dantodd

dantodd t1_j64pyzi wrote

What an awesome and insightful question.

Yes, and no.

Let's make a few assumptions. First. Let's assume that both planets are aware of each other and have tech's assumed at each other. Second let's assume that the communication is instantaneous to take out the math issues. Third, only one planet can transmit the messages but the other can recurve them. Finally, assume I'm a random stranger on the Internet and I don't have a PhD in physics.

Both planets are looking at each other and they are seeing photons that bounced off the other planet 4 years in the past. (i.e. they are 4 light years apart) If one planet transmits this instantaneous signal the planet that received the signal will see it as coming from the future because it was transmitted 4 years before the images they are recording on their telescope. So, if they could see the transmitter being built they might see it still under construction for four years after they get the first transmissions.

To the planet transmitting the signal they would get feedback via light speed communications or actual light images in only 4 years rather than the anticipated 8 with communications limited by the speed of light. I think this would look like time dilation rather than time travel to the planet transmitting.

It is not dissimilar to shooting something at long range. If you are the shooter you hear the gun fire and then see the target get hit. If you are standing near the target you see the target react to getting hit long before you hear the gun shot. So, which order you perceive things happening depends on where you are. Of course we are used to the difference in asked between sounds and light so it seems natural but it takes a bit more to shift ourc thinking you you're question

1

dantodd OP t1_j2ebuif wrote

>Go out to where? It's gong to have to overcome the pressure of the physical bottle, which is going to be way over 1. The gas will go into the bottle. The squeezed bottle will just be filled with CO2 to the point of deforming until it either reaches the equilibrium pressure. Of course if you remove almost all the air the CO2 will escape the soda but the pressure in the bottle will not go over one atmosphere so you have perfectly flat soda.

>Let's use the example of a metal bottle, how does a drink go flat in a metal bottle without any air in it? You don't even need a metal bottle, just use a normal unopened bottle, how does a normal bottle of coke go flat? It doesn't since there is only a tiny amount of air for the CO2 to go into.

The CO2 doesn't go "into the air" it goes "out of the soda" which may seem a small difference but it is the gas pressure in the bottle that keeps the CO2 dissolved and this the soda carbonated. If you placed that in an open vacuum with no air at all it would go flat even faster because of the pressure differentiall. (There is less pressure holding the gas in solution) the CO2 will continue to leave the soda until the gas itself builds up enough pressure to hold what's left in solution. If there is a lot of air in the bottle it will take less CO2 to build up that pressure. If you remove the air it will take more CO2 to build up that pressure. Squeezing a bottle didn't reduce its volume, only the volume of air inside that must be filled by CO2 if it is ever going to reach equilibrium pressure. If you squeeze a bottle from the store before opening it you will know how much pressure it takes to keep CO2 in solution for "full carbonation" there is no way for a bottle with the air evacuated will resist anything close to that much pressure so as the CO2 is released the bottle will start expanding to accept the CO2 but there is not enough CO2 to replace all the air quizzes out do the dogs hours flat long before at reaches equilibrium pressure.

0

dantodd OP t1_j2e5rpg wrote

Of course. Soda is carbonated by dissolving carbon dioxide gas into the base drink. You can dissolve other gases into liquid too. For example nitrogen dissolved into a liquid is pretty common and they call it "nitro" which is where a nitro stout beer and nitro coffee get their names from. In fact, I just saw nitro Pepsi on the shelf the other day for the first time.

So, now we have a gas dissolved into our liquid. As the gas escapes the solution it comes out in the form of bubbles. And what we are trying to prevent is all the bubbles escaping from the soda left over in the bottle..

In order to prevent the gas escaping you want to apply pressure to the liquid. You can imagine it like the high pressure prevents the bubbles from growing larger and coming out of the solution.

You can see this every day in a plastic soda bottle. When all the CO2 is in solution the bottle is very hard. If you open a bottle and then pour out half the bottle and put it in a large cup in the counter and then tightly reseal the bottle. After a few hours the bottle will be very hard and the suits inside will still be carbonated but the soda you poured out will be flat, the gas will have mostly escaped. The same volume but one under pressure container in the bottle but the other open to just atmospheric pressure.

This is because the CO2 in the bottle begins to come out of solution just like the open cup but the bottle holds in the gas that does escape so high pressure builds again and prevents the rest of the by gas from coming out of solution which means your soda is still carbonated though at a slightly lower level than a new bottle.

(In brewing beer is often carbonated simply by pressurizing containers of flat beer with CO2 and the high pressure will force CO2 into solution thus carbonating the beer. )

If you squeeze all the air out of the 2 litter bottle all you are doing is removing air from the bottle. The gas still inside the soda is going to continue coming out of solution until it reaches equilibrium with the pressure in the bottle but a lot more gas will have to come out before that happens because there is less air inside the bottle to begin with.

0

dantodd OP t1_j2agt17 wrote

Why would you assume that someone who lacks the logical ability to understand partial pressure is blue collar? I suspect the person with the bias here is you. Ignorance is nothing to be ashamed of but willfully refusing the learn.... there the problem.

In fact, the person who inspired this has a college degree and a white collar job that requires a relatively high degree of both interpersonal communication skills and more than basic math and business accounting skills. In fact, I suspect, though do not know for certain, that he has attended business school and may even have obtained an MBA.

−3