NASA's Curiosity rover finds organic matter on Mars

That doesn't even make sense.

 

You hiding somewhere on the third rock from the sun since that TV ad for what happens in Vegas stays in Vegas for all of spacetime ?

 

I guess I don't understand how it applies to what I said.

 

And when you consider billions of galaxies with an average of maybe 5 planets each, the probability of life on other planets is about 100%, including intelligent life. It's a matter of time.

 

There may be more Earth-like planets than grains of sand on all our beaches
New research contends that the Milky Way alone is flush with billions of potentially habitable planets -- and that's just one sliver of the universe.
https://www.cnet.com/news/the-milky-way-is-flush-with-habitable-planets-study-says/

 

With a moniker like that, I'm going to assume you know a bit about cosmology. And I'm looking for someone to answer a question for me. Regarding the expansion of space immediately following the Big Bang, how can something that is infinite expand? Expanding space suggests there is increasing space. Where does it go if there are no boundaries to expand? "Expand" into what? Any idea?

 

Prior to the Big Bang the theory posits that all matter was compressed in the Singularity and that the surrounding space was devoid of all matter.

The expansion was the matter of the singularity expanding into the empty space around it.

The above is from my layman's understanding.

Personally I am a proponent of what is sometimes called the Cyclical Universe. This is where the Big Bang and current expansion is nothing more a single part of an expansion/contraction/explosion cycle that continues ad infinitum. Given that there is no limit to space it is possible that these cycles occur in other parts of space that are beyond our ability to detect. Granted this is still a theory but serious scientists are evaluating it.

https://en.wikipedia.org/wiki/Cyclic_model

 

I have also believed in the cycle as well. Since everything seems to be cyclical and since it makes no sense that there was never, for ten to the trillionth power years, anything (except a singularity waiting for the right time?), then there was the "Big Bang", and now all matter just keeps flying apart . . . . FOREVER???? No. Not believable. So I have believed in a cyclical universe. But cosmologists for some time now have been saying that the B.B. was not an "explosion" but an "expansion", and so in the first fraction of a second after the beginning of the B.B. the universe was "expanding". (The distinction is subtle it seems.) Matter in the form of quarks and then electrons was flying out from the point of origin, but after it began condensing into electrons and protons and then hydrogen, it was all still "expanding" apart and it continued. I suspect it may be a way of getting around the messy notion of matter in space changing from occupying a point, to occupying the volume of a lightyear or two in a second. Normally, that would mean the matter had to fly apart traveling at much more than the speed of light, and we can't have that! No! Matter can't move faster than the speed of light! So the notion of "expanding space" was developed and space can "expand" faster than the speed of light.

I asked some very informed and advanced "students" of cosmology on a cosmology forum about this a while back. I was told that to understand it I would have to be able to understand the math involved. I persisted in requesting someone to "translate" the math and explain in words how "expansion" is different from "explosion" and I was thrown off the forum for being "too lacking in understanding to be able to discuss the subject" and that I was "disrupting the high-level discussion that was going on".

While I was there I asked if physics explains this "expansion". They said physics does not apply within a black hole and the B.B. was essentially (in the early nanoseconds) a black hole blowing apart and physics didn't apply in those early moments. So I told them that like physics doesn't apply in those cases, so too science would eventually discover that math didn't apply either. Maybe that helped get me banned. They didn't know what to do with it.

So the question remains, how can infinity expand?

 

I'm not a physicist. So, take this as perhaps a hint as to what to ask:

My understanding is that there wasn't an "infinity" that was expanding, but a singularity. All space-time was included in that singularity. The notions of what is "outside" the universe and what the universe is expanding "into" don't apply - the universe IS all space time.

As for the end of the universe, measurements show that there isn't nearly enough mass to allow for gravity to reverse the expansion that is clearly going on. And, there isn't any other known force to bring things back together again. Distant stars have been identified so far away that the distance between those stars and us is increasing at faster than the speed of light - due to the continuing expansion. This is general relativity theory, not special relativity. It's not really going faster than light speed - it's just that the universe is expanding at a particular rate, and that rate adds up over huge distances.

To come back together, there would have to be something seriously significant to reverse that, and there are no hints of that as far as I know.

So, physicists say this universe will just gradually cool off, decomposing into ever smaller pieces, with even black holes, electrons, etc., breaking down.

 

This is just desperation for publicity, which all scientists want.

The discovery is - as another member noted above - nothing.

 

Then the Big Bang was a one-time event? ....and then ............... nothing?

I understand that in order for there to be anything we can refer to as "space", at least two particles, or atoms, or pieces of matter are needed. If you pause a moment and think about it, it become obvious. So yes, when matter first spewed forth, space was created . . . space being the distance between two or more things. And so with the same logic we can say that out beyond the last, farthest out matter, there is nothing, and therefore no "universe". One theory says that if you were to travel to the boundary or limit of the universe and keep going beyond, you would find yourself re-entering this universe at the opposite side. Hence there is no escape. (But BTW, notice that if you did that, as you travel beyond, since you are matter, you are creating space, distance, etc.)

Anyway, the theory says this universe is all that is and there is nothing else and no space beyond it.

Now, suppose the theory that says it is highly likely that somewhere, maybe 20, 50, or 1,000 "universe widths/diameters" beyond this universe there is another universe, and in other places another and another and another, .... is correct. Just suppose. That would mean that the idea that this universe is all of space-time fails. "Infinity" again becomes a question and a possibility. And it's all just competing theories. And none is provable today. And each one negates the others or major parts of the others.

So if both of those are viable theories, they prove conclusively that it is all speculation and you are free to believe anything you want to believe because no one knows and anything is a valid as anything else. Yes?

 

What the hell does it matter if the universe is expanding or contracting, even if there were a way to prove it? Who cares?

 

He who has a scientific mind understands.

 

While I cannot address the math or the difference between expansion and explosion I can apply logic to the concept under discussion.

If all matter is condensed into a singularity then it is surrounded by an infinity of empty space. Irrespective as to whether the singularity expanded or exploded it went from a single object into trillions of trillions of trillions of particles in a very small period of time. Space itself did not expand but rather the particles of matter expanded out into space regardless as to whatever triggered the expansion/explosion.

 

From what I gather the expansion is occurring because stars are heating dark matter and that is driving the expansion in much the same way as two dots on a balloon would move apart if the air inside the balloon was to be heated. Under that dark matter scenario when the stars burn out the heat source disappears and the dark matter cools and contracts thus drawing the physical matter back together under the gravitational force of the dark matter.

This next part is speculation on my part that I came up with as a means of explaining to myself how this works.

If we imagine that dark matter is similar to a photon that does not shine but can be altered from a cold state to a warm state when it is impacted by a photon then the dark matter expands from that interaction. When there are no more photons the dark matter contracts again. Since all physical matter is surrounded by dark matter then the pressure from the coldest dark matter would push against the physical matter thus causing it to contract. Once the physical matter contracts sufficiently it will condense into black holes and ultimately another singularity.

Yes, I know that is a highly simplified layman's understanding of the process.

 

But then the problem remains of how matter moved much faster than the speed of light.

 

My head hurts.

 

Well, my understanding is that space is actually considered to come in tiny granules - that it is not just distance within some medium. I don't know how strongly that is supported by evidence. But, I'm quite sure cosmologists do not accept the idea of there being "space" that our universe is expanding into. It is space itself that is expanding.

As for the rest, I suspect we're smooshing together what is an actual scientific theory (which includes physical evidence, repeated review and testing.) and what is a theory in the sense of somebody's idea. We have "theoretical physics" which explores the universe through math and ideas, and comes up with stuff like multi-verses, string theory, etc. That tends to have value in giving hints as to where experimentalists might look, but there isn't anywhere near the amount of physical evidence that would cause these ideas to become lasting theories of experimental science.

There is a lot that isn't known, obviously.

 

I'm certainly not going to be critical of that. However, just to toss out questions I have ...

The astrophysicists I've read have said that the expansion of the universe is accelerating.

I would say that expansion means cooling, so if expansion were due to radiation pressure it would seem logical that the expansion of the universe should be slowing, not accelerating.

Does dark matter actually respond to radiation differently than normal matter? That one surprises me as my understanding is that dark matter interacts only through gravity and possibly the weak force. I would have thought that dark energy would be more of a deal. Then, there is also the new repulsive force discovered in 1999 which seems to overcome gravity at cosmological distances.

It would be great to get a better picture of this universe and its physics within my lifetime - maybe one I could hope to understand!

 

trying to understand the truth is important to some, answer the age old questions, plus sometimes the journey of learning can have huge effects on humanity

kinda like when humans learned the earth was not flat, or we revolved around the sun rather then a Sun God revolving around the earth

 

true but the key difference being I can't foresee an expanding or contracting universe ever impacting our lives as did discovering the earth was indeed round...I just don't see humanity ever leaving our solar system, forget about leaving our galaxy...

 

Sure. However, I'd point out that our standard model of physics is known to have holes.

The last time we fixed a major hole in our standard model was when Einstein started dreaming about the speed of light.

I'm not going to travel at light speed, either.

But, I do like my GPS!

 

sure but what could the knowledge of an expanding universe do for us other than satisfy our curiosity? ...it's interesting but as I'm not astrophysicist I don't see how it'll ever benefit us...

someone needs to improve UBER's GPS, it really sucks...

 

All of the technology we have today is a result of our knowledge of physics - from the gasoline engine to the transistor. Who could have predicted any of what exists, 100 years ago? It is impossible to know what benefits will result from fundamental, academic research. But we do know that it does yield great benefits.

Consider for example that 1854, British mathematician George Boole published a landmark paper detailing an algebraic system of logic that would become known as Boolean algebra. It had no useful purpose.

100 years later it became the basis for every computer in existence.

 

Well, Voyager I is now about 140 times as far from the sun as the earth is from the sun ("astronomical units"). And all the published news and coverage just tells about covering distances at a bit more than 10 miles per second (!). They haven't mentioned granules and of course there is no "medium" in a vacuum. (This stuff can be hard to talk about!) Sometimes I feel like all the mystery and incomprehensible ideas being tossed around is just unnecessary mystification. Voyager 1 and 2 are just traveling and at least Voyager 1 is beyond the heliopause. No mysteries that I know of. No granules, no black matter found, no warped space, no expanding space detected.

See, that's one of those mystery thingys. Obviously (it seems) a galaxy would remain a galaxy that it is, even while speeding away from another galaxy. (However the Milky Way is speeding toward Andromeda.) So I still don't know what this "expansion" stuff is. I know it doesn't just mean that galaxies as units are flying farther apart. But I can understand galaxies flying apart if that's what they are doing yet can't grasp the idea of space "expanding". I suppose it's in the math.

Right, and so I feel justified in holding my own theories about it.