Ask any question you want about Physics

a reply to: BASSPLYR
That site is probably correct because that's about what I'd expect. The great lakes are pretty big by the way.

originally posted by: dragonridr
Now Fresh water has a density of 1.0 while salt water has a density of 1.025. Meaning to a boat they don't see the difference. Boyancy levels on boats are by design the 1/2 in the boat sets higher on fresh water won't make a difference.

Well there's a difference but it may not have a significant effect. It might be along the lines of the tides in ponds question, where there might be theoretical differences but they aren't significant. I test drove my boat in brackish water and then operated it in a freshwater lake and at maximum throttle I saw no difference in speed, but the speedometer wasn't accurate enough to tell if there was a tiny difference in speed. Even if I'd had a more accurate speedometer, it wasn't a very carefully controlled test, such that differences in wind speed/direction could have overwhelmed the effects of salt content.

originally posted by: BASSPLYR
a reply to: Arbitrageur

found an answer for the lake/pond tide thing on some meteorological site.

apparently lakes and ponds do have tides. however they are so small and inconsequential that they are concidered non-tidal. barometric and wind pressures will cause greater changes/fluctuations in the water height. for instance the strongest tide for the great lakes a is 5 centimeter change in height.

The answer is no we could never see it. tthe Big Bang happened 13.7 billion years ago.. At the very beginning of the Universe, seconds after the Big Bang, everything was mushed together. Energy and matter were the same thing.It took 380000 years the for the universe to cool off enough for photons to escape,, also when atoms started to form. This is the point we should see all the light that escaped. But we can't because the region of space where it exists is so far away, and travelling away from us so quickly. The light’s wavelengths have been stretched out to the point that light has been turned into microwaves. Want to see the early universe look at cosmic microwave background radiation. But even that won't see the big bang as I said earlier.

a reply to: Arbitrageur

Have to work on my "psychics speak"
. Use I see and future much more.

a reply to: Arbitrageur

Hi Arbitrageur,

Thanks for your reply.

So, with regard to my Big Bang theory question, does Physics suggest that the inflation to the current size of the universe was instantaneous? I think my question came about because i've always wondered if matter is moving about randomly in space or if there is some sort of large scale pattern to their movement, such as away from a point. Perhaps the term "Big Bang" itself conjures up an inappropriate mental image!

My EM spectrum question came about 'cos I once read somewhere that the spectrum itself is theoretically infinite, which to my particularly non-physics brain suggests there is something beyond the extremes at which we can physically measure.

originally posted by: AdmiralTriceratops
So, with regard to my Big Bang theory question, does Physics suggest that the inflation to the current size of the universe was instantaneous?

No. The most popular model suggests that inflation was very fast right after the big bang, then it slowed down, and then it sped up due to dark energy. At 6 minutes in this video George Smoot shows and explains a graphic illustration showing how we think it happened and he explains some of the research leading to these conclusions:

George Smoot-Design of the Universe

There's a low resolution version on youtube but there's a lot of detail in the high resolution video that it helps to be able to see.

originally posted by: dragonridr
The answer is no we could never see it. tthe Big Bang happened 13.7 billion years ago.. At the very beginning of the Universe, seconds after the Big Bang, everything was mushed together. Energy and matter were the same thing.It took 380000 years the for the universe to cool off .......

So energy and matter were the same thing...in effect one single thing...so why bother turn into 2 things ?
Also if the universe cooled, what took that energy and to where ? For one thing to cool, it's heat must be absorbed by something else.
edit: if you're gonna say it cooled because of expansion...then what is it expanding into...this unknown space that keeps creating itself to allow the universe to expand into it....kinda seems to have a property specific to a god like entity on the outside of the universe, god like entity in the sense that it might actually be some ''universe containment device'' that truly controls and contains this universe and we might not ever ever be able to interact with it...it is in effect untouchable.
Where else could this self creating space come from if not from some form on universe containment device ?

originally posted by: Choice777
edit: if you're gonna say it cooled because of expansion...then what is it expanding into...

That's probably one of the most frequently asked questions, and the standard answer from Ned Wright's cosmology faq is:

What is the Universe Expanding Into?

This question is based on the ever popular misconception that the Universe is some curved object embedded in a higher dimensional space, and that the Universe is expanding into this space. This misconception is probably fostered by the balloon analogy which shows a 2-D spherical model of the Universe expanding in a 3-D space. While it is possible to think of the Universe this way, it is not necessary, and there is nothing whatsoever that we have measured or can measure that will show us anything about the larger space. Everything that we measure is within the Universe, and we see no edge or boundary or center of expansion. Thus the Universe is not expanding into anything that we can see, and this is not a profitable thing to think about.

That's the short answer. The reason it's not "profitable" to think about as Wright says is Newton's flaming laser sword: "what cannot be settled by experiment is not worth debating", because there's no known way to confirm any answer by observation since if there is any boundary (and there may be no boundary) it would be beyond the observable universe.

We don't know if the universe is finite or infinite. If it's infinite, then it's not expanding into anything, it's just stretching. If it's finite, then it's possible it could be expanding into "something", but since we can never observe what that "something" (it would be beyond the observable universe), there's no way to answer the question. I put "something" in quotes because it could be just the absence of anything, maybe a void of some sort, but we will never know. Another astronomer expands on that topic in a different astronomy faq.

So actual short answer nobody knows.
It its infinite then we have problems, if it's finite then we have problems.
''It's just stretching'' is perfectly equal to it's expanding. You can't stretch something ''into'' itself, it has to stretch towards the outside. And there's no evidence the universe is stretching into itself aka getting looped inside of it or something like that.

I'm agnostic/deistic...and right now it seems it's the best bet. We know nothing about the actual state of the universe. And all along people like, but especially himself, L. Krauss keep saying ...the universe doesn't need a god, it's all random, universe keep creating themselves like in his book ''A Universe from nothing''. Quite dumb as we have 0 info about the edge of the universe/it's real shape/ it's expansion OR what's outside it. So there's no logic in saying ''there's no god'' just because we can't see ''god'' inside the universe.


Edit: What about the cooling ? Where did the heat go ?

Have you ever applied physics in any problem that you haven't created yourself or that has never been solved? Is physics a complete waste of brain matter? You work so hard at computing theoretical math with explanations that no normal human being could understand anyway. Would it have been as beneficial to become a Sudoku master? What, after physics, do you hope to ever achieve if anything? I mean like did learning your math puzzles unlock any other reasoning skills? Sorry it just seems pretentious.

a reply to: Arbitrageur

originally posted by: Choice777
So actual short answer nobody knows.
It its infinite then we have problems, if it's finite then we have problems.
''It's just stretching'' is perfectly equal to it's expanding. You can't stretch something ''into'' itself, it has to stretch towards the outside. And there's no evidence the universe is stretching into itself aka getting looped inside of it or something like that.

If it's infinite you can try to imagine an example of an infinite series of even numbers, 2, 4, 6, 8... to infinity. Now, what happens when you add the odd numbers? You have a bigger infinity, the number series didn't stretch into itself, right?

It's possible we might someday be able to determine if the universe is finite or infinite, if we can make more precise measurements of the curvature with lower uncertainty, but with current observations all we can say is the total universe must be at least 20 times larger than the observable universe, which of course allows for infinity. Maybe some future measurement could say the curvature of the universe indicates it's 25 times the size of the observable universe, which would eliminate the infinite possibility.

Edit: What about the cooling ? Where did the heat go ?

I thought you answered your own question which is why I quoted you saying "if you're gonna say it cooled because of expansion...then what is it expanding into...". As the expansion continues,the universe will end up in a "big freeze" which wikipedia calls "Future of an expanding universe". We expect the universe to become too cold to sustain life at some point in the distant future. The more immediate problem on Earth is that the expanding sun will boil away all the water in the oceans, but only more immediate in cosmological time scales, as that's probably at least a billion years in the future.

originally posted by: Arbitrageur

originally posted by: Choice777
edit: if you're gonna say it cooled because of expansion...then what is it expanding into...

That's probably one of the most frequently asked questions, and the standard answer from Ned Wright's cosmology faq is:

What is the Universe Expanding Into?

This question is based on the ever popular misconception that the Universe is some curved object embedded in a higher dimensional space, and that the Universe is expanding into this space. This misconception is probably fostered by the balloon analogy which shows a 2-D spherical model of the Universe expanding in a 3-D space. While it is possible to think of the Universe this way, it is not necessary, and there is nothing whatsoever that we have measured or can measure that will show us anything about the larger space. Everything that we measure is within the Universe, and we see no edge or boundary or center of expansion. Thus the Universe is not expanding into anything that we can see, and this is not a profitable thing to think about.

That's the short answer. The reason it's not "profitable" to think about as Wright says is Newton's flaming laser sword: "what cannot be settled by experiment is not worth debating", because there's no known way to confirm any answer by observation since if there is any boundary (and there may be no boundary) it would be beyond the observable universe.

We don't know if the universe is finite or infinite. If it's infinite, then it's not expanding into anything, it's just stretching. If it's finite, then it's possible it could be expanding into "something", but since we can never observe what that "something" (it would be beyond the observable universe), there's no way to answer the question. I put "something" in quotes because it could be just the absence of anything, maybe a void of some sort, but we will never know. Another astronomer expands on that topic in a different astronomy faq.

I tend to believe there is no edge there fore no thong to expand into. Also thought id mention we do know the rate of expansion. It appears to be 74 kilometres per second per megaparsec (where one megaparsec equals around 3.26 million light years).

a reply to: mikethedevil

You know that thing you're typing on to communicate with strangers across the globe? Physics. And that's just obe of a near-endless list of technological applications of physics.

Ultimately, everything comes down to physics.

a reply to: Arbitrageur

Bump, physics guys how many of you do anything more than your imaginary problem solving.

Please go use your superior intellect to create an entire new mathematical system. I've noticed personally that you guys are really douchey to the point that you feel you possess an intellect greater than those around you.

I have created my own mathematical system that I dropped within a few days but it had to do with an algorithm that I noticed based off random numbers, that eventually after 5 lines simplified to 12300=123004, it was interesting at the time but I didn't keep any docs.

Anyway, sorry for hating on you.. I just have met your types. I think physics is nothing more than a hobby.

That's rude of me sorry.

a reply to: Arbitrageur

Yeah, i missed that cooling thing....that i already linked it to expansion...
Anyway ..the universe isn't made of numbers....numbers are imaginary, the universe is very physical...the number play doesn't have anything to do with reality.

S now , if the universe has indeed cooled, and some theory even predicts freeze, then it means the universe is expanding/stretching.
So it means it's ''total'' size as 1 single entity is getting bigger in 2 ways:
a) its total size including non visible portions are just acting like a sea and are wobbling all over the plane, skewing, while our universe section which is the visible one remains more or less round and expands equally in all direction but is in fact encompassed by the larger rest of the universe which isn't in fact gaining any extra space because it is losing space on one axis and expanding on the other perpendicular axis.
b) it's all of it expanding/stretching outward into something, so that means there exists some space which is not space as we know it but still space-like OR it's all contained in some ''universe containment device'' with unlimited or very large internal space created by some race of beings.
This picture is of point a) Black is the wobbling unseen universe that keeps its total volume constant, and white is the visible universe that seems to expand infinitely but in fact will stop someday.

originally posted by: mikethedevil
a reply to: Arbitrageur

Bump, physics guys how many of you do anything more than your imaginary problem solving.

Please go use your superior intellect to create an entire new mathematical system. I've noticed personally that you guys are really douchey to the point that you feel you possess an intellect greater than those around you.

I have created my own mathematical system that I dropped within a few days but it had to do with an algorithm that I noticed based off random numbers, that eventually after 5 lines simplified to 12300=123004, it was interesting at the time but I didn't keep any docs.

Anyway, sorry for hating on you.. I just have met your types. I think physics is nothing more than a hobby.

That's rude of me sorry.

Failure to understand something is no reason to attack others that do. As far as inventing math plenty have done so especially in physics to help explain comcepts.The creation and development of calculus were strongly linked to the needs of physics. As far as you inventing math looks like you discovered a relationship hardly surprising In a base ten Sustem.

originally posted by: mikethedevil
Have you ever applied physics in any problem that you haven't created yourself or that has never been solved?

Engineering is the way we apply physics, I have a strong background in both, and yes I've applied physics to lots of practical problems both myself and via teams of people who worked for me.

Here's an interesting way to think about your question. When physicists were researching quantum mechanics, they weren't trying to build the device you're using to post your question (computer, tablet, smartphone or whatever), they were trying to develop a better understanding of the world.

Later, people applied that fundamental knowledge of physics to develop the devices you're using today, so whatever you used to post your question is an example of applied physics.

I'd suggest you search for some old episodes of Mr. Wizard's world, where he invites kids to the studio and allows them to conduct simple experiments to help them better understand the world around them. That's the basic idea behind physics, not a series of mathematical equations, though it turns out that math is a useful tool to explain what's observed and make predictions about what to expect in a future case.

Of course the leading edge of physics research is far more complex than Mr. Wizards world physics, but the idea is the same: physicists want to understand more about the world we live in. Engineers want to apply that knowledge to make things we can use, like your smart phone, which is chock full of applied physics.

I do apologize, imaginary math club is probably very fun. I choose to not understand because I like to keep a mild basis of reality, and when I know some of the theories can be never proven because extrapolation has limits, a community considered intellectual using make believe as science isn't quite interesting to me.

a reply to: dragonridr

a reply to: mikethedevil

originally posted by: mikethedevil
I do apologize, imaginary math club is probably very fun. I choose to not understand because I like to keep a mild basis of reality, and when I know some of the theories can be never proven because extrapolation has limits, a community considered intellectual using make believe as science isn't quite interesting to me.

a reply to: dragonridr

Physics is the understanding of reality. Choosing to ignore it as you said for being boring is to not learn the why. Luckily for you others do which leads to advancements of our species in technology. Physics is applied in your daily life all around you open your eyes and you may learn sonething. Then again may be to boring for you not everyone is cut out to educate themselves, some are content with just existing. For others the how and why are important questions.

originally posted by: mikethedevil
Have you ever applied physics in any problem that you haven't created yourself or that has never been solved? Is physics a complete waste of brain matter? You work so hard at computing theoretical math with explanations that no normal human being could understand anyway. Would it have been as beneficial to become a Sudoku master? What, after physics, do you hope to ever achieve if anything? I mean like did learning your math puzzles unlock any other reasoning skills? Sorry it just seems pretentious.

a reply to: Arbitrageur

That simply isn't true. I gather you think the likes of Archimedes, Copernicus and Einstein are all but useless. There are theoretical physicists and experimental physicists. The theoretical guys and gals are dependent on the experimental folks to prove or disprove their work.

As Arb mentioned, all engineering is based on physics. Nuclear magnetic resonance was discovered in the '30s. Magnetic imaging used in medicine is based on that physics. So if your doc tells you to get an MRI, maybe you should remind him/her that the guys who thought up the concept were useless, therefore, an MRI is probably useless as well.
Ignorance might be bliss, but it's still ignorance.