Ask a physicist anything. (5)

[Wiccan_Child]

What would happen if we shot all of our planet's nuclear missiles at the sun, either because we were being super moody that day or wanted to finally rid the Earth of them?

Nothing at all. All the Earth's nuclear warheads would be a drop in a very large ocean. Each missile does a miniature version of what the Sun does on a much larger scale every day: thermonuclear fusion.

 

[Wiccan_Child]

Is any one else concerned about the formatting of the thread title when it "breaks" into another thread?

I was going to PM you about that I was gonna ask if this could be prematurely closed, and the old thread reopened. We may have to go through (5) again, or they might be able to skip to (6). Who knows

 

[Wiccan_Child]

In the first world we generally design hydro plants and wind farms with fish, and other wildlife, in mind.

It is more bats that should be concerned about wind farms than birds. Despite their amazing hearing abilities they don't listen to us when we tell them not to fly into the blades.

According to the omniscient Stephen Fry, it's their lungs that are damaged; they get sucked inside out by the drop in air pressure near the blades. Ouch.

 

[Steffenfield]

This is more of a computer and internet savvy question...

How can I solve this puzzle immediately?

Like can I type wild card letters into Google's search engine or something?

While you're at it, I need this solution as well...


--ll-a- --l------c-


Letters already used are a,n,s,t,c,l.

This one I've come really close using this site for the second puzzle but I'm falling short for some reason.
The Crossword Solver

Any help on this?

Oh, and please don't let this drive you mad though like it has done with me.

 

[Faith24]

Hey physicist, is the universe created or was it always here? For argument sake, you take the position that the universe was created ok... and I tell you the universe is an endless recycle phenomenom - that would be my position. Can you give me some philosophical issues and logical problems with my view? Thanks! I need some criticism for my view.

 

[chris4243]

Hey physicist, is the universe created or was it always here?

Unknown. It is possible that the universe is eternal; see the cyclic universe for an example.
Cyclic model - Wikipedia, the free encyclopedia

However, in all models I know of, anything made of molecules would not have been eternal. Therefore, you could also say the universe was destroyed and recreated, depending on how you define those terms.

Other models such as M-theory have the universe created from other things outside the universe.

The current view is mostly just trying to explain our own universe and makes no mention of the origin of the Big Bang.

For argument sake, you take the position that the universe was created ok... and I tell you the universe is an endless recycle phenomenom - that would be my position. Can you give me some philosophical issues and logical problems with my view? Thanks! I need some criticism for my view.

Any cyclic model of the universe will have a problem with the Second Law of Thermodynamics, which states that entropy increases. This law, I believe (but don't take my word for it) is statistical and not a law of the universe, so violating it isn't necessarily bad, and would just necessitate extremely unusual conditions.

 

[Wiccan_Child]

Hey physicist, is the universe created or was it always here? For argument sake, you take the position that the universe was created ok... and I tell you the universe is an endless recycle phenomenom - that would be my position. Can you give me some philosophical issues and logical problems with my view? Thanks! I need some criticism for my view.

Scientifically, we don't know how the universe started, or even if it started. All we know is that it is at least 13.5 billion years old, and has been expanding from a singularity during that time. Personally, I think the universe is of finite age with a quantum mechanical origin.

I don't see any problems with your position, though I could play Devil's Advocate and mention entropy (an infinite universe would have run down into a cold soup by now)

 

[Michael]

Scientifically, we don't know how the universe started, or even if it started. All we know is that it is at least 13.5 billion years old,

I buy that.

and has been expanding from a singularity during that time.

Er, no, that was a "leap of faith". Alfven's "bang" never involved a 'singularity', and your whole claim about age is directly related to an *INTERPRETATION* about redshift and a belief you hold that it is somehow related to 'expanding space'. In other words, this is your belief, not mine.

 

[Wiccan_Child]

Any cyclic model of the universe will have a problem with the Second Law of Thermodynamics, which states that entropy increases. This law, I believe (but don't take my word for it) is statistical and not a law of the universe, so violating it isn't necessarily bad, and would just necessitate extremely unusual conditions.

I used to have the following quote in my sig:

The second law of thermodynamics holds, I think, the supreme position among the laws of Nature. If someone points out to you that your pet theory of the universe is in disagreement with Maxwell's equations - then so much the worse for Maxwell'sequations. If it is found to be contradicted by observation, well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation.

- Arthur Eddington

That pretty much sums up the untouchability of the Second Law
​

 

[chris4243]

I used to have the following quote in my sig:

The second law of thermodynamics holds, I think, the supreme position among the laws of Nature. If someone points out to you that your pet theory of the universe is in disagreement with Maxwell's equations - then so much the worse for Maxwell'sequations. If it is found to be contradicted by observation, well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation.

- Arthur Eddington

That pretty much sums up the untouchability of the Second Law
​

It's not as untouchable as you think.
Phys. Rev. Lett. 89, 050601 (2002): Experimental Demonstration of Violations of the Second Law of Thermodynamics for Small Systems and Short Time Scales

 

[Naraoia]

I looked into this and of course I found the platypus. Although the platypus is semi-aquatic and I am pretty sure they are a joke that biologists made up.

Weird beasties, aren't they? I think their electric sense is mostly a substitute for sight when they hunt underwater. So not really an exception. Still, clever of you to think of them.

As a biologist you can confirm that platypi don't exist. Right? Because that animal makes no sense.

I can't confirm a negative Having never seen a live platypus, I also can't confirm the opposite.

I hope they exist, though. I used their Hox genes for my Honours project.

Because light has the distressing tendency to muck up otherwise nice physics It travels at a constant c, so if the space under it is being stretched, then it too is stretched. But it doesn't slow down; Relativity demands it travels at the same speed. So it stretches out as a sort of 'compromise' - i.e., its frequency drops, its wavelength spikes, etc. I tend to imagine it as a standing wave between two poles, and the poles are moved apart. The wave traverses at a constant rate, but the energy is 'stretched' further than it otherwise would be, so it appears (or, indeed, actually is) to have a longer wavelength.

But but but if space itself stretches, then light travelling at the same speed should cover the same new-space distance in the same new-space time as it did in the smaller space. There should be no need for adjustment.



Light also has the distressing tendency to make me feel stupid.

 

[selfinflikted]

I have a question for you, OP. Hopefully this hasn't been asked prior, as I haven't been able to read the entire array of threads. Disregard if this has been asked thus far.

I was watching (purely for entertainment purposes) a film documentary on Netflix last night about alleged physical evidence that the earth and its human inhabitants are being visited by extraterrestrials.

In this film, they showed clips of a small, triangular metallic object being removed from a man's jaw area - a man who claims to have been "abducted" by aliens. The object was sent to a couple of different universities for metallurgical testing and results from each experiment were roughly the same - extraterrestrial origin. One study even reported that it was a small fragment of an extremely rare meteorite, of which only very few samples have ever been recovered worldwide. That particular conclusion was reported before it was disclosed that the fragment had been removed from human tissues. I did find this sort of interesting.

Personally, I highly doubt we are "alone" in this universe, given the probabilites of alien lifeforms, but I am extremely skeptical that such alien life has been visiting Earth, much less performing "experiments" on humans. So my question, is what do you think about "aliens" or extraterrestrials and the claim that we are being "visited", and more specifically "adbucted" for experimental purposes?

 

[Steffenfield]

Haven't you read the Bible bro?

It states, in the beginning, God created the Heavens, and the Earth, and the enemy planet Saturn.

 

[mzungu]

But but but if space itself stretches, then light travelling at the same speed should cover the same new-space distance in the same new-space time as it did in the smaller space. There should be no need for adjustment.

You can bend the fabric of space time but if you stretch it then it will rip and the consequences are as yet unknown. Perhaps a wormhole will appear but this is highly unlikely for wormholes create paradoxes which are not allowed.

 

[pgp_protector]

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[pgp_protector]

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[Steffenfield]

Should I be seriously spooked about those upcoming solar flare thingies of unhappiness that will be hitting somewhere between 2012 and 2013?

I'm not much too fond of the thought on losing global electrical power and being without a functioning blow dryer for my hair.

 

[Naraoia]

I'm not much too fond of the thought on losing global electrical power and being without a functioning blow dryer for my hair.

The priorities

 

[Nostromo]

Should I be seriously spooked about those upcoming solar flare thingies of unhappiness that will be hitting somewhere between 2012 and 2013?

As there isn't anything between 2012 and 2013 I wouldn't worry too much

 

[Wiccan_Child]

It's not as untouchable as you think.
Phys. Rev. Lett. 89, 050601 (2002): Experimental Demonstration of Violations of the Second Law of Thermodynamics for Small Systems and Short Time Scales

I can't read the full article, but it sounds like just local entropy decreases in an open system, rather than a decrease in total entropy of a closed system.