The Moon is able to eclipse the Sun because it’s distance from the Earth is 400 times closer than the Sun and is about 400 times smaller. So they look similar in size.
But there is a twist..
The Moon can sometimes cause an annular eclipse where the Sun can be seen behind it. That’s because the Moons orbit is elliptical and has two focuses. So in the furthest position, it’s apogee, means that it appears slightly smaller. Hence an annular eclipse. The Moon is gradually receding from the Earth. The mirrors left on the Moon by apollo astronauts are used to check it’s distance. By using lasers reflected from them they have found it is moving away by about 3.8cm a year. Eventually it will be far enough away that no full eclipses will happen anymore.
I love this phrase, standard candles, it’s a way of looking at the universe to work out distances in light years.
But I keep getting conspiracy theories about the universe from people on the Internet. I decided to try and explain my point of view.
I explained I’m not a physicist or optical expert. But I’ve read a lot over the years so this is my take on measuring the universe’s size.
This is what I wrote. Please accept my apologies if this is totally wrong. I only have a scant understanding.
I’m no
t an expert in optics but I think they have found the universe is over 13 billion years old based on the time light takes to arrive at earth. The science uses standard candles (globular clusters of stars that have the same light production so they can be used to judge distance because of light intensity). John Gribben explains this well in his popular science books. Parallax can also be used to measure distance. If you look out of one eye at your thumb at arms length, then at it from your other eye you will see it apparently move. The same can be done from earth observatories. Look at a star at one end of Earth’s orbit around the sun then 6 months later at the other end… Effectively creating a very long thin triangle. The star will move a tiny fraction against the background of other stars. Using simple geometry you can measure the distance. These methods helped to work out how far other galaxies are outside the milky way. I read all of this from books by authors like Issac Asimov, Sir Patrick Moore, Carl Sagan, Brian Cox, and John Gribben among others. Not by watching Fox news.
(the last bit because I was accused of believing things that are on TV)
I don’t get to speak to some people often enough. My sisters live away from here, miles away, so I’ve got to talk to them over the phone, or on the Internet. It’s the same as being on a zoom call, still friendly but no hugs. I get to see one of them occasionally.
I know I have lots of friends, but I still isolate myself when I’m feeling down. Certain things like choir cheer me up but it’s still a big effort and when I’ve had a shaky day like today it’s just hard to reach out. I don’t want to impose on them. I wish my cats could speak, what gems would they pass on? I imagine the words feed me would come up frequently!
As you get older you become more aware of your infirmities. If you are sensible you will take that into account when you drive. It’s not just for your benefit, it’s for the people who are driving or who are travelling around you.
Things like sight, strength, hand eye coordination, reaction times are all important. You must notify the relevant authorities if there is something wrong with you.
There are many places I would have happily visited until recently, but I’m nervous of travelling any distance without someone alongside me. I will continue to take care and drive carefully and not put anyone else at risk.
I was just wondering how big the UK is relative to the USA. Turns out according to Google it’s 40 times smaller than the USA! (also 32 times smaller than Australia).
We can drive across the country in a day. I could drive for maybe two or three days North to South John O’groats to Lands end, although it has been done much faster. The direct distance is 603 miles, but the road distance is 837 miles. So driving over the limit at 83.7 mph you could drive it in ten hours. But if you drove at just 40mph you could do it in less than 24 hours!
Goodness knows how long it would take to drive across America and I guess it also depends where on the coasts you drive from. America is wider in the north than in the south?
Third painting. I used the reference photo less and added leaves on the left hand side that were further towards the centre than was on the original photo. The lady who lent me the photograph told me this was taken at Delamere forest, which I think is in Cheshire.
I tried to emphasise the blues in the background to give it a distant feeling. Then I emphasised the reds and greens to ring them to the fore. The leaf litter was fun to paint trying to shape it and add light shining through the leaves onto the ground. It’s a small acrylic on canvas.
The world I’d bleak and I don’t know what to say or think. Words and thoughts churn round in my head. I feel anxiety about not getting something right, something I should have done months ago that could have massive consequences now or in the future.
Because I was focused on myself I didn’t see other people or a person who might have needed my help. It’s six months and the Earth has travelled half way around the Sun. That’s 186,000,000 miles. And now I’ve only just realised I should have been there for someone 186 Million miles ago! I feel idiotic, I feel great anxiety that I will not be forgiven. I feel I have lost a chance where I could have been of help…..
Even now, writing this, it seems a trivial response, too self serving, am I writing something that will help, or to just try and exonerate myself. Guilt and anxiety, mixed emotions and sadness…
Today’s #bandofsketchers prompt was distant. I used to like to play with perspective drawings, using either one or two vanishing points. Both show how buildings or streets dwindle into the distance, becoming distant. It’s also fun to make up your own architecture.
There’s something called the Drake equation that hypothesises whether there is other intelligent life out in the universe. I don’t know it and can’t quote it, but I looked it up (see above). The fact that the scientists have even found amino acids in space (the building blocks of life) means that there are possibilities of finding other beings.
The equation looks at how many possible inhabitable planets are out there, whether life could evolve, and whether intelligent life might come about. Then you have to think about time. If an intelligent life form was to exist somewhere else they might send out signals, but it could take millions or billions of years to travel across space before we detected it, and by then they could be long gone. So it would only be possible to communicate if they were closer, tens of years away? But then a conversation with someone even twenty light years away (the distance of a possible habitable planet) would be very boring. One question every forty years, one reply eafter another forty years. And space travel would only be possible at a small percentage of the speed of light, according to the laws of physics. So we might be able to talk but not visit.
It might be great to get a signal, but even if there are other civilisations it doesn’t mean we will ever find out.
I turned my painting upside down because I’m struggling to reach the top with my aching and shaking arms. I’m working on the background. But it also helps me see shapes and tones and proportions. I need to decide if I want the background to be blurry? Perhaps I should change my brush size and try and blur the edges. I will turn it back in a while….
Mallaband-Brown 