Ask a physicist anything. (5)

[Upisoft]

Linearity is not possible where gravity exists; And gravity is everywhere in the universe.

I said "locally".

 

[mzungu]

I said "locally".

Sorry but I don't follow? Are you referring to the quantum level

Is that your kid on the photo? Nice lad you've got there Reminds me of my son when he was the same age

 

[Steffenfield]

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?

 

[pgp_protector]

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?

Before or after we modify the missiles to leave the earth's gravity well?

 

[chris4243]

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?

They run out of fuel and fall back down to earth?

 

[Naraoia]

I was going to give the directional vector in spherical polar coordinates, but the conversion just got hideously messy

It's like the metric expansion of space. Two points are 5m apart forever and ever, but it's the metre that expands. Crazy stuff.

I'm suddenly not sure I understand cosmological redshift... Why does the expansion of space cause redshift? Shouldn't the distance between the observer and the source stay the same forever and ever, and the observer just see an unshifted spectrum...?

*is befuddled*

 

[Steffenfield]

They run out of fuel and fall back down to earth?

I didn't think about that.

Okay, what would the long term effects be on the planet if that happened instead?

 

[pgp_protector]

I didn't think about that.

Okay, what would the long term effects be on the planet if that happened instead?

How long term?
100 years or 10,000,000 years?
I doubt we'd be around in either case though.

 

[Steffenfield]

I haven't followed the arms race in quite a long time.

I'm not even sure how many times we can completely blow ourselves over anymore.

 

[Maxwell511]

No, I don't think I know of any. I'd be surprised, because of the insulation issue.

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.

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

 

[chris4243]

I didn't think about that.

Okay, what would the long term effects be on the planet if that happened instead?

Nothing much; we got radioactive material out of the earth and some of it goes back, albeit on the surface. Weapons grade plutonium/uranium isn't really that radioactive, not like the waste products after fission. We'd want to make sure certain people didn't go out to collect it though.

However, if they were set to explode, in which case nasty things happen starting with massive destruction (presumably in random places since they weren't targeted), then a nuclear winter would cause wide-scale starvation in humans and other species, lots of species going extinct and perhaps a collapse of civilization. In plants probably an adaptation toward using redder light (since that is less easily blocked) and larger seeds and food storage (since the others would die out), and in all survivors an increase in radiation and poison resistance and adaptive radiation of the survivors into new species/sub-species to occupy the new niches.

 

[Maxwell511]

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

 

[pgp_protector]

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

Not personally.

 

[TheReasoner]

In deaths per kwh which energy source is best, and which is worst?

 

[TheReasoner]

I guess I'll just answer my own question. A Norwegian magazine for engineers called "Technical weekly magazine" (Directly translated) revealed a study a couple of days back:

tu.no - Fossil energi tar flest liv - Teknisk Ukeblad
(might want to use Google Translate on that)

From left to right:
Coal, charkoal, peat (of all things), oil, gass, nuclear power, bio fuel, hydroelectric and wind.

Oil really takes off as you can see, providing a rather high number of deaths per TWh, hydroelectric wins the 'battle' being very safe indeed it would seem. But nuclear hits a second best. Not bad! Not surprising, but not bad.

 

[pgp_protector]

I guess I'll just answer my own question. A Norwegian magazine for engineers called "Technical weekly magazine" (Directly translated) revealed a study a couple of days back:

tu.no - Fossil energi tar flest liv - Teknisk Ukeblad
(might want to use Google Translate on that)

From left to right:
Coal, charkoal, peat (of all things), oil, gass, nuclear power, bio fuel, hydroelectric and wind.

Oil really takes off as you can see, providing a rather high number of deaths per TWh, hydroelectric wins the 'battle' being very safe indeed it would seem. But nuclear hits a second best. Not bad! Not surprising, but not bad.

Fish might not agree(and birds might not agree about wind being safe)

 

[Steffenfield]

Wow.

I'm not sure what other sites everyone visits outside of CF here, but I've been spending the last hour on this one.

PhysOrg.com - Science News, Technology, Physics, Nanotechnology, Space Science, Earth Science, Medicine

 

[Maxwell511]

Fish might not agree(and birds might not agree about wind being safe)

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.

 

[pgp_protector]

Wow.

I'm not sure what other sites everyone visits outside of CF here, but I've been spending the last hour on this one.

PhysOrg.com - Science News, Technology, Physics, Nanotechnology, Space Science, Earth Science, Medicine

right now doing some reading on a few new projects, so lots of time on sites like
CodeCall Programming Forum
and
CodeProject - Your Development Resource

 

[Wiccan_Child]

I'm suddenly not sure I understand cosmological redshift... Why does the expansion of space cause redshift? Shouldn't the distance between the observer and the source stay the same forever and ever, and the observer just see an unshifted spectrum...?

*is befuddled*

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.