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Feedback Q&A on Astronomy

by Ron Kurtus

Readers have sent in a total of 303 comments and questions on Astronomy issues. They are listed according to date.

You can read them to further your understanding of the subject.

List of next 10 letters




General What is responsible to elliptical acceleration? Pakistan
General Want to get into the field of astrophysics Canada
Moon The other side of the Moon Phillipines
General Topics Theories about space India
General Topics Wants information about planet Mercury South Africa
General Powering spaceships with light rays India
Constellations Can the big dipper appear upside down? Canada
The Earth How would seasons change if the Earth moved away from Sun? Australia
The Earth Why do the planets travel in elliptical orbits? India
General Topics Opinion that planets do no travel around the Sun Australia

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First 10 letters

What is responsible to elliptical acceleration?

Topic: General


November 14, 2010

earth is revolving around the sun in elliptical orbit some times its speed is high(peiehelion) som time less(aphelion). Question arises that which force is responcable for this tangentel accelaration

Javed - Pakistan



It is uncertain whether the Earth is from an explosion on the Sun or was moving and captured by the Sun's gravitation. However, it does have motion and the best orbit is in a circle.

If the initial speed was greater than required for a circular orbit, plus the gravitation from other planets, will result in an elliptical orbit. The acceleration on the ends is a property of elliptical orbits to satisfy proper movement around the Sun.

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Want to get into the field of astrophysics

Topic: General


November 12, 2010

i want to get into the field of astrophysics. and i understand i need my chemistry. its hard to memorise the physical and chemical states, and the bohr-rutherford diagram, and the lewis dot diagram, anddiatomic elements. aswell.also i am trying to understand the nomenclature, polyatomic ions, cross over methods, ionic bonding, and how to understand the change in names while valence is changed.
i need a better understanding of this, i enjoy science to the fullest, but i do get confussed. i would like some help if avaiable. if you have any questions for me i would be happy to answer, and also if you can show me how it works in a way for me understand instead of just writing them down would be great

Morgan - Canada



Typically, to get a degree in astrophysics, you primarily need to take many astronomy and physics classes. Unless you are specializing in the chemistry of celestial objects, you usually only need to take a basic college chemistry class.

However, even some high school college classes can be difficult. In such a case, it is good to get a introduction to chemistry book to give you some background on more of the basics.

Here is an example of requirements for a degree in astrophysics:

Best wishes on getting a better understanding of chemistry and in advancing in your astrophysics career.

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The other side of the Moon

Topic: Moon


November 3, 2010

who can discover the side of the moon?

jessa - Phillipines



Because of the way it rotates, one side of the Moon always faces the Earth. When spaceships were sent up to the Moon, the orbited the Moon when and took photographs of its other side. There are now pictures available for people to see what it looks like

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Theories about space

Topic: General Topics


August 9, 2010

Analysis on Beginning of the Universe, The Humble Beginning

At the beginning of the universe it has to be simple, a simple situation, a simple thing, it cant be complex, rather very simple, too simple, simplest of all situations or things (Ground Rule:- Nothing can be simpler than the beginning, beginning is always simple), thin air like, or space like void, or more like Nothingness, as nothingness is the simplest situation.
Then it has to be derived Nothingness is not possible in nature, as nothingness is not even space sans matter, not even eternity (of space), or a compressed space or matter at a point (even not at a point, even beyond pointlessness) or a pointless situation.
As soon as the universe reaches this simplest situation of Nothingness it blasts off for a new universe, the Big bang.

Now we have to prove mathematically or experimentally, why Nothingness is not possible (I could not do that), why Big bang happens at this situation or happened in the case of our existing Universe.
It also proves why multiverse is not possible as proposed by some physicists.

It also settles the questions if any about place of origin of the universe, that is where or at what point the universe originated.


Nothingness is also a constant as nothing is possible below it & anything above it, is not Nothingness, so this is also a constant, the biggest constant, The Super Constant, the mother of all constants, all constants arise from it.

It also proves why any other constants values are not possible, as debated by some physicists that why values of constants cant be different from what they are now (may be, values of constants change over time as physicists are trying to prove through experiments but value of a constant changes with all other constants values & that change is simultaneous & along the line, so if you happen to reach a place billions of years back in time or billions of light years far, your own set of values will change to that times & place or vice versa, that is if you start from there & come to the present, your constants values will keep changing & at last be that of present, so going back or forth or fetching from past is only relative, is unproductive, as you cant bring one of the past values to the present or you cant take back one of the present values to the past as values will keep changing accordingly as per time & space.

Why is that Super Constant?
At Nothingness or in Super Constant only two extreme situations are possible, one no matter energy (more natural it would have been that there were no universe & us, only nothingness, but we are here & universe is there) and 2nd, limitless matter energy, endless mass.
That means The Super Constant could give birth to eternal, unlimited matter energy or continue with nothing (void) situations, but we have a constant quantity of matter energy in the universe, that the total mass (matter energy) of the universe is fixed, if not otherwise it has been proved that the quantity of mass energy of the universe is changing, increasing or decreasing by the days, or destruction or creation of mass energy are happening (not decay as decay gives forth to another form of energy, it does not vanish), so total mass of the universe is fixed.

It also advances the theory that no other possibility existed or exists for the nature, means The Super Constant (whatever form it may be, small or big, pointless or eternal) at the point of Nothingness, can give forth (generate) only THIS MUCH QUANTITY of matter energy (the total mass of the universe), no more, no less, as we have now.

And that also becomes a constant THE MASS CONSTANT or in other words the universe can have this much of mass (matter energy) from the blast at the Nothingness, from the original, quintessential THE SUPER CONSTANT.

The universe begins from a single Super Constant, from The Nothingness with a blast, which cant exist even for a moment in nature, as soon as the universe reaches this simplest situation of Nothingness, the Super Constant is created, then & there it blasts off for a new universe, the Big bang.

Or as the Super Constant takes place at the end of universe (may be trillions of years will be taken to decay all matter energy & convert them into lowest form or due to some other unknown chain of events it may happen, I cant postulate, perhaps still now it is unknown, what happens at the end, but surely all researches & observations from the day Hubble Telescope sending down data that the universe is fast expanding & degenerating, all scientists are unanimous that the universe is heading towards a doomsday, it may take unimaginably long time, but time too is measured by our standard, what we think very long, may be is not that long by the universal standard) the blast (Big bang) occurs & it gives away a constant quantity of matter energy.
Also other CONSTANTS that we have now are created from the Super Constant at the very moment of blast, not after or before. And these constants start to shape the universe.

Subhro - India



Thank you for your observations and theories.

The question of what space is has puzzled scientists for many years. Some consider it "something", while others say it is "nothing" or the state of being without substance. The problem with saying that space consists of nothing makes it difficult to explain how force fields can travel through space.

A constant is usually defined as an unchanging value. Certainly, you could say that the amount of all matter and energy in the Universe is a constant. That is providing there are no other universes or multiverses.

Definition of terms should be done carefully so that there are no misunderstandings.

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Wants information about planet Mercury

Topic: General Topics


July 31, 2010

the distance of the planet(mercury) from the sun inkm.
number of moons
composition (made up of which)
the colour
inner/outer planet
picture of your planet
15 more interesting facts about the planet

muhammad - South Africa



For information about the planet Mercury, see:

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Powering spaceships with light rays

Topic: General


July 20, 2010

Could Space ships be powered by light rays?

Anubhav - India



Yes. Once a spaceship is up in space, they deploy a large solar sail that propels the spaceship without having to use fuel.

The Mariner 10 mission, which flew by the planets Mercury and Venus, and the MESSENGER mission to Mercury used solar sails to conserve fuel.

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Can the big dipper appear upside down?

Topic: Constellations


June 18, 2010

Is it true that the Big Dipper can be viewed upside down anywhere in the world? I live in Newfoundland, Canada, and I have never seen the Big Dipper upside down. I traveled to Ghana earlier this spring and was amazed that the Big Dipper was upside down.


Alanna - Canada



The big dipper rotates around the North Star, such that it appears upside down half the time at night. Since you live in Newfoundland, you are closer to the North Pole, such that the North Star is much higher in the sky than in Ghana. Thus, it would not appear to be upside down as much as it would in Ghana.

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How would seasons change if the Earth moved away from Sun?

Topic: The Earth


May 24, 2010

Hi i would like to know that if the Earth moved farther away from the sun what would the characteristics of the seasons be?

Jaytten - Australia



The seasons are determined by the tilt of the Earth with respect to the Sun. The tilt causes the days to be longer when the axis is facing toward the Sun, as in the summer and shorter when the axis is away from the Sun in the winter.

If the Earth moved further away from the Sun, the length of the year would be longer and the temperatures would be lower, depending on how far away the Earth moved. The seasons still would be the same.

Note the since the Earth travels in a slight elliptical orbit, the Earth is closer to the Sun in the summer in Australian and also closer to the Sun in the winter in the US. This shows that the tilt is most important.

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Why do the planets travel in elliptical orbits?

Topic: The Earth


May 15, 2010

why earth and other planets revolve in the elliptical path why not in circular path, because the force of attraction is same at any instant so it should maintain a constant gap.

Atul - India



Most travel in a path that is close to a circular path. But since there is a gravitational pull from other sources, such as other planets, they stray off the perfect circle.

For example, when the Moon travels around the Earth and is closer to the Sun, its orbit gets pulled into an elliptical shape.

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Opinion that planets do no travel around the Sun

Topic: General Topics


April 8, 2010

Dear Professor;
Astronomers can observe Jupiter from Earth for 2 or 3 days of each calander month of the year. Yerks and Keck observatories (or myself) can confirm the rising & setting dates and times of these observations. If the planets are allegedly circumnavigating the Sun, ( the Standard Model, gravity and planetary circumnavagation have NEVER been proven) why can observations be possible during the three Mo. period when the Earth & Jupiter are allegedly on opposite sides of the Sun to each other (180 degrees)? The ephemeral rule does not apply to actual observations and the 3 dimensional arc of travel of the two planets, does not explain them being able to observe each other (even with filters) through or over the alleged obstruction and glare of the (1200x's larger) Sun during that 3 mo. period. Does explain this phenominum? The web site states the Solar Winds, (not Quantum Gravity, disproved in 1956) are the energy source propelling the planets in front of the Sun. It presents a new and enlighting heliocentric model, improving on the Standard Model. The theory is a logical explanation for Mercury and Venus's "transit" and Jupiter's confirmed observation during ALL 12 calander months . Please read it. Your comment is welcome.
Respectfully, A. Pettolino,

A. - Australia



Numerous space probes have been sent to observe and study the planets in our solar system. The Galileo space probe orbited Jupiter and verified that it did circumnavigate the Sun.

Observations from the Earth can be deceiving. Consider the ancient view that the Sun revolved around the Earth. However, a full range of available data needs to be studied and not just a few observations or speculations.

Although improvements on many of the accepted theories can be made, there is so much evidence that they are basically correct.

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