Common misconceptions about astronomy

[GiannKall]

Bing Bang is NOT a fact. Through observations we know that galaxies are accelerating which constradicts the idea of Bing Bang. It like having an explosion and seeing pieces gaining speed momentum later not earlier. It doesnt make sense. So science has created a new thery to fill the vacuum(the dark force theroy).

 

[500]

Thanks. The radius of the visible universe is estimated to be 46 billion years
29) Dividing by the surface won't do the justice the total influx of the solar energy is responsible for the life on the planet Earth.

Sorry but radius of visible universe has absolutely nothing to do with solar energy.

Both radius of visible universe and solar energy data u can check on wikipedia:

https://en.wikipedia.org/wiki/Observable_universe
https://en.wikipedia.org/wiki/Sun

As u can see numbers I posted are absolutely correct.

 

[Moon]

1) The Big Bang was a huge explosion.

When people are told about a Big Bang they are imagining something like this:

However the Big Bang was not an explosion in space like in this pic, it was a rapid expansion of space itself. Thus it does not have any center and we cant actually imagine it.

2) Universe is a sphere with ~13 bln light year radius.

Its linked to previous point. We know that universe is ~13 bln years old. Thus many people think that its expanded from the bing bang to a sphere with 13 bln light years diameter. But as I noted it was not an explosion. U cant show a point in universe where the Big Bang happened. Simply the space between the galaxies is expanding. Thus the more far is a galaxy the faster it is moving away from us and there is no speed limit. Very distant galaxies are moving from us faster than light! No one knows the actual size of the universe and its shape. We only know its much much larger than sphere with13 bln light years radius, maybe its infinite.

3) Nebulas are dense clouds in space.

In sci fi nebulas usualy look like this, you can hide ur spacecraft inside:

View attachment 287289

In fact the density of nebulas is extremely low: most dense one have only about 10,000 atoms per cm3. For comparison space at LEO orbit where most satellites are flying has MILLIONS atoms per cm3. From close range u wont see a nebula at all.

4) Flying through asteroid belt is very dangerous.

This misconception is similar to above. Flying through asteroid belt looks like this in sci fi:

Although there are billions of asteroids in asteroid belt, the space is so huge that the average distance between two asteroid is hundreds of thousands km.

5) The asteroid belt might be an exploded planet.

The total weight of asteroid belt is less than 1/2000 of earth's. If u merge all asteroids together they will form a tiny moon, much smaller than our own.

6) Black holes are like giant vacuum cleaners which suck everything around them.

In order to notice the gravitational difference between the black hole and star of same mass u need to come very very close (to star radius). Thus is sun magically collapses into a black hole we wont notice any difference except the lack of light and heat. The orbit will remain the same.

7) Our galaxy rotates because of a giant black hole in its center.

In the center of our galaxy there is indeed a supermassive black hole with mass of 4 million sun. But the milky way galaxy has mass of over trillion suns. If u remove a black hole from our galaxy it will keep rotating as before. Supermassive black hole does not affect the galaxy rotation at all.

8) The moon color is yellow/whitish.

The albedo (reflection rate) of the moon in visual light is only 7%. That's very dark grey close to black. The moon seems bright only compare to black space. If moon was yellow it would be many times brighter.

9) The Sun is yellow.

The sun emits all spectrum of colors, but the peak lies in green! But our eye sees it as clear white in space. And on earth because of atmosphere it seems yellowish to our eyes.

10) Our Sun is very small star.

Although there are stars much much bigger than our sun, the average size of stars in universe is much smaller than our sun.

11) Winter is colder because the orbit is oval and we are further from the sun then.

Winters are colder because of inclination of the earth. In fact in Northern hemisphere we are actually closer to the sun in winters.

=================

You can add other misconceptions u know.

I have a question,
Point 5,
Are we to take the "weight" of the asteroids or their mass? Because in space, weight will vary.

 

[500]

I have a question,
Point 5,
Are we to take the "weight" of the asteroids or their mass? Because in space, weight will vary.

You are right, tnx. It should be mass not weight. There is no weight in space.

Bing Bang is NOT a fact. Through observations we know that galaxies are accelerating which constradicts the idea of Bing Bang. It like having an explosion and seeing pieces gaining speed momentum later not earlier. It doesnt make sense. So science has created a new thery to fill the vacuum(the dark force theroy).

There is no any contradiction, rather on contrary. Energy of vacuum is actually necessary for the push and inflation stage.Except that during inflation vacuum had uncounted times more energy than today.

 

[Hamza913]

You are right, tnx. It should be mass not weight. There is no weight in space.


There is no any contradiction, rather on contrary. Energy of vacuum is actually necessary for the push and inflation stage.Except that during inflation vacuum had uncounted times more energy than today.

Impressive knowledge.

 

[GiannKall]

You are right, tnx. It should be mass not weight. There is no weight in space.


There is no any contradiction, rather on contrary. Energy of vacuum is actually necessary for the push and inflation stage.Except that during inflation vacuum had uncounted times more energy than today.

This is though a convenient theory to hide the fact that observations contradict the Bing Bang theory. Fact is that galaxies should slow down instead of accelerating

 

[500]

30) Greenhouse effect for Earth (planets) is always a bad thing.

Without a greenhouse effect the average temperature on Earth would be below 0 C. Possibly the civilization would never develop.

 

[Salik]

Consistent use of maps with North up^ is building misconception that world has any specific up and down sides. So we must use maps with other dimensions up interchangeably, like this one:

 

[500]

31) Supernova explosion is one of the most luminous events in Universe.

While Supernova explosion produces insane amounts of energy, most it goes to kinetic expansion of outer star layers and only a small portion into electromagnetic radiation (light). Supernova reaches the peak of its luminosity only weeks after the explosion as result of Ni56 nuclear fission (Type I supernova) or Hydrogen recombination (Type II supernova). Only then it becomes one of the most luminous events in universe.

 

[Sparkle229]

Thanks a lot I learned very cool things from this topic,by the way I am really interested in astronomy

 

[500]

Thanks a lot I learned very cool things from this topic,by the way I am really interested in astronomy

My pleasure. Anyone who have questions is welcome to ask here.

32) Supernova and/or Quasar are brightest events in Universe.

Typical Supernova II type radiates 7.5X10^42 erg per sec at its peak.

Typical Supernova I type radiates 4.5X10^43 erg per sec at its peak.

Quasars radiate 10^47-10^47 erg per sec.

The brightest events in universe are Gamma ray bursts: 10^47-10^54 erg per sec.

What are these gamma ray bursts? - We dont know for sure. The common theory is that they are produced either by rare case of Supernova (that means misconception is only partially wrong) or by merging Neutron stars. According to theory Supernova which produces gamma ray burst is super giant (over 50 star masses) very fast rotating star which after collapsing into a black hole creates fast rotating accretion disk and two narrow beams emitting out of poles. Thus in contrast to regular supernova it gives most of its energy directly into radiation and not into expanding of layers (as I mentioned in #31). In addition its radiation is beamed and not spherical like regular Supernova. As result Gamma ray burst is only thing we can see from billion light years with naked eye (for very short period).

 

[Sparkle229]

My pleasure. Anyone who have questions is welcome to ask here.

32) Supernova and/or Quasar are brightest events in Universe.

Typical Supernova II type radiates 7.5X10^42 erg per sec at its peak.

Typical Supernova I type radiates 4.5X10^43 erg per sec at its peak.

Quasars radiate 10^47-10^47 erg per sec.

The brightest events in universe are Gamma ray bursts: 10^47-10^54 erg per sec.

What are these gamma ray bursts? - We dont know for sure. The common theory is that they are produced either by rare case of Supernova (that means misconception is only partially wrong) or by merging Neutron stars. According to theory Supernova which produces gamma ray burst is super giant (over 50 star masses) very fast rotating star which after collapsing into a black hole creates fast rotating accretion disk and two narrow beams emitting out of poles. Thus in contrast to regular supernova it gives most of its energy directly into radiation and not into expanding of layers (as I mentioned in #31). In addition its radiation is beamed and not spherical like regular Supernova. As result Gamma ray burst is only thing we can see from billion light years with naked eye (for very short period).

Can you tell us about DARK MATTER what is it made up of and other info if you have any?what does it do

 

[500]

Can you tell us about DARK MATTER what is it made up of and other info if you have any?what does it do

When object rotates around something with mass M its speed calculated by this formula (simplified way):

R - orbit radius, G - gravitation constant. Thus the higher is Mass of central object the higher is rotation speed. This formula predicts very well speeds of planets around the Sun, or speeds of moons around planets, satellite speeds etc etc...

But when astronomers checked speeds of stars rotating around galaxies they noticed that speeds are much higher than this formula shows. And its not just one star in one galaxy, but all stars in all galaxies have same problem.

There are two possible solutions to this problem:

1) Propose there is some additional mass in galaxies which we can't see (called Dark Matter theory).
2) Propose that formula at very big ranges and masses is wrong and should be modified (MOND theory).

https://en.wikipedia.org/wiki/Dark_matter
https://en.wikipedia.org/wiki/Modified_Newtonian_dynamics

Dark Matter currently is much more accepted theory than MOND. It gives better predictions and has much less problems. However all attempts to detect these unseen particles which create the Dark Matter so far have failed. That means Dark Matter remains only a theory. So I'll add a misconception:

33) Dark Matter is not a fact.

 

[Sparkle229]

When object rotates around something with mass M its speed calculated by this formula (simplified way):

R - orbit radius, G - gravitation constant. Thus the higher is Mass of central object the higher is rotation speed. This formula predicts very well speeds of planets around the Sun, or speeds of moons around planets, satellite speeds etc etc...

But when astronomers checked speeds of stars rotating around galaxies they noticed that speeds are much higher than this formula shows. And its not just one star in one galaxy, but all stars in all galaxies have same problem.

There are two possible solutions to this problem:

1) Propose there is some additional mass in galaxies which we can't see (called Dark Matter theory).
2) Propose that formula at very big ranges and masses is wrong and should be modified (MOND theory).

https://en.wikipedia.org/wiki/Dark_matter
https://en.wikipedia.org/wiki/Modified_Newtonian_dynamics

Dark Matter currently is much more accepted theory than MOND. It gives better predictions and has much less problems. However all attempts to detect these unseen particles which create the Dark Matter so far have failed. That means Dark Matter remains only a theory. So I'll add a misconception:

33) Dark Matter is not a fact.

Thanks for the info appreciate it

 

[LeGenD]

24) Big Bang is a fact.

We know for sure that universe is expanding and that 13.7 billion years ago it was very hot and dense. But still it does not prove a Bing Bang. Big Bang theory does not work without inflation theory and in order to prove inflation we need to register gravity waves from it. Best way is to detect polarization of CMB by gravity waves. So far it was not detected thus Big Bang remains a theory.

25) Known universe started from the Big Bang.

According to current model, first was a "cold" Inflation stage expansion and only after that inflation field energy transformed into matter and heat, making it super dense and super hot, creating a Big Bang.

This misconception we can see in popular shows for example "How the universe works":

How the Universe Works S03E04 First Second HDTV XviD-AFG - Vidto (what they say from 10:46 is WRONG)

Big Bang remains the most reliable explanation of creation of the Universe as we have come to know it. The confirmation of Higgs Boson particle in an experiment in 2012, reinforces the credibility of Big Bang phenomenon a bit more: http://www.ibtimes.co.uk/cern-higgs-boson-news-glimpse-god-particle-266449