What is the point with observable Universe?

I already mentioned in one post how freaking big is the place where we life (the Universe). And in the end of the post I mentioned something about observable Universe. So well what is that?

So observable universe is a sphere and its center is Earth, or rather your head so you are in your own observable universe.

This is area that is possible to observe right now since the places outside of this sphere are too far away, their light did not have time yet to reach us.

The diameter of such sphere is 93 giga light years. The reason for this is that as the light left some place and traveled towards you the space expanded making the path longer and thanks to this we are able to see much farther away.

There is another thing called Hubble sphere. It is the area beyond which we will never be able to observe because the stuff there is traveling faster than the speed of light, or rather to make it accurate.. the space between you and outside of Hubble sphere is expanding so fast the light can not get through it.

Actually it can since your Hubble sphere is expanding too and the stuff from first 5 billions years is seen due to this expansion of Hubble sphere.

Actually Hubble sphere is smaller then observable Universe.

Confusing? Watch this video.


How big really is the new prime?

it has been few weeks/days since the last prime was found. It was a huge boom since it happens less and less often as the prime increases and we are getting to even bigger numbers. How big this number actually is? Well in this post I will try to show it, and it is really huge.

I heard some great analogies to 52! (factorial) which is pretty big number. What I decided to do is to do the same thing with the new prime, but oops, this number is way too big.

This is the number which has been found: 274,207,281

It has 22,338,618 million digits, which is way too high to tell you something.

Now imagine that you are counting, every second you add one. How long time would it take you to get to this number? Long time.

More accurately since that is very relative: 6.80348129009742 × 1022338599

This many times of Universes, roughly. What? The number did not even change! Actually there is like 19 less digits.. still not quite good.

So I started to do those analogies for the time written above.

Ok you have a normal can of coca-cola. Such a can has about 330 milliliters. One drop of water (that is actually SI unit) has 0.05 ml. This means that if you would fill it with the rate of one drop per second you would fill it in 6,600 seconds which means almost two hours.

On height, one can has 0.000122 kilometers. Now imagine that if you would fill it you would then put it on one another. You would rise this tower of cans to the height of Sun, that is 150,000,000 kilometers. With filling each of these cans it would take you about 8 trillion seconds [1], this is roughly 253,678 years.

Then you would destroy such tower and take one drop (0.05 ml) from the Atlantic ocean. Atlantic ocean has volume of 323.6 million of cube kilometers. Before you would take another drop of water from the Atlantic you would have to create this tower again.

It would take you about 1.6 sextillion of years to do this thing [2].

Now imagine that after emptying whole Atlantic ocean, you would fill it again (immediately) but you would take one atom from your body (imagine that your body does not change). Then you would fill those cans, stack them to the sun, do that so many times that you would empty Atlantic ocean and do that so many times that you would actually move all atoms from your body to some different place (there are 7*1027 atoms in your body). Too bad, this would take you only 1.2*1049 years.

When I did those analogies I did not really thought about how big the number was going to be so I was a bit dissapointed, at the same time I realised that the prime number is whole next level and I could equal it only with another monstrosity.

Imagine doing all the previous steps and then arranging 3,900,000 numbers into one row. There are 3900000! combinations and you would do all of them, but between each step you would have to do all the previous. Roughly such a thing would take you the same time as counting by one every second to get to the new prime number.

Thanks for reading!

[1]8 trillion is 8,000,000,000,000
[2]1.6 sixtillion is 1,600,000,000,000,000,000,000

If you really want to see the source of the image: here.


The Universe is enormous

I was thinking what topic should I mention today and remembered that the Universe is huge, and it is so huge that we completely underestimate it (at least I think that I still do).

First I will turn towards our planet, the Earth.
Here the biggest misconception is the size of Africa, you see the problem is that in most maps of Earth which you will see is Africa in the middle. If you know little about geography you know that there is no way to perfectly put our planet to scale on map. There are some ways which will be more accurate than other but most of the time Africa is going to be smaller than other continents. continent_infographic-01 copy

OK, now compare this map above with the scale on your home atlas, Africa is going to look tiny probably with Greenland, Siberia and Canada huge.

Now look at the picture of Earth and Moon distance, they are so little, Earth would be able to fit there so many times!

Now, seriously, look at this amazing page: THIS You start with Moon which is wide as one pixel. Next you will see Sun which seems to be pretty huge. Now if you click the speed of light button you will start to move slowly to right. Oh my god, the speed is so awfully low!

On top of page you have the bar with planets so you can click on them and ride from one another, remember, it is TO scale, and after you drive through whole map they say: You would have to travel 6,500 more maps like this to get to something.

This is huge, we are from Sun only 150,000,000 km.

OK´, Sun is small, lets see why:
1st picture shows that Sun is big:

2nd picture, well Sun gets little smaller:

3rd picture is actually a whole different story:
Now here is the last to compare it all, with little bonus of Canis Majori:
Ok but all of this stuff is so freaking small compared to whole Milky way! The radio signal from Earth which traveled for tens of years is not even visible on map of Milky way!
You can fit Sun 1420 times next to each other inside VY Canis Majoris.
And  you can fit Earth like this 109 times.
This means that you can fit Earth 157,780 times inside VY.
The diameter of Milky way is roughly 140,000 light years. Where one light year is 9,460,730,472,580,800 meters.

This is 741,669,055,548 Earths for diameter of Milky way. 2,540,000 light years is the distance to Andromeda galaxy, the closest galaxy.

Virgo Supercluster has 110,000,000 light years. Easy. On the next picture from @HighTechPanda , you can see the comparison of largest galaxy to Milky way, enjoy!And last, observable universe has 93,000,000,000 light years in diameter.

Still so underrated.


Africa picture


How it started, featuring Big Bang!

when you read the title of this post it is pretty clear that I am going to write about Big Bang, I already wrote about the ends of the Universe but it feels as lot of people are interested in the beginning and there are some misconceptions.
For example even the title is little bit wrong since you could assume from it that Big Bang was the start of everything..

So I will try to explain Big Bang and what happened right after and I want to start with first big misconception.
People think that Big Bang was explosion, nope it was not. It is thought that Universe expanded into space but actually Universe is already everything and it kind of expands into itself, if it makes sense.

BigBangIsExpansionOn the picture above you can see the example of expansion where space expanded not the things inside but the fabric itself. The space in the grid increased while nothing happened to the objects except that they are further apart. This is what is happening all the time and even if the Universe was infinite it could get bigger, kind of, because everything is going away from the rest of the stuff and NOTHING can be the center of the Universe. There was no explosion.
For the rest of the post I will follow the picture on the left.

On the bottom of the picture is the start of the big bang. This is outside of the graph because we are not able to investigate it using the laws we know now. This is until Planck time passed (10^-43 seconds). After Planck epoch which is big unknown, the time of grand unification came. This is time with extremely high energies involved and it is assumed that 3 fundamental forces are working as one at this time: electromagnetism, weak and strong nuclear force. This is extremely important but we are not able to reach such energies even in particle accelerators while it could help us a lot with Theory of Everything.

Few really really short moment later strong force separated and started to work alone. This took some really long time before all the forces separated to the state we know today. This is one picosecond after big bang. Then quarks became grouping together into hadrons. Those are particles with zero “color” charge like neutron or proton.
Some time later finally deuterium is created and through big bang nucleosynthesis some heavier elements like lithium, beryllium and helium too.

Then it takes really a long time before everything calms down so that first stars and then galaxies form.

Some time I will probably return to background radiation.

At the beginning I said that you can not really say that big bang was the start of everything since there are some theories like big bounce.


1st picture
2nd picture

Space NEWS #1

I decided to write about Space NEWS! Most of them probably would be from NASA page.
Today I want to start with WT1190F impact of Earth and then about cloud which was found in Titan`s atmosphere.

First, yesterday 13th November some space debris entered the Earth`s atmosphere.
Most of it burned up in the atmosphere but still it made a WT-reentry-fireball-tight.jpgfireball.
For few years object named WT1190F orbited Earth in more and more eliptical orbit. Finally this object falled down entering atmosphere in 11 kilometers per second. Nobody was in danger because it fell about 100 kilometers south of Sri Lanka.
For some time it was not Trvalý odkaz na vložený obrázekknown if its asteroid or not but finally when its density was calculated astrophysicists were sure that it is hollow and manmade. This event was important for improvment of calculating of stuff falling from the space.
Pictures taken from wikipage about WT1190 and twitter page.

A cloud system called the south polar vortex on Titan's south poleIn Titan`s atmosphere (Titan is Saturn`s moon) Cassini found a giantic storm forming.
Those clouds are about 200 kilometers tall. Cassini used its infrared toll called Composite InfraRed Spectrometer (CIRS).
Those clouds form in very strange way. Not by water evaporating from ground but by flow of gases from warmer pole to the other where those gases sink and in different levels of atmosphere they condensate forming those clouds.
Titan`s seasons last more than 7 years and this is the time when winter starts on Titan`s southern hemisphere.
This page by NASA.


Apollo missions: Apollo 10

what a surprise! I am here again with Apollo missions this time with fourth manned Apollo-10-LOGO.pngmission.

Apollo 10 was launched in the year 1969 May 18 and 16:49:00 The Apollo 10 Prime Crew - GPN-2000-001163.jpgPM. Members of crew were three of course: from left to right Cernan, Stafford and Young.

Stafford was captain. Apollo 10 crew were unique because it was first Apollo mission where all members were already in space (Apollo 11 was second and last). Both Young and Stafford were flying for the third time while Cernan for second.

There was also back up crew if some problems occurred but Cooper and Eisele (Apollo 7) were not in favor of NASA because of some incidents on their missions so it was not planned to move them on next mission (as was usual) and they were back up crew only because NASA did not have enough experienced astronauts.

Highlight of this mission were prepared so that they had all data they needed for Apollo 11 which would two months later land on Moon. Everything they needed to do was done, the most important thing was to approach Moon as close as possible.
By one historian it is said that NASA had to give them low amount of fuel so they could not land Moon even if they wanted.

This approaching was achieved by departing a little Lunar module (called Snoopy, it is on the picture with moon) leaving Apollo 10 Lunar Module.jpgonly Young on the board of “Mothership” while Stafford and Cernan achieved the distance from surface of 15.6 km.

Apollo 10 orbited Moon thirty times and then after 8 days and 3 minutes and 23 seconds they splashed down in the Pacific ocean (actually mission was planned 1 minute shorter this means that they really messed it up).

One of Snoopy´s stage was left there and nobody knows where it landed (crushed) but in the year of 2011 group of amateurs started project to find it out.


I was taking data from these pages:


Read about Apollo 9!

Moons of our Solar System: Phobos

today I will write about second moon. This time it is Phobos, the bigger of the two moons of Mars.
His name comes from the son of Ares (Mars) and Aphrodite (Venus). Phobos is really strange, he orbits closer to its planet than any other moon. Every year it is closer by 2 meters so one day, about 50 million years in the future Phobos will either crush onto Mars' Moon Phobos
Mars´s surface or he will be ripped by tidal forces so only ring will be left of him.

Phobos was found in the year of 1877 by Asaph Hall. His surface is one of the darkest of any object in our Solar System (this picture has enhanced colors). There are lot of craters and the biggest has almost the same diameter as whole Phobos. You can see it on the right of the picture and it is called Stickney crater after Asaph´s wife. Temperatures can go from -4°C to -112°C.

Phobos has too low gravity so he could not round himself, that is why he looks as potato. Escape velocity from his surface is 41km/h which means that Usain Bolt would be able to run into space on his own feet. The gravity is 0.000581 of gravity on Earth.

Phobos is small but even than he weights about  10,658,529,896,187,200 kg (or 10.6 quadrillion).

One more strange thing about him is that he is orbiting faster than Mars turns around his axis so he can be seen thrice a day rising from west and setting east.


PS: thanks for those who are reading my blog, I have written 50 posts already!

Planets of our Solar System: Mars

today I am getting to fourth planet of Solar System since I skipped Earth.
It is Mars, The Red Planet.

Mars is very pretty planet. There are actually nice conditions, really the best for us if we are not counting Earth of course. This makes Mars very kind of nice for research and everything.
We are able to see him in the morning below Venus but it is not really bright. Still if you have good eye you may be able to see the reddish color of its surface, I will get later to it.

Mars orbits 1,52 AU from the Sun. The difference between closest and furthest distance from our star is over 40.000 km compared to Mercury´s 23.000 km and Jupiter´s 76.000 km.

You wont get overheated very much on its surface, there is average temperature about -60°C. Surface color is red, right you guessed it and it because of iron oxide (hematite). It Mars map scale-coloured.pngMapa Marsualso makes sense that people named it Mars, after roman god of war (Greek version is

There are two main things about physical geography “up” there. Some time in the past Mars collided with huge rock
which made crater over whole north part. Same on the Moon, lava could easily bubble up through thin crust and smooth everything out (as a proof you can see it on the picture). While on the south there are lot of impact craters.

When you see this map immediately your eye moves to huge red spot on the right, those are mountains, actually volcanoes with tallest mountain in the whole Solar System: Olympus Moons which is 27 km tall with surface area about the size of France. This one and also other volcanoes were made when tectonics of Mars were still active.

Really cool thing is in the middle of map, such a small blue line cutting few kilometers to earth. It is Vales Marineris (picture is from Celestia).
This canyon is crack which was made when the crust was cooling. It is 4000 km long, 200 km wide and 7 km deep.

Water on Mars
You have probably heard of it and I will make sure to make separate post about it.
So yes, NASA found liquid water on Mars. Problem is that it is full of soil so you can call it water, yes but it is more kind of mud which is flowing from season to season with its low freezing temperature. There are also polar ice caps on the poles with little water on them and mostly dry ice (CO2).

Even that Mars has atmosphere, it is extremely week and when it is winter on Mars one third of it is in solid form on surface.
Scientists are sure that there was liquid water before (even oceans) but it evaporated and solar winds blew it away because Mars´s gravity was not strong enough to hold it (Mars has only 0,3G).

Mars has two moons but I will talk about them in different episode since I made this: “Moons of our Solar System” thing.


I also wrote about visiting of Mars

Previous post about Mercury
Previous post about Venus

What could happen to our Universe: Big Bounce

with little break from Solar System I am returning to last post about end of our Universe. This time it is very optimistic, but we will die anyway..

Right now the Universe is expanding, it is expanding in high speeds but this theory is assuming that this process due to decreased amount of dark energy reverses at one point and everything will start to shrink back. This would heat Universe over time. About 100,000 years before big crunch space would be hotter than surface of stars which would make them cooked from outside (FUN).

Then all matter would fall into black holes and all of those black holes would fall into each other so that final singularity would be created.

Well then it could start all over again, big bang, zero expansion and big crunch. This scenario also assumes that Universe is going through infinite cycles of banging and crunching. While this is most optimistic, in the new Universe would be nothing from the one before.
Measuring of expansion of Universe does not give much points to big crunch because now it seams that expansion is speeding up. Scientists are not yet able to know why is this happening Big Bounce is still an option.


PS: I just lost the game… Here is post about heat death. And here about big rip.

Apollo missions: Apollo 9

today I am here again with Apollo missions, this time as yApollo-9-patch.pngou can see I will write about Apollo 9.

Again there were three persons in this third manned flight: James A. McDivitt who was captain and this was his second flight. David R. Scott was module pilot and also, this was his second flight. Russel L. Schweickart was flying for the first time ever. (You can see the crew below from right to left McDivitt…)

Posádka Apolla 9 (zleva: McDivitt, Scott a Schweickart)This mission started on the day of 3rd March 1969 at 16:00. Plan was to go around Earth few times and measure some stuff about our planet and take multi-spectral photos of Earth. Also it was planned that Schweickart will go out of spacecraft and over to other modul but he was space sick so it was not achieved (It is called EVA = extra vehicular activity). They also tested new spacesuit which had its own life support system.

They also moved both parts (lunar module and captain module) apart for more than 6 hours and then successfully joined it back together. Whole mission lasted ten days and one hour before they splashed down near Bahamas.

This was yet another successful mission which was another step to land on Moon.