You find yourself in the cretaceous

[untermensche]

You can't add or subtract from the totality of matter/energy in the universe.

Taking an atom from today into the past is adding to the totality of matter/energy in the universe. Impossible.

Saying you can just get rid of the atom in the past is claiming to be able to subtract from the totality of matter/energy in the past. Also impossible.

Fantasy. Not science or any potential science.

Disagree--time travel means there is a temporary period with excess matter. It's a loan, it gets repaid.

No such thing as a temporary excess.

It has never happened and can't happen.

Humans can't create matter.

 

[skepticalbip]

Humans can't create matter.

Damn... CERN is a scam???

 

[untermensche]

Humans can't create matter.

Damn... CERN is a scam???

They are not creating matter.

Transforming energy to matter is not creating anything.

Trying to shove some present matter into the past is trying to create matter.

 

[Loren Pechtel]

Actually, I wouldn't worry too much about microbes. Few things attack both humans and reptiles.

Are you attempting to communicate that you believe only reptiles and reptile-associated microbiota were the only inhabitants of the Cretaceous?

They are the only things large enough you would be doing much associating with them.

 

[Loren Pechtel]

The Spanish Conquistadors were not greatly effected by the viruses of the new world, yet the native populations were decimated by the viruses introduced by Cortez and his crew.

Correct, but there was a big factor at work: population density. The New World simply didn't have the density the Old World had. Also, the New World is tall, the Old World is wide. You can go great distances in the Old World and experience similar climates, you can't in the New World. That makes it easier for hosts to move disease around.

In the New World a highly lethal pathogen would likely burn out and go extinct. In the Old World a highly lethal pathogen had enough other places to go that it could wander around and survive long enough for the survivors to be replaced. This also meant that those particularly susceptible to the pathogen would tend to have their genes culled from the pool, leaving the population as a whole more resistant.

It's not that the Old World viruses were any more virulent in the New World, it's that in the Old World they took their toll over the generations and the New World it happened all at once.

(And I strongly suspect the traditional problems Native Americans have with alcohol is related to this, also--the Old World had alcohol at all times, the New World did not. Darwin culled those who were particularly vulnerable, the Native Americans didn't have that culling and thus got hit all at once when the Old Worlders brought alcohol.)

 

[Loren Pechtel]

Humans can't create matter.

Damn... CERN is a scam???

He's talking about matter in an e=mc^2 world. Change between matter and energy, yes, but he's saying that we can't change the total. With current physics he is right--but that can't be used as proof you can't travel in time, any more than Newton can be used as a refutation of relativity.

 

[untermensche]

Humans can't create matter.

Damn... CERN is a scam???

He's talking about matter in an e=mc^2 world. Change between matter and energy, yes, but he's saying that we can't change the total. With current physics he is right--but that can't be used as proof you can't travel in time, any more than Newton can be used as a refutation of relativity.

From what would you create this new matter?

Adding matter to the universe is no small problem.

 

[Politesse]

Actually, I wouldn't worry too much about microbes. Few things attack both humans and reptiles.

Are you attempting to communicate that you believe only reptiles and reptile-associated microbiota were the only inhabitants of the Cretaceous?

They are the only things large enough you would be doing much associating with them.

I guess you've... somehow never heard of the dinosaurs?

Also, I don't see why you think we wouldn't have cause to interact with fellow mammals, when a human being trapped in the Cretaceous would almost certainly be drawn to the same places and food sources as their Cretaceous ancestors, needing as we would a similarly omnivorous diet, as well as being threatened by many of the same environmental and biological threats.

 

[DBT]

Our fellow mammals would probably become our food source.

 

[Politesse]

Our fellow mammals would probably become our food source.

I think that would be a prudent option, actually. You may have noticed that a lot of humanity's preferred foods are animals with a similar nutritional budget to our own, and that is no accident.

 

[Politesse]

Actually, I wouldn't worry too much about microbes. Few things attack both humans and reptiles.

Reptiles weren't the only animals in the Cretaceous. Mammals had been around since the Triassic. And bacteria will live in almost anything. Unexpected bacteria, or even symbiotic ones that find themselves in the 'wrong' tissues or with the 'wrong' immune responses, cause all kinds of nasty diseases and conditions.

If it comes to that, influenza viruses and pox viruses (to take just two of many examples) can easily jump species from birds (ie Dinosaurs) to humans. That's why 'bird flu' and 'chicken pox' are a thing.

Indeed, zoonotic illnesses - the sciencey name for this concept - are frequently much more dangerous to human life than pathogens which evolved to occupy our system. Parasites that kill their primary reservoirs die out when they die out. But a pathogen whose natural reservoir is a alphadon has no selective pressure not to be accidentally fatal to a single human who wanders in and unknowingly ingests it along with said alphadon.

 

[bilby]

He's talking about matter in an e=mc^2 world. Change between matter and energy, yes, but he's saying that we can't change the total. With current physics he is right--but that can't be used as proof you can't travel in time, any more than Newton can be used as a refutation of relativity.

From what would you create this new matter?

Adding matter to the universe is no small problem.

Time travel opens the "closed system" to include all of time, as well as all of space. Creating matter and/or energy in an open system is a trivial matter of logistics.

 

[Jokodo]

... snip ...

And if you are right, then the departing traveller's matter is destroyed - so there's your source of at least some of the necessary energy.

There containment of that energy being only a minor technical concern to be worked out..

What's the explosive yield of the total annihilation of one human body's worth of matter?

ETA: Preliminary calculations using some of the examples given in https://en.wikipedia.org/wiki/Joule#Multiples suggest that one human body is about 300 times the Tsar Bomba or 40 times the 2011 earthquake off the coast of Japan.

 

[Jokodo]

It is the same cells in my nervous system this year as last.

and they didn't pick up any nutrients or discharge any waste since? Let alone discharge neurotransmitters and ions? Nutrient-deficient food in adulthood never ever has any effects whatsoever on the nervous system, since it's fully encapsuled and using the same potassium ions it was using last year?

 

[Jokodo]

No I am not claiming that at all. According to Einstein's block universe, nothing is stored, it exists. Your illusion is that you are just now. In the block universe, you are everything from conception to death. If you could step into a higher dimension and look at you, you would see something like a long snaky worm winding through spacetime... birth on one end and death on the other. Your view of a now is what Einstein described as a stubbornly persistent illusion.

People live with illusions of reality. I remember describing the Apollo moon landing a week after it happened to a rural Vietnamese farmer. His reaction was that I was talking nonsense because his 'reality' was that the moon was only a light in the sky, not something that people could stand on.

If both the present configuration of matter exists and so do all the previous configurations of matter that means the other configurations are stored somehow. To exist would mean to be stored somehow. Like a movie on a tape.

I exist. I am not, in any meaningful sense and to the best of my knowledge, "stored somehow".

Your argument goes poof.

 

[Jokodo]

They know about T-Rex.

What microbes might be around, nobody knows.

Or will ever know.

Nobody knows, but a traveler to the Cretaceous should absolutely be worried.

Actually, I wouldn't worry too much about microbes. Few things attack both humans and reptiles.

Not so few things attack both humans and birds. Dinosaurs are more closely related to birds than to any extant reptile.

 

[Jokodo]

Actually, I wouldn't worry too much about microbes. Few things attack both humans and reptiles.

Are you attempting to communicate that you believe only reptiles and reptile-associated microbiota were the only inhabitants of the Cretaceous?

They are the only things large enough you would be doing much associating with them.

I guess that's why rodents and bats never function as reservoir species or alternate hosts for germs that (systematically or opportunistically) attack humans - they're just too small.

Thanks for clearing this up.

 

[Jokodo]

To the OP: I guess the biggest problem would not be being eaten, but finding something to eat which you know to be non-toxic. As far as this problem goes, the cretaceous is already a much better place than the triassic age, since flowering plants were already dominating the flora and you could expect to find wild relatives of many food crops, unlike a 100 million years earlier. Unfortunately, being a distant relative of a food crop isn't a guarantee for non-toxicity, many food crops do have toxic relatives even today.

If you only eat a small amount of each new candidate food source and watch out for side effects like nausea, dizziness, numbness of the fingers, you'll probably live to identify a handful of wild plants you can eat with no ill (short term) effects, but it could be a rough couple of weeks till you get there, a d you might still suffer malnutrition in the long run.

 

[untermensche]

He's talking about matter in an e=mc^2 world. Change between matter and energy, yes, but he's saying that we can't change the total. With current physics he is right--but that can't be used as proof you can't travel in time, any more than Newton can be used as a refutation of relativity.

From what would you create this new matter?

Adding matter to the universe is no small problem.

Time travel opens the "closed system" to include all of time, as well as all of space. Creating matter and/or energy in an open system is a trivial matter of logistics.

Nonsense.

Creating matter or energy is a physical impossibility.

Adding to the totality of matter/energy in the universe, at any time, is impossible.

You can't shove some present matter into the past.

It is already there in some other form.

 

[untermensche]

It is the same cells in my nervous system this year as last.

and they didn't pick up any nutrients or discharge any waste since? Let alone discharge neurotransmitters and ions? Nutrient-deficient food in adulthood never ever has any effects whatsoever on the nervous system, since it's fully encapsuled and using the same potassium ions it was using last year?

In the enamel of the teeth there is no atomic turnover.

No waste no nutrition.

It really doesn't matter however.

Taking your matter back to the past would add to the total matter/energy of the universe.

If you could add matter to the past in that manner then you could easily add matter to the totality of matter/energy in the universe now.

That would be much easier than trying to do it at some past time.