Ask a physicist anything.

[AV1611VET]

So what is this 13.7 billion years all about?

It is based on the false assumption that a big universe is an old universe.

 

[Wiccan_Child]

So what is this 13.7 billion years all about?

That is the age of the universe. Or, more precisely, it is the duration for which the universe has been expanding. What happened longer than 13.7 billion years ago is anyone's guess (according to Hawking, anything that happened then has absolutely no influence on what happened after, so we may as well consider it to be the start of the universe, for all intents and purposes).

The age is derived from numerous methods, though that number itself largely a result of the Big Bang theory (e.g., it is the time it took for the universe too cool to its current temperature, the time it took to expand to its current size, as described by ΛCDM). It is in agreement with minimum ages derived from other methods*, so we know it is in the right ballpark.

Interestingly, the age of the universe could be increased by one order of magnitude if some rather more exotic theories of particle physics prove true. But we are certain (to scientific standards) that it is at least 13.7 billion years old.

*If the age of the oldest stars and galaxies is X years, then the universe must be at least X years old. For example, a gamma ray burst has been dated to ~13 billion years old, so the universe is at least as old as that burst.

 

[Wiccan_Child]

It is based on the false assumption that a big universe is an old universe.

Can you demonstrate they're false without resorting to the Bible?
Can you demonstrate they're false if I let you use the Bible?

 

[AV1611VET]

Can you demonstrate they're false without resorting to the Bible?

No.

Can you demonstrate they're false if I let you use the Bible?

Yes.

 

[Doveaman]

What happened longer than 13.7 billion years ago is anyone's guess (according to Hawking, anything that happened then has absolutely no influence on what happened after, so we may as well consider it to be the start of the universe, for all intents and purposes).

You lost me at “Hawking”.

The reason is because astronomers hypothesized the observed “dark flow” we discussed as being influenced by gravity beyond the event horizon which we cannot observe.

Astronomers seem to see an influence between the “then” (beyond the event horizon) and the “after” (the observed universe), so I guess when Mr. Hawking made that statement the “dark flow” was not yet observed. Either that or he is not keeping up with his work load.[FONT=&quot]
[/FONT]

 

[laconicstudent]

No.

Yes.

Um... then your argument has no merit, and the scientific community is perfectly correct in considering it your personal religious belief, and ignoring it.

 

[AV1611VET]

Um... then your argument has no merit, and the scientific community is perfectly correct in considering it your personal religious belief, and ignoring it.

Bully for science ---

 

[laconicstudent]

Bully for science ---

Just why are you in the science forum then?

 

[pgp_protector]

Just why are you in the science forum then?

Fishing

 

[AV1611VET]

Fishing

Yup ---

And he saith unto them, Follow me, and I will make you fishers of men.

 

[kangitanka]

Just why are you in the science forum then?

Simply being hypocritically antagonistic towards science, that's all.
Which is why AV1611VET deserves to be ignored on this specific forum.

Not that anyone will actually take that step
Too many people enjoy attacking non-sequitur statements made by him (because he's an EASY target) and others like him, to the end that they are supposedly "educating the lurkers".
All they're doing is feeding AV's ego.

 

[AV1611VET]

Simply being hypocritically antagonistic towards science, that's all.

I liked pgp's answer better.

 

[Wiccan_Child]

Calm down ladies, I don't want my shiny thread sullied by a flame war.

 

[Wiccan_Child]

No. Yes.

I thought so. Thanks for answering .

You lost me at “Hawking”.

I thought I might. He's a very smart man, much smarter than you or I. That doesn't make him automatically right, but it does make him an expert on the field. I, for one, defer to his expertise over those of a layman.

The reason is because astronomers hypothesized the observed “dark flow” we discussed as being influenced by gravity beyond the event horizon which we cannot observe.

I believe you mean the particle horizon. Event horizons are associated with black holes.

Astronomers seem to see an influence between the “then” (beyond the event horizon) and the “after” (the observed universe), so I guess when Mr. Hawking made that statement the “dark flow” was not yet observed. Either that or he is not keeping up with his work load.[FONT=&quot]
[/FONT]

If you're going to use his epithet, use the right one. He's a professor at Cambridge.

Anyway, dark flow simply refers to a supposed net movement of galaxies towards a patch of sky. If there is such a movement, and there is much debate on whether it actually exists as a statistical phenomenon, I hardly see that as a problem for our theories. What, exactly, is your problem with dark flow?

 

[AV1611VET]

Calm down ladies, I don't want my shiny thread sullied by a flame war.

--- sorry.

 

[Doveaman]

I believe you mean the particle horizon. Event horizons are associated with black holes.

I thought they were use interchangeably, are they not?: Event horizon of the observable universe. Am I wrong?

I think I'll use 'particle horizon' from now on, though, to avoid any confusion. Thanks.

Anyway, dark flow simply refers to a supposed net movement of galaxies towards a patch of sky. If there is such a movement, and there is much debate on whether it actually exists as a statistical phenomenon, I hardly see that as a problem for our theories.

We'll see if that's true when they continue to find more. And I believe they will.

What, exactly, is your problem with dark flow?

No problem for me, but they're sure to become a problem for big bang theorists. I'm sure they'll just tweak the model to make them fit, though.

Dark holes, dark matter, dark energy, and now dark flows. I think the universe is going dark on the big bang theory. Don't you?

Need some electricity?

 

[Wiccan_Child]

I thought they were use interchangeably, are they not?: Event horizon of the observable universe. Am I wrong?

Eh, I suppose it's technically the horizon beyond which we can't see events. But the phrase 'event horizon' refers specifically to black holes. The particle horizon is analogous to the one in black holes, but it's not the same.

But this is just splitting hairs.

We'll see if that's true when they continue to find more. And I believe they will.

Let's not jump the gun.

No problem for me, but they're sure to become a problem for big bang theorists. I'm sure they'll just tweak the model to make them fit, though.

I'm sure they will. All science works that way: adapting to new data, throwing out the old if it proves unworkable.

 

[catzrfluffy]

Why does coca-cola and menthos explode?

YouTube - coke + menthos

it's beautiful ... is it what all scientists want for Christmas?

 

[TerranceL]

Why does coca-cola and menthos explode?


it's beautiful ... is it what all scientists want for Christmas?

Always liked this video better.

YouTube - Mentos Ultimate Experiment

 

[catzrfluffy]

This one's pretty cool:
YouTube - Water Cooler Bottle Methanol Fireball (Mad Physics)​