Carrock

Depends what you mean by steady state. Non cosmologists use a definition like this: https://en.wikipedia.org/wiki/Steady_state_(electronics) The steady state theory of Bondi and Gold was disproved mathematically and the steady state theory of Hoyle was disproved observationally. These are the only theories that most cosmologists would describe as steady state. Basic lambda-cdm (and some theories modified for dark energy) predict that startup transients such as the cmbr and stars and cosmologists will eventually become unimportant as the universe continues expanding, becoming colder and emptier and approaching an unchanging state. No cosmologist will ever describe that as steady state for historical reasons. An implication of my previous post is that that unchanging state must end after limited or unlimited time. An infinite universe whose volume does not eternally increase or decrease exponentially is the only one which can exist for infinite time and be topologically consistent with current physics. A non cosmologist might describe that as 'steady state.'

Exponential expansion can continue for unlimited but finite time. A/the universe has finite or infinite (i.e. aleph-null) units of volume. If this universe doubles in size an infinite number of times in infinite time it contains 2^(aleph-null) units of volume. This is equal to aleph-one units of volume (assuming the continuum hypothesis). That is, there would be as many units of volume in this universe as there are dimensionless points. This is topologically inconsistent with current physics. Philosophy of Science Vol. 32, No. 1 (Jan., 1965), pp. 21-31 has a good description of this. (The article was very aggressively peer reviewed but some on this forum are convinced it is too old to be correct.) Of course the universe is not constrained by what seems to be (im)possible....

Figure skaters moving their arms closer to the body requires work to be done by the arms. External energy input could used for a similar result.

No. But erasing low entropy data increases overall entropy. The necessity of discarding data gives a theoretical limit to the efficiency of computers. The effect has been observed.

The non bolded points have conveniently been dealt with while I took a break. The finite observable universe originated (probably) in a volume smaller than a proton but because of the lack of observable edge effects the big bang is either spatially infinite or too large to measure. 'Originates' here really means 'this is the earliest time when plausible physics can be invoked.' Inflation is an explanation of why the observable universe is so smooth but I doubt anyone will ever come up with a remotely plausible smoothing mechanism to ensure the big bang was of infinite extent. So while the universe may or may not be infinite in time and/or space I believe the big bang was finite in space. If the universe is spatially infinite I'd expect an infinite number of big bangs.

Take one infinite multiverse. Chop it in two (rather difficult in practice) and you have two infinite universes. You can repeat this an unlimited (but not necessarily infinite) number of times for as many universes as you want. Alternatively, simply say that the (infinite) multiverse is twice as big as the (infinite) multiverse or infinitely many times as big. This is a verbal description of perfectly valid maths. See e.g. http://gizmodo.com/5809689/a-brief-introduction-to-infinity

K-J-U was too late. They've been employed by D Trump as military advisors.

That does mess me up. I thought each portion was finite. Or infinite.

The possibility of pre-emptive defence by USA etc is unfortunately a very good reason for non nuclear countries to acquire nuclear weapons. Once there are viable ICBMs in North Korea the possibility they would be protected against EMP ( or just stored underground) would discourage the above as North Korea would likely launch them, confusing pre-emptive defence with an act of war.

Many theories predict something critical becoming infinite (or zero) in certain situations e.g. inside a black hole. This is usually described as a singularity. The definition of singularity is a bit vague, but it generally means that the theory is useless in that situation, and unknown physics or a new theory is required.

Gone. Someone at arjonline reads this forum.

I thought it best in my previous post to indicate nothing I said was inconsistent with rangerx's posts. Your omission of "Note: this is consistent with the previous post" in your quote of me so that you could claim I disagreed with rangerx is an unscientific but very effective way of ensuring that you won't be taken seriously. I won't waste my time with any of your future posts.

That view hasn't changed significantly. The main damage from these pollutants is on land and freshwater lakes. Locally,SO2 and NOx pollution swamps the effects of increased CO2 in the atmosphere. Unlike CO2 , these pollutants would soon return to preindustrial levels in the atmosphere if the polluting industries were shut down. Note: this is consistent with the previous post.

IIRC Robert Heinlein in "The man who sold the moon" came up with a similar idea in the 1940s or 1950s, to eliminate the first stage in a manned lunar spacecraft.

An investment with no return for 600 years. Ten years with no return maybe.

True for windows; running antivirus, rebooting fairly quickly after an update, windows processes etc require a state of the art computer for current windows OSs. Linux is particularly good for older hardware (up to 10 years old or more) as there's been more time to develop drivers for hardware. Unless you want to run some dodgy unapproved software, antivirus has been been run at the software sources. A common complaint by new users is 'how can linux be more secure than windows when it comes without antivirus software?" I reboot linux about once a month. Sadly I don't get paid for this as linux is free.

No need to swallow explosives, just absorb the neutrons through your skin. I was referring to your statement Starting from scratch, it would just be a matter of using smaller quantities of conventional explosives to cause a slower precursor implosion, less constraints on initial expansion of fissile material so that it becomes subcritical more quickly etc. There's probably been a few 'failures' where a prototype bomb released 'only' e.g. 2 tons TNT equivalent of energy. Just discovered https://en.wikipedia.org/wiki/Variable_yield The Neutron_bomb, loosely any device with a yield of < 10 kilotons, designed to provide a lethal radiation dose with minimal damage to property, approximates a nuclear grenade for a suicide bomber who would survive to fight another day, but not another week.. Happily in America at least, the last of these seems to have been dismantled in 2006. Overdoing 'tickling the dragon' does not lead in general to an explosion since even slight thermal expansion or at worst melting would quickly make the fissile material non critical. No need. There's still enough for a good few megadeaths (gigadeaths?).

You can have an indefinitely small explosion e.g. accidentally bringing two subcritical hemispheres together. The difficult part is normally maintaining a supercritical mass long enough for significant fission. e.g. from https://en.wikipedia.org/wiki/Louis_Slotin

I always liked thermionic valves, not least because you could actually see inside them and sometimes diagnose a dodgy valve by visual inspection. So a defence.... Inefficient, certainly. AFAIK, magnetrons are still used in domestic microwave ovens. Producing a few hundred watts at 2.45 GHz from a solid state device is still not cheap and it's hard to protect a solid state device from all the possible loads in a cooker. Producing high power at high frequency, and the CRT, were the last holdouts against solid state devices. However valves are much slower to die when you maltreat them. I used to have an ancient A.M. transmitter with an ex battleship power supply that required four people to carry it. The 50 watt directly heated white hot tungsten cathode in the output valve glowed brightly enough to read a newspaper. If the 1/8" thick carbon anode started glowing red hot I knew to reduce power. I had a mere 2000 volt H.T. supply so I can't be sure the valve would have survived arcing between electrodes... 'New' mains powered radios had a long warm up time. Older battery powered radios had directly heated cathodes which warmed up almost instantly. The same thing happened with transistors. Initially they were 'instant on.' Now somewhere in tv adverts' small print for 'smart' devices there's always a 'sequence shortened' warning. You can instead leave the device "on" all the time and find the battery flat if you've left it too long. I worked on an early British mobile phone which had a (very) quick heat output valve to reduce the size of the optional battery pack for portable use away from a car battery. The police liked it as well since you just had to connect a loudspeaker to a winding on the modulator transformer to have a powerful P.A. system. Happy days...

If the pressure is high, most of the (small number) of free electrons are slowed by collisions and never acquire enough energy to ionise other atoms and create more free electrons. The higher the voltage (i.e. volts/meter) the higher the pressure can be for a discharge. At lower pressure, there are fewer collisions and electrons gain enough energy from the electric field to ionise some of the atoms they do hit. If you slowly increase the voltage, eventually there is a chain reaction with a sudden large increase in conductivity, loosely called a discharge.

Theresa May: From previous attempts, this likely means longer detention without trial, curfews etc. In South Africa during apartheid, there were 90 day detention orders, renewed every 90 days. In Guantanamo Bay, there is lifetime detention for some, although even Trump so far has approved nothing worse than waterboarding. Anyone who criticizes such things will be constantly wondering if their speech qualifies them as terrorist suspects. Detention etc is of course likely to convert wrong thinking people who were not a threat into a threat. Supporters of such policies usually think it will never happen to them; trials are an unnecessary impediment to justice.

Your understanding of climate science is almost as good as Donald Trump's.

Evidence? I've dual/multiple booted linux with windows on at least four different computers using win98 up to win 8 with no windows related problem after installation. I only dual boot because I occasionally want to run an obscure program that hasn't been ported to linux and I am not short of disc space. I've read there is sometimes a problem with windows overwriting the boot menu, but that is easily fixed; if it happens a lot then you could remove windows, or just remove its entry from the boot menu. Standard windows does not understand the linux filesystems; if windows ever infects a linux partition Microsoft would have problems claiming this is an 'accident'. Only running a command like 'format d:' in windows would cause a problem. Stored backups should be kept physically separate from the computer whatever the OS.

Rather a lot of money to spend just not to have to select an OS from the menu. It's just as easy/hard to install linux as sole OS as to dual boot with windows if you start with a windows computer. If you delete windows, you may find UEFI still prevents you installing any other OS. https://forums.linuxmint.com/search.php?keywords=UEFI+boot returned 9815 matches, roughly half about problems with Microsft's UEFI. From https://en.wikipedia.org/wiki/Unified_Extensible_Firmware_Interface So UEFI can prevent users installing OSs, but allows hackers to install boot viruses...

Or just install linux to dual boot with windows 10. The hardest part is persuading windows 10 that you're not installing a boot virus. Some beginner friendly distros like mint make it almost easy unless the computer has been designed to be very compliant with the windows ethos i.e. thou shalt have no OS but me. Sadly the linux BSOD screensaver is rather pathetic compared to the real thing.