This paper makes a very fundamental mistake, IMO. If you were to time travel to the future and do a query, you wouldn't query about a past event. You'd query about a present event.
For example, if time travel were created today, we wouldn't go back to 2000 and query about something that happened in 2001. We'd query about Lebron James or Obama.
They should be looking for queries about technology/people/events that are relevant/interesting in the era when time travel is done. Unfortunately, in order to know that you probably need to time travel to the future. :-)
The amount of information you could access would be limited to a transportable device (assuming an inability to communicate temporally--probably reasonable). You would have to supplement your knowledge with local information.
With the Internet, maybe perfect information is valid, but I suspect not.
Try hunting down what was once widespread knowledge about Visual Basic 6. Or anything which was mostly exchanged on NetNews. There is a lot of lossage already and we're only about 20 years from it.
The real problem is that you need a mediocre search that a time traveler would do. Something that would not be indexed in a portable computing device and yet would still be interesting enough to require using temporally local search capabilities.
I'm not sure it's a fundamental mistake. To make a counter-argument, if one travels back to some point in time, but can't remember (or don't know[0]) exactly when a major event happened, one might query it, to see if/when it has happened. Or one might query it because one is mistaken about when it happened. In either case, one might expect to see queries about things in advance of their occurrence. So while this particular work certainly doesn't rule out time travel, I don't think it's fundamentally flawed. Perhaps overly optimistic though.
[0] One might presume historical records are somewhat corruptible, and therefore someone from the future might not have perfect knowledge of when major events in the past actually occurred.
The iPhone 42s contains all the worlds knowledge past present and future and you just need to think about what you want to know and it will send it to you telepathically. Why on earth would I use something as archaic as Google search from the 21st century?
Siri is a still humourless cow though.
For example, if time travel were created today, we wouldn't go back to 2000 and query about something that happened in 2001. We'd query about Lebron James or Obama.
They should be looking for queries about technology/people/events that are relevant/interesting in the era when time travel is done. Unfortunately, in order to know that you probably need to time travel to the future. :-)