Endy0816

3 minutes ago, Tom Booth said:

Not really.

The formula for heat engine efficiency is: Th - Tc / Th.

On a scale that begins at absolute zero.

So if a heat engine reduces the temperature of the heat from T-hot down to T-cold that is simply the percentage of cooling produced on the absolute temperature scale, or how far the engine has cooled the "working fluid" on the way down to absolute zero.

It simply states that at best, the engine cannot reduce the temperature any lower than Tc.

It derived from Carnot who conceived the "flow of caloric" as including all that caloric down to the absolute zero temperature.

The "rejected" heat is the un-utilized percentage of caloric below Tc down to absolute zero, which Carnot conceived as also flowing through the engine.

That is the actual original basis of this engine efficiency formula.

That is, of course, my understanding after some rather extensive reading and research on the subject.

 

You'll always have some losses though.  You mentioned swapping out the bolts to reduce parasitic losses for instance.

Note the idealized nature of the Carnot equation. Any real engine will have all kinds of issues reducing theoretical efficiency.

Does it stop once the heat source reaches the cooler ambient temperature?

Somewhat separate, but is there any chance your vacuum flask has developed micro cracks?

59 minutes ago, Janus said:

???

Basing this on there being the same amount of mass on all sides. Not 100% sure here, however, so feel free to correct me if I'm wrong lol

I think if the Earth were to stop spinning and had all of its mass evenly distributed in a sphere, it would be close to zero at the exact center.

3 hours ago, MigL said:

Grown men don't play with dolls, Endi.

*Tucks Universe back into pocket*

Balloon example is all good until someone asks you about those dots expanding or us colliding with Andromeda, lol.

3 hours ago, HAMKiiNG said:

Please excuse me as i am trying to simplify this as best as possible without having to draw a picture 😃

I questioned earlier about perpetual motion and it led me to idea no2.

You have two cylinders.

One filled with water and one in a vacuum.

You have a container that is denser than air but still buoyant.

The container passes through the water filled cylinder pulling a cable that turns a generator.

Once it reaches the top it passes into the cylinder with the vacuum and falls to the bottom still pulling the cable.

Would this create a positive energy output?

It would just end up floating on top of the water.

@Airbrush

Not sure if this is the best  example, but might imagine the Universe as a set of reverse Matryoshka dolls, with larger dolls nested within smaller dolls. The volume each doll contains increases rapidly, but internally.

4 hours ago, Paul Singh Jr said:

I do know that the Big Bang Happened practically everywhere but some ppl  recently theorised that all matter came from one source 

The space we and everything else is occupying today is where that 'source' was. Everything was at a single point(roughly speaking) before that became less dense.

@IDoNotCare Sorry if you're feeling attacked but you need to be able to summarize(and no I'm not a sock puppet). Nobody can read minds here. I might hazard a guess that you're talking about a post scarcity society and more specifically 'fully automated luxury communism', but you need to spell that out. Without a good reason to, nobody wants to sit through a bunch of YouTube videos or go offsite to a random link.

5 hours ago, swansont said:

“We will automate everything” is a pipe dream.

1. For processes where it was cheaper to automate, it would have already happened.

2. Some things we are trying to automate and are finding that it’s very hard (see:self-driving cars)

3. Things like R&D will likely never be automated 

 

Also, if you want to propose communism, you need to not only draw a path of how to get there, but also how you will avoid the catastrophes observed in previous attempts

In some cases there is just an initial investment hump that automation has to be pushed over. Admittedly communist countries also tend to nationalize simultaneously, which is a great way to kill outside investment. I think we'll at least see automated trucks. For long-hauls along a highway it would be simple enough. Even if legally they end up needing a truck tender, you could find someone cheaper than a full time driver.

At it's heart most R&D boils down to an optimization problem, so algorithms can work for some things. We might still need either a person or possibly a well trained AI, to define problem constraints.

I don't think work will be truly eliminated but it might be more of what people actually like or want to dedicate themselves to.

Can you describe what the Venus Project is for us?

Banning gloves might improve things. Recently saw a video discussing how gloves made attacks to the head more common, as fighters no longer ran the risk of damaging their own hands as a result.

Not true Antigravity but there is acoustic levitation.

https://en.m.wikipedia.org/wiki/Acoustic_levitation

@sethoflagos

You can read about an experiment showing this here:

Quote

Denis J. Evans and colleagues have discovered, not how to beat the house, but what happens in the realm between a single coin toss and a weekend in Las Vegas. To do so they measured water molecules' influence the motion of tiny latex beads held between lasers.

They found that over periods of time less than two seconds, variations in the random thermal motion of water molecules occasionally gave individual beads a kick. This increased the beads' kinetic energy by a small but significant amount, in apparent violation of the second law.

The gain is short-lived, and so could never amount to a source of free energy or perpetual motion. But it is big enough to confirm what physicists have long suspected.

https://www.nature.com/news/2002/020722/full/news020722-2.html

Second Law is true on average though, so you won't ever see a cup spontaneously unbreak or all the air move to one side of a room.

Should really consult a doctor or nurse about this(over the phone if necessary).

Just as an example, there is DPD deficiency. Where a lack of the enzyme can impact how quickly your body is able to break down some chemotherapy drugs.

https://www.cancerresearchuk.org/about-cancer/cancer-in-general/treatment/chemotherapy/side-effects/dpd-deficiency

Good luck and I hope your sister recovers.

Quite a bit is pretty fanciful from a scientific perspective, but is an extremely well done production. The setting is a fair sized city set inside of a large martian dome. Heavily modified assets and ridiculous level of detail really make the city come to life.

The actual build aspects may not be everyone's cup of tea, but I've found it easy enough to skip past when things become too dry.

Here's a good demonstration of a fire piston. A very cool bit of ancient technology.

6 hours ago, iNow said:

When the US was first founded, there was no "VP pick." Whomever came in 2nd place (the runner up) was automatically the VP.

It'd almost be worth bringing it back for the entertainment factor.

"I know you just lost to that guy, but guess who your new boss is?"

Always wonder what the Founding Fathers' thought process was on that one.

20 hours ago, Ken Fabian said:

"Habitable for humans" rather than habitable in the sense of being able to support it's own biology. Habitable for humans is going to be a very narrow subset of "capable of supporting life that is like life on Earth".

Any native life would not only be of exceptional scientific interest it seems like a big assumption that human life would be compatible with the biochemistry. Surely life throws up more complex poisons and allergenic compounds than lifeless processes - besides the more obvious hazards like wrong atmosphere or getting eaten or parasitised.

Very true.

Quote

If we have the technology to get to the planets of other stars we won't need planets for survival purposes - but that urge to find new pastures, to occupy and possess, is a primitive one and I would not trust humans from Earth to restrain themselves if they are within landing distance of a world they thought they could conquer and occupy.

This does make you think. We have the Antarctic as an example where we have exercised restraint, but whether this will remain so is of course unknown.

Quote

Although humans with a long history of life in artificial habitats/spacecraft may not find planets or life supporting moons attractive.

Yeah, main thing is that they simply wouldn't be accustomed to the rigors involved or would consider the risks to be extreme compared with their controlled environments. Reasonable to assume by then that they could build habitats to suit any particular preference both in space and on lifeless bodies. Possible though that some might not find that as enough of a challenge.

I earnestly hope not. I've had dreams that would be bad for our whole species.

Practically speaking you never actually gain any outside knowledge as you dream beyond what your standard senses provide. If it is something possible/probable you might however imagine it occurring only to see it actually happen later. Should note that false memories can also play a role here.

The ones around our own Gas Giants do tend to have some decent resources or novelties so similar exomoons would definitely be of interest.

Realistically travelers would have to be living in space already to reach that far. One that shared a similar atmospheric composition might even be forbidden from inhabitation as that could harm future research into native life.

2 hours ago, Mordred said:

Unfortunately this is not true in the case of a coordinate singularity such as the EH. 

A coordinate singularity is not invariant under coordinate change. The r_s=2GM is an artifact of the Schwartzchild metric. 

I'm going to add a hypothetical question. Would a near c observer see the same radius for the event horizon as the at rest observer. You would see a different Blackbody temperature and as a result a different rate of Hawking radiation. Ie Unruh effect.

(PS the answer cannot rely on the Schwartzchild metric ). One can argue the Schwartzchild metric is only suitable to a far away observer.

 

Wouldn't the radius shrink and mass increase proportionally?

1 hour ago, random_soldier1337 said:

 

Lol, I dunno. I just take people's word for these things. For all I know everything is an anime behind the scenes with cyborg ninjas and psychic super soldiers running around performing black ops, having death battles and philosophizing in the quiet moments, especially their death throes. Or maybe it's like a schoolyard with someone being nice and then someone being a jerk, "Hey you can't do that!" "Why not?" "Because you can't." "Sure I can." and that's all that happens.

Anyway the project was supported by the IAEA.

Yeah, might have been the IAEA. Considered a generally authorized destination for distributions(assuming I've parsed the legalese correctly).

https://rsicc.ornl.gov/default.aspx

https://www.law.cornell.edu/cfr/text/10/appendix-A_to_part_810

-snip

2 hours ago, rjbeery said:

GR's treatment of gravity already accounts for stellar motions and accretion discs without requiring event horizons. It's entirely possible that black holes exist, but then it's also possible that the center of galaxies are full of unicorns and lemon ice cream. If GR has "a number of failings with regard to BHs" then you have no model whatsoever to predict them.

No. We know something has to occur due to the finite speed of light when density crosses the critical threshold.

Other thing is nothing else can match a BH for compactness. Accretion disk of an equally massive star still can't orbit as closely.

Whatever goes in is lost. Outside we never learn what has happened, if anything, past the Event horizon.

4 hours ago, rjbeery said:

I have some problems/questions regarding the existence of black holes. First, here is the current state-of-affairs in the physics community AFAIK:

1. Black holes "exist" in the sense that they are physical objects in the Universe
2. Black holes contain an event horizon, located at the Schwarzschild radius, beyond which "nothing can escape"
3. Black holes are likely located at the center of many galaxies, including our own; "micro black holes" are also likely formed and quickly evaporate in our atmosphere due to relativistic cosmic rays
4. Quantum mechanics is anticipated to resolve any mathematical singularity issues at the center of black holes
5. There are a variety of theories, most notably Hawking Radiation, that predict an "evaporation" of black holes over extraordinarily long periods of time

Does anyone feel this any of these statements are inaccurate?

The last is potentially inaccurate.

Only fairly large ones take long periods of time.