flight of dragons, most depictions of the creatures show a large rounded body with bat-like wings. These look to be as aerodynamic as my foot, surely incapable of flight. But it is important to remember that giant reptilians are well known to be capable of flight, just think of the pterodactyls of Jurassic Park. Furthermore, the Chinese description of dragons rarely include wings – picture the snake-like costumes often seen in Chinese holidays where many people dance around wearing a long narrow papier-maché type of dragon, without the wings.

There are some aspects of dragons that have been created specifically for dramatic effect in books/TV shows such as wisdom, the ability to speak or blood with magical properties but the core features of dragons are very much possible.

So there you have it. Why can’t dragons have existed? A lot of their defining features have already existed in one form or another.

 
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Posted by on December 17, 2012 in Fantasy

 

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Star Trekking Today

For many Star Trek fans, one of the main attractions of the show is the futuristic technology. For some it’s the battle scenes where we watch bursts from the phaser banks and hear “Shields down to 60%” while others are excited by the concept of exploring the galaxy for the sake of scientific research, seeking out new life and colonising new planets.

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One Star Trek enthusiast (who admittedly is a genuine engineer) has started a campaign to build a full scale replica of the Enterprise over the next 20 years which can travel to Mars in under 90 days using Ion Propulsion Engines. The Build The Enterprise campaign has been turning heads of Trekkies (or Trekkers for the die-hards) around the world.

Obviously, the plan has received mixed reviews. There has been much admiration of the boldness and detail of the plan but equally there has been criticism, particularly at the cost – $40 billion per year for 20 years.

Anyway, the Enterprise is a 24th century ship. Even if we did have the money to build it, we don’t have the technology to kit it out. Or do we…

A lot of the technology we use in our everyday lives today featured prominently in the Star Trek arsenal of high tech gadgets. For example, the iPad is credited with being a revolutionary new technology developed by Steve Jobs. Please, Jean Luc was rocking that shit years ago.

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Surprisingly, some of the technology, particularly from the original series, seems somewhat archaic compared to our devices. Look at Kirk’s communicator, it looks more like a phone that’s ten years out of date by todays standards than a 24th century technology. Especially when you consider that our phones are now looking more like tricorders, with all the tricks they can do. It was particularly surprising to see Spock show Captain Pike a paper printout in the episode ‘The Menagerie’. Although this can be forgiven considering it was a rehash of the pilot episode.

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While we can pat ourselves on the back for surpassing the series in these respects, they won’t be much use in getting an Enterprise through space. For the full experience you need warp drive, tractor beams, phasers, transporters, shields, replicators, etc. You may be surprised to learn that we have already taken the first steps to these technologies too. Some of the most significant developments will leave you very impressed.

Replicators

These seemed like one of the most fictitious and unlikely pieces of kit. All the other elements of the ship seemed possible given enough time and research, but to make stuff appear out of thin air always seemed to be truly science fiction. Surprisingly, of all the elements of the Enterprise, this is the one we have made the most progress with. Everyone with even a passing interest in technology has heard of 3D printers, which can literally print complex objects with moving parts. Have a look at this video to see how invaluable 3D printers will probably become in the coming years.

Still a long way to go until we can say “Tea. Earl Grey. Hot.” Another Picardism.

Tractor Beams

These beams were regularly used to apply forces to objects/ships to either pull them in or push them away. The Borg were fond of tractor beams to capture ships undamaged so that they could be harvested for new technologies. Scientists have made a small but significant breakthrough by using light beams to draw particles towards its source. Applications include possibly collecting particles from the tails of comets from a distance rather than risking entering the debris trail. This video explains it excellently (by the way, that youtube channel looks to be very good for science news based on first glance).

Warp Speed

Arguably the most important system on an interstellar spaceship, faster than light speed is essential to make manned journeys to planets outside our solar system viable. Consider Proxima Centauri, the nearest star to or own Sun. Even if we could travel at near the speed of light, it would take at least 4.24 years to reach the star and a similar time to make the return journey. Adding to this the time needed to carry out tasks such as research etc. It is clear these time scales dictate that a ship must carry vast stores of supplies and energy.

While travelling faster than the speed of light is well known to be impossible, scientists (including NASA) believe it may be possible to manipulate the fabric of space-time itself to ‘push’ the ship across the cosmos. By expanding the empty space behind the ship and contracting the space in front of it the ship slips through space-time at speeds high enough to shorten the journey to Proxima Centauri to just two weeks.

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Note the bubble around the ship in this picture showing no change in the immediate vicinity, so the crew would not perceive anything unusual from their point of view. Unfortunately, the energy required to manipulate space-time like this is far too high but NASA actually have people working on how to make it a reality. Physicist Harold White has published work on this for them, exploring means of reducing the energy needed and proposing possible ship designs.

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Phasers

The concept of firing energy beams has been the dominant choice of weapon by science fiction writers for some time now. The development of this technology is probably just a matter of time now. High power lasers already exist, in fact the Curiosity rover is currently blasting rocks on Mars by delivering a million watts of power for a few billionths of a second in order to analyse the glow from resulting plasma. See the before and after images of Curiosity’s wrath below. A high power beam like this would most likely be lethal if fired at a person considering the body doesn’t cope well with being turned into plasma.

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Considering the level of knowledge on star trek technology already discovered today, it may not be unreasonable to say that humans will be leaving our solar system and exploring the cosmic neighbourhood by the end of this century. Gene Roddenberry may have been bang on with his predictions on the timetable of space exploration. After all, it’s only about 50 years until ‘First Contact’. Then, we boldly go where no man has gone before.

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Posted by on December 13, 2012 in Future, Science Fiction, Technology

 

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Quote

“There is nothing new to be discovered in physics now. All that remains is more and more precise measurement.” – Lord Kelvin, 1900.

Clearly nobody told Einstein this. He would have been around twenty one at the time. Already on his way to becoming the father of modern physics, a field that seems to create ten new questions for each one it answers.

Lord Kelvin

 
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Posted by on December 11, 2012 in Technology

 

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