How big is the universe?

The universe as we know it in space and time began about 13.7 billion years ago.  That’s a very very long time, but at least it’s a compact number that, with a little effort, most of us can at least remember.

How big is the universe is a much more challenging concept to get our human minds around.  The numbers are mind-boggling.  And to make matters even trickier, the universe is still getting bigger.

Space in the universe is measured in light years because scientists are pretty sure that nothing can travel faster than light can.  To us that is very very fast.  Here are some examples, all of which are so far beyond human experience that some people are reduced to laughter when they try to grasp the concept.

In a second, light travels:

  • almost 300 million meters (a meter is 40 inches, so just a little more than a yard),
  • which is equal to 186,282 miles
  • which is equal to  299,792 kilometers

Light travels from

  • the moon in 1.3 seconds
  • the sun in 8.3 minutes
  • across the Milky Way in 100,000 years
  • from the Andromeda Galaxy to Earth in 2.5 million years.

Light that first appeared after the Big Bang 13.7 billion years ago has not yet reached us.

It’s a very big place we live in.

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I thought that I had written the shortest book on all of time in 6 chunks and 86 events.

But I am humbled by Marc Brecy who has condensed 13+ billion years into a two-minute video.   It’s impressive.

All of Time

And if, like me, you wanted to spend a little extra time on any of the images, click your mouse pointer on the image.

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The amazing Homo sapiens

Homo sapiens, that species of which we are members, is an astonishing organism.  We have learned, invented, ventured, discovered, and done things that no other species in the five billion years of our planet’s history has ever accomplished.

And yet for all our brilliance, we might be responsible for actually destroying ourselves.

Other organisms have flourished on this planet, some for far longer than we humans.  Other organisms, plants and animals, have become extinct even after surviving hundreds of millions of years.  Other organisms on Earth have even died as a result of their own success, using up the resources on which they depend, or destroying the very environment which sustained them.

But we are almost certainly the first organism in the entire life of our planet which may be aware that we could be in the process of self-destruction, and yet continue head-long down this self-defeating path.

Look at what we have been able to do!  We’ve invented everything from writing to ships, from inter-space travel to the internet.  We’ve discovered vaccines for small pox and learned how to reattach severed limbs.  We’ve electrified almost every square meter of earth’s living space, we drive everything from cars and planes to gas balloons and drones.

But somehow we seem only halfheartedly convinced that our environmental pollution could kill us, and that wars are a poor way to resolve our differences.

Life is dangerous, and not every serious danger is of our own making.  And there are many who are doing more than their bit for our planet and for future generations.

Let’s do everything we can to make sure they are the ones who win this life-and-death battle.



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A little problem in space

At current speeds of space travel, it would take humans several hundred years to reach the closest known habitable planet outside our solar system.  That seemed to suggest that if Homo sapiens is going to colonize a planet beyond our immediate neighbourhood, we would have to spend several generations in a space ship.

Since even now we could get there in less than two years, the biggest problem we thought we had with colonizing Mars, though, was the planet itself – the cold, an adequate supply of oxygen, water, and food.

But researchers are now suggesting the possibility that we may have a more fundamental problem.  Sex in space might be seriously dangerous to health.

If this sounds like a tasteless joke, it isn’t.  Scientists have known for some time that reproductive cells on Earth can sense gravity.  Tests are now suggesting that cells’ response to gravity is not just incidental, and that changes in gravity affects processes involved in reproduction.  Earth’s gravity is also significant in controlling illness and disease, and it now looks as if sexual activity by humans beyond Earth could trigger serious brain disease and various kinds of cancer.  In other words, sex in space could kill you.

That might require astronauts headed for Mars or planning on setting up a home-away-from-home there to abstain from sex for years.  It would also make it impossible to colonize another planet with new generations born there.

Unless, or until, scientists figure out how to circumvent the deadly effects of leaving the comforting grip of Earth’s gravity.

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Mars Menus

Right now there are two privately funded manned-missions planned to set out for Mars.  One is set to leave in 2018, the other in 2023.  They are unlikely to be the only departures for Mars in the next decade.

At current speeds of deep space travel, it’s a 520-day trip, and astronauts in the simulated flight in 2011 said one of the worst parts of the “trip” was the utterly boring food.  The powdered orange drink Tang and freeze-dried ice cream might prevent starvation, but the threat of starvation seems to have become the only motivation for eating at all.

So scientists are preparing an alternative.  Plants will grow in zero-gravity conditions, and on the real trips to Mars, astronauts will be able to grow their own ready-to-eat food. Spinach, tomatoes, spring onions, strawberries, sweet potatoes, soy beans, and even wheat, fresh from the spaceship’s garden will be on the menu

There is also a slim chance that Mars itself might produce its own plants one day.  Astronomers in an observatory in Australia have identified a comet coming from outside the solar system that will  pass quite near Mars on October 19, 2014.  They estimate that there is one chance in about 700 that the comet will actually crash into Mars.  If it does, it could produce a produce a blast a million times the blast of the largest hydrogen bomb ever tested.

A comet as small as 25 feet crashing into Mars would form a crater 100 miles wide.  But something far more dramatic would almost certainly be uncovered – the underground ice on Mars that is now been confirmed as certain.  Astrobiologists estimate that the impact would melt ice, much of which would find its way to the surface as water.

Right now, Mars is so cold that water would quickly return to ice.  But the comet’s impact would heat rocks in a swathe of ground the size of New Jersey and keep it warm and wet for millions of years.  New New Jersey might become the first Garden State on Mars.

That freeze-dried ice cream would taste a lot better garnished with a bowl of Martian strawberries.

The idea isn’t nearly as wild as it might have seemed just a couple of years ago.

But then, the comet probably won’t hit Mars in 2014 either.  And if it does, we’d better get out of the way first.

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Organic soup or hot bubbles?

For eighty years, scientists have had a theory about how and where life got started on Earth.  It’s known as the Organic Soup theory, which suggests that early life got started in a soup of methane, ammonia and water that combined into the first organic compounds in the ocean when they were bombarded with UV radiation.  It’s a widely accepted theory, but so far, no one has been able to replicate these supposed events in a variety of laboratory attempts.

Now another theory of life is being tested in a NASA laboratory in California.  It’s the Hot Bubbles theory, developed after scientists discovered that, against all expectations, bacteria called “extremeophiles” could survive – even flourish – under conditions of extreme heat.  Scientists are trying to discover if  carbon molecules, the early building blocks of life, could have been transformed into the hydrocarbons methane and ethane, the next step up toward the construction of chains of DNA and RNA.

Their set up doesn’t look very primitive, but the vials and tubes contain the same elements subjected to the same conditions as those existing around the ocean vents at the deep floor of the ocean almost four and a half billion years ago.

If their research produces positive results, the bubble bath may replace hot soup as the source of our origins.

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Meteror hits and asteroid misses

Yesterday a ten-ton meteor exploded above the Urals in Russia, injuring at least a thousand people, shattering windows, and even buildings.

Tonight scientists say that an asteroid missed crashing into Earth several hours ago by a mere 17,000 miles,  eerily close by standards of spatial distances.

So what’s the difference between an asteroid and a meteor? or between an asteroid and a comet? or between a meteor and meteorite?  or a meteoroid?

The differences are not always clear cut because in part it depends on what they do.  So an asteroid might not remain an asteroid, or a meteor might become a meteorite.

An asteroid in basically a planetoid made of rock and basic metals that orbits the Sun in the same way that Earth and the other planets revolve around the Sun..

A comet is different from an asteroid in that it is composed of dirt and ice.  When they are close to the Sun,  it is possible to see a comet’s tail of dust and gas.  Apart from that, a comet is pretty much like an asteroid, and it is sometimes hard to tell which is which.

A meteoroid is a small chunk from an asteroid or comet.  They also have their orbits around the Sun but are too small to be asteroids or comets.

A meteor is a shooting star.  It’s a meteoroid that enters the atmosphere of another object – like Earth – and streaks through the sky as it burns up in the atmosphere of a planet like Earth.

meteorite is a meteoroid that survives its passage through Earth’s atmosphere and impacts an object like Earth.  They are the ones that create the most damage to life on Earth.  Historically, meteor strikes may have been responsible for some of the 54 major extinctions we know have taken place in the last 550 million years.  The dinosaurs may have been felled by the catastrophic destruction caused by a meteor strike.

It’s a very busy Universe out there.  Nothing ever sits still.

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