by Tom Kando
The Oort Cloud is believed by astronomers to surround the solar system. It is the ultimate outer boundary of our sun’s domain. This cloud is believed to consist of icy planetesimals - cosmic dust/grains. It was named in 1950 after the Dutch astronomer Jan Oort, who worked on this hypothesis.
According to astronomers, the Oort Cloud is a belt which surrounds the sun and the solar system at a distance which begins at about 2,000 Astronomical Units (AUs) and may go as far out as 200,000 AUs.
This is an astounding size. If the Oort Cloud hypothesis is correct, it means that the domain of the solar system is enormous.
Consider this:
One Astronomical Unit is the distance between earth and the sun, which is 150 million kilometers, or 93 million miles. If the Oort Cloud’s outer edge reaches all the way out to 200,000 Astronomical Units from the center of the solar system (the sun) then its diameter is 400,000 AUs.
In kilometers and miles:
The Oort Cloud’s inner edge: 150 million kilometers x 2,000 = three hundred billion = 300,000,000,000 kilometers, or 186,000,000,000 miles.
The Oort Cloud’s outer edge: One hundred times the figures in the previous paragraph. That is: 30 trillion kilometers = nearly 19 trillion (18,600,000,000, 000) miles.
Time
|
Distance Traveled by Light
|
one second
|
300,000 kilometers or 186 miles
|
one minute
|
18 million kilometers or 11 million miles
|
one hour
|
1.1 billion kilometers or 670 million miles
|
one day
|
25.9 billion kilometers or 16.1 billion miles
|
one year
|
9.46 trillion kilometers or 5.9 trillion miles
|
distance
|
equivalent
|
one kilometer
|
.62 mile
|
one mile
|
1.61 kilometer
|
one AU (Astronomical Unit)
|
150 million kilometers or 93 million miles or 8 light minutes
|
one light day
|
25.9 billion kilometers or 16.1 billion miles or 180 AUs
|
one light year
|
9.46 trillion kilometers or 5.9 trillion miles or 65,700 AUs
|
Now Consider this:
The closest stars to us are Proxima Centauri and its twin neighbors Alpha Centauri A and B - Only 4.2 to 4.3 light years away. Another neighbor is Sirius, which is 8.6 light years away.
Today, some of our manned spacecrafts may be able to travel at, say, 50,000 miles per hour, or 1.2 million miles a day. We can reach the sun in 77 days, i.e. cover one AU in that amount of time.
Proxima Centauri is 4.2 light years away, or 4.2 times 65,700 AUs = 275,940 AUs.
Since it takes us, at best, 77 days to cover one AU, traveling to Proxima Centauri would take us 21,247,380 days = 58,372 years.
This is twice as far into the future as Cro Magnon and Neanderthal men lived in the past.
Astronauts taking a roundtrip would return as far in the future as dinosaurs lived in the past.
But we already know this. It’s long been clear that we are the prisoners of the solar system. That, as long as Einstein rules, telling us that nothing can exceed the speed of light, we are unlikely to ever visit another star.
Let’s say we develop highly advanced rocket technology and manage to speed up human space travel tenfold, to 500,000 miles per hour. We would then be traveling at close to one thousandth the speed of light. This way, we could reach our closest neighbor star in less than 6,000 years - only fifteen hundred years more than the time that has lapsed since the Great Pyramid of Giza was built.
But today, I am writing about the solar system, and its outer belt, the Oort Cloud. Just to travel to the inner border of that asteroid belt, the side closest to us, would require 422 years, traveling at 50,000 miles per hour. At its current speed of about a million miles a day, NASA's Voyager 1 spacecraft won't enter the Oort Cloud for about 500 years. And it won’t exit the outer edge for maybe 50,000 years.
To reach Oort’s outer edge would take one hundred times longer, i.e. 42,000 years. And to traverse the entire Solar system would require twice as long, i.e. 84,000 years.
What is amazing is that some stars are only slightly further than the outer extremity of the Solar system. Or to put this in reverse: The solar system’s sphere of influence reaches out nearly three quarters of the way to our neighbor stars.
And: It takes light six years to cross the entire Solar system, which is a longer voyage than going to the nearest star!
© Tom Kando 2020;All Rights Reserved
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7 comments:
Hi Tom,
Very well done and with your permission I will pass it on to my 74 seminar attendees in my Renaissance Seminar at Sac State.
Best,
Bob
Interesting, but also, according to Einstein, at the speed of light, time stops. So something, or someone, traveling at light speed, would not age. But, also, general relativity tells us that as speed increases, mass increases, so that at light speed, mass reaches infinity, which means, according to most scientists, that cannot happen. Infinity is a game changer, or, a non-starter, a number which cannot be measured.
To me that seems to mean that human beings can never travel at the speed of light. Ergo, the distances we can reach from our planet are decidedly limited. Through instruments, we can look into the deep past, but it seems extraordinarily unlikely that we can travel, physically to where we can see. Our minds, and our instruments can go where we cannot. We seem to be bound forever to the planet on which we were born.
Some science fiction writers, and some scientists entertain the idea that humans can escape the cage of earth, and the eventual swallowing up of our planet by the sun, by creating habitats that can enable people to live in deep space, and hence, over generations, to travel to some other world where we can live.
Good luck.
I think we are trapped here for the duration (Which will not be eternal). As Curtis Mayfield said, "We've all got to go."
Its one thing to accept your mortality. I think it borders on insanity to accept your extinction without at least some serious sadness Dave. I recommend you keep track of Space X just to keep the hope alive.
Hey Tom,
Congratulations!
This is what poetry and the fascination around it is all about!
Poetry gives us a vague possibility of conceiving the inconceivable: The universe and its entropy. The numbers are sooo mind boggling,that they become (rationally :):):) )
poetic.
Thank you for this short space trip!
Oh dear. If that’s the case, why are we spending time and money on space travel? Is the space program on a fool’s errand?
Very interesting. Thanks.
Thanks everyone for your comments.
Great that Bob will share this piece with his seminar.
Paul, the Dutchman, approves of my calculations. I hope they are right.
Dave extends (and confirms) my analysis.
In response to him and also to Lita:
One thing I didn’t touch upon in this short piece is this:
What about the solar system, its 8 or 9 planets and their many moons?
Are any of these bodies potentially colonizable? So far, this doesn’t look very promising. Most of what we know about the rest of the solar system is that it is pretty inhospitable. However, many of these bodies are certainly VISITABLE. We have already traveled to one, and soon we’ll go to Mars.
Exploring the solar system is a huge and very nice project. And there is the outside chance of colonizability. To be sure, chances are that Earth is the only possible place for us, which, by the way, makes the environmental/climate change warning even more imperative...
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