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Sticks
2008-Nov-01, 07:31 PM
I was thinking about the problem that Fraser point's out in his blog, namely the dearth of anti-matter and wondered a possible scenario.

It is not one I am wedded to, even though it might seem ATM

Assuming the Big Bang to be true,

If you picture the expansion of the universe as on a line, then when the universe was created as the universe expanded, creating space, and matter going one way, could you have had, anti space and an anti universe expanding the other way so to speak?

In this universe you would have mostly anti matter and any dwellers there would ponder the absence of matter.

Assuming we do not have anti-time, as Professor Hawking has pointed out, could the big bang have in effect created two universes, one of matter and one of anti-matter, so we can keep the favourite concept in physics, that everything sums to zero.

Veeger
2008-Nov-01, 07:45 PM
Hello...moderators? This one slipped through.
I thought sticks was supposed to be blocked from asking questions!

PraedSt
2008-Nov-01, 07:55 PM
Hello...moderators? This one slipped through.
I thought sticks was supposed to be blocked from asking questions!

We've been abandoned (http://www.bautforum.com/off-topic-babbling/80736-doth-my-eye-percieve-we-moderatorless.html) :(

Anyway, Sticks, I like this question. I'll be lurking.

Jeff Root
2008-Nov-02, 01:41 AM
Sticks,

That's the idea I had approximately 33 years ago, in the mid-1970s.
I've now got a better idea that is in part derived from that one. I probably
have said enough about it in various different threads that you would be
able to figure out what I have in mind, but I'm less inclined to talk about
it now than I was, say, a year ago. I'm going to discuss it more with some
others first, and try to keep my idea somewhat proprietary for a while
longer, just in case there eventually turns out to be anything to it.
My idea is falsifiable! :D So it'll probably be falsified. :(

-- Jeff, in Minneapolis

grant hutchison
2008-Nov-02, 02:43 AM
Asimov's Cosmogonic Principle, expounded in 1966. :)
He talked about this in his F&SF essay I'm Looking Over A Four-Leafed Clover, in September of that year. It's collected in Science, Numbers and I.

Grant Hutchison

Ken G
2008-Nov-02, 02:50 AM
Assuming we do not have anti-time, as Professor Hawking has pointed out, could the big bang have in effect created two universes, one of matter and one of anti-matter, so we can keep the favourite concept in physics, that everything sums to zero.If physics was really about keeping favorite concepts, this would all be physics.

Theophage
2008-Nov-02, 05:53 AM
Here is a link to that essay:

http://wayneholland.org/fourleafclover.htm

Jeff Root
2008-Nov-02, 08:09 AM
I see that the roots of all the ideas I have are in that essay by Isaac Asimov.
Although I don't remember reading it, I may very well have borrowed it from
the library and read it in the late 1960s or early 1970s. The title of the book
is certainly familiar to me.

Grant, can you tell me how to correctly pronounce "cosmogonic", and about
the etymology of the "gon" part? I would have expected "cosmogenic".

-- Jeff, in Minneapolis

grant hutchison
2008-Nov-02, 01:27 PM
Grant, can you tell me how to correctly pronounce "cosmogonic", and about
the etymology of the "gon" part? I would have expected "cosmogenic".it's pronounced coz-moh-GON-ik, and comes from cosmogony (coz-MOG-uh-nay). The Greeks had two words meaning more or less the same thing: γέννεσις (genesis) and γονή (gone), for a begetting or a creation. They spawned parallel families of words in English, but the genesis line has largely won out, so we don't hear much of -gony these days.

Grant Hutchison

Sticks
2008-Nov-02, 01:36 PM
If physics was really about keeping favorite concepts, this would all be physics.

But this is what our high school physics teacher told us

Everything sums to zero

As for this being around before, my thoughts on this matter, I had not read anything prior, I just thought I would see if it was possible to apply invariance and this sum zero concept could account for the lack of anti-matter observed in this universe.

Ken G
2008-Nov-02, 01:56 PM
But this is what our high school physics teacher told us

Everything sums to zero


There are some pretty important lessons about how physics works here. Let's look at conservation of energy as an example. First we define kinetic energy, intentionally, in such a way that if you have a force that depends on location, you can calculate how kinetic energy changes in a way that depends only on location-- not on the details of how you got there. So instead of simply saying "kinetic energy depends on location in a simple way", we say "let's invent something called potential energy, and call it the negative of this simple rule about how kinetic energy depends on position. Then if we add the kinetic and potential energies, we can always get zero." Voila, we'll call the sum "total energy", and say that everything sums to zero!

Now let's note several things about this example. First of all, is it reality that is summing to zero, or just our choices of mental constructions? And do they sum to zero because they had to, in reality, or do they sum to zero because that's just what we built them to do? (Yes, it is amazing that there is something we can find that does sum to zero, but we invent the concept to reflect something we see, we don't tell reality it has to do this because we like our concept.) But the real point is, we find the whole concept convenient because indeed forces do tend to depend on the distances between the objects involved, so we get just the situation described above. The concept of a "conservation law" is very handy, when potential energy is so easy to define and use.

But now, contrast that situation with a situation where every time we find kinetic energy changing, instead of creating the concept of potential energy, we simply postulate an alternate universe which is just the same as ours but all the masses are negative, so all the kinetic energies are negative. Would this be a useful thing to do? We could now get the total energy in both universes to be zero, but it gives us zero predictive power about our own universe. It is a completely empty and useless form of the principle of conservation of energy-- nothing like the one we actually do form and find useful in our own universe.

The bottom line is, if all the interactions we've seen in our universe create equal amounts of matter and antimatter, but the universe has more of one, then we had better either start looking for interactions that don't produce equal amounts, or we better start accepting that we don't have a useful creation model for our universe that is based on the familiar physics we know. The latter is currently true, so there's no requirement to find the former, but it would be a useful thing to look for anyway. But the worst possible thing we can do is postulate some alternative universe to let us maintain our prejudices about matter and antimatter-- that would be pretend physics (or as I like to call it, "magical thinking").

Jeff Root
2008-Nov-02, 02:26 PM
I've taken Asimov's ideas (whether I got them from reading his essay
years ago or not) and made them into something that applies to our
Universe. So far my ideas are every bit as speculative as his, but
mine have the advantage that they will soon be tested!

-- Jeff, in Minneapolis

Ken G
2008-Nov-02, 02:36 PM
Yes, the ability to make testable predictions is certainly the difference between real physics and make-believe physics. If an unconfirmed theory can lend insight into where or how to look for something interesting, then it has done its job, whether or not what is being looked for is ever actually found.

cran
2008-Nov-03, 06:00 PM
I was thinking about the problem that Fraser point's out in his blog, namely the dearth of anti-matter and wondered a possible scenario.

It is not one I am wedded to, even though it might seem ATM

Assuming the Big Bang to be true,

If you picture the expansion of the universe as on a line, then when the universe was created as the universe expanded, creating space, and matter going one way, could you have had, anti space and an anti universe expanding the other way so to speak? ...

Like Jeff, it was in the 70s when I first wondered if a bi-lobal BB might be an elegant solution to the apparent matter/antimatter imbalance ...

and I remember getting quite excited years later when I first saw some Hubble images of Eta Carinae and supernovae ...

Ken G
2008-Nov-03, 11:18 PM
And when I stand in front of a mirror, I'm talking with my alter ego in an alternate universe. But is it physics?

Jeff Root
2008-Nov-04, 01:05 AM
No, Ken, you're usually not talking physics when you talk to your reflection
in the mirror. More often it's cosmetology. Or biology. Or psychology.

-- Jeff, in Minneapolis