/sci/ - Science & Math

Ice sun melts before collission.

It would depend on the composition of the ice and the temperature. Is the ice supposed to be at absolute zero?

We're waiting for the results which would demonstrate whether a sun made of ice would necessarily be ice-IX or not.

>Implying that a sun made of Ice wouldn't start fusion.

As
>>4707786
said, I would like to know more info.
We can't say much without knowing certain stuff.


Are the suns of the same size?
Are they moving at the same speed?
Do they have an equal mass?
What is their temperature?
What movement do they describe?

>>4707800
OP here.

Can't we just solve for the general case and then look at special cases?

It would depend on the combined momentum of both objects before collision. If the collision is nice and slow, a certain percentage of the ice sun would evaporate before the collision, altering the effect. If the collision is very quick, then the ice may not have as much time, altering the effect in a different way.

tl;dr : How fast is the collision?

>>4707809
But my case is the general case.
We need aproximate information.

What you provided is like saying a car made of fire and a car made of ice collide.

????

No profit.

there are way to many unknowns to make an educated guess. do you even lift?

Okay let's say they move at 0.999.. c in straight motion while spinning and the ice sun is -1000 K, the lava sun +1000 K.

>>4707809
We can simplify things by assuming the sun are the same size, and that they have an equal density (even if this is impossible), but we still need info on the speed and nature of collision before we can get anywhere

These objects can't exist. They'd collapse under their own weight and become stars, so the collision would just work out like a collision between two small-to-medium sized stars.

Nice touch with the lecture story though, that was cute.

>>4707823
> do you even lift?

Wtf

>>4707841
>mfw -1000K


what the fuck is going on in this thread

why exactly is there a star made of lava and not hydrogen?

>>4707859
I thought they were already stars?
Do you mean neutron stars/black holes?
Also, both probably could exist.

>>4707861

th...thanks

>>4707861
fat as fatass detected

u bothered?

>>4707875
I don't think the ice one could exists.

A body of such size made entirely of ice, wouldn't have enough mass to create a gravity field, it doesn't produce light.
I don't think it even fits the description of star, but rather celestial body.

>>4707889

he jangled

>>4707886
Point taken. :)

>>4707875
There's no such thing as a 'sun made of ice'. The word sun is defined as a body large enough to undergo nuclear fusion, and if there's nuclear fusion, there won't be any ice left. What you could do is asume a body of ice the size of the sun spontaneously popping into existence, collapsing etc.

>>4707907
well we're kind of past that but the point OP is trying to make is that is it calculable. which is a resounding yes, only the way its presented is a trick question

>>4707896

>>>4707861

>>4707875

A celestial object made of ice the size of a star can't exist.

God the gullable in this thread

>>4707907
>>4707921
I refer you to
>>4707904

>>4707921
looks like they really did take the word gullible out the dictionary

I already solved this problem 2 weeks ago.

I assumed that the stars are initially binary systems, treated them as point particles, and ignored tidal and general relativistic effects on their orbits. I then used the N-code (Aarseth 1999) and corresponding computational methods to get an answer. I had to make some assumption, sure, but the answer was reasonable.

Ice + Lava is like saying:

H₂O(s) + ΔH

and


H₂O(s) + ΔH -> H₂O(g)

so, a sun made of ice plus a sun made of lava obviously makes a sun made of steam

>>4707841
When temperature goes below absolute zero, an object becomes incredibly hot.

>>4707940

Or not, depending on the speed of the collision

>>4707947

Troll detected.

>>4707947
Excuse me, sir.
What?

>>4707861
obviously not

also what is it with meatheads posting all over /sci/?

>>4707940
There would be a lot of leftover hydrogen. So so much leftover hydrogen from the hot sun.

Our sun isn't made of lava, it's made of photons and with every photon that gets emitted, the sun loses mass. One day the sun will have lost all of its mass.

>>4707993
>photons have no mass

Highschooler detected. You probably never heard of E=MC2

>>4707989
photons have no mass though so the sun can create infinite photons and go on for ever

>>4707989
Are you fucking retarded? It's made of hydrogen

>>4707994
Hydrogen has no mass and it gets converted into photons because the sun is hot.

>>4707951
This is correct, though I simplified the explanation. Look up the concept of negative temperature. You can start with Wikipedia.

>>4708000
>implying there's any hydrogen left in the sun
if there was there'd be dark spots on it where there are no photons

>This whole thread

>>4707989

>Thinks the sun is made out of photons.

O God, my sides

>>4708000
If the sn made of ice is at -10^10000 ºK, then we cam start to discuss

>>4708000
>hydrogen has no mass

>>4707998
No, he's right. Photon's don't have mass. Photons are mass that have been converted into energy, but hold no mass themselves.

>>4707954
I also copied the relevant paragraph from Wikipedia:

>A system with a truly negative temperature is not colder than absolute zero; in fact, temperatures colder than absolute zero are impossible by definition. Rather, a system with a truly negative Kelvin temperature is hotter than any system with a positive temperature (in the sense that if a negative-temperature system and a positive-temperature system come in contact, heat will flow from the negative- to the positive-temperature system).

You can find more from other sources. It's pretty interesting.

>>4708009
if hydrogen had mass then hydrogen balloons would sink

>>4708017

Photons have no rest mass. They do however have relativistic mass.

>>4708012
Hey lad, if the sun's gravity comsume atoms or subatomic particles, why the sun don't suck we all up? Do you think you're smart? Answer this one then

Me: 1
Anon: 0

>>4708018
Thanks. And sorry for calling you a troll.

>>4708018
This has awoken my interest.
Thanks, will do some research into the matter. I'm not much into this kind of things and only know the basics.

We're actually talking of the heatflow moving from a colder body to a hotter body, but the cold body is so cold that it actually heats?

Don't know if I explained myself good there.

>>4708028
if photons have mass why do we see colour then?

>>4708037
qualia

Apparently I saved my previous work:

The volume of the sun is 1.4E27 cubic meters. The density of ice is 917 kg/m3. Therefore the mass of an "ice sun" would be 1.3E30 kg. The mass of our sun is 2.0E30 kg. The mass of a sun made out of lava would be 3.6E30 kg, which is heavier than our sun.

The mass required for transformation into a star is 80 Jupiter masses. This is 80*1.8986E27 kg or 1.5E29 kg. Both of these "suns" have the mass to become stars and sustain fusion. Therefore, they will cease to be suns made of ice or lava. In reality, you'd need a substantial amount of hydrogen for star formation to occur and this might not be possible with lava, but for all intents and purposes we can say that purely on a mass basis, you'd get two stars.

Using the N-code (Aarseth 1999) on my not-so-powerful laptop, I calculate that at velocities below 750 km/s the stars would coalesce. At higher velocities the lava star would destroy the ice star, but be severely damaged in the process. Obviously I'm not going to use university resources for this problem, so my laptop might be a little bit off.

>This calculation uses the assumptions I stated earlier.

>>4708038
but colour photons would destroy the iris so that's irrelevant

>>4708037

The fuck? Fact is they have mass when they are traveling at the speed oof light.

l2 relativity

>>4708020
no. you...youre trolling

>>4708037
2/10

Some trolling effort, but otherwise poor. Gets an extra 2 marks for prompting a response.

>>4708045
exactly.

No, not exactly. Light moves slower when passing through a medium, and our atmosphere counts as a medium.

>>4708043

>>4708066
But our athmosphere doesn't slow it down enough for it to be noticeable or accountable.
It's almost negligible.

>>4708066

Light doesn't actually move slower when passing through a medium, it travels from 1 point to another slower, because of the absorption and re-emission through any said medium might take longer. But its velocity is always constant.

>>4708072
is it enough to reduce their mass enough to prevent blinding?

>>4708076
Dude, leave it already.

>>4708076
Yeah, it is.

>>4708082
sorry i hope i didnt upset you ill go now have a good day bye

For all those saying that a photon doesn't have mass.
It's semantics.

http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/photon_mass.html

>>4708090
No, no I'm not upset.
It's just that this whole thing is getting me tired.

>>4708094
k

>>4708035
Not exactly. The idea is that nothing is "colder" than absolute zero, where "hot" and "cold" can be defined as the average kinetic energy of the atoms/molecules. Interestingly, you could theoretically walk into a room at 1 trillion degrees wearing a spacesuit and be unharmed provided that room contains one single atom with an incredibly high kinetic energy, thus giving it that 1 trillion degree temperature. At absolute zero, atoms don't have kinetic energy and you can have less kinetic energy than zero.

What Wikipedia is saying, is that at negative temperature, the atoms have kinetic energy...lots of kinetic energy. Therefore, they are not "cold", or colder than absolute zero. In fact, an atom with a slightly negative temperature on the Kelvin scale is hotter than infinite temperature on the positive kelvin scale.

For example, an atom at positive 100 trillion degrees Kelvin is colder than an atom at negative 5 degrees Kelvin. However, an atom at negative 100 trillion degrees K is colder than that same atom at negative 5 degrees K. It's strange, I know!

>>4708035
Not exactly. The idea is that nothing is "colder" than absolute zero, where "hot" and "cold" can be defined as the average kinetic energy of the atoms/molecules. Interestingly, you could theoretically walk into a room at 1 trillion degrees wearing a spacesuit and be unharmed provided that room contains one single atom with an incredibly high kinetic energy, thus giving it that 1 trillion degree temperature. At absolute zero, atoms don't have kinetic energy and you cannot have less kinetic energy than zero. So at least that is intuitive, right?

What Wikipedia is saying, is that at negative temperature, the atoms have kinetic energy...lots of kinetic energy. Therefore, they are not "cold", or colder than absolute zero. In fact, an atom with a slightly negative temperature on the Kelvin scale is hotter than infinite temperature on the positive kelvin scale.

For example, an atom at positive 100 trillion degrees Kelvin is colder than an atom at negative 5 degrees Kelvin. However, an atom at negative 100 trillion degrees K is colder than that same atom at negative 5 degrees K. It's strange, I know!

A sun-sized object made of something as dense as molten rock would fall within it's own Schwarzschild radius, becoming a black hole. A collision between anything and a black hole has only one outcome.

>>4708164
I feel forced to say that my mind is blown.

I do understand that it's like a limit, whereas there is no thermal energy but only kinetick energy.
Does this mean that a body with a temperature under the absolute zero can not be completely stopped?
Would it transfer it's negative energy then?
What would happen then, extreme heat or freezing? If the temperature is negative and it has a tendency to positive, it should first freeze, shouldn't it?

Wow, this is actually impressive.

>>4708190
Now you're getting into an even more complicated area. Temperature, as I said before can be defined as the average kinetic energy of the atoms in a given volume. By this definition, however, negative temperature is impossible. This is because there is no upper bound on positive temperature. In other words you can go from a million degrees, to a billion, to a trillion, and so forth. Therefore there will be no transition from positive to negative infinity.

However, as the article says, temperature can be defined by statistical mechanics as well. When there are more particles in a higher energy state than in a low energy state in a local system (think laser), then the temperature is statistically defined as being negative. Unfortunately, I don't research lasers and my knowledge doesn't extend too far past this. For example, I can't give you the "why" in this paragraph.

Temperature can be interesting though. Here's another fun problem. Imagine you have an ocean filled with pure, distilled H2O. Now imagine that you are at a deep point, say, 5000 meters. It could be 3000, or 8000, the number really isn't important so long as it's deep. What is the temperature at that point in the ocean (of pure water, remember)? No equations are necessary.

>>4708243
The temperature would be zero, right?

>>4708257
It would be 4 degrees Celsius, actually. There is immense pressure at great depths, and water is slightly compressible. Water is at its densest form at 4 degrees, and to be above or below that temperature would cause an expansion of the liquid volume. Expansion is impossible at such high pressures, so the water stays at 4 degrees.

If it were salt water, then the answer would be 0 degrees.

>>4708270
Thanks for the info.
Sadly I'm not into chemistry but rather technology, and some of this things are pretty old and rusty to me.

You're being helpful, anyways, now I'm going to leave, it's 1:20 Am and tomorrow I gotta work.

>>4708287
No problem, have a god night