Bufofrog

Then I recommend that you drink more water.

1 minute ago, dimreepr said:

I can't believe I have to explain further, what would you deduce from >< % x?

I can't believe you think it would be so difficult.  So I guess we will just have to disagree.

55 minutes ago, dimreepr said:

What if their symbol + actually meant - etc... how common could the languge be?

Then if they send a message saying 2-2=4 then we would deduce that their '-' sign is our '+' sign.  It really would be relatively easy for us to communicate mathematical ideas.  It certainly would take a long time especially if they are like 40 ly away but it would be amazing.

4 hours ago, Moontanman said:

Unless you are thinking of instantaneous communication this is not true. Travel takes a finite amount of time, you could not travel back to a time at your launch site before you launched.

I of course said nothing of the sort.  What I said is that faster than light travel can result in a violation of causality.  It is a simple matter for you to google this idea to read for yourself why this is true.  There is no need to argue with me about it because it is not my idea.  This is the view of mainstream physics and a consequence of relativity.  You can choose to not believe it if you like.

10 hours ago, Moontanman said:

The warp bubble isolates you from the rest of the universe while its on. Of course that makes steering a bit of thrill!

And when the warp bubble (or whatever) turns off then you have traveled faster than light so it is possible to violate causality, so the problem remains.

23 minutes ago, Moontanman said:

If I understand the current crop of FTL warp drives that are being proposed the spacecraft is causally isolated from the rest of the universe and this stops the time travel aspects.

How could that be done?

I start from the premise that FTL propulsion is impossible.  

The first reason is relativity.

The second more important reason is that FTL travel can violate causality.  The universe is very stubborn about some things.  For instance the universe will not allow you to know your absolute velocity.

I think causality is another thing that the universe is stubborn about.  I don't think any potential technology that could violate causality would actually work.

2 hours ago, Sensei said:

..you're right.. I just put the equation to the Google calculator:

https://www.google.com/search?q=299792458%2F+400*10^-9

but it should be:

https://www.google.com/search?q=299792458%2F(400*10^-9)

or

https://www.google.com/search?q=299792458%2F+400e-9

I could easily be just loosing my mind but isn't the equation this:

= c ∆t / λ = 299792458 m/s X 1sec / 400*10^-9 m = 299792458 m / 400*10^-9 m = 74,931,145,000,000?

400 nm X  (10^-9 m/1 nm) = 400 x 10^-9 m

3 hours ago, lidal said:

Go to the formula for the fringe shift, n :

               n = ( ∆λ₁  -  ∆λ₂ )/ λ

where ∆λ₁ and ∆λ₁ are the difference in path lengths of the two beams for two absolute velocities.

I asked you for a source for N  = c ∆t / λ, so are you saying ( ∆λ₁  -  ∆λ₂ )/ λ = c ∆t / λ?

9 minutes ago, Sensei said:

N = 299792458 m/s * 1s / 400*10^-9 m = 0.00074948114

I think you made a math error, you're dividing by 10^-9.

15 minutes ago, lidal said:

You may read " Michelson-Morley experiment", Wikipedia

That didn't help, I could not find that equation in the article

46 minutes ago, dimreepr said:

Why would you believe that?

Because we both are intelligent and we have a common language, mathematics.

2 hours ago, lidal said:

N  = c ∆t / λ

Could you give a source for that equation?   N = 7.5 x 10^14 for a time of 1 sec.  I don't really know what that is supposed to tell me.  Thanks

31 minutes ago, dimreepr said:

To them (and us) they wouldn't know the difference, it would be like trying to have a conversation with an ant; not because they/us are better, but because such a conversation would be impossible to comprehend, for both...

I don't agree, I believe that communication with an alien would be rather easy.  Communication with ants is difficult because ants don't have anything to say, they're ants.  

2 hours ago, Funghiarrosto said:

Thank you very much for your answer! I still do not understand why I need to refer to 150ml ethanol though.. the alcohol I'm using is not pure, so why shouldn't I use 215mL of ethanol 70%, which is the equivalent of 150mL at 100% purity?

You certainly can, I just think it is easier to find densities of pure substances in general.

2 hours ago, Funghiarrosto said:

as for number 2), what I did was taking 1part of solution and added 9 parts diluent, not 10. So 1 part solute + 9 parts solvant = 10 parts in total which is the whole solution. In the end I'll have 1part solute : 10parts solution (1part solute + 9parts solvant). Is it wrong??

That's right.

C1V1 = C2V2.  

47 minutes ago, Funghiarrosto said:

500mL – 215mL (alcohol) = 285mL of water.

Looks right to me.  The easiest way to calculate it is to use this equation C1 X V1 = C2 X V2.

47 minutes ago, Funghiarrosto said:

Molecular weight: 2(12,001g/mol) + 6(1,0079g/mol) + 15,9994g/mol = 46,046g/mol.

Density of ethyl alcohol with 70% purity: 885,56kg/m3 = 0,88556g/cm3. (found this online)

Mass (g) = Volume (mL) x Density (g/cm3)

Mass = 215mL x 0,88556g/cm3 = 190,40g (total weight of ethyl alcohol in the aqueous solution)

That doesn't seem right.

How about this...

500ml solution X .3 ethyl alcohol = 150 ml ethyl alcohol (100% pure).

50 minutes ago, Lan Todak said:

I would like to publish my idea.

Go ahead and present your idea, it will published here for all to read and it won't cost you anything.

26 minutes ago, NTuft said:

No, kinetic energy is... let's say a function of momentum, a vector quantity.

Just to be clear to Capiert, that does not mean KE is a vector, it isn't.

I think that handguns and semiautomatic guns should be banned.  I know that is unfair for all of the responsible people who have a hobby of collecting and shooting guns, but life isn't particularly fair.  The realization that in many states in the USA if you are in a bar having a drink there are probably several people in that bar that are armed with hand guns is unsettling.

10 hours ago, Willem F Esterhuyse said:

I have seen a mathematical definition of consciousness somewhere online.

Are you sure?

10 hours ago, Willem F Esterhuyse said:

Although I can't criticize it.

Sure you can.

3 hours ago, Capiert said:

Please explain that problem.

The KE equation you wrote would mean that an object moving at a constant speed would have zero KE.  That is incorrect, hence the equation is incorrect.

31 minutes ago, Capiert said:

KE=m*(v_f²-v_i²)/2.

It looks like you are saying an object moving at a constant velocity has zero KE, since v_{f =} v_i   

That's a problem. 

13 hours ago, ScienceNostalgia101 said:

I'm picturing a triangular prism, at least as wide as a hurricane, (angled to it to force upslope flow) meaning at least 5 surfaces, at least 3 of which would be hundreds of kilometres wide, with some means to securely and airtightly connect the surfaces after they are formed. Perhaps aluminum, with the sides smelted together?

And it would need to be maybe 1000 meters high?  This would be insanely expensive and probably impossible to build with todays technology.  

I think the answer, if we assume God was created, would the in the mind of people or God's mom and dad.

What's SP?  

1 hour ago, Danijel Gorupec said:

If I choose a galaxy near the edge of the observable universe, and I send a ray of light toward this galaxy, will the light ever reach the galaxy?

No.  

2 hours ago, Heizen said:

This is probably a totaly crazy idea and probably has a pluthora of problems.

Agreed.