# Red Bull Stratos and its giantic balloon

Hi,
we all know that helium balloon raises up which makes it such a fun object, most things in every day life do not do that. This attribute can be used to raise objects or even humans quite high, but at one point you get a problem, the atmosphere is less and less dense.

Red Bull Stratos was a project involving helium filled balloon and a capsule with human (Felix Baumgartner). In the year 2012 it raised up to almost 40 kilometers and then the skydiver jumped down. He reached supersonic speeds (faster than sound: 1234 km/h).

In my physics class we talked mostly about the balloon because of what I mentioned in the first paragraph. 40 kilometers is very high and the pressure there is only about 0.497325257421 Pa which is basically vacuum since the atmospheric pressure is 100 000 Pa. (I used the barometric equation)

Because of this, the balloon can not rise so high in thinner air even though the helium is lighter than air. There is so little of it that it does not provide the necessary lift and the balloon has to be huge. In this case it had 9 144 000 cubic meters! Thats a huge thing. The problem of course was that it was not lifting up only one human but the capsule with all equipment weighted 1315 kilograms and the material of the balloon had 1681 kilograms[0].

The whole project was kind of supposed to be for science and finding out how body reacts to high speeds and for further development of pressurized suits[1]. At the same time there was a lot of helium used which was then of course lost. Beware because helium is on the list of endangered elements!

Dragallur

Btw. You can check out my Patreon site here!

[0]The helium also has to be lifting itself.

[1]At about 18 kilometers the pressure is so low that the water in human body starts to evaporate (not all because blood is enclosed but for example saliva). I wrote about that in this other post. To survive you need to be in a suit.

Logo source: By Source, Fair use, https://en.wikipedia.org/w/index.php?curid=37329038

# These telescopes are huge (E-ELT, OWL, VLT)

Hi,
today I will write more about telescopes. In a previous post I already mentioned why radio telescopes like Arecibo are so huge, its because of the long wavelength. Today though I will concentrate on another type of telescopes and those are the ones that sit on Earth and collect information from visible light (those are called optical telescopes).

Comparison of various telescopes. Note OWL, the big circle in the background and even bigger white Arecibo.

I already mentioned Hubble telescope and James Webb Telescope (JWT) that is planned for launch next year. Those are in space so they have quite limited size. Down here we can build bigger ones. Right now in building phase is the E-ELT (European Extremely Large Telescope). Its primary mirror will have 39 meters [1] making it the largest optical telescope. It has to be so big because otherwise it could not match the ones in space. This is because we have our lovely atmosphere in the way and it makes harder for telescopes to distinquish small objects (though these days we have software that is able to account for that).

VLT aka Very Large Telescope is already working optical/infra-red telescope. It consists of 4 telescopes each of them with primary mirror of 8.2 meters in diameter. They can work together to make images of angular resolution 0.001 arcsecond. In one post I said that we are not able to take an image of star other than just point like source of light but apparently that is not true so I apologize for it:

First confirmed image of an exoplanet. The ones that we can see are bigger than Jupiter and usually quite far away from their star. Credit: Gemini Observatory

VLT is second, right behind Hubble in the amount of scientific papers that its work produced (in the field of visible light/infrared telescopes).

There are many other telscopes that I might mention in the future like Thirty Meter Telescope but I will end it with OWL – Overwhelmingly Large Telescope. It was supposed to be the largest telescope ever, with primary mirror of 100 meters! The price was estimated to be about 1.5 billion euro and because of that it was decided that its not worth it. If we do not kill ourselves we might see giants like those in the future though I have no idea how the scientists, or whoever does it, will name them (UGHT – Unimaginably Giantic Huge Telescope).

Dragallur

[1]Just as JWT, the mirror is made from smaller segments. In the case of E-ELT it is because the mirror would be too heavy and we do not have the technology to build it and in the case of JWT it is because you have to somehow get it into orbit.

Comparison of telescopes: By Cmglee – Own workiThe source code of this SVG is valid., CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=33613161

# Cassini + Huygens = Purpose of life

Hi,
today I will write about Cassini-Huygens spacecraft because lately there has been so much hype about its final destination (Saturn’s atmosphere).

Cassini was launched in 1997. Its flight towards Saturn itself was very interesting. The spacecraft did a flyby around Venus, two times, then did flyby around Earth.. if you have been paying attention in elementary school you might notice that this is a bit weird since Venus is closer to the Sun and one might one to rather fly in exactly opposite direction. Well first of all that would not neccesarily be the reason since the planets are not in a row all the time but the reason why one does not go directly towards the destination is that it takes high velocity to escape Sun. In all those flybys Cassini got few extra kilometers per second so that it was able to get to Saturn without extra fuel.

The probe made a flyby of Jupiter though at that time Galileo was already orbiting him. In 2004 it reached Saturn and succesfully started to orbit him. Throughout whole mission it did a lot of work of course, for example found new moons of Saturn, discovered water on the moon Enceladus, taught us about the nature of rings and much more. What I found most interesting though is the landing of Huygens spacecraft which was a part of Cassini until it landed on Titan. It was first ever landing on surface in outer solar system (only one so far), and brace yourselves.. it took pictures:

On the left you can actually see the surface. The lander was not functioning very long time, it had battery for 180 minutes and most of the time was spent in atmosphere.

Now Cassini’s mission is comming to an end. This is because it does not have much energy to power its instruments and there is risk that we would lost it completely and then it could fall on Enceladus for example and contaminate it. For that reason Cassini is taking very dangerous dives close to Saturn and its rings to provide some more info and in the end, it will burn up in the atmosphere of the giant planet.

Every single time it is possible that it will be destroyed by some piece of stone. Because of that it uses its antenna as protection but still, it is moving very quickly, so far it dived once, we will see how it goes in the future.

North pole, blue color is actually there.

Dragallur

Titan picture: By ESA/NASA/JPL/University of Arizona; processed by Andrey Pivovarov https://commons.wikimedia.org/w/index.php?curid=5685589

North pole picture: Credit: NASA/JPL-Caltech/Space Science Institute/Sophia Nasr

# Knowing the future, brain twist?

Hi,
two weeks back I wrote about the movie Arrival. I did not really get into the problems that arise when somebody knows the future, I will try to settle this today.

Alright, lets say that you just acquired the ability to know what will happen in the future. Cool huh?

First problem, do you have free will (meaning if you can choose to do something or there is no way to actually choose anything)? Lets start with the answer: yes, you have free will. Basically two things can happen, if you truly know what will happen then you can not choose any other option which means that by knowing the future you and everybody else will lose free will if you could choose something else than what the ability tells you then it would not be telling the future. Something else could happen though, you could know all the possibilities that arise from your decisions and the decisions of others. Funny would be if you would see it for the decisions of others, then the ability would be useless for longterm predictions where people all across the globe would interconnect with their decisions (do animals have free will, which ones do and which ones do not?). You could for example see that in 40 years there are couple (a lot) of lines that go to Third World War but there would be so many people involved in changing couple of important people that you could hardly do anything with it. At the same time if your brain would be organized in the mess you would immediately know what option you need to take to optimize whatever you want to optimize. Much easier would be if everybody else lost their free will and you alone had it.

The real fun begins if you consider no free will aka determinism. You know exactly what will happen but you can not change it. Imagine standing on cross roads, you know you will turn to left, its the future and you can not decide otherwise but there does not seem to be anything that would actually prevent you from turning right. If you do it, it means that the ability was telling you exactly that from the beginning but then you would turn left…

Lets consider thought experiment:

There is a robot that has very strict type of thinking. It is standing in a hall way that splits into two corridors, left and right (it is driving towards the left). Nothing miraculous can happen there, nothing that would prevent the robot to go where it is programmed to go.

You are at the headquarters and know where the robot will turn or simply what will happen there. You tell this information to the robot and the robot will turn exactly the other way. For example you know that he will turn left. You send him the information and he according to his program turns right which means that your ability is not working and this simply can not happen, you can not tell him the direction because he would do the opposite. What will you tell him? What is the future?

There is one more line of code in the robot: if you get the information “you did not decide”, you will turn left. This is to make it harder, the future would switching between left and right indefinitely, meaning the robot would not do anything and we do not want it. The only solution that I came up with is that he will actually not decide, you will send him the information: “You will start going left but when you will get this information you will turn right. After hearing this you will turn left but when you hear this information you will turn right again…” it will continue and then it depends how the robot is made. If it waits until the stream of information halts then it wont ever decide and you will speak to him forever. If it will take the information and while it processes the next part it will start to act accordingly to it (meaning the opposite way), the robot will slowly move towards left or right. At some point it will be on the threshold which raises a problem of course and I guess there is nothing stable to tell him without destroying the ability that you gained, you know what he will do but you can not tell him.

The last part would be the same scenario as if the robot could teleport from the beginning but if you have to say the information then it will result in a paradox. In normal non-robot life you would probably run into more complicated scenarios where knowing the future would not alternate you decision which is the whole problem we are dealing with. But if you would not and your ability would HAVE TO work then… ???

Dragallur

# Pareidolia

Hi,
today I will write about pareidolia a commonly seen phenomena. People often see familiar objects in completely random things, like rocks.

Clearly there is face in the upper middle part of the picture on the left. There is definitely sign of both eyes, of nose and mouth, thats more than one needs to recognise face in something, consider the following one on the right. Do you see the black thick circle filled with yellow color, two ellipses and curved line extended in the ends? Yeah me too.

The point is that humans are great in recognizing (most often faces) in things that are actually not them. The first picture is photo of region Cydonia which is a area on Mars. It was taken in 1976 by Viking 1 and of course people thought that it was proof for extraterrestrial life! Well if you take enough photos of Mars there is high probability that some of the rocks there will resemble primitive faces.

“I am the evidence of life on Earth, beware!”

Pareidolia does not happen only in images but also in sounds. For example there is a group of people who listen to so-called “ghost boxes” (sub category of ghost hunters). Ghost box is a box that is skimming quickly through radio channels. This creates lot of background noise and static noise with mix of what you can hear from the actual radio.. they say that the ghost can easily communicate through it.

Simplest explanation is of course that they just interpret extremely bad audio as some kind of words, plus if they listen for many hours they will eventually pop out something that will be an answer to your question, here is a link so you can consider for yourself, remember humans are great in interpreting random noise as actual words[1] (skip like 3 minutes for actual talk).

The story of the original Mars picture got stretched over many years. 2 decades after taking the picture, there was much better one taken by Mars Express as you can see below it was just the low resolution of Viking spacecraft.

There are many things that can trick us so it is not best to take the first explanation that we can think of, be sceptical and do not share if you do not know anything about it.

Dragallur

Smiley: By en:User:Mystìc – Originally created by en:User:Mystìc at en:Image:SNive.gif. Vectorized by Psiĥedelisto, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=55079042

# Rant against Arrival

Hi,
my fellow blogger (Jitka unfortunately writes in Czech) reviewed in her last post the movie Arrival. Since I saw it yesterday I decided that I will continue with my own thoughts.

The movie is about linguist who is offered the chance to communicate with aliens that just landed on Earth on 12 different locations. Her job is to learn how they speak and ask them what is their purpose here.. thats what the movie is about.

Now if you have not seen the movie, there will be spoilers:

First I will comment on what she said on her blog:

So in the movie the aliens apparently know the future, now this puts into question ones free will of course but I do not think we have it anyway so yes, they simply know what will happen. Why do they send 12 vessels and not only one where Louisa would learn the language (which is the whole point of their Arrival). Well they needed the conflict to happen in more countries, how could she save general Shang from China if he was not going to attack? There would be a lot of differences in the story and who knows what would happen. If you know the future and you want it to happen again you will do exactly the same things and not risk small changes, yes you will act accordingly even to small details because of butterfly effect.

Now lets return to the problem of free will here. If you actually had a free will and knew the future you would have to know the future of all your decisions and combination of these decisions with other people’s decision, that would certainly be mess. Then you would choose the decision line that fits you best and would go with it… which also means that you would probably know what you will choose from the beginning, huh..

Then there is this theoretical physicist, alright his being there was completely random. Actually I think that he was there only to say the dumbest line ever in the beginning of the movie when Louisa and he (Ian) were in the helicopter and he was citing her work. It went something like “language is the cornerstone of civilisation” and he said that it is wrong that the cornerstone is science. Aha, ok really? Science would not even exist without language not speaking about the fact that if you do not learn language your mind capability is extremely reduced.. I am not saying that language is cornerstone of civilisation either, I am not really sure about it.

Jitka mentiones the idea of the heptods (aliens) to communicate via smells, that sounds interesting but I think that for animals (as we know them) it is much better to communicate with sound. This simply because sound is more reliable. If you are animal it is a matter of seconds before you and your family gets eaten and you move all the time. When monkey screams on the rest of the tribe to get away they will know it immediately, but if the monkey lets out some aggresive smell it might take minutes before it reaches the right destination.

I guess one of the aliens let himself be blasted away because he knew it was necessary for the future, though I would doubt they would have such a bad glass that would not be able to withstand the explosion.

Oh and it does not make sense how Louisa persuaded the general Shang, she only recited what his wife told him that would not probably impress him so much, there would also be pressure from other people and why would Russia and Saudi Arabia stop so suddenly?

Louisa starts to teach the language, that seems dangerous because anybody can then probably access memories from the future.. ouch, that could cause some problems. At the same time the future that she sees is not really a future since she speaks with general Shang without knowing the phone number but then in the future it can not happen since she knows it already.

Overall it was not very good movie. The amount of time left was decreasing lineary but the same was with thrill in the movie, which finally led me into seeing it whole, sadly.

Dragallur

# Book review 14) Grimms’ Fairy Tales

Hi,
so apparently I have to read lot of books for my school in Czech Republic. Just about a week back I finished Grimms’ Fairy Tales. They do not really have much to do with science but here you go, next week something different.

### Grimms’ Fairy Tales

Grimms’ Fairy Tales (GFT) are collected tales by Wilhelm and Jacob Grimm. For the first time they were published in 1812 and in the next editions more and more tales were added. In 1857 GFT included 211 tales. Thats helluva of stories. In the internet version that I read was only 62 and it was not very short book.

The stories repeat in a way. Kingdoms with princesses and princes. Dwarfs are usually bad. Maidens are beautiful, foxes are smart (except the one where fox dies), people want to kill their pets (Bremen Musicians and others), random forms of magic, dumb people are lucky, step mothers are nasty wenches and on and on.. the themes are simply quite similar.

In the case you think that all of them are happy and tell a tale like Hansel and Gretel or Ashputtel.. no way. Lot of them are quite brutal and throughout the editions they somewhat changed. For example in Hansel and Gretel it was their own mother who wanted to kill them and not their step-mother.. then there is this tale where the step-mother kills her son and mixes him in pudding, I am not kidding.

The Straw, The Coal and The Bean

That one is extremely random tale. Some woman wants to cook and one straw, coal and bean escape. They decide to go together and then they have to cross a stream. Straw lays itself across and the coal starts to walk over it. It is still hot though so both of them fall into the stream and die, the bean starts to laugh and bursts out. Luckily tailor walks around and sewes the bean together … thats why beans have black seams.

Overall because of fairy tales like these, it was great book, nice for relaxation. Bit too long, I would not be able to read 211 of those since as I said, they repeated in the main points.

Dragallur

Picture source: Public Domain, https://commons.wikimedia.org/w/index.php?curid=471797

Hi,
today I will write about passwords and their security. Mostly I want to explain what “hashing” means in this context. Its certainly important issue considering that for example last year in May there were 164 million passwords from LinkedIn offered for sale.

This means that when you create your account instead of storing the password which could be simply stolen away, the website will run the string through one-way function that will put out some long combination of various letters and numbers, unrecognizable from the original password.

One-way function means that you can not take the nonsense, put it into the function other way around and get the password out, one-way function may for example lose some of the original information so that the process is not reversible.

Now on the server is only saved hash of the password[1] but even that is not enough to be quite secure. The thing is that there are only several commonly used hashing functions and crackers (correct term for hacker) can still break it…

What crackers can own is called rainbow table. That is huge (in terms of gigabytes easily) table of hashes. These hashes were made from random letters or from combination of words from dictionaries. When somebody cracks the database of some website and get hands on all those saved hashes they will start to compare them in huge amounts with their rainbow table. The hash functions always create the same string from the same password so the cracker only needs to have these rainbow tables for couple of most used hash functions.

This is of course why it helps from the side of the user to have long and random password, one can not have everything on the rainbow table because of its size and it takes a long time to compate a lot of hashes.

For extra protection most pages also “salt” hashes. That means that after your password they add some random characters and makes a stronger hash with it. Every password has to have original long salt. With the salt it does not matter if it is known or not because cracker can not precompute rainbow tables for all the possible strings and the technique will become unusable.

Sites might also add time that it takes to log into account, not noticable for user but catastrophic for cracker. For example if user has to use CAPTCHA or if simply you use hash function that takes longer time to go through, you will be way more secure from brute force attacks attacks which are cracking hashes one by one simply by trying random strings.[2]

Dragallur

[1]When you log in the password that you entered will be hashed again and compared to the hash that is already saved in the database.

[2]On the other hand you might me more fragile against attacks that try to make your site overloaded.

Source

# Vacuum decay and Trump

Hi,
today I want to do a fun post inspired by a meme that I saw some weeks ago on Theoretical Physics Memes. Well here it is:

If you dont understand the joke, its alright, I will explain. If you do understand the joke you can continue reading for the sake of… reading?

Disclaimer: I have not been using disclaimers before but the truth is I am no physicist so I do not claim to actually comprehend this stuff.

So vacuum decay or also false vacuum is the idea that you could die any second. (See I am no physicist)

Basically fields (meaning electromagnetic and other types) want to get into the lowest energy state possible. Also electrons rather like lower energy states to be more stable so, if they have more than they “need”, they will radiate it away in form of photons. Now it is assumed that these fields are either in stable position (lowest energy level) or they might be in metastable position[1], which means that there is energy barrier between the metastable level and stable, if it is “reached over” and the field drops into lower stable or again metastable level it will release energy.

If we were in false vacuum[2] we would just need to reach over the hill to get to true one.

Since particles arise from these fields some new types would appear and Universe in this place would look a bit different inside. The reason why this is connected to the discovery of Higgs Boson is that the mass that it has indicates that we may live in false vacuum, if our physics is right than we could die any moment since the false vacuum is expanding almost at the speed of light.. means we can not know if it is coming on us or not, which also means that you do not need to worry really.

Now you understand the joke though if you are Trump supporter than you do not find it very funny in which case I pity you because it is great joke 😉 [3]

Dragallur

Pic. source: By User:Stannered – Adapted from en:Image:Falsevacuum.png, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=1711800

Post source mostly.

[1]They can also be in unstable position but not for long.
[2]The name false vacuum has nothing to do with the vacuum of space.
[3]Proper explanation: it is so bad that Trump is elected, I hope that Universe will end soon, oh hmm.. what is the probability of it happening?

# SpaceX meets Moon (soon)

Hi,
private space company SpaceX aka Elon Musk decided to visit make a flyby around Moon in 2018.

Where to start? Well it probably began with two private citizens who were willing to pay many MANY millions of dollars to get a nice trip. Yes, space tourism, exactly.

This trip is planned to be done with Falcon Heavy which is rocket (not build yet) designed by SpaceX and is supposed to have 2/3 of thrust of Saturn V (the rocket that got Apollo to Moon). The crew will stay for about 8 days in Dragov v2 (v standing for version) capsule that is also not tested yet. Both of these things are supposed to be run later this year.

Dragon V2 in hover test [1]

The crew are definitely some rich people but as of now they are staying anonymous. At the end of this year they are supposed to start some training but otherwise the mission will be automated so they wont have to do much stuff.. also that means that they wont do much science either.. only some tests on their bodies but otherwise it really is only “sightseeing” trip.

Why this whole thing though? Well it will add lot of publicity and earn some money and it is place to test Falcon Heavy and D2 capsule[2]. The last time people went to the Moon was in 1972 and this mission is quite similar to Apollo 8 which was also such a flyby.

Otherwise we do not really know much details, SpaceX will have to do a lot to be able to accomplish this goal and right now it is behind schedule.. there were some rocket explosions which slowed the company down. We will see how it looks like in the upcoming months.

Dragallur

[1]When the rocket starts to explode and there are people on board, you need to be able to escape really fast. The capsule was not tested on rocket yet.

[2]Also if part of it is payed by somebody else.. well why refuse?

Picture source: By SpaceX Photos – Dragon 2 hover test, CC0, https://commons.wikimedia.org/w/index.php?curid=46531492