Hello Barbara; There are some modern objects that will last into the far geological future. Glass bottles and the crumbling remains of concrete roads immediately come to mind as things that have obviously been manufactured. There will surely be lots of other stuff in the future fossil record. Consider how many fossils there are of Cambian era creatures that were very delicate yet we find millions of bits of their remains.

More interestingly, how will future biogeographers interpret the descendents of all of the species of plants and animals that we have moved all over the planet. Maybe they will think that these odd global distributions were due to a multitude of vicariant dispersal events....Hmmm. In good fun, Jim Des Lauriers

Dear Prof. James Des Lauriers , thank you for taking part in these 'would be' considerations. I suppose that our concrete constructions seem much more prone to corrosion than ancient Romanian ones. There, likely, will be no trace of them after next 2KYs, not saying about geological time, I am positive. The only valid remnants will be, possibly... deposits of radionuclear wastes, I am afraid. And maybe footprints on the surface of the Moon.

Barbara; Roads - The buried shape of a roadbed consistently overlain by the sand and aggregate of disintegrated concrete would be an obvious construction artefact. The glass bottles - buried in any muddy deposit they should last "for ever". Don't you think that they would be interpreted as artefacts? Jim Des Lauriers

Dear Prof. James Des Lauriers . Therefore, you are also taking for granted that only burried artefacts can remain (preserved at suitable enough conditions). As you see from the above photo glass bottles are very prone to destruction. Pressure of many meters of ground can crush them to the similar tiny debris. So, no visual traces on the surface, also according to you? There are remnants of ancient roads which can be detected on aerial photos. You may be right that similar remnants can be detected of our highways even at few KYs time horizon. But will be there someone who will be able to take such photos?

Road from the time of the first emperor of China

by Wojciech Pastuszka - October 17, 2007 Posted in: Archeology, China

" While listing monuments in the Hunan province (map), it turned out that fragments of a road built over 2,200 years ago survived in the village of Dengjiatang, when Shi Huangdi of the Qin dynasty reigned, the first emperor of China whose grave is guarded by the famous terracotta army. Chinese scientists learned from ancient records that the trail along the road was marked out by the great army of the first emperor as they marched to conquer southern China. Later, this trail was paved with stone slabs 2-3 meters wide, and thus a road was created for mules and horses connecting central China with southern - the ancient equivalent of the highway. In the first century CE inns and post offices appeared along the way. Chinese scientists say the road served for about 2,000 years. They are probably not exaggerating, because even now the inhabitants of Dengjiatang use the surviving fragments of the ancient artery. The long-term use is also evidenced by the numerous deep traces of hooves engraved in the plates by the impact of thousands of animal legs."

https://archeowiesci.pl/2007/10/17/droga-z-czasow-pierwszego-cesarza-chin/

https://www.ancient.eu/Shi_Huangdi/

Qin Interstate Highway System was built 2.2KY ago:

"An imperial road network was built to aid troop movements in the campaigns against the Xiongnu (barbarian Huns). This imperial transportation network extended north to the Great Wall and south to Fujian, Guangdong, and Guangxi as shown in Figure 5 [1]. Imperial highways of uniform size connected key political, economic, and military centers. Imperial trunk roads were 69 meters wide and lined with protective walls. Secondary and support roads branched out to cities of lesser economic and strategic importance in the frontier binding together the two million square miles of Qin Empire. Secondary roads were 34.5 meters wide and support roads were 11.5 meters wide. The imperial trunk roads totaled over 5,200 miles in length. By comparison, circa 150 AD, Roman roads totaled 3,750 miles and were only 8.5 meters wide [5, 6]. "

[1] Mark Edward Lewis, Early Chinese Empires Qin and Han, Harvard University Press, 2007.

[5] Chun,-shu Chang, The Rise of the Chinese Empire Vol. 1, Univ of Michigan Press, Ann Arbor, 2007.

[6] Twitchett and Fairbanks, Cambridge History of China Vol. 1, Cambridge University Press, 1986. https://www.researchgate.net/publication/257719343_The_Formation_of_the_Qin_Dynasty_A_Socio-technical_System_of_Systems

In 1974 the oldest Australopithecus fossil was found which was called Lucy. It has been estimated that Lucy dates back to around 3.2 million years ago. Perhaps in a few tens of millions of years it will still be possible to find some artifacts in platinum or other materials. But who will be looking for it and finding it? The Homo sapiens?

Dear Dr. Leonardo Cannizzaro , there are many artifacts which survived after some ancient civilisations capable for building megalithic stone cathedrals, we only hardly could mimicre nowadays. They are so old that many of them are sunken dozens meters deep in the sea. Nothing like that will remind after us, most likely, but small gold and platinum artefacts, really, I am also afraid.

"Having sunk 5000 years ago, no one knows what this city was called. Pavlopetri happens to be the modern name given to it. Nobody knows who built this town or which civilization it belonged to, but if archaeologists are to be believed, it was part of the Minoan dynasty. This town is said to have been destroyed due to an earthquake."

https://in.musafir.com/Blog/6-submerged-cities-around-the-world.aspx

"As far as the most stunning underwater city is concerned, China’s lion city is miles ahead than the rest. Over 1400 years old, it was built during the Han dynasty and spans the area of 62 football fields."

https://in.musafir.com/Blog/6-submerged-cities-around-the-world.aspx

"According to folklore, Dwarka is the home town of Lord Krishna, a placed believed to be an old wives tale, a myth, that is until the ruins were discovered 131 feet below the ocean. The ruins were found beneath the surface of modern-day Dwarka. The complexities and the beauty of this city, has baffled even experts."

https://in.musafir.com/Blog/6-submerged-cities-around-the-world.aspx

Pyramids of Yonaguni Jima - Japan

"These pyramids that lie underwater are fraught with mystery. Experts argue as to whether these pyramids are man made or a naturally occurring phenomenon. If you believe with the former, then these structures were made during the last ice age, around 10,000 BC. To make things strange, these pyramids resemble those found in Mexico and Central America. Here's where things get stranger, there are no other underwater structures found in this area."

https://in.musafir.com/Blog/6-submerged-cities-around-the-world.aspx

The true images of Pyramids of Yonaguni Jima - Japan:

https://www.youtube.com/watch?v=jYBJnX9AHOg

Probably all information stored in silico will be lost after a short time. However a lot of plastic items will give for a long time (as long as plastic survives) the impression that our civilization was essentially based on such polymers. In addition many remains of road constructions and dams will survive for millennia

Dear Dr. Ozodbek S. Abduraimov

What concerns reinforced concrete, it seems that empty spaces occurred pretty soon after their total oxidation become the main cause for their deterioration by frozen water penetrating this spaces sooner or later. However, in conditions of farthcoming global warming...

"There have been instances where concrete buildings not more than 20-30 years old have collapsed. However, there are cases where concrete buildings that were constructed 100-150 years back are still going strong without any kinds of damage or problems. Unfortunately, the fact that housing projects are being mass-produced today has resulted in countless buildings being constructed with inferior quality materials."

https://www.linkedin.com/pulse/how-long-does-modern-concrete-building-last-amit-enterprises-housing

Dear Eng. Jean-Pierre Jost , "Normally, plastic items can take up to 1,000 years to decompose in landfills."

https://www.thebalancesmb.com/how-long-does-it-take-garbage-to-decompose-2878033

Traces of our civilization would be very rapidly lost especially for all the digital information stored. A few constructions may survive but everything else from our civilization could be destroyed by the vegetation and bacteria and other organisms, Only plastic items may survive much longer and could be the most common thing recovered from our civilization thus we may be coined as the “plastic civilization” what an irony!

What is the probability that interstellar travel is even possible? I'm willing to conjecture that life - even intelligent life - is widespread in the galaxy. We've been able to search for only a little while and the expanse of area to search is enormous. Be patient! Best regards, Jim Des Lauriers

Dear James Des Lauriers , When a civilisation attains the in-practice-immortality of its citizens, even the distances between galaxies become... insignificant.