Can you live forever? Two experts argue immortality

It’s a Friday morning and they enter the cafe. Bortz appears first: tall, lean, tanned, in a white polo shirt and brown sport coat, with a shock of white hair. Three months ago, Bortz participated in his 10th Boston Marathon, and 43rd marathon overall. He is 83.
De Grey, 50, materialises next. He looks like some sort of steampunk shaman: long russet-gray hair, pulled back in a ponytail; equally long beard, with a footlong mustache to match; lavender striped shirt unbuttoned past his sternum; dark jeans; and what appear to be black Dr Martens boots. De Grey is six feet, 150 pounds or so. Wraithlike. He has saved us a table near the window.