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Venera Space Program

11 Apr

While we initially started this blog to focus on the interesting things on Earth, we soon realized that some of man’s greatest achievements involve our quest for exploration of our solar system. Because of this, we decided to have an ‘Out of this World’ category that  focuses on human achievements and discoveries that are not on this planet. This post will be the first in the category, with more to come soon.

The Venera Space Program was a Soviet attempt to create space probes to gather data about the planet Venus.

The missions began in 1961, with the Venera 1 craft, and ran through until 1984 with Venera 16.

 Venera 11 Lander - NASA

Venera 11 Lander – NASA

Venera 1 & 2

Venera 1 (1961) & 2 (1965) were meant to be pass-by probes that would collect data as they passed Venus. Unfortunately, both missions suffered from telemetry failure before reaching Venus.

The Soviet Union launched several other probes in the early 1960’s, but these were not announced as planetary observation missions.

Venera 3, 4, 5 & 6

Venera 3 was special. Although the Venera crafts 3-6 were all very similar, Venera 3 was the first craft to reach the surface of another planet. This occurred on March 1st, 1966, when the Venera 3 craft crash landed on the surface of the planet. Unfortunately, due to the entry through the atmosphere, all the data probes on board burned up and were unable to record any data.

Venera 4 was able to provide minor information about the atmosphere of Venus. Unfortunately, the hull of the craft was only able to handle 25atm, much less than the 75-100atm pressures on the surface of Venus.

Venera 5 and 6 were sent as atmospheric probes, and were able to record approximately 50 minutes of data before the batteries drained.

Venera 7 & 8

Venera 7 was the first craft to transmit data back from the surface of another planet. It was designed to survive the pressures, but its parachutes failed on entry and it toppled over during the landing. The signal was weak from the craft, but there was enough time for a transmission to be made.

Venera 8 was very similar; it was able to transmit data during its descent, measure sunlight and transmit data for nearly an hour.

Venera 9, 10, 11 & 12

The Venera craft 9-12 were designed to take photos and transmit the data back to Earth. They were all equipped with two cameras, but during the first two missions (9 &10), only one camera each time was able to capture photos due to the other camera’s lens cap failing to release. Venera 11 and 12 suffered worse; neither of the lens caps on these craft were released. Throughout these missions, the craft were operational for between 50 and 110 minutes.

Venera 13 & 14

These two Venera craft were equipped with much more scientific instrumentation. Here is a list of what was on board, taken from Wikipedia.

  • Accelerometer, Impact Analysis – Bison-M
  • Thermometers, Barometers – ITD
  • Spectrometer / Directional Photometer – IOAV-2
  • Ultraviolet Photometer
  • Mass Spectrometer – MKh-6411
  • Penetrometer / Soil Ohmmeter – PrOP-V
  • Chemical Redox Indicator – Kontrast
  • 2 Color Telephotometer Cameras – TFZL-077
  • Gas Chromatograph – Sigma-2
  • Radio / Microphone / Seismometer – Groza-2
  • Nephelometer – MNV-78-2
  • Hydrometer – VM-3R
  • X-Ray Fluorescence Spectrometer (Aerosol) – BDRA-1V
  • X-Ray Fluorescence Spectrometer (Soil) – Arakhis-2
  • Soil Drilling Apparatus – GZU VB-02
  • Stabilized Oscillator / Doppler Radio
  • Small solar batteries – MSB
Image from the right camera of Venera 13

Image from the right camera of Venera 13 – NASA

Image from the left camera of Venera 13

Image from the left camera of Venera 13 – NASA

Venera 15 & 16

These probes were similar to the previous probes, but were equipped with surface imaging radar to help with the entry that was obstructed by the thick clouds of Venus’ atmosphere.

For more detailed information, see the Wikipedia article on the Venera craft:

http://en.wikipedia.org/wiki/Venera

Bog Bodies

28 Mar

Depending on certain variables, human decomposition is generally a very short process, and a dead body buried underground will normally be completely skeletonized in a maximum period of 50 years. If left out in the open, a body will decompose much faster than this. However, the mummified remains of bodies found in peat bogs, known as ‘bog bodies’, can be up to thousands of years old and almost perfectly preserved.

Tollund Man - Found in Denmark and found to be around 2600 years old. Credit: Sven Rosborn

Tollund Man – Found in Denmark and dated to around 2400 years ago. Credit: Sven Rosborn

Grauballe Man - Found in Denmark and dated to 2300 years ago. Credit: Malene Thyssen

Grauballe Man – Found in Denmark and dated to 2300 years ago. Credit: Malene Thyssen

Rendswühren Man - Found in Germany and dated to around 1900 years old

Rendswühren Man – Found in Germany and dated to around 1900 years old

Brammer Man - Found in Germany and dated to around 500 years ago. Note the still visible beard on his face.

Brammer Man – Found in Germany and dated to around 500 years ago. Note the still-visible beard on his face.

Peat bogs are most prevalent in cold, temperate areas of the Northern Hemisphere (it is possible for them to occur in the Southern Hemisphere, but they are much smaller and less common), and thus, all the bog bodies located so far have been in Northern Europe and North America. Not all are well-preserved, but many still have intact hair, skin and internal organs. So, how is this possible? And, how did the bodies get there in the first place?

Peat bog - Credit to Boréal

Peat bog. Credit: Boréal

The water in peat bogs is cold, acidic, and lacks oxygen, and combined, these factors lead to amazing tissue preservation. Also, tannin (a compound present in tea – this is the stuff that can stain your tea-cups) in the bogs leads to the darker appearance of the skin, and has anti-bacterial properties that aid in the preservation. Unfortunately, the acid in the bog water often destroys the bones, as it dissolves the calcium phosphate in them, leaving only the tissue and hair preserved.

Because of the good soft-tissue preservation, the stomach contents of the bodies can be analysed in some cases, which tells us something about the diets of people during whichever period they lived in. In cases where bones have been preserved, archaeologists can tell what kinds of activities the person engaged in, and even if they were right-handed or left-handed! Also, forensic techniques have been applied to some of the bodies in order to reconstruct their appearances. Here’s some examples:

Reconstruction of Lindow Man's face - Credit: www.culture24.org.uk

Reconstruction of Lindow Man’s face. Credit: http://www.culture24.org.uk

Reconstructed face of the Girl from Uchter Moor - Credit to AxelHH

Reconstructed face of the Girl from Uchter Moor. Credit: AxelHH

The bodies that have been recovered from peat bogs cover a very wide time span, with some dated from 10,000 years ago and others all the way up to World War II. It seems that some of the bodies belonged to unlucky individuals who simply fell in, but many others appear to have died violently, after which they were thrown into the bogs. This may have been as punishment for a crime, or, perhaps it was human sacrifice. The majority of the violently-killed bodies have been dated to the Iron Age (this began around 3000 years ago, and lasted about 500 years), so some archaeologists believe that Iron Age groups may have had this means of execution or ritual sacrifice as a cultural tradition.

Overall, the bog bodies are not only interesting, but very useful to historians, archaeologists, and anthropologists, as they yield so much useful information in regards to past peoples who lived around the bogs. For more reading on the topic, check out

http://archive.archaeology.org/online/features/bog/

http://ngm.nationalgeographic.com/2007/09/bog-bodies/bog-bodies-text

Amazing Genetics – Are Some People Immune to HIV?

27 Mar

HIV, the virus that leads to AIDS, has led to the deaths of over 30 million people since its discovery. Something that many people may not be aware of is that scientists and doctors classify different species and subtypes of the virus. There are two ‘species’; HIV 1 and HIV 2, and these are further divided into subgroups, and then subtypes within the subgroups.

So, put very simply, there are many different ‘strains’ of the virus, with each having varying rates of transmission, transmission pathways, and resistance to treatment. Many of these forms of HIV bind to a certain protein on white blood cells in order to infect a person, and this protein is known as CCR5.

Amazingly, however, some people are naturally resistant to these forms of HIV, because they carry a mutation. So, what is this mutation, and how does it work?

Computer-generated image of CCR5 receptor in cell membrane. Credit to Thomas Splettstoesser

Computer-generated image of CCR5 receptor in cell membrane. Credit to Thomas Splettstoesser

Basically, these people carry a mutated version of the CCR5 gene, known as CCR5-delta-32. This mutation results in the ‘deletion’ of part of the CCR5 gene, which leads to the virus being unable to bind to the protein and enter the white blood cells like it normally would.

It is thought that this mutation arose in Europe, and around 10% of Europeans are thought to carry it, along with this resistance to certain forms of HIV. Furthermore, it has also been suggested that the mutation confers resistance to smallpox, and may have actually originated and spread via natural selection during the plague period in Europe’s history, which challenges the assumption that the plague period was caused by the spread of bubonic plague. Apparently, the normal frequency of the mutation’s occurrence is 1 in 20,000, but the plagues are thought to have increased the rate to 1 in 10 amongst Europeans. Of course, people from other regions can also carry the gene mutation, but it is a lot rarer for them.

Depiction of the horrors of the plague within medieval Europe - By Pieter Bruegel (1562)

Depiction of the horrors of the plague within medieval Europe – By Pieter Bruegel (1562)

Interestingly, a man suffering from leukaemia and AIDS was cured of both illnesses when given bone marrow transplants as part of his cancer treatment. It turns out that the donor of the bone marrow was a carrier of the ccr5-delta-32 mutation, and this has led scientists to believe that the mutation could be used as a potential cure for HIV infections.

For further reading on this matter, check out http://www.sciencedaily.com/releases/2005/03/050325234239.htm and http://online.wsj.com/article/SB122602394113507555.html

The Bystander Effect

26 Mar

This post is not going to be on anything physical, but instead a psychological phenomenon called the ‘The Bystander Effect’.

It refers to situations in which an individual is unlikely (or less likely) to provide help or assistance to someone in need while there are other people around. Studies have shown that the probability of help someone will receive is inversely related to the number of bystanders.

Wikipedia provides a nice summary for the origin of research in to this effect (sourced below):

“The bystander effect was first demonstrated in the laboratory by John Darley and Bibb Latané in 1968 after they became interested in the topic following the murder of Kitty Genovese in 1964. These researchers launched a series of experiments that resulted in one of the strongest and most replicable effects in social psychology. In a typical experiment, the participant is either alone or among a group of other participants or confederates. An emergency situation is then staged. The researchers then measure how long it takes the participants to act, and whether or not they intervene at all. These experiments have often found that the presence of others inhibits helping, often by a large margin. For example, Bibb Latané and Judith Rodin staged an experiment around a woman in distress in 1969. 70 percent of the people alone called out or went to help the woman after they believed she had fallen and gotten hurt, but when there were other people in the room only 40 percent offered help.

Source:  Meyers, David G. (2010). Social Psychology (10th Ed). New York: McGraw- Hill. ISBN 978-0-07-337066-8.

I first heard about this phenomenon a few years ago; it jogged my memory and I remembered when I had once experienced the bystander effect. I was driving a friend home at approximately 3pm, and on the way we passed a bus stop where there was a man waiting. He was wearing a hoodie and other baggy clothes that looked quite dirty, which was nothing unusual for the area it was in. About 45 minutes later during my trip home, I passed the same bus stop and the man was lying down on the bench. It seemed odd, because buses past that stop are frequent so he shouldn’t have had to wait long. There were also plenty of people walking past the stop. I went home and walked to a cafe near the bus stop to get a coffee. The man was still there. I decided that there were plenty of other people walking past, so if something was wrong someone would have done something about it. I went home and forgot about it. Later that evening I turned on the news to a camera-shot of the bus stop, with a news presenter saying that a man had overdosed and was rushed to hospital after he had been seen lying down at the stop for a couple of hours. He survived the incident, and was lucky that people living across the road from the bus stop noticed and called the emergency services.

I was of the mentality that there were plenty of people walking by and if the man really needed help, someone else would have helped out already.

In attempting to explain the bystander effect, scientists have come up with 3 steps that must occur to overcome it, and these are outlined below.

Noticing:

This step requires that the bystander notices the situation. With a limited number of people around, an individual is more likely to take note of what is occurring, whereas a large group of people in the area will draw an individual’s attention away from the situation.

Interpretation:

This step can only occur after a bystander notices the situation. They need to interpret what is happening and decide whether it is an emergency situation or not. We often look at the reactions of people around us to help form our own interpretation of an incident. The problem is that everyone is looking around trying to make an interpretation, the fact that no one is moving means everyone stands there and figures it must be OK.

Taking Action:

This is where things can really fall apart, even if the first two steps have been overcome. Even if someone notices the situation and interprets it as an emergency, they must take action.  The thing is, people fall victim to the diffusion of responsibility, they think that others will step in and help, or that other people standing by might be more qualified to provide assistance. Whatever the reason, as a group, we fail to act.

Looking back on my account, I noticed the incident, interpreted it as nothing unusual and failed to act. 

After learning about this phenomenon, I have been able to act accordingly in similar situations. I was out shopping one day when I noticed an old lady lying on the ground. There were a few other people standing around but not really doing anything. I walked over and as I did, a few other people joined me. It turns out that the lady had had a fall and was a little dazed. It was hot out so we got her some water while someone phoned an ambulance.

Hopefully, you now have an understanding of what is going through your mind when you see a situation and are trying to make a decision on whether or not to act. Even just walking towards the situation could trigger others to do the same, in which case someone who may need help will get it.

Cenote Angelita’s Underwater River

24 Mar

An underwater river? How does that work? It seems impossible, but somewhere in Mexico, there is an underwater cave that has exactly that; an underwater river. The place I am describing is known as Cenote Angelita, and photographer/scuba diver Anatoly Beloshchin has managed to capture some amazing photographs of this river.

Firstly, let’s have a look at the logistics of a ‘cenote’. Cenotes, common to Mexico, are basically deep holes in the ground that result from the collapse of bedrock, and the groundwater is exposed from its normally subterranean hiding spot. These cenotes attract daring cave divers from all over the world, especially in the Yucatan Peninsula of Mexico.

Cenote Angelita is a special kind of cave, because of the especially beautiful scenery that awaits scuba divers. Here are some of Anatoly Beloshchin’s photographs of the cave:

cenote1

cenote2

cenote3

cenote4

cenote5

cenote6

As you can see from the pictures, it appears that although the divers are already underwater, there is a river at the base of the cave. This river even seems to come complete with trees; branches and leaves are visible around it. So, how is this possible?

Well, the ‘river’ isn’t actually a river. It’s a large layer of hydrogen sulphide, and just has the appearance of a real river. Either way, it makes for some incredible scenery, and is definitely a spot worth looking at if you are a trained scuba diver. I am not a trained scuba diver myself, but images like this definitely make me want to go and learn how to do it!

Special thanks to reader Callum for sending us the idea for this article!

The Antikythera Mechanism

24 Mar

The Antikythera shipwreck, discovered off the Greek coast by divers in 1900, has yielded several artefacts that have been dated back to just over 2000 years ago, including coins and statues. The most important find, however, was something that is now known as the ‘Antikythera mechanism’.

antikythera1

The mechanism as it appears today

This mechanism has the honor of being known as the world’s most ancient analog computer. Archaeologists and other researchers examining the mechanism have been astounded, claiming that technology didn’t even begin to approach the same level of complexity until 14th century AD Europe. That’s an enormous gap in time! But, what was it actually used for?

antikythera2

Computer-generated model of what the mechanism’s front side would look like today

Scientists have found that it was used for more than one purpose, and research is still being conducted today to find out any other uses. Basically, it was used as an astronomical clock; it could determine the relative positions of the sun, moon, stars and even some planets, and also predict things like eclipses. The mechanism showed the sun revolving around the Earth on a 24-hour dial, although as we know now, it is the other way around.

It was also apparently used as a calendar, but not just your typical one-year calendar; it showed four-year cycles, each divided into one year each. This is thought to have represented the Olympic Games of the time, which occurred in two and four year cycles. On top of this, it also tracked something known as the Metonic calendar, which is a period of 19 years used by ancient astronomers for astronomical and calendar studies.

Overall, the Antikythera mechanism is definitely high on my list of the most fascinating archaeological discoveries of the ancient Greek world. Many people seem to think that complex technologies couldn’t possibly have been used by ancient peoples, but this artefact would certainly prove them wrong.

For a more in-depth discussion of the mechanism, check out the articles in Nature science journal.

Viking Sunstone

23 Mar

 

Modern replica of a Viking ship. Source

The Viking sunstone has been mentioned in various Icelandic texts throughout the 13th-15th centuries. It is said to have assisted Vikings in navigation when the sun was below the horizon or covered during an overcast day. One of the texts is the “Rauðúlfs þáttr“, it specifically mentions an account where the sunstone was used to locate the sun in overcast skies. Here is a translation of part of the text (Source):

“The weather was thick and snowy as Sigurður had predicted. Then the king summoned Sigurður and Dagur (Rauðúlfur’s sons) to him. The king made people look out and they could nowhere see a clear sky. Then he asked Sigurður to tell where the sun was at that time. He gave a clear assertion. Then the king made them fetch the solar stone and held it up and saw where light radiated from the stone and thus directly verified Sigurður’ s prediction”

Recently, a crystal was discovered in an Elizabethan ship wreck, and is believed to be an original sunstone artifact. Chemical analysis has shown that the artifact is made from calcite; in the past, it has been suggested that this could possibly have been the mineral that the Viking sunstones were made from. The reason for this is that calcite has an optical property called ‘birefringence’. This means that the speed at which light travels through the mineral varies depending on the polarization and propagation direction of the incident light rays.

A calcite crystal showing the effect caused due to birefringence.

A calcite crystal showing the effect caused due to birefringence.

To explain this in more detail I will use an analogy. Imagine you are pushing a pram along a footpath (light travelling through air), to the right of the footpath there is a lot of sand (a material other than air, in this case calcite). If the right hand wheels of the pram were to go in to the sand, the pram would be pulled in the direction of the sand because the pram travels slower in sand. When this happens with light going from air to another material such as water or glass, it is called diffraction. The difference with calcite is that that change in speed depends on the angle that the light enters the crystal and also the polarization of the light waves.

This image shows how light rays polarized in different orientations diffract by different amounts. This is what causes the doubling effect seen in the picture above.

This image shows how light rays polarized in different orientations diffract by different amounts. This is what causes the doubling effect seen in the picture above.

So what does this have to do with calcite being the sunstone? If you were to hold a calcite crystal up to the horizon and rotate around, you would see the doubling effect occur at different angles from the sun due to the change in polarization of light entering the atmosphere. If you were facing the direction of the sun, the double image would begin to line up as the light would be all polarized in the same direction. This would allow you to know which direction you are travelling and therefore whether you were on the right path or not.

The sunstone had been thought of as just a legend for quite some time, but the recent discovery mentioned above adds much credibility to the mentions of this fascinating object in historical texts.

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