Voyager I and II are leaving our Solar system

In august and September 1977 NASA launched the satellites Voyager I and II. I am always curious about them because they are launched just before and after my birthday. They are human made objects with the greatest distance to Earth ever. But where is that? Voyager I is at the unbelievable distance of 18,42 billion kilometers (that is 18,42 terameters for real nerds). Voyager II is only 15 terameters away from Earth.

A schematic to show the flight paths of Voyager I and II. Voyager II left
Earth two weeks earlier, but Voyager I took the lead very soon. Both
satellites are now about the leave the heliosphere, the zone of solar
influence.

Those distances are huge, but not yet as great as light-years  The time it takes before a radio message from Voyager I to received on Earth is more than 17 hours. A message like that travels with the speed of light. You could say, Voyager I is at a distance of 17 light-hours at the moment. A light-years is 515 times further than the distance between the satellite and Earth.

A picture of the Voyager satellite. In the metal tube at the
bottom is the atomic generator. The big dish is needed to
communicate with earth. The very long antenna is used to
measure the weak magnetic effects of the solar wind.

Sometime in the next 10 to 15 years Voyager I will finally leave the solar system. Probably it will run out of energy before that time. Or the distance towards the Earth is getting too problematic. Hopefully they will be still alive to witness this special moment. In any case these two satellites will once become the furthest pieces of garbage we even sent into space.

Golden sign on the Voyager satellites with information for
alien species. It says who we are and where they can find
us. I will write another blog once about what all these
figures mean.

More information:
- Live information on the distance between Voyager I and II and Earth: Voyager.jpl.nasa.gov
- The latest measurements of Voyager I made scientists doubt about the size of the heliosphere. Maybe Voyager I will be busy for another decade before it has really left the solar system: Voyager 1: 'reports of my exit are greatly exaggerated'

De Nederlandse versie van deze blog bijdrage: Voyager I en II verlaten bijna het zonnestelsel

Sinking volcanoes in the Pacific Ocean

How is it possible that tiny little circular islands exist in the middle of the Pacific Ocean? Even on a sea floor which is 4 or 5 kilometer deep? These little round islands are atolls. They have been build up from volcanic rock and corals for over millions of years. Charles Darwin already published a theory on the formation of atolls over a century ago. His vision is still generally accepted.

The atoll Marakei, which was visited by curators
 from Museon in the Hague in October 2012.

The theory is in fact that a volcano slowly sinks down into the ocean and the island slowly changes shape. At first this mountainous island is a separate volcano at sea. When the (millions of) years pass this island slowly sinks down because the sea floor sinks down as it becomes older. Also erosion helps to break down the volcano. It changes into an smaller mountain with a barrier reef around it. This process continues until the mountain is long gone and the circular coral reef is only thing left over.This is called an atoll.

The steps in which a volcanic island
changes into an atoll.

The island Bora Bora. The growing coral reef around the island
is already visible as a ring around a shallow lagoon. In the
middle are still the remains of an old volcano.

Darwin reasoned that corals which are located around the volcanic island, slowly grow and follow the sea level. At the same time the island slowly disappears under water. Once the volcano is completely under water, the corals form an atoll. The ring of corals is called a barrier reef, because the lagoon in the middle is an shallow area. There corals cannot grow as good as at the edge of the island. The lagoon often contains brackish or even sweet water.

The islands of Hawaii show from East to West this development towards
becoming atolls. The youngest island, Hawaii, is a very active volcano.
The slightly older islands not anymore. Towards the West the islands are
older, eroded and further down in the ocean. The original volcano is not
visible above the water anymore.

More information:
- Nice explanation of the development of atolls on the beach: YouTube.com/watch?v=btRCAQHqbdY
- Colleagues of Museon in The Hague visited an atoll in Kiribati for in preparation for an exhibition. The text in this blog item is inspired on their request for more information about the development of atolls. Check their work for Museon on: Klimaatverhalen.nl

Nederlandse versie van dit artikel: Wegzinkende vulkanen in de stille oceaan.

American presidents, evolution and climate

Today is a big day for the US. A new President is being elected. I'm often surprised by the Americans. Did you know, for example, that about 32% of the American people* do not accept evolution, that living things have evolved due to natural processes? And that even educated people like Mitt Romney actually believe in something else? I think, the opinions about climate are slightly better. Since this year more then half of the Americans (54% **) believe scientists who say climate change is caused mostly by human activities.

Science is hardly discussed this Presidential election campaign.

But since when is science a belief or religion? Science is roughly "knowledge attained through study or practice". There are several methods to study or practice, but they all generate more or less verifiable information, information which is proven. Global warming by human activities is already proven for at least 10 years and evolution in different ways for longer than that. Religious systems with a 'creator' or a God, may work in people's daily life. But these constructions do not work very well in finding answers to all questions. While researching something you need to 'believe' one ingredient of the system in stead of to 'know' it for sure. I guess that's why religion is called a belief in the first place.

Oh, and now Sandy has wrecked the east coast of the US, suddenly climate change is proven? The first politicians are trying to put the whole disaster on climate change. When money and economy is at stake, science can be very handy, I guess. Unfortunately is is impossible to link individual disasters like Sandy to climate change. And it's even harder to link it to people or companies. Insurances will not get any climate lawsuits soon. I will write another blog item on why weather and climate should not get confused. It's a rather complicated story... Follow this blog to find out soon.


More information:
- Romney Elaborates on Evolution: thecaucus.blogs.nytimes.com/2007/05/11/romney-elaborates-on-evolution/
- BBC News, Superstorm Sandy triggers climate blame game: www.bbc.co.uk/news/science-environment-20181266
- In an interview Writer Ben Goldacre says he was shocked that politicians were "reluctant to put their great ideas to the test of science": www.bbc.co.uk/news/uk-politics-20179603

Follow the Down to Earth blog also on Facebook: facebook.com/DownToEarthScience

* source: 2009 poll by Pew Research Center
** source: 2012 poll by Yale

From the edge of space; highest marketing campaign ever!

Welcome at my blog about science which is mis-used or mis-interpreted. This first item is dedicated to Felix Baumgartner. That guy in Red Bull-outfit who jumped from 39 km height. A big scientific step as it says everywhere in the media. I guess it is clear to you, that I cannot stand this. And the worst is that Red Bull and its media partners keep on bringing 'new' stuff about the jump every day

"From the edge of space" is the ever repeating slogan. Normally the Kármán line is defined as the hight where space begins. This is 100 km high. And did you know that  even at the height of 355 km, the international space station ISS is slightly being slowed down by the last molecules of the earths atmosphere? Baumgartner wasn't even close the space yet.

The records which Baumgartner set (the highest jump, the highest ballon ride and the falling faster that the speed of sound) are no new things of 2012. They are just perfectioned versions of records Joseph Kittinger set in 1960. Yes, that long ago! Kittinger jumped from 31 km high and was even longer in free fall than Baumgartner. That last record Baumgartner did not even break. Kittinger fell down with a maximum speed of 988 km/h, not even too much from the speed of sound (1236 km/h). In more that 50 years not much was added...

Joseph Kittinger jumps at 31,3 km height out of a balloon
at Augustus 16th 1960.

I have always been a fan of Joseph Kittinger. He is the perfect example of someone who puts his life at risk, just to see what would happen. Someone has to do it, right? He almost lost his hand because his glove failed with -50 degrees centigrade. This was real scientific exploration, although it didn't look very fancy.

Red Bull turnes this into a nice commercial. It is a marketing machine not a scientific discovery! Unfortunately it fits with the era in which we live at the moment. No new content, no fresh ideas that change the world, but just 'old wine in new bottles'. It's all about amusement and spectacle, all at the cost of innovation. And where are those (scientific) heroes when you need them...

More info?
The site of Red Bull, without much detailed information: www.redbullstratos.com/the-mission/world-record-jump/
For those interested in the real deal. De jumps Joseph Kittinger did around 1960: wikipedia.org/wiki/Project_Excelsior

De Nederlandse versie van deze blogbijdrage: From the edge of space, de hoogste marketingstunt ooit.